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Auswahl der wissenschaftlichen Literatur zum Thema „PCL nanofibers“
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Zeitschriftenartikel zum Thema "PCL nanofibers"
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Henrique Lima, Tadeu, Gabriella Maria Fernandes-Cunha, Carlos Eduardo de Matos Jensen, Rodrigo Lambert Oréfice, Armando da Silva-Cunha Junior, Min Zhao, Francine Behar-Cohen und Gisele Rodrigues da Silva. „Bioactive Glass Nanoparticles-Loaded Poly(ɛ-caprolactone) Nanofiber as Substrate for ARPE-19 Cells“. Journal of Nanomaterials 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/4360659.
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Bioactive glass nanoparticles-loaded poly(ɛ-caprolactone) nanofibers (BIOG PCL nanofibers) were synthesized and evaluated as substrates for ocular cells (ARPE-19). BIOG PCL nanofibers were characterized using SEM, FTIR, and DSC, and thein vitrodegradation profile was also investigated. Thein vitroocular biocompatibility of nanofibers was exploited in Müller glial cells (MIO-M1 cells) and in chorioallantoic membrane (CAM); and the proliferative capacity, cytotoxicity, and functionality were evaluated. Finally, ARPE-19 cells were seeded onto BIOG PCL nanofibers and they were investigated as supports forin vitrocell adhesion and proliferation. SEM images revealed the incorporation of BIOG nanoparticles into PCL nanofibers. Nanoparticles did not induce modifications in the chemical structure and semicrystalline nature of PCL in the nanofiber, as shown by FTIR and DSC. MIO-M1 cells exposed to BIOG PCL nanofibers showed viability, and they were able to proliferate and to express GFAP, indicating cellular functionality. Moreover, nanofibers were well tolerated by CAM. These findings suggested thein vitroocular biocompatibility and absence of toxicity of these nanofibers. Finally, the BIOG nanoparticles modulated the protein adsorption, and, subsequently, ARPE-19 cells adhered and proliferated onto the nanostructured supports, establishing cell-substrate interactions. In conclusion, the biodegradable and biocompatible BIOG PCL nanofibers supported the ARPE-19 cells.
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Prosecká, Eva, Matej Buzgo, Michala Rampichová, Tomáš Kocourek, Petra Kochová, Lucie Vysloužilová, Daniel Tvrdík, Miroslav Jelínek, David Lukáš und Evžen Amler. „Thin-Layer Hydroxyapatite Deposition on a Nanofiber Surface Stimulates Mesenchymal Stem Cell Proliferation and Their Differentiation into Osteoblasts“. Journal of Biomedicine and Biotechnology 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/428503.
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Pulsed laser deposition was proved as a suitable method for hydroxyapatite (HA) coating of coaxial poly-ɛ-caprolactone/polyvinylalcohol (PCL/PVA) nanofibers. The fibrous morphology of PCL/PVA nanofibers was preserved, if the nanofiber scaffold was coated with thin layers of HA (200 nm and 400 nm). Increasing thickness of HA, however, resulted in a gradual loss of fibrous character. In addition, biomechanical properties were improved after HA deposition on PCL/PVA nanofibers as the value of Young's moduli of elasticity significantly increased. Clearly, thin-layer hydroxyapatite deposition on a nanofiber surface stimulated mesenchymal stem cell viability and their differentiation into osteoblasts. The optimal depth of HA was 800 nm.
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Kamaruzaman, Nurul Asyikin, Abdull Rahim Mohd Yusoff, Nik Ahmad Nizam Nik Malek und Marina Talib. „Fabrication, Characterization and Degradation of Electrospun Poly(ε-Caprolactone) Infused with Selenium Nanoparticles“. Malaysian Journal of Fundamental and Applied Sciences 17, Nr. 3 (29.06.2021): 295–305. http://dx.doi.org/10.11113/mjfas.v17n3.2183.
