Journal articles: 'Fibrous biological membrane'

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Borri-Brunetto, Mauro, Bernardino Chiaia, and Marco Deambrosi. "A Micromechanical Model for Fibrous Biological Membranes at Finite Strain." Journal of Biomimetics, Biomaterials and Tissue Engineering 3 (July 2009): 1–23. http://dx.doi.org/10.4028/www.scientific.net/jbbte.3.1.

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The mechanical model of a number of biological tissues is a membrane, i.e., a sheetlike structure with small thickness, where deformation and stress can be described locally in two dimensions. Many bio-membranes, particularly if subjected to large mechanical loads, present a fibrous structure, with stiff fibers, sometimes with preferential orientations, embedded in a more compliant matrix. Among this tissues are, e.g., the arterial walls, the amniotic membrane, and the skin. The stiff fibers, typically made of collagen, are initially wrinkled and they follow the deformation of the embedding matrix without contributing to the mechanical response until they are fully distended. In this paper, the response of a fibrous membrane is described in the framework of hyperelasticity, with aim to the implementation in an existing finite element code. A micro-mechanical recruitment model, based on the statistical distribution of the activation stretch of the collagen fibers is introduced, leading to the definition of a simple form of the strain-energy function, depending on physically well-defined parameters. After some validation tests performed in homogeneous strain conditions, an application to the study of the stress field around circular holes in large deformation is presented, showing the capabilities of the proposed model.

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Wu, Sijia, Longhe Yang, and Junde Chen. "Preparation and Characterization of Tilapia Collagen-Thermoplastic Polyurethane Composite Nanofiber Membranes." Marine Drugs 20, no. 7 (June 30, 2022): 437. http://dx.doi.org/10.3390/md20070437.

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Marine collagen is an ideal material for tissue engineering due to its excellent biological properties. However, the limited mechanical properties and poor stability of marine collagen limit its application in tissue engineering. Here, collagen was extracted from the skin of tilapia (Oreochromis nilotica). Collagen-thermoplastic polyurethane (Col-TPU) fibrous membranes were prepared using tilapia collagen as a foundational material, and their physicochemical and biocompatibility were investigated. Fourier transform infrared spectroscopy results showed that thermoplastic polyurethane was successfully combined with collagen, and the triple helix structure of collagen was retained. X-ray diffraction and differential scanning calorimetry results showed relatively good compatibility between collagen and TPU.SEM results showed that the average diameter of the composite nanofiber membrane decreased with increasing thermoplastic polyurethane proportion. The mechanical evaluation and thermogravimetric analysis showed that the thermal stability and tensile properties of Col-TPU fibrous membranes were significantly improved with increasing TPU. Cytotoxicity experiments confirmed that fibrous membranes with different ratios of thermoplastic polyurethane content showed no significant toxicity to fibroblasts; Col-TPU fibrous membranes were conducive to the migration and adhesion of cells. Thus, these Col-TPU composite nanofiber membranes might be used as a potential biomaterial in tissue regeneration.

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Ha, Sung Hoon, Soo Jin Kim, Hyoungjun Kim, Chae Won Lee, Kyu Hang Shin, Hae Won Park, Soonwoo Kim, et al. "Fibrous all-in-one monolith electrodes with a biological gluing layer and a membrane shell for weavable lithium-ion batteries." Journal of Materials Chemistry A 6, no. 15 (2018): 6633–41. http://dx.doi.org/10.1039/c8ta01405a.

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Ramírez-Cedillo, Erick, Wendy Ortega-Lara, María Rocha-Pizaña, Janet Gutierrez-Uribe, Alex Elías-Zúñiga, and Ciro Rodríguez. "Electrospun Polycaprolactone Fibrous Membranes Containing Ag, TiO2 and Na2Ti6O13 Particles for Potential Use in Bone Regeneration." Membranes 9, no. 1 (January 10, 2019): 12. http://dx.doi.org/10.3390/membranes9010012.

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Biocompatible and biodegradable membrane treatments for regeneration of bone are nowadays a promising solution in the medical field. Bioresorbable polymers are extensively used in membrane elaboration, where polycaprolactone (PCL) is used as base polymer. The goal of this work was to improve electrospun membranes’ biocompatibility and antibacterial properties by adding micro- and nanoparticles such as Ag, TiO2 and Na2Ti6O13. Micro/nanofiber morphologies of the obtained membranes were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, energy-dispersive X-ray spectroscopy and a tensile test. Also, for this study optical microscopy was used to observe DAPI-stained cells. Membranes of the different systems were electrospun to an average diameter of 1.02–1.76 μm. To evaluate the biological properties, cell viability was studied by growing NIH/3T3 cells on the microfibers. PCL/TiO2 strength was enhanced from 0.6 MPa to 6.3 MPa in comparison with PCL without particles. Antibacterial activity was observed in PCL/TiO2 and PCL/Na2Ti6O13 electrospun membranes using Staphylococcus aureus bacteria. Bioactivity of the membranes was confirmed with simulated body fluid (SBF) treatment. From this study, the ceramic particles TiO2 and Na2Ti6O13, combined with a PCL matrix with micro/nanoparticles, enhanced cell proliferation, adhesion and antibacterial properties. The electrospun composite with Na2Ti6O13 can be considered viable for tissue regenerative processes.

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Prekajski, Marija, Biljana Babic, Dusan Bucevac, Jelena Pantic, Jelena Gulicovski, Miroslav Miljkovic, and Branko Matovic. "Synthesis and characterization of biomorphic CeO2 obtained by using egg shell membrane as template." Processing and Application of Ceramics 8, no. 2 (2014): 81–85. http://dx.doi.org/10.2298/pac1402081p.

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A new technology based on bio-templating approach was proposed in this paper. Egg-shell membrane (ESM) has been employed as a natural biotemplate. Fibrous oxide ceramics was prepared by wet impregnation of biological template with water solution of cerium nitrate. The template was derived from membranes of fresh chicken eggs. Repeated impregnation, pyrolysis and final calcination in the range of 600 to 1200?C in air resulted in template burnout and consolidation of the oxide layers. At low temperatures, the obtained products had structure which corresponded to the negative replication of biological templates. Unique bio-morphic CeO2 microstructures with interwoven networks were synthesized and characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD), whereas low-temperature nitrogen adsorption (BET) method was used in order to characterize porous properties.

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Liu, Shuo, Ji Fu Wang, Bao Zhen Wang, Bing Wang, and Wei Wan. "Pilot Scale Study on Biological Nutrient Removal and Membrane Fouling Alleviation in Combined Membrane Bioreactor for Municipal Wastewater Treatment." Advanced Materials Research 365 (October 2011): 354–60. http://dx.doi.org/10.4028/www.scientific.net/amr.365.354.

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To solve the problem of eutrophication in receiving water, a novel Membrane Bioreactor (MBR) with combined configuration was designed for municipal wastewater treatment and reclamation. By dividing bioreactor into three zones, the combined MBR operated under anoxic, anaerobic and aerobic conditions. It provided optimum conditions for nitrification, denitrifying and phosphate accumulating bacterial growth which resulted in high biological nutrient removal rate directly. The operational performance of combined MBR pilot plant showed that it exhibited high nutrient removal rate on Chemical oxygen demand (CODcr), total nitrogen (TN) and total phosphorus (TP). The mean value of effluent CODcr, TN and TP removal rate was 90.63%, 63.05% and 60.51% respectively during 180 days of operation. In order to obtain stable membrane flux, the combined MBR packed with fibrous bio-film carrier and added diatomite. Furthermore, it could alleviate membrane fouling effectively. As a result, the combined MBR improved effluent water quality significantly and alleviated membrane fouling remarkably.

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Owston, Heather E., Katrina M. Moisley, Giuseppe Tronci, Stephen J. Russell, Peter V. Giannoudis, and Elena Jones. "Induced Periosteum-Mimicking Membrane with Cell Barrier and Multipotential Stromal Cell (MSC) Homing Functionalities." International Journal of Molecular Sciences 21, no. 15 (July 23, 2020): 5233. http://dx.doi.org/10.3390/ijms21155233.