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Polycaprolactone (PCL) is widely used in the fabrication of nanofibers through electrospinning technique. PCL is a biodegradable material that is economical, simple and can be scaled up for industrial production. In this study, PCL was infused with selenium nanoparticles (SeNPs) via electrospinning to fabricate PCL-SeNPs nanofiber. Field emission scanning electron microscopy (FESEM) images of the samples revealed ‘aligned fibers’ was successfully fabricated with a diameter size of less than 350 nm and an average diameter of 185 nm. The presence of Se in the nanofiber was confirmed by energy dispersive X-ray analysis (EDX) and Raman spectra. Based on the X-ray diffraction (XRD) pattern, the structure of PCL did not change and remains in the PCL-SeNPs nanofibers. The functional groups of PCL, as indicated by infrared (IR) spectra remained the same after SeNPs infusion. These results demonstrated that the physical and chemical properties of PCL nanofibers were not affected by the infusion of SeNPs. In addition, the hydrophobicity of the PCL decreased slightly in the presence of SeNPs. The first month after degradation, disorganized and fibrous fibers of PCL-SeNPs nanofiber were observed followed by the formation of large fiber clumps as degradation time increased. An agglomerated SeNPs made PCL-SeNPs nanofiber pores looser and easier to be hydrolyzed after 4 months of degradation. The sticky surface of PCL-SeNPs nanofiber shows acceleration in the hydrolysis process after 24th weeks of degradation. The presence of SeNPs enhanced the degradation behavior as well as reducing the degradation time to break into pieces, starting after 6 months of degradation. The ‘aligned’ PCL-SeNPs nanofiber, which can mimic the natural tissue extracellular matrix (ECM) morphology, can potentially be used in biomedical applications such as tissue engineering, wound dressing, biomedicine, sensor and filtration application.
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Barbak, Zarife, Hale Karakas, Imren Esenturk, M. Sedef Erdal und A. Sezai Sarac. „Silver sulfadiazine Loaded Poly (ε-Caprolactone)/Poly (Ethylene Oxide) Composite Nanofibers for Topical Drug Delivery“. Nano 15, Nr. 06 (Juni 2020): 2050073. http://dx.doi.org/10.1142/s1793292020500733.
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In this study, silver sulfadiazine (SSD) loaded Poly ([Formula: see text]-caprolactone)/Poly (ethylene oxide) (PCL/PEO) nanofiber patches were prepared via electrospinning method for topical drug delivery applications. SSD was loaded for the first time into PCL/PEO nanofibers. Nanofiber patches were characterized by Attenuated Total Reflectance Infrared Spectroscopy (FTIR-ATR) to check the presence of chemical bonding between SSD and polymer matrix. The surface morphology of the nanofibers was observed by Scanning Electron Microscopy (SEM). SEM images showed that uniform and smooth composite nanofibers were obtained. The diameter of the nanofibers decreased with the addition of SSD. X-Ray Diffraction (XRD) analysis was carried out to examine the crystallinity of composite nanofiber patches. Energy dispersive spectroscopy (EDS) analysis was performed to confirm Ag and S contents in the SSD loaded composite nanofibers and EDS Mapping was used to show the homogeneous distribution of SSD in the fiber structure. In order to investigate the release and solubility properties of SSD, an unused buffer solution; Water/Propylene Glycol/Phosphoric Acid (82:16:2) was prepared. The release of SSD was performed in this buffer and the release amount of SSD was calculated by UV-Visible Spectrophotometer. Thereby, SSD containing PCL/PEO composite nanofiber carriers were electrospun to achieve the enhancement in solubility, effective drug release and efficient drug loading of SSD. All experimental studies demonstrated that SSD loaded PCL/PEO composite nanofibers have great potential to be used in topical drug delivery applications.
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Kalantary, Saba, Farideh Golbabaei, Masoud Latifi, Mohammad Ali Shokrgozar und Mehdi Yaseri. „Feasibility of Using Vitamin E-Loaded Poly(ε-caprolactone)/Gelatin Nanofibrous Mat to Prevent Oxidative Stress in Skin“. Journal of Nanoscience and Nanotechnology 20, Nr. 6 (01.06.2020): 3554–62. http://dx.doi.org/10.1166/jnn.2020.17486.
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Some occupational skin exposures lead to the formation of reactive oxygen species (ROS). The occupational exposure of workers to ROS has been found to be associated with an increased risk of developing skin injuries; therefore, it is essential to protect skin against ROS formation. Recently, some studies have been conducted on introducing better alternatives for skin protection. Nanofibers are good candidates for this purpose. The current study was carried out to assess vitamin E-loaded hybrid Poly(ε-caprolactone) (PCL)/gelatin (Gt) nanofibres mats as protective layers of skin exposed to occupational exposures. Vitamin E (VE) was successfully incorporated into PCL/Gt nanofibers while they were formed by electrospinning method. Nanofibers mats were characterized using scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). Their degradation behavior, in vitro release, biocompatibility, and antioxidant activity were studied. The diameters of the PCL/Gt/VE nanofibers decreased with the addition of vitamin E. The degradation rate of nanofibers was equal to 42.98 and 50.69% during 7 and 14 days, respectively. Nanofibers containing vitamin E showed an initial burst followed by a sustained release. The PCL/Gt/VE nanofibers exhibited good free radical scavenging activities despite being exposed to a high electrical potential during electrospinning. PCL/Gt/VE nanofibers supported a higher level of viability compared to PCL/Gt ones and significantly assisted human skin cells against tert-Butyl hydroperoxide (t-BHP) induced oxidative stress. Overall, PCL/Gt/VE nanofibers can potentially be used to protect skin against oxidative stress as a novel approach for worker’s healthcare.
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Putri, Nur Rofiqoh Eviana, Dhimas Agung Kurniawan, Bintang Adi Pradana, Nadya Alfa Cahaya Imani und Yuni Kusumastuti. „Preparation of Chitosan-Polycaprolactone (PCL) Composite Nanofiber as Potential for Annulus Fibrosus Regeneration“. Key Engineering Materials 840 (April 2020): 368–76. http://dx.doi.org/10.4028/www.scientific.net/kem.840.368.
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Tissue engineering has shown a remarkable result in medical applications. Further exploration, these multidisciplinary fields are also given a possibility as an alternative medication for intervertebral disc (IVD) degeneration. Focusing on the annulus fibrous repair, to improve the mechanical properties of biomaterials, a composite made of chitosan and polycaprolactone (PCL) was developed in this present study. Due to its tuneable properties, the electrospinning-based method was used in the experiment to create the chitosan/PCL composite. Varies concentration of PCL (11, 12, and 13 wt%) and a different ratio of precursors chitosan to PCL (1:1; 1:3; 1:5) were used to optimize the composition of natural and synthetic polymer in the composite nanofibers. The obtained nanofibers were then characterized using Scanning Electron Microscopy (SEM) to observe the morphology, swelling test, Fourier Transform Infrared (FTIR) spectroscopy, and Differential Scanning Calorimetry (DSC). The results show that the increasing concentration and composition of PCL could form the more homogeneous and larger diameter of nanofiber with fewer beads compare to the lower composition of PCL nanofiber. Meanwhile, the swelling percentage decreases by increasing the amount of PCL. FTIR results also show that all samples of composite nanofibers contain both chitosan and PCL.
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Kupka, Vojtěch, Eva Dvořáková, Anton Manakhov, Miroslav Michlíček, Josef Petruš, Lucy Vojtová und Lenka Zajíčková. „Well-Blended PCL/PEO Electrospun Nanofibers with Functional Properties Enhanced by Plasma Processing“. Polymers 12, Nr. 6 (22.06.2020): 1403. http://dx.doi.org/10.3390/polym12061403.
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Biodegradable composite nanofibers were electrospun from poly(ε-caprolactone) (PCL) and poly(ethylene oxide) (PEO) mixtures dissolved in acetic and formic acids. The variation of PCL:PEO concentration in the polymer blend, from 5:95 to 75:25, revealed the tunability of the hydrolytic stability and mechanical properties of the nanofibrous mats. The degradation rate of PCL/PEO nanofibers can be increased compared to pure PCL, and the mechanical properties can be improved compared to pure PEO. Although PCL and PEO have been previously reported as immiscible, the electrospinning into nanofibers having restricted dimensions (250–450 nm) led to a microscopically mixed PCL/PEO blend. However, the hydrolytic stability and tensile tests revealed the segregation of PCL into few-nanometers-thin fibrils in the PEO matrix of each nanofiber. A synergy phenomenon of increased stiffness appeared for the high concentration of PCL in PCL/PEO nanofibrous mats. The pure PCL and PEO mats had a Young’s modulus of about 12 MPa, but the mats made of high concentration PCL in PCL/PEO solution exhibited 2.5-fold higher values. The increase in the PEO content led to faster degradation of mats in water and up to a 20-fold decrease in the nanofibers’ ductility. The surface of the PCL/PEO nanofibers was functionalized by an amine plasma polymer thin film that is known to increase the hydrophilicity and attach proteins efficiently to the surface. The combination of different PCL/PEO blends and amine plasma polymer coating enabled us to tune the surface functionality, the hydrolytic stability, and the mechanical properties of biodegradable nanofibrous mats.