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The current management of critical size bone defects (CSBDs) remains challenging and requires multiple surgeries. To reduce the number of surgeries, wrapping a biodegradable fibrous membrane around the defect to contain the graft and carry biological stimulants for repair is highly desirable. Poly(ε-caprolactone) (PCL) can be utilised to realise nonwoven fibrous barrier-like structures through free surface electrospinning (FSE). Human periosteum and induced membrane (IM) samples informed the development of an FSE membrane to support platelet lysate (PL) absorption, multipotential stromal cells (MSC) growth, and the prevention of cell migration. Although thinner than IM, periosteum presented a more mature vascular system with a significantly larger blood vessel diameter. The electrospun membrane (PCL3%-E) exhibited randomly configured nanoscale fibres that were successfully customised to introduce pores of increased diameter, without compromising tensile properties. Additional to the PL absorption and release capabilities needed for MSC attraction and growth, PCL3%-E also provided a favourable surface for the proliferation and alignment of periosteum- and bone marrow derived-MSCs, whilst possessing a barrier function to cell migration. These results demonstrate the development of a promising biodegradable barrier membrane enabling PL release and MSC colonisation, two key functionalities needed for the in situ formation of a transitional periosteum-like structure, enabling movement towards single-surgery CSBD reconstruction.

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Giragosyan, Krikor, Ivan Chenchev, Vasilena Ivanova, and Stefan Zlatev. "Immunological response to nonresorbable barrier membranes used for guided bone regeneration and formation of pseudo periosteum: a narrative review." Folia Medica 64, no. 1 (February 28, 2022): 13–20. http://dx.doi.org/10.3897/folmed.64.e60553.

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Here we review the knowledge on the local biological immunological response (formation of “pseudo periosteum” of the host) to two types of nonresorbable membranes used in the horizontal and vertical alveolar ridge augmentation: the titanium-reinforced polytetrafluoroethylene membrane and the titanium mesh membrane. A literature search was conducted including available in vitro, in vivo, and clinical studies on cellular and molecular immunological response to these two types of nonresorbable membranes, in particular the formation of “pseudo periosteum”. Emerging data demonstrates that despite barrier membranes being considered as bioinert, they still elicit an immunological response from the body. The outcome of this reaction is the formation of a thin fibrous capsule referred to as “pseudo periosteum”. There are almost no biomaterials that are truly bioinert and this makes no exception for the nonresorbable membranes used in the guided bone regeneration. This iatrogenically made tissue is hypothesized to have a number of advantages and drawbacks. However, more research is needed in that area to truly understand its nature and importance to the guided bone regeneration process.

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Fiorito, Silvana, Laura Magrini, and Robert Streicher. "Circulating Cytokines as Biological Indicators for PE and Ceramics Articulations." Key Engineering Materials 361-363 (November 2007): 1323–26. http://dx.doi.org/10.4028/www.scientific.net/kem.361-363.1323.

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We studied the role of cytokines (TNF-α, IL-6,IL-1β, TGF-β) as markers of osteolysis in patients who underwent to a hip prosthesis implantation subdivided in two groups: group A with an ultrahigh molecular weight polyethylene (UHMWPE) insert articulating against a metal ball head , and group B with an all alumina ceramic combination. Profibrogenic (TGF-β) and pro-inflammatory cytokines (TNF-α, IL-6,IL-1β) are secreted by the periprosthetic synovial-like fibrous membrane in hip artificial implants. They are secreted by inflammatory activated cells and trigger the cascade of biochemical events leading to the activation of osteoclasts and bone resorption. A statistically significant increase of TGF-β serum levels was observed between TGF-β values in implanted patients as compared to normal subjects and between TGF-β values after versus before implantation in Group A. A progressive decrease in TNF-α and IL-6 serum levels has been observed in both Groups, when compared with the initial values before the implantation. IL-1β levels decreased up to 60 months after the implantation Our data suggest that monitoring circulating cytokines could be a good indicator for the proliferation and activity of the periprosthetic synovial-like membrane and potential osteolysis. This could allow for an adequate early treatment.

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Goldberg, Martin W., and Terence D. Allen. "HRSEM of the nuclear envelope (NE): Nuclear pore substructure; baskets and fibrous components." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 1 (August 1992): 492–93. http://dx.doi.org/10.1017/s0424820100122861.

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The nuclear envelope (NE) of eukaryotic cells has been studied for many years by a variety of em techniques yielding a three dimensional model of the nuclear pore complex (NPC) consisting of two rings (∼120nm diameter), one at the outer NE and one at the inner NE. Between the rings are eight spoke structures and a central plug. The cytoplasmic ring may be decorated with up to eight particles. The NPCs are embedded in a proteinaceous network: the nuclear lamina. Recently, low voltage HRSEM was used to show the existence of a basket-like structure attached to the nucleoplasmic ring. SEM is an ideal technique for the study of membrane surfaces. High resolution can be achieved in SEMs by the use of a field emission source which produces a high brightness probe of less than lnm diameter and a specimen stage within the objective lens, reducing chromatic abberations and production of SEIII electrons. Resolution of biological specimens can be further enhanced by coating with thin, continuous films of refractory metals such as chromium or tantalum which allows the use of higher accelerating voltages and magnifications. The NEs of Xenopus oocyte germinal vesicles have been prepared as previously described for HRSEM without detergent except they have been coated nominally with 3nm of tantalum by magnetron sputtering instead of ion beam sputtered platinum. NEs have then been examined at 30kV. The ring, plug/spoke complex and particles can all be seen at the cytoplasmic surface as well as details of the outer membrane structure and particles associated with it (Fig. 1). On the nucleoplasmic surface (Fig. 2) the inner ring is observed. It has a subunit appearance with eight filaments extending from between the subunits to a third ring structure: these make up the basket-like structure. When ‘baskets’ are close together they are joined by fibres at the ‘basket ring’ (Fig. 2). When several baskets are in close proximity these fibres form a network like a canopy over the baskets (Fig. 3). Other fibres are present on the inner membrane surface which may be membrane associated fibres or canopy fibres that have collapsed. It is uncertain which, if any, of these fibres are lamins as a further level of fibres is observed at the level of the nucleoplasmic ring when the membrane is removed with detergent (Fig. 4). These fibres are consistent with previously described lamina.

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Zheng, Gaofeng, Zungui Shao, Junyu Chen, Jiaxin Jiang, Ping Zhu, Xiang Wang, Wenwang Li, and Yifang Liu. "Self-Supporting Three-Dimensional Electrospun Nanofibrous Membrane for Highly Efficient Air Filtration." Nanomaterials 11, no. 10 (September 29, 2021): 2567. http://dx.doi.org/10.3390/nano11102567.

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High-performance air filtration was the key to health protection from biological and ultrafine dust pollution. A self-supporting, three-dimensional (3D) nanofibrous membrane with curled pattern was electrospun for the filtration, of which the micro-fluffy structure displayed high-filtration efficiency and low-pressure drop. The flow field in the 3D filtration membrane was simulated to optimize the process parameters to increase the filtration performance. The qualification factor increased from 0.0274 Pa−1 to 0.0309 Pa−1 by 12.77% after the optimization of the electrospinning parameters. The best filtration efficiency and pressure drop were 93.6% and 89.0 Pa, separately. This work provides a new strategy to fabricate 3D structures through the construction of fiber morphology and promotes further improvement of air filtration performance of fibrous filters.

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Bazgir, Morteza, Wei Zhang, Ximu Zhang, Jacobo Elies, Morvarid Saeinasab, Phil Coates, Mansour Youseffi, and Farshid Sefat. "Fabrication and Characterization of PCL/PLGA Coaxial and Bilayer Fibrous Scaffolds for Tissue Engineering." Materials 14, no. 21 (October 22, 2021): 6295. http://dx.doi.org/10.3390/ma14216295.

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Electrospinning is an innovative new fibre technology that aims to design and fabricate membranes suitable for a wide range of tissue engineering (TE) applications including vascular grafts, which is the main objective of this research work. This study dealt with fabricating and characterising bilayer structures comprised of an electrospun sheet made of polycaprolactone (PCL, inner layer) and an outer layer made of poly lactic-co-glycolic acid (PLGA) and a coaxial porous scaffold with a micrometre fibre structure was successfully produced. The membranes’ propriety for intended biomedical applications was assessed by evaluating their morphological structure/physical properties and structural integrity when they underwent the degradation process. A scanning electron microscope (SEM) was used to assess changes in the electrospun scaffolds’ structural morphology such as in their fibre diameter, pore size (μm) and the porosity of the scaffold surface which was measured with Image J software. During the 12-week degradation process at room temperature, most of the scaffolds showed a similar trend in their degradation rate except the 60 min scaffolds. The coaxial scaffold had significantly less mass loss than the bilayer PCL/PLGA scaffold with 1.348% and 18.3%, respectively. The mechanical properties of the fibrous membranes were measured and the coaxial scaffolds showed greater tensile strength and elongation at break (%) compared to the bilayer scaffolds. According to the results obtained in this study, it can be concluded that a scaffold made with a coaxial needle is more suitable for tissue engineering applications due to the improved quality and functionality of the resulting polymeric membrane compared to the basic electrospinning process. However, whilst fabricating a vascular graft is the main aim of this research work, the biological data will not present in this paper.

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Birbrair, Alexander, Tan Zhang, Zhong-Min Wang, Maria Laura Messi, Akiva Mintz, and Osvaldo Delbono. "Type-1 pericytes participate in fibrous tissue deposition in aged skeletal muscle." American Journal of Physiology-Cell Physiology 305, no. 11 (December 1, 2013): C1098—C1113. http://dx.doi.org/10.1152/ajpcell.00171.2013.

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In older adults, changes in skeletal muscle composition are associated with increased fibrosis, loss of mass, and decreased force, which can lead to dependency, morbidity, and mortality. Understanding the biological mechanisms responsible is essential to sustaining and improving their quality of life. Compared with young mice, aged mice take longer to recover from muscle injury; their tissue fibrosis is more extensive, and regenerated myofibers are smaller. Strong evidence indicates that cells called pericytes, embedded in the basement membrane of capillaries, contribute to the satellite-cell pool and muscle growth. In addition to their role in skeletal muscle repair, after tissue damage, they detach from capillaries and migrate to the interstitial space to participate in fibrosis formation. Here we distinguish two bona fide pericyte subtypes in the skeletal muscle interstitium, type-1 (Nestin-GFP−/NG2-DsRed+) and type-2 (Nestin-GFP+/NG2-DsRed+), and characterize their heretofore unknown specific roles in the aging environment. Our in vitro results show that type-1 and type-2 pericytes are either fibrogenic or myogenic, respectively. Transplantation studies in young animals indicate that type-2 pericytes are myogenic, while type-1 pericytes remain in the interstitial space. In older mice, however, the muscular regenerative capacity of type-2 pericytes is limited, and type-1 pericytes produce collagen, contributing to fibrous tissue deposition. We conclude that in injured muscles from aging mice, the pericytes involved in skeletal muscle repair differ from those associated with scar formation.

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Sasano, Yasuyuki, Itaru Mizoguchi, Ichiro Takahashi, Manabu Kagayama, Takashi Saito, and Yoshinori Kuboki. "BMPs induce endochondral ossification in rats when implanted ectopically within a carrier made of fibrous glass membrane." Anatomical Record 247, no. 4 (April 1997): 472–78. http://dx.doi.org/10.1002/(sici)1097-0185(199704)247:4<472::aid-ar5>3.0.co;2-t.

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Saidov, M. Z. "Autophagy, apoptosis, necroptosis, pyroptosis and netosis in pathogenesis of immune-inflammatory rheumatic diseases." Medical Immunology (Russia) 24, no. 4 (July 13, 2022): 659–704. http://dx.doi.org/10.15789/1563-0625-aan-2482.

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There are organized forms of cellular infiltrate observed in immune-inflammatory rheumatic diseases, i.e., ectopic follicle-like lymphoid structures and delayed-type response granulomas, whereas diffuse cellular inflammatory infiltrates represent non-organized forms. In these types of cellular infiltration, an integral pathogenetic link includes programmable cell death variants, with autophagy, apoptosis, necroptosis, pyroptosis and netosis being the most significant. There is a close relationship between these forms of cell death. This relationship occured in the process of biological evolution, being characterized by pronounced conservatism, and it follows general biological laws of molecular cellular processes. The “danger signals” (DAMPs) released during cell death induce a state of autoreactivity caused, e.g., by modulation of cell death processes using cellular PRR receptors of the innate immune system. When analyzing the processes of endocytosis, signaling pathways, adaptive molecules, transcription factors involved into these modes of cell death, we discuss pathogenetic role of changing membrane structures and molecular pathways of programmed cell death in immune-inflammatory rheumatic diseases. In this regard, there are fundamental membrane-associated cellular processes, genesis of various types of intracellular inflammasomes, cross-presentation of MHC-restricted products of disorganized loose fibrous connective tissue, and induction of innate and adaptive immune autoreactivity. Causal relationships of the molecular pathways for initiation of these forms of cell death, thus enabling identification of the molecular targets, in order to modulate productive inflammation.

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Pinilla, M., R. Ramírez-Camacho, C. Salas, F. González, C. López-Cortijo, and J. Vergara. "Development of Interface in Hydroxyapatite Implanted in the Middle Ear of the Rat: A Light and Scanning Microscopy Study." Otolaryngology–Head and Neck Surgery 128, no. 1 (January 2003): 124–31. http://dx.doi.org/10.1067/mhn.2003.55.

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OBJECTIVE: The aim of this work is to study the chronology in the biological covering of the hydroxyapatite bioprostheses in the healthy middle ear of the rat. STUDY DESIGN AND SETTING: Dense hydroxyapatite is implanted into the middle ear of 45 Long-Evans rats, between stapes and tympanic membrane. The sample was divided into 3 groups for morphologic, functional, and chemical studies at 15 days, 3 months, and 6 months after surgery, respectively. RESULTS: The short-term studies reveal that the prostheses is surrounded by a fibrous epithelial tissue referred as the interface; it presents a marked inflammatory reaction that decreases gradually in the medium-term and long-term studies; in this way, we observe a progressive adhesion between implant and the contact tissues. CONCLUSIONS AND SIGNIFICANCE: This model has enabled us to study the cell reaction produced by the contact of the prostheses with bone and soft tissue and their impact on the functional qualities of the prostheses.

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Sydorenko, M. I. "Structural organization of the ileum of laboratory animals in normal and in a comparative view aspect." Reports of Morphology 25, no. 2 (June 26, 2019): 72–77. http://dx.doi.org/10.31393/morphology-journal-2019-25(2)-09.

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In recent decades, diseases of the digestive system that require immediate, both therapeutic and surgical treatment, have become widespread, and it is therefore a natural task to find new and optimize existing technologies and methods for correcting the above-mentioned nosologies. Preclinical studies of such developments are conducted exclusively on laboratory animals and knowledge of the morphological features of their structure for further comparison with the morphology of similar human organs is an urgent task of modern medical and biological science. The purpose of the study was to study the structural organization of the ileum of rabbits in comparative species and to obtain control data on its morphological features. Adequate research methods were used in the work according to the set goal, namely: histological, histochemical, electron microscopic, morphometric and statistical and biopsies of the ileum of 10 rabbits were studied. The correctness of the distribution of traits by each of the variations obtained, the average values for each trait studied, standard errors and standard deviations were evaluated. The significance of the difference of values between independent micrometric values in the normal distribution of features was determined by Student’s criterion. The paper describes the main structural components of the ileum of rabbits and compared with similar structures of the human ileum. The ileum of rabbits, as in humans, has been determined to have four membranes: mucous, submucosal, muscular and serous. The mucous membrane is constructed from the epithelial layer, which is located on the basement membrane and the muscular plate and contains cellular elements (exocrinocytes, enterocytes of various kinds, elements of the diffuse endocrine system associated with the mucous membrane, intraepithelial lymphocytes), blood and lymphatic vessels and nerve endings. The submucosa is composed of loose fibrous connective tissue, which contains collagen and reticular fibers, elements of diffuse lymphoid tissue, blood vessels, and nerve endings. The muscular and serous membranes are constructed in the same way as in the human ileum. Thus, after the study, it was determined that the morphological organization of the ileum of rabbits at the optical and electron microscopic levels has general patterns of structure similar to those in the ileum of the person.

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Pacella, Alessandro, Paolo Ballirano, Marzia Fantauzzi, Antonella Rossi, Cecilia Viti, Lorenzo Arrizza, Elisa Nardi, Raffaela Caprioli, and Maria Rita Montereali. "Surface and Bulk Modifications of Fibrous Erionite in Mimicked Gamble’s Solution at Acidic pH." Minerals 11, no. 9 (August 24, 2021): 914. http://dx.doi.org/10.3390/min11090914.