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Che, Hui-Lian, Hwa Jeong Lee, Koichiro Uto, Mitsuhiro Ebara, Won Jong Kim, Takao Aoyagi und In-Kyu Park. „Simultaneous Drug and Gene Delivery from the Biodegradable Poly(ε-caprolactone) Nanofibers for the Treatment of Liver Cancer“. Journal of Nanoscience and Nanotechnology 15, Nr. 10 (01.10.2015): 7971–75. http://dx.doi.org/10.1166/jnn.2015.11233.
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In this study, we present anti-cancer drug containing nanofiber-mediated gene delivery to treat liver cancer. Electro-spun nanofibers have big potential for local delivery and sustained release of therapeutic gene and drugs. We reported a temperature-responsive nanofibers mainly compounded by branched poly(ε-caprolactone) (PCL) macro-monomers and anti-cancer drug paclitaxel. The nanofiber could be administrated into liver tumors to dramatically hinder their growth and prevent their metastasis. As a result, paclitaxel encapsulated PCL (PTX/PCL) nanofibers with diameters of around several tens nanometers to 10 nm were successfully obtained by electro-spinning andobserved in scanning electron microscopy (SEM). Nanoparticles composed of disulfide cross-linked branched PEI (ssPEI) and anti-cancer therapeutic gene miRNA-145 were complexed based on the electrostatic interaction and coated over the paclitaxel-loaded nanofiber. MicroRNA 145/ssPEI nanoparticles (MSNs) immobilized on the PTX/PCL nanofiber showed time-dependent sustained release of the microRNA for enhanced uptake in neighboring liver cancer cells without any noticeable cytotoxicity. From this study we are expecting a synergistic effect on the cancer cell suppression since we have combined the drug and gene delivery. This approach uses the nanofibers and nanoparticles together for the treatment of cancer and the detailed investigation in vitro and in vivo must be conducted for the practicality of this study. The polymer is biodegradable and the toxicity issues must be cleared by our approach.
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Cheng, Liang, Yi Wang, Guoming Sun, Shizhu Wen, Lianfu Deng, Hongyu Zhang und Wenguo Cui. „Hydration-Enhanced Lubricating Electrospun Nanofibrous Membranes Prevent Tissue Adhesion“. Research 2020 (19.03.2020): 1–12. http://dx.doi.org/10.34133/2020/4907185.
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Lubrication is the key to efficient function of human tissues and has significant impact on the comfort level. However, the construction of a lubricating nanofibrous membrane has not been reported as yet, especially using a one-step surface modification method. Here, bioinspired by the superlubrication mechanism of articular cartilage, we successfully construct hydration-enhanced lubricating nanofibers via one-step in situ grafting of a copolymer synthesized by dopamine methacrylamide (DMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) onto electrospun polycaprolactone (PCL) nanofibers. The zwitterionic MPC structure provides the nanofiber surface with hydration lubrication behavior. The coefficient of friction (COF) of the lubricating nanofibrous membrane decreases significantly and is approximately 65% less than that of pure PCL nanofibers, which are easily worn out under friction regardless of hydration. The lubricating nanofibers, however, show favorable wear-resistance performance. Besides, they possess a strong antiadhesion ability of fibroblasts compared with pure PCL nanofibers. The cell density decreases approximately 9-fold, and the cell area decreases approximately 12 times on day 7. Furthermore, the in vivo antitendon adhesion data reveals that the lubricating nanofiber group has a significantly lower adhesion score and a better antitissue adhesion. Altogether, our developed hydration-enhanced lubricating nanofibers show promising applications in the biomedical field such as antiadhesive membranes.