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This study aimed at investigating both the surface and bulk modifications occurring on fibrous erionite during leaching in a mimicked Gamble’s solution (MGS) at pH of 4.5 and T = 37 °C, up to one month of incubation. Samples were characterized by a multi-analytical approach: field-emission scanning electron microscopy (FE-SEM) was employed to investigate the morphological changes of both pristine and reacted fibres, inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure the concentration of the released cations; X-ray photoelectron spectroscopy (XPS) was exploited for highlighting possible modifications of surface chemistry; X-ray powder diffraction (XRPD) and high-resolution transmission electron microscopy (HR-TEM) were applied aiming to get information on the structural state of the fibres following the incubation. ICP results integrated with those obtained by both bulk- and surface-chemical characterization highlighted that erionite binds Na especially in the first 24 h of sample incubation in the MGS, following ion exchange with the extra framework cations, in particular Ca. Moreover, our new results show that the Na binding process caused structural modifications with the migration of Na toward the Ca2 site and redistribution of the cations within the erionite cage. TEM investigation pointed out that the interaction between erionite and MGS results in the formation of a new surface amorphous layer with an irregular lobate pattern on an earlier surface weathered layer. However, the silicate framework is not weakened by incubation in the MGS at acidic pH. In addition, on the basis of the Si release normalized to the mineral surface area, fibrous erionite resulted significantly more biodurable than amphibole asbestos. Notably, considering the primary role played by biodurability in inducing pathogenicity, this result certainly supports in vivo observations showing that erionite is much more tumorigenic than asbestos. Moreover, the ions released by erionite when immersed in MGS may trigger biological effects, such as those on lipid packing and membrane permeability. On this basis, we expect a regulatory definition that would provide protection from this carcinogenic fibre.

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Tani, T., R. D. Allen, and Y. Naitoh. "Cellular membranes that undergo cyclic changes in tension: Direct measurement of force generation by an in vitro contractile vacuole of Paramecium multimicronucleatum." Journal of Cell Science 114, no. 4 (February 15, 2001): 785–95. http://dx.doi.org/10.1242/jcs.114.4.785.

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The contractile vacuole of the fresh water protozoan Paramecium is a membrane-bound vesicle that expels excess cytosolic water, acquired osmotically, through its periodic exocytotic activity. The in vitro contractile vacuole, isolated in a small amount of cytosol from the Paramecium cell and confined under mineral oil, showed periodic rounding and slackening at regular intervals for an extended time. The contractile vacuole rounded against the cytosol-mineral oil boundary tension. The tension at the surface of the contractile vacuole is, therefore, assumed to increase during the rounding phase. We first estimated the tension relative to the boundary tension from the degree of compression of the contractile vacuole by the boundary. We then determined the absolute value for the tension at the surface of the contractile vacuole from the degree of bending of an elastic carbon fiber microcantilever (8 microm thick; 2 mm long), whose free end was placed at the surface of an in vitro contractile vacuole. The tension was found to increase to its maximum value of approximately 5 mN m(-)(1) when the contractile vacuole rounded. This value was more than 35 times higher than that for the slackened contractile vacuole. Electron micrographs of conventional thin sections of chemically fixed in vitro contractile vacuoles as well as those of in vivo contractile vacuoles obtained from rapid frozen and cryosubstituted cells revealed the lack of any ultrastructural evidence for the presence of a fibrous network system surrounding the contractile vacuole. Thus we conclude that the mechanism(s) by which tension is developed at the surface of the contractile vacuole membrane resides in the contractile vacuole membrane itself. We propose a hypothesis that periodic changes in the spontaneous curvature of the contractile vacuole's lipid bilayer membrane is involved in the periodic development of higher contractile vacuole membrane tension. The isolated CV promises to be an excellent model system for understanding the molecular mechanisms of the dynamics of biological membrane.

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Dolan, E. B., C. E. Varela, K. Mendez, W. Whyte, R. E. Levey, S. T. Robinson, E. Maye, et al. "An actuatable soft reservoir modulates host foreign body response." Science Robotics 4, no. 33 (August 28, 2019): eaax7043. http://dx.doi.org/10.1126/scirobotics.aax7043.

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The performance of indwelling medical devices that depend on an interface with soft tissue is plagued by complex, unpredictable foreign body responses. Such devices—including breast implants, biosensors, and drug delivery devices—are often subject to a collection of biological host responses, including fibrosis, which can impair device functionality. This work describes a milliscale dynamic soft reservoir (DSR) that actively modulates the biomechanics of the biotic-abiotic interface by altering strain, fluid flow, and cellular activity in the peri-implant tissue. We performed cyclical actuation of the DSR in a preclinical rodent model. Evaluation of the resulting host response showed a significant reduction in fibrous capsule thickness (P = 0.0005) in the actuated DSR compared with non-actuated controls, whereas the collagen density and orientation were not changed. We also show a significant reduction in myofibroblasts (P = 0.0036) in the actuated group and propose that actuation-mediated strain reduces differentiation and proliferation of myofibroblasts and therefore extracellular matrix production. Computational models quantified the effect of actuation on the reservoir and surrounding fluid. By adding a porous membrane and a therapy reservoir to the DSR, we demonstrate that, with actuation, we could (i) increase transport of a therapy analog and (ii) enhance pharmacokinetics and time to functional effect of an inotropic agent. The dynamic reservoirs presented here may act as a versatile tool to further understand, and ultimately to ameliorate, the host response to implantable biomaterials.

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Jindal, Deepti Garg, Sandhya Singh Kushwaha, Sonia Joshi, Namita Sepolia, Varun Jindal, and Kanu Jain. "Peripheral Giant Cell Granuloma: A Case Report with Review on Its Histogenesis and Recurrence." Dental Journal of Advance Studies 07, no. 02 (May 27, 2019): 095–98. http://dx.doi.org/10.1055/s-0039-1688548.

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AbstractGiant cell granulomas (GCGs) of the jaws are non-neoplastic lesions that arise either peripherally in periodontal ligament, mucoperiosteum, or centrally in the bone. Histologically, both peripheral and central giant cell granuloma are characterized by the presence of numerous multinucleated giant cells in a prominent fibrous stroma. Peripheral giant cell granuloma is an infrequent reactive, exophytic lesion of the oral cavity, also known as giant-cell epulis, osteoclastoma, giant cell reparative granuloma, or giant cell hyperplasia. It is the most common giant cell lesion of the jaws and originates from the connective tissue of the periosteum or from the periodontal membrane, in response to local irritation or chronic trauma. The lesion develops mostly in adults, commonly in the lower jaw, with slight female predilection although is uncommon in children. Clinically, it shows resemblance to pyogenic granuloma, peripheral ossifying fibroma, and many other peripheral lesions seen in the oral cavity, but in our case it resembled a squamous cell carcinoma, thereby histopathology is mandatory for the diagnosis of this lesion. The lesion although being relatively common, still has a lot of ambiguity. The ambiguity is in terms of its etiology, growth potential, biological behavior (recurrence), histogenesis of its cells, and its treatment. The entity further holds significance because of its notorious behavior and high tendency to recur. This is a case report of a 30-year-old female patient with history of swelling in the lower anterior region of jaw since 1 year. After complete excision of lesion, lesion reoccurred after few months.

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Krausser, Johannes, Tuomas P. J. Knowles, and Anđela Šarić. "Physical mechanisms of amyloid nucleation on fluid membranes." Proceedings of the National Academy of Sciences 117, no. 52 (December 16, 2020): 33090–98. http://dx.doi.org/10.1073/pnas.2007694117.

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Biological membranes can dramatically accelerate the aggregation of normally soluble protein molecules into amyloid fibrils and alter the fibril morphologies, yet the molecular mechanisms through which this accelerated nucleation takes place are not yet understood. Here, we develop a coarse-grained model to systematically explore the effect that the structural properties of the lipid membrane and the nature of protein–membrane interactions have on the nucleation rates of amyloid fibrils. We identify two physically distinct nucleation pathways—protein-rich and lipid-rich—and quantify how the membrane fluidity and protein–membrane affinity control the relative importance of those molecular pathways. We find that the membrane’s susceptibility to reshaping and being incorporated into the fibrillar aggregates is a key determinant of its ability to promote protein aggregation. We then characterize the rates and the free-energy profile associated with this heterogeneous nucleation process, in which the surface itself participates in the aggregate structure. Finally, we compare quantitatively our data to experiments on membrane-catalyzed amyloid aggregation of α-synuclein, a protein implicated in Parkinson’s disease that predominately nucleates on membranes. More generally, our results provide a framework for understanding macromolecular aggregation on lipid membranes in a broad biological and biotechnological context.

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Li, Jiang Feng, Zhong Min Chen, Qin Luo, Guang Hui Zhang, and Fu Ping Wang. "Preparation and Biological Properties of Nano-Silk Fibroin/Polyurethane/Silver Nanoparticles Composite Membranes." Materials Science Forum 848 (March 2016): 557–66. http://dx.doi.org/10.4028/www.scientific.net/msf.848.557.

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A series of the blending membranes comprised of the different mass ratio of silk fibroin peptide (SFP) power, silver nanoparticles (NanoAg) and polyurethane (PU) were prepared with mixing the SFP power, silver nitrate and PU, and the silver nitrate was reduced to NanoAg by SFP in this mixing process. UV spectrum was used to detect the nanoAg. The experimental results confirmed the formation of NanoAg. The dissolution of the obtained membranes in simulated body fluid (SBF) were determined, and showed that the membranes had good stability. Their mechanical properties were also determined. The results revealed that the mass ratio of SFP to PU was an important influence factor, and the mass ratio 30/70 (SFP/PU) of the membrane was the optimum. The Antibacterial properties against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, were examined, the results of which indicated that the membranes containing NanoAg had a good bactericidal effect. The SFP/PU/NanoAg membranes also showed good cell and blood compatibility, and then they have application prospect as an antibacterial materials using for medical catheters.

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Echeverri-Correa, Estefanía, David Orlando Grajales-Lopera, Santiago Gutiérrez-Restrepo, and Claudia Patricia Ossa-Orozco. "Effective sericin-fibroin separation from Bombyx mori silkworms fibers and low-cost salt removal from fibroin solution." Revista Facultad de Ingeniería Universidad de Antioquia, no. 94 (October 17, 2019): 97–101. http://dx.doi.org/10.17533/udea.redin.20190731.

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Silk from Bombyx mori has two main proteins: fibroin and sericin. Fibroin is a protein that exhibits good biocompatibility and high surface reactivity, desirable properties for many biomedical applications. Sericin is related with adverse immune response in some medical uses. Therefore, its removal (degumming) is desirable in almost all fields, including the textile industry and biological applications. In this study, three degumming methods (distilled water, liquid neutral detergent and sodium carbonate solution) were evaluated using Raman spectroscopy. Degummed silk treated with sodium carbonate solution exhibits a pattern consistent with previous studies for sericin-free fibroin, and significant differences with the untreated silk pattern. Also, degummed fibroin fibers were dissolved in a calcium chloride solution, in pursuit of a more versatile material. Additionally, different porous membranes of dialysis tubes were tested to remove residual salts, and were compared by conductivity measurements and EDS analysis, identifying good performance for an affordable food cellulose membrane. The results showed that it is possible to obtain fibroin with adequate chemical properties, using low-cost process and membrane of dialysis tubes.

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de Cesar Netto, Cesar, Lew Schon, Lucas Furtado Da Fonseca, Camilla Maccario, Apisan Chinanuvathana, and Jan Fritz. "MR Imaging of Ankle Arthroplasty Implants." Foot & Ankle Orthopaedics 2, no. 3 (September 1, 2017): 2473011417S0000. http://dx.doi.org/10.1177/2473011417s000035.

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Category: Ankle Introduction/Purpose: Metal artifact reduction magnetic resonance imaging (MRI) of the ankle allows for comprehensive imaging evaluation of pain and dysfunction after arthroplasty including periprosthetic bone resorption and osteolysis, synovitis, infection, periprosthetic fractures, arthrofibrosis and component malalignment. The aim of this study was to show the appearance of normal ankle arthroplasties and common pathologies using optimal imaging parameters including newer multispectral MR techniques such as MAVRIC and SEMAC. Methods: We included adult 20 asymptomatic volunteers (12 men and 20 women, mean age of 62.41 years (range, 42-74 years), mean body mass index (BMI) of 29.02 kg/m2 (range, 20.30-41.15 kg/m2), average postoperative time of 13.84 months (range, 3-29 months)) and 12 symptomatic patients (12 men and 20 women, mean age of 62.41 years (range, 42-74 years), BMI of 29.02 kg/m2 (range, 20.30-41.15 kg/m2) and an average postoperative time of 13.84 months (range, 3-29 months)) with total ankle replacement that agreed to cooperate and signed a written informed consent. The MRI exams of asymptomatic volunteers were obtained for research purposes only, whereas the clinical and MRI exams of asymptomatic volunteers were obtained for research and clinical purposes. Images were assessed by two different readers. Results: The following key pathophysiologic issues were assessed regarding imaging findings: Normal MRI appearances and MRI diagnosis of complications: Implant integration: Biological and cement fixation, fibrous membrane formation, bone resorption and osteolysis Bone: progressive osteoporosis, implant subsidence, osseous stress reaction and focal overload, fracture, osteonecrosis Synovium: non-specific synovitis, wear-induced synovitis, infection, arthrofibrosis Impingement syndromes Sagittal implant alignment Musculotendinous abnormalities Neurovascular compromise Types and frequency of modes of failure of ankle arthroplasty. Conclusion: Ankle arthroplasties can be evaluated using metal artifact reduction MRI by optimizing the imaging protocol. Newer imaging sequences can provide optimal diagnostic value with shorter acquisition time and better metal artifact reduction using commercially available MR scanners. These imaging characteristics and scan techniques can provide optimal diagnostic value for patients with ankle arthroplasties, improving patient care.

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Cheng, Qinghui, Zhi-Wen Hu, Yuto Tobin-Miyaji, Amy E. Perkins, Terrence Deak, and Wei Qiang. "Fibrillization of 40-residue β-Amyloid Peptides in Membrane-Like Environments Leads to Different Fibril Structures and Reduced Molecular Polymorphisms." Biomolecules 10, no. 6 (June 8, 2020): 881. http://dx.doi.org/10.3390/biom10060881.

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The molecular-level polymorphism in β-Amyloid (Aβ) fibrils have recently been considered as a pathologically relevant factor in Alzheimer’s disease (AD). Studies showed that the structural deviations in human-brain-seeded Aβ fibrils potentially correlated with the clinical histories of AD patients. For the 40-residue Aβ (Aβ40) fibrils derived from human brain tissues, a predominant molecular structure was proposed based on solid-state nuclear magnetic resonance (ssNMR) spectroscopy. However, previous studies have shown that the molecular structures of Aβ40 fibrils were sensitive to their growth conditions in aqueous environments. We show in this work that biological membranes and their phospholipid bilayer mimics serve as environmental factors to reduce the structural heterogeneity in Aβ40 fibrils. Fibrillization in the presence of membranes leads to fibril structures that are significantly different to the Aβ40 fibrils grown in aqueous solutions. Fibrils grown from multiple types of membranes, including the biological membranes extracted from the rats’ synaptosomes, shared similar ssNMR spectral features. Our studies emphasize the biological relevance of membranes in Aβ40 fibril structures and fibrillization processes.

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Aleksandrov, Luba A., Adrei A. Aleksandrov, Timothy J. Jensen, Joshua D. Strauss, and Jonathan F. Fay. "Conformational Variability in Ground-State CFTR Lipoprotein Particle Cryo-EM Ensembles." International Journal of Molecular Sciences 23, no. 16 (August 17, 2022): 9248. http://dx.doi.org/10.3390/ijms23169248.

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Cystic fibrosis transmembrane regulator (CFTR) is a dynamic membrane protein belonging to the ABC transporter family. It is unusual within this family as it is an ion channel, as opposed to a transporter. Activation of CFTR requires ATP and phosphorylation by PKA, and dysregulation of CFTR mediated salt and water homeostasis can lead to cystic fibrosis. Recent advancements in structural biological methods have led to more than 10 published CFTR structures, and, so far, all of these structures of CFTR, determined by cryo-EM, have been limited to detergent-purified protein preparations. To visualize CFTR in an environment that more closely represents its native membranous environment, we utilized two different lipoprotein particle encapsulation techniques: one in which the ion channel is first purified and then reconstituted using the membrane scaffolding protein Saposin A and another that uses the solubilizing polymer Sokalan CP9 (DIBMA) to extract CFTR directly from membranes. Structures derived from these types of preparations may better correlate to their function, for instance, the single-channel measurements from membrane vesicles.

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Huang, Ching-Cheng. "Characteristics and Preparation of Designed Alginate-Based Composite Scaffold Membranes with Decellularized Fibrous Micro-Scaffold Structures from Porcine Skin." Polymers 13, no. 20 (October 9, 2021): 3464. http://dx.doi.org/10.3390/polym13203464.

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Alginate-based composite scaffold membranes with various ratios of decellularized extracellular matrices could be designed and obtained from porcine skin tissue by using supercritical carbon dioxide fluid technology. Retention of decellularized extracellular matrix (dECM) and scaffold-structure integrity was observed. This work provides a simple and time-saving process for the preparation of biomedical alginate-based composite scaffold membranes with fibrous dECM micro-scaffolds, which were further characterized by Fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA), and scanning electron microscope (SEM). The introduction of fibrous dECM micro-scaffolds enhanced the thermal stability and provided expected effects on the biological properties of the designed composite scaffold membranes in regenerative applications.