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Chong, Lor Huai, Mim Mim Lim und Naznin Sultana. „Fabrication and Evaluation of Polycaprolactone/Gelatin-Based Electrospun Nanofibers with Antibacterial Properties“. Journal of Nanomaterials 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/970542.
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Nanofibrous scaffolds were fabricated through blending of a synthetic polymer, polycaprolactone (PCL), and a natural polymer, gelatin (GE), using an electrospinning technique. Processing and solution parameters were optimized to determine the suitable properties of PCL/GE-based nanofibers. Several characterizations were conducted to determine surface morphology by scanning electron microscopy (SEM), wettability using water contact angle measurement, and chemical bonding analysis using attenuated total reflectance (ATR) of PCL/GE-based nanofibers. Experimental results showed that 14% (w/v) PCL/GE with a flow rate of 0.5 mL/h and 18 kV demonstrated suitable properties. This nanofiber was then further investigated for itsin vitrodegradation, drug loading (using a model drug, tetracycline hydrochloride), and antibacterial testing (using zone inhibition method).
Dissertationen zum Thema "PCL nanofibers"
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Groppo, Mônica Feresini 1965. „Efeito de uma membrana de PCL impregnada com hidroxiapatita em defeito ósseo induzido na calvária de ratos“. [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288467.
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Orientador: Ana Cláudia RossiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: O objetivo do presente estudo foi observar o efeito de uma membrana de nanofibras poliméricas a base de poli-epsilon-caprolactona (PCL), impregnadas ou não com hidroxiapatita (HA), na reparação óssea em defeitos críticos produzidos artificialmente na calvária de ratos. Foram utilizados 36 ratos, divididos aleatoriamente em seis grupos de seis animais. Para a indução do defeito ósseo padronizado foram realizadas duas perfurações, por meio de trefina de 3 mm de diâmetro, na calvária dos animais, uma em cada lado, sendo que o lado direito recebeu os tratamentos (HA ou PCL-HA) e os controles (coágulo ou PCL) foram feitos no lado esquerdo. Decorridos 30, 60 e 90 dias da cirurgia, os animais foram mortos por aprofundamento da anestesia. As cabeças foram submetidas à tomografia, considerando um voxel de 0.12 mm, com campo visual de 06 × 16 cm e tempo de aquisição de 40s. Foram utilizados 120 kV, 8 mA e 36.12 mA/s na aquisição. Os diâmetros dos orifícios foram medidos por meio do software Invesalius 3.0. As cabeças foram fixadas com solução de formol tamponado (pH 7,2) em tampão fosfato de sódio a 0,1 M, durante 72 horas e submetidas à descalcificação em solução de EDTA a 7% e formol a 5% até verificação de completa descalcificação (aproximadamente 30 dias). Cortes semi-seriados de 7 ?m foram corados por Hematoxilina-Eosina e foram observadas as características histológicas do processo de cicatrização óssea nas lâminas nos diferentes tempos do estudo. A comparação quantitativa das medidas dos orifícios obtidas com a tomografia foi feita pelo teste de Kruskal-Wallis (teste de Dunn como post hoc), considerando um nível de significância de 5%. As imagens tomográficas revelaram uma tendência de redução do volume do orifício ao longo do tempo, a qual foi maior após 90 dias para todos os tratamentos. O tratamento com PCL+HA mostrou menor volume de orifício do que os outros tratamentos independentemente do período. As medidas histológicas mostraram maior formação de osso induzida pela membrana de PCL com ou sem HA do que os outros tratamentos independentemente do período. A HA mostrou maior aumento da cicatrização óssea com ou sem o PCL. Concluímos que a HA adicionada às nanofibras de PCL melhorou significativamente a cicatrização óssea em defeitos provocados na calvária de ratos