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Miller, Christopher. "David Christopher Gadsby. 26 March 1947—9 March 2019." Biographical Memoirs of Fellows of the Royal Society 68 (March 13, 2020): 175–93. http://dx.doi.org/10.1098/rsbm.2019.0048.

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Over nearly five decades, David Christopher Gadsby pioneered biophysical research that advanced our mechanistic understanding of ion-transporting proteins in biological membranes. His passion for hands-on do-it-yourself electrophysiology, his depth of analytical rigor, and his idiosyncratic scientific aesthetic expanded the edge of discovery in two areas: the electrical character of the Na + pump, and the molecular workings of ‘cystic fibrosis transmembrane regulator’ (CFTR), the chloride ion channel whose mutations cause cystic fibrosis. His approach was flavoured by an appreciation for common underlying features between these ostensibly distinct types of membrane-transport systems. While David's focus was first on the basic molecular biophysics of a problem, he was always attuned to implications of his discoveries for human health. Based in New York at The Rockefeller University throughout his independent scientific career, and at the Marine Biological Laboratory in Woods Hole, Massachusetts, as a squid-season research-scientist, he was proficient in wrestling with problems spanning a wide swath of membrane biology: from determinants of the cardiac electrical waveform, to microsecond-timescale ionic currents in squid axons, to details of structure–mechanism relations in membrane pump and ion-channel proteins. He wore his eminence lightly and never distanced himself from the laboratory, where he often performed experiments with his own hands right up to his retirement. His reserved scientific personality, which demanded equally from his colleagues and himself immaculate data, unclouded logic, and substantive pertinence to the issues at hand, contrasted with his palpable joy in a good experiment and in his sea-loving life outside the lab.

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Xu, Xiao Xu, Yong Peng Yu, and Li Qun Yang. "The Progress in Research on Silk Fibroin Blend Membranes." Advanced Materials Research 311-313 (August 2011): 2052–58. http://dx.doi.org/10.4028/www.scientific.net/amr.311-313.2052.

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Silk fibroin film, which has good biological compatibility, is suitable for use as biomaterials and medical materials. However, silk fibroin film in dry state is too brittle to be used by itself. Blending with other natural or synthetic polymers could improve the poor mechanical properties of silk fibroin film. In this paper, recent researches in blend film of silk fibroin and their application were summarized.

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Kim, Kyoung-Hwa, Lim Jeong, Ho-Nam Park, Seung-Yun Shin, Won-Ho Park, Sang-Chul Lee, Tae-Il Kim, et al. "Biological efficacy of silk fibroin nanofiber membranes for guided bone regeneration." Journal of Biotechnology 120, no. 3 (November 2005): 327–39. http://dx.doi.org/10.1016/j.jbiotec.2005.06.033.

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Lubarda, Vlado, and Robert Asaro. "Viscoelastic response of anisotropic biological membranes. Part II: Constitutive models." Theoretical and Applied Mechanics 41, no. 3 (2014): 213–31. http://dx.doi.org/10.2298/tam1403213l.

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In Part I of this series [7] we described the structure of the biopolymer interlayers found in the shell of the mollusk Haliotis rufescens (the red abalone). There we described how the layers can be viewed as a viscoelastic composite reinforced by a network of chitin fibrils arranged in an often nearly unidirectional architecture. Mechanical testing documented the response to tensile testing of layers removed via demineralization. Herein in Part II we describe a general viscoelastic constitutive model for such layers that may be both transversely isotropic or orthotropic as would follow from the network of nearly aligned chitin fibrils described by Bezares et al. in Part I [7]. Part III of this series will be concerned with applying the models to more fully describing the response of these types of biological membranes to mechanical loading.

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Khan, Atta ur Rehman, Muhammad Nadeem, M. Aqeel Bhutto, Fan Yu, Xianrui Xie, Hany El-Hamshary, Ayman El-Faham, Usama A. Ibrahim, and Xiumei Mo. "Physico-Chemical and Biological Evaluation of PLCL/SF Nanofibers Loaded with Oregano Essential Oil." Pharmaceutics 11, no. 8 (August 2, 2019): 386. http://dx.doi.org/10.3390/pharmaceutics11080386.

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Essential oils are complex volatile compounds, extracted from specific plant species, with promising therapeutic potentials. However, their volatile nature presents a major hindrance in using them as therapeutic agents. In the current study, we successfully encapsulated oregano essential oil (OEO) into Poly (l-lactic acid-co-e-caprolactone) /Silk Fibroin (PLCL/SF) polymers through electrospinning. The nanofibrous membrane (NF) was fabricated and characterized for various physico-chemical and biological attributions. Homogenous and bead free morphology was confirmed by scanning electron microscopy (SEM). Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) confirmed the successful loading of OEO and its physical interaction with the blend of PLCL/SF. Moreover, thermogravimetric analysis (TGA) also confirmed the successful loading and thermostability of the OEO. Although a significant change was noted in tensile strength due to the loading of OEO, the mechanical behaviour still falls into the acceptable ranges required for skin tissue engineering. Similarly, fabricated material was evaluated for its biological significance. Liquid chromatography-mass spectrometry (LC-MS) was employed to determine the release behaviour of OEO from electrospun membranes. LC-MS data, noted for 48 h, confirmed the biphasic release of OEO. Furthermore, NF membranes have shown strong antioxidant and anti-tumor activities. This material is promising and can be implanted to avoid the recurrence of the tumor after its surgical removal.

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Kelly, Jeffery W., and William E. Balch. "Amyloid as a natural product." Journal of Cell Biology 161, no. 3 (May 12, 2003): 461–62. http://dx.doi.org/10.1083/jcb.200304074.

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Amyloid fibrils, such as those found in Alzheimer's and the gelsolin amyloid diseases, result from the misassembly of peptides produced by either normal or aberrant intracellular proteolytic processing. A paper in this issue by Marks and colleagues (Berson et al., 2003) demonstrates that intra-melanosome fibrils are formed through normal biological proteolytic processing of an integral membrane protein. The resulting peptide fragment assembles into fibrils promoting the formation of melanin pigment granules. These results, along with the observation that amyloid fibril formation by bacteria is highly orchestrated, suggest that fibril formation is an evolutionary conserved biological pathway used to generate natural product nanostructures.

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Yuasa, Takeshi, Jorge D. Rivas-Carrillo, Nalú Navarro-Alvarez, Alejandro Soto-Gutierrez, Yasuhiro Kubota, Yasuhiko Tabata, Teru Okitsu, et al. "Neovascularization Induced around an Artificial Device Implanted in the Abdomen by the Use of Gelatinized Fibroblast Growth Factor 2." Cell Transplantation 18, no. 5-6 (May 2009): 683–88. http://dx.doi.org/10.1177/096368970901805-625.

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The development of a bioartificial pancreas (BAP) with immunoisolating fashion has been gaining attention as a new method for treating diabetes. We have been proceeding with the development of a bag-type BAP that can be easily implanted and that allows for the optional injection or rejection of cells at any time. If fibrosis develops around a BAP device, then the permeability of substances transmitted through a semipermeable membrane will decrease, thereby reducing the reactivity with glucose, so it is necessary for the material of the device to have an excellent histocompatibility. Furthermore, in order to improve the efficacy of BAP treatment, it is important to maintain an environment of ample blood flow around the device. We have created a bag-type device for BAP that is 20 × 20 mm in size and comprises two layers of membranes. We have used an EVAL membrane for the outer membrane of the two layers. The EVAL membrane is a semipermeable membrane with good insulin permeability, which functions as an immunoisolation membrane. The inner membrane consists of PAU-coated HD-PE (nonwoven material processed with polyaminourethan) and it is designed to function as a scaffold for cells. We used Lewis rats to determine whether the effectiveness of fibroblast growth factor 2 (bFGF) can be improved by concomitantly using bFGF with a capacity for blood vessel regeneration as well as bFGF immersed in a sheet of gelatin. We placed the BAP in the abdominal cavity and covered it with the greater omentum. We were able to significantly increase the blood flow and the number of new blood vessels in the tissue surrounding the BAP device by using gelatinized bFGF. There were only a few instances of fibrosis as a biological reaction to the EVAL membrane, and the infiltration of inflammatory cells was mild. There were no adverse effects related to implantation of the device. We confirmed in this study that the use of an implantable BAP device and bFGF allowed for a better blood flow around the BAP device. There were only minor instances of fibrosis and inflammation reaction around the BAP, thus indicating the BAP that we are currently developing to have an excellent histocompatibility.

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Nahar, Saifun, Yoshiki Nakashima, Chika Miyagi-Shiohira, Takao Kinjo, Naoya Kobayashi, Issei Saitoh, Masami Watanabe, Hirofumi Noguchi, and Jiro Fujita. "A Comparison of Proteins Expressed between Human and Mouse Adipose-Derived Mesenchymal Stem Cells by a Proteome Analysis through Liquid Chromatography with Tandem Mass Spectrometry." International Journal of Molecular Sciences 19, no. 11 (November 6, 2018): 3497. http://dx.doi.org/10.3390/ijms19113497.

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Adipose-derived mesenchymal stem cells (ADSCs) have become a common cell source for cell transplantation therapy. Clinical studies have used ADSCs to develop treatments for tissue fibrosis, such as liver cirrhosis and pulmonary fibroma. The need to examine and compare basic research data using clinical research data derived from mice and humans is expected to increase in the future. Here, to better characterize the cells, the protein components expressed by human ADSCs used for treatment, and mouse ADSCs used for research, were comprehensively analyzed by liquid chromatography with tandem mass spectrometry. We found that 92% (401 type proteins) of the proteins expressed by ADSCs in humans and mice were consistent. When classified by the protein functions in a gene ontology analysis, the items that differed by >5% between human and mouse ADSCs were “biological adhesion, locomotion” in biological processes, “plasma membrane” in cellular components, and “antioxidant activity, molecular transducer activity” in molecular functions. Most of the listed proteins were sensitive to cell isolation processes. These results show that the proteins expressed by human and murine ADSCs showed a high degree of correlation.

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McKee, Matthew G., John M. Layman, Matthew P. Cashion, and Timothy E. Long. "Phospholipid Nonwoven Electrospun Membranes." Science 311, no. 5759 (January 20, 2006): 353–55. http://dx.doi.org/10.1126/science.1119790.

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Nonwoven fibrous membranes were formed from electrospinning lecithin solutions in a single processing step. As the concentration of lecithin increased, the micellar morphology evolved from spherical to cylindrical, and at higher concentrations the cylindrical micelles overlapped and entangled in a fashion similar to polymers in semi-dilute or concentrated solutions. At concentrations above the onset of entanglements of the wormlike micelles, electrospun fibers were fabricated with diameters on the order of 1 to 5 micrometers. The electrospun phospholipid fibers offer the potential for direct fabrication of biologically based, high-surface-area membranes without the use of multiple synthetic steps, complicated electrospinning designs, or postprocessing surface treatments.

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YOSHIMURA, Tohru, Yusuke SHIMIZU, Wataru KUROTANI, Ryohei YAMAOKA, and Keizo HAYASHIYA. "Application of fibroin membrane to immobilizing coenzymes." Agricultural and Biological Chemistry 52, no. 12 (1988): 3201–2. http://dx.doi.org/10.1271/bbb1961.52.3201.

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Guerra, Nayrim Brizuela, Júlia Bünecker Cassel, Nathália Oderich Muniz, Nicole Andréa Corbellini Henckes, Fernanda dos Santos de Oliveira, Elizabeth Obino Cirne-Lima, and Luis Alberto Loureiro dos Santos. "Dense and Fibrous Membranes of Poly(lactic-co-glycolic acid)/Epoxidized Poly(isoprene): Chemical and Biological Evaluation." Fibers and Polymers 22, no. 8 (April 26, 2021): 2079–89. http://dx.doi.org/10.1007/s12221-021-0971-4.

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40

Caruana, Mario, Angelique Camilleri, Maria Ylenia Farrugia, Stephanie Ghio, Michaela Jakubíčková, Ruben J. Cauchi, and Neville Vassallo. "Extract from the Marine Seaweed Padina pavonica Protects Mitochondrial Biomembranes from Damage by Amyloidogenic Peptides." Molecules 26, no. 5 (March 7, 2021): 1444. http://dx.doi.org/10.3390/molecules26051444.

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The identification of compounds which protect the double-membrane of mitochondrial organelles from disruption by toxic confomers of amyloid proteins may offer a therapeutic strategy to combat human neurodegenerative diseases. Here, we exploited an extract from the marine brown seaweed Padina pavonica (PPE) as a vital source of natural bioactive compounds to protect mitochondrial membranes against insult by oligomeric aggregates of the amyloidogenic proteins amyloid-β (Aβ), α-synuclein (α-syn) and tau, which are currently considered to be major targets for drug discovery in Alzheimer’s disease (AD) and Parkinson’s disease (PD). We show that PPE manifested a significant inhibitory effect against swelling of isolated mitochondria exposed to the amyloid oligomers, and attenuated the release of cytochrome c from the mitochondria. Using cardiolipin-enriched synthetic lipid membranes, we also show that dye leakage from fluorophore-loaded vesicles and formation of channel-like pores in planar bilayer membranes are largely prevented by incubating the oligomeric aggregates with PPE. Lastly, we demonstrate that PPE curtails the ability of Aβ42 and α-syn monomers to self-assemble into larger β-aggregate structures, as well as potently disrupts their respective amyloid fibrils. In conclusion, the mito-protective and anti-aggregator biological activities of Padina pavonica extract may be of therapeutic value in neurodegenerative proteinopathies, such as AD and PD.

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Anderson, M. P., D. N. Sheppard, H. A. Berger, and M. J. Welsh. "Chloride channels in the apical membrane of normal and cystic fibrosis airway and intestinal epithelia." American Journal of Physiology-Lung Cellular and Molecular Physiology 263, no. 1 (July 1, 1992): L1—L14. http://dx.doi.org/10.1152/ajplung.1992.263.1.l1.

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Cl- channels located in the apical membrane of secretory epithelia play a key role in epithelial fluid and electrolyte transport. Dysfunction of one of these channels, cystic fibrosis transmembrane conductance regulator (CFTR), causes the genetic disease cystic fibrosis (CF). We review here the properties and regulation of the different types of Cl- channels that have been reported in airway and intestinal epithelia. We begin by describing the properties of the CFTR Cl- channel and then use those properties as a point of reference. We focused particularly on the evidence that localizes specific types of Cl- channel to the apical membrane. With that background, we assess the biological function of various Cl- channels in airway and intestinal epithelia.

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YOSHIMURA, Tohru, Wataru KUROTANI, Yusuke SHIMIZU, Ryohei YAMAOKA, and Keizo HAYASHIYA. "Selective permeability of fibroin membrane for amino acids." Agricultural and Biological Chemistry 52, no. 8 (1988): 2103–4. http://dx.doi.org/10.1271/bbb1961.52.2103.

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Zhao, Bin, Feng Wu, Ying-ying Bai, Min Fang, and Lu Wang. "Preparation and biological properties of a graphene oxide/silk fibroin barrier membrane loaded with simvastatin." Carbon 144 (April 2019): 843. http://dx.doi.org/10.1016/j.carbon.2018.11.096.

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Li, Jingang, Shuwen Li, Xiaohui Wang, Fan Fan, Kongyin Zhao, Junfu Wei, Linhua Zhang, and Dunwan Zhu. "Biologically inspired silk fibroin grafted polyacrylonitrile filtration membrane prepared in ZnCl2 aqueous solution." Chinese Chemical Letters 30, no. 1 (January 2019): 239–42. http://dx.doi.org/10.1016/j.cclet.2018.07.016.

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Hellstrand, Erik, Agnieszka Nowacka, Daniel Topgaard, Sara Linse, and Emma Sparr. "Membrane Lipid Co-Aggregation with α-Synuclein Fibrils." PLoS ONE 8, no. 10 (October 11, 2013): e77235. http://dx.doi.org/10.1371/journal.pone.0077235.

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Unruh, Colin, Nicolas Van Bavel, Max Anikovskiy, and Elmar J. Prenner. "Benefits and Detriments of Gadolinium from Medical Advances to Health and Ecological Risks." Molecules 25, no. 23 (December 7, 2020): 5762. http://dx.doi.org/10.3390/molecules25235762.

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Gadolinium (Gd)-containing chelates have been established as diagnostics tools. However, extensive use in magnetic resonance imaging has led to increased Gd levels in industrialized parts of the world, adding to natural occurrence and causing environmental and health concerns. A vast amount of data shows that metal may accumulate in the human body and its deposition has been detected in organs such as brain and liver. Moreover, the disease nephrogenic systemic fibrosis has been linked to increased Gd3+ levels. Investigation of Gd3+ effects at the cellular and molecular levels mostly revolves around calcium-dependent proteins, since Gd3+ competes with calcium due to their similar size; other reports focus on interaction of Gd3+ with nucleic acids and carbohydrates. However, little is known about Gd3+ effects on membranes; yet some results suggest that Gd3+ interacts strongly with biologically-relevant lipids (e.g., brain membrane constituents) and causes serious structural changes including enhanced membrane rigidity and propensity for lipid fusion and aggregation at much lower concentrations than other ions, both toxic and essential. This review surveys the impact of the anthropogenic use of Gd emphasizing health risks and discussing debilitating effects of Gd3+ on cell membrane organization that may lead to deleterious health consequences.

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Cong, Xiaofei, Rolf D. Hubmayr, Changgong Li, and Xiaoli Zhao. "Plasma membrane wounding and repair in pulmonary diseases." American Journal of Physiology-Lung Cellular and Molecular Physiology 312, no. 3 (March 1, 2017): L371—L391. http://dx.doi.org/10.1152/ajplung.00486.2016.

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Various pathophysiological conditions such as surfactant dysfunction, mechanical ventilation, inflammation, pathogen products, environmental exposures, and gastric acid aspiration stress lung cells, and the compromise of plasma membranes occurs as a result. The mechanisms necessary for cells to repair plasma membrane defects have been extensively investigated in the last two decades, and some of these key repair mechanisms are also shown to occur following lung cell injury. Because it was theorized that lung wounding and repair are involved in the pathogenesis of acute respiratory distress syndrome (ARDS) and idiopathic pulmonary fibrosis (IPF), in this review, we summarized the experimental evidence of lung cell injury in these two devastating syndromes and discuss relevant genetic, physical, and biological injury mechanisms, as well as mechanisms used by lung cells for cell survival and membrane repair. Finally, we discuss relevant signaling pathways that may be activated by chronic or repeated lung cell injury as an extension of our cell injury and repair focus in this review. We hope that a holistic view of injurious stimuli relevant for ARDS and IPF could lead to updated experimental models. In addition, parallel discussion of membrane repair mechanisms in lung cells and injury-activated signaling pathways would encourage research to bridge gaps in current knowledge. Indeed, deep understanding of lung cell wounding and repair, and discovery of relevant repair moieties for lung cells, should inspire the development of new therapies that are likely preventive and broadly effective for targeting injurious pulmonary diseases.

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ZHAO, Bin, Feng WU, Ying-ying BAI, Min FANG, and Lu WANG. "RETRACTED: Preparation and biological properties of a graphene oxide/silk fibroin barrier membrane loaded with simvastatin." New Carbon Materials 33, no. 5 (October 2018): 460–68. http://dx.doi.org/10.1016/s1872-5805(18)30011-8.

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Hasegawa, Tomoka, Hiromi Hongo, Tomomaya Yamamoto, Miki Abe, Hirona Yoshino, Mai Haraguchi-Kitakamae, Hotaka Ishizu, Tomohiro Shimizu, Norimasa Iwasaki, and Norio Amizuka. "Matrix Vesicle-Mediated Mineralization and Osteocytic Regulation of Bone Mineralization." International Journal of Molecular Sciences 23, no. 17 (September 1, 2022): 9941. http://dx.doi.org/10.3390/ijms23179941.

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Bone mineralization entails two mineralization phases: primary and secondary mineralization. Primary mineralization is achieved when matrix vesicles are secreted by osteoblasts, and thereafter, bone mineral density gradually increases during secondary mineralization. Nearby extracellular phosphate ions (PO43−) flow into the vesicles via membrane transporters and enzymes located on the vesicles’ membranes, while calcium ions (Ca2+), abundant in the tissue fluid, are also transported into the vesicles. The accumulation of Ca2+ and PO43− in the matrix vesicles induces crystal nucleation and growth. The calcium phosphate crystals grow radially within the vesicle, penetrate the vesicle’s membrane, and continue to grow outside the vesicle, ultimately forming mineralized nodules. The mineralized nodules then attach to collagen fibrils, mineralizing them from the contact sites (i.e., collagen mineralization). Afterward, the bone mineral density gradually increases during the secondary mineralization process. The mechanisms of this phenomenon remain unclear, but osteocytes may play a key role; it is assumed that osteocytes enable the transport of Ca2+ and PO43− through the canaliculi of the osteocyte network, as well as regulate the mineralization of the surrounding bone matrix via the Phex/SIBLINGs axis. Thus, bone mineralization is biologically regulated by osteoblasts and osteocytes.

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K.J. Kinnunen, Paavo. "Amyloid Formation on Lipid Membrane Surfaces." Open Biology Journal 2, no. 1 (December 31, 2009): 163–75. http://dx.doi.org/10.2174/1874196700902010163.

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Several lines of research have concluded lipid membranes to efficiently induce the formation of amyloid-type fibers by a number of proteins. In brief, membranes, particularly when containing acidic, negatively charged lipids, concentrate cationic peptides/proteins onto their surfaces, into a local low pH milieu. The latter together with the anisotropic low dielectricity environment of the lipid membrane further forces polypeptides to align and adjust their conformation so as to enable a proper arrangement of the side chains according to their physicochemical characteristics, creating a hydrophobic surface contacting the lipid hydrocarbon region. Concomitantly, the low dielectricity also forces the polypeptides to maximize intramolecular hydrogen bonding by folding into amphipathic α-helices, which further aggregate, the latter adding cooperativity to the kinetics of membrane association. After the above, fast first events, several slower, cooperative conformational transitions of the oligomeric polypeptide chains take place in the membrane surface. Relaxation to the free energy minimum involves a complex free energy landscape of the above system comprised of a soft membrane interacting with, and accommodating peptide polymers. The overall free energy landscape thus involves a region of polypeptide aggregation associated with folding: polypeptide physicochemical properties and available conformation/oligomerization state spaces as determined by the amino acid sequence. In this respect, of major interest are those natively disordered proteins interacting with lipids, which in the absence of a ligand have no inherent structure and may adapt different functional states. Key sequence features for lipid and membrane interactions from the point of view of amyloid formation are i) conformational ambiguity, ii) adoption of amphipathic structures, iii) ion binding, and iv) propensity for aggregation and amyloid fibrillation. The pathways and states of the polypeptide conformational transitions further depend on the lipid composition, which thus couples the inherent properties of lipid membranes to the inherent properties of proteins. In other words, different lipids and their mixtures generate a very complex and rich scale of environments, involving also a number of cooperative transitions, sensitive to exogenous factors (temperature, ions, pH, small molecules), with small scale molecular properties and interactions translating into large scale 2- and 3-D organization. These lipid surface properties and topologies determine and couple to the transitions of the added polypeptide, the latter now undergoing oligomerization, with a sequence of specific and cooperative conformational changes. The above aggregation/folding pathways and transient intermediates of the polypeptide oligomers appear to have distinct biological functions. The latter involve i) the control of enzyme catalytic activity, ii) cell defence (e.g. antimicrobial and cancer killing peptides/proteins, as well as possibly also iii) control of cell shape and membrane traffic. On the other hand, these processes are also associated with the onset of major sporadic diseases, all involving protein misfolding, aggregation and amyloid formation, such as in Alzheimer’s and Parkinson’s diseases, prion disease, and type 2 diabetes. Exemplified by the latter, in an acidic phospholipid containing membrane human islet associated polypeptide (IAPP or amylin, secreted by pancreatic β-cells) efficiently transforms into amyloid β-sheet fibrils, the latter property being associated with established sequence features of IAPP, involved in aggregation and amyloid formation. IAPP sequence also harbors anion binding sites, such as those involving cationic side chains and N-terminal NH-groups of the α-helix. The association with acidic lipids neutralizes ‘gatekeeping’ cationic residues, abrogating electrostatic peptide-peptide repulsion. The subsequent aggregation of the α-helices involves further oligomerization and a sequence of slow transitions, driven by hydrogen bonding, and ending up as amyloid β-sheet fibrils. Importantly, the above processing of IAPP in its folding/aggregation free energy landscape under the influence of a lipid membrane involves also transient cytotoxic intermediates, which permeabilize membranes, allowing influx of Ca2+ and triggering of cell death, this process resulting in the loss of β-cells, seen in type 2 diabetes. Similar chains of events are believed to underlie the loss of tissue function in the other disorders mentioned above.

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Journal articles on the topic 'Fibrous biological membrane'

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