Abstract: The aim of the present study was to observe the effect of a polymeric-nanofiber membrane of poly-epsilon-caprolactone (PCL) with or without hydroxyapatite (HA) on bone healing of critical defects induced in rat calvaria. 36 animals were randomly divided into six groups. The standardized bone defects were obtained by two perforations with 3.0 mm diameter trephine directly into the animals¿ calvaria, one in each side. The right side received the treatments (HA or PCL-HA) and the left side the controls (blood clot or PCL). After 30, 60 and 90 days of the surgical procedure, all animals were killed; the head was sectioned and submitted to tomography (voxel of 0.12 mm, visual field of 6x16 cm, acquisition time of 40s, 120 kV, 8mA and 36.12 mA/s). The perforation diameters were measured using the software Invesalius 3.0. After tomography, all heads were fixed by buffered formol (pH=7.2) in 0.1M sodium-phosphate buffer during 72 hours and submitted to decalcification in 7% EDTA/5% formol solution until complete decalcification (approximately 30 days). Semi-serial 7 µm cuts were stained with Hematoxicilin-Eosin. Histological characteristics of bone healing were observed according to groups and periods. Quantitative comparisons of perforation measurements from both tomography and histological analysis were performed by Kruskal-Wallis (Dunn post hoc) test with a 5% significance level. Tomography images revealed a tendency to reduce the perforation volume along time, which was higher after 90 days for all treatments. The treatment with PCL+HA showed the lower volumes of perforations than the other treatments irrespectively of the period. Histological measurements showed more osseous formation induced by treatment with PCL with or without HA than the other treatments irrespectively of the period. HA appear to increase bone healing with or without PCL. We concluded that HA added to PCL nanofibers significantly improved the bone healing in bone defects of rat calvaria
Mestrado
Anatomia
Mestra em Biologia Buco-Dental
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Nasir, Wafaa. „Effect of Topography on Mouse Embryonic Stem Cells During Pluripotency and Neural Differentiation“. University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1533098386697352.
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Dvořák, Pavel. „Biomedicínské aplikace polykaprolaktonových nanovlákenných membrán“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-444549.
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The diploma thesis deals with the treatment of polycaprolactone (PCL) nanofibers. PCL fibers were subjected to the deposition of plasma amine polymers in a low pressure pulsed radiofrequency capacitively coupled discharge using cyclopropylamine monomer (CPA). Collagen as an extracellular matrix (ECM) protein was immobilized and cell proliferation on the modified nanofiber surface was monitored. Untreated PCL fibers were also subjected to the deposition of an antibacterial copper layer, and the fibers were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDX).
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Baddour, Joelle. „An Approach to Lens Regeneration in Mice Following Lentectomy and the Implantation of a Biodegradable Hydrogel Encapsulating Iris Pigmented Tissue in Combination with Basic Fibroblast Growth Factor“. University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1335916825.
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Santana-Melo, Gabriela de Fátima [UNESP]. „Efetividade de scaffolds de poli (butileno adipato-co-tereftalato) / nanohidroxiapatita obtidos por eletrofiação para aplicação biomédica: avaliação in vitro“. Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/141468.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A necessidade da fabricação de novos biomateriais que possam, além de mimetizar o tecido ósseo, fornecer resistências mecânicas favoráveis próximas às do tecido ósseo natural têm despertado interesse de pesquisadores com o objetivo de melhorar a qualidade de vida de pessoas que sofreram algum tipo de lesão. Scaffolds de nanofibras poliméricas fabricados por eletrofiação apresentam características tridimensionais (3D) e poros interconectados que permitem a colonização de toda a superfície 3D por células com a consequente formação de tecidos. O scaffold de poli (butileno adipato-co-tereftalato) (PBAT) mostra-se um biomaterial promissor para regeneração óssea, porém tem sido pouco explorado até a data. Embora do uso da HA seja consagrado para uso biomédico, sua utilização em polímeros ainda é pouco estudada, principalmente em associação ao PBAT. Desta forma, o objetivo deste estudo foi avaliar a efetividade in vitro de scaffolds poliméricos (PBAT) com incorporação de nanopartículas de HA (nHAp) em diferentes concentrações, produzidos por eletrofiação, por meio da bioatividade celular e expressão gênica de osteoblast-like MG63. Células (MG63) foram cultivadas sobre scaffolds de PBAT; PBAT/3%nHAp e PBAT/5% nHAp e sem a presença dos mesmos (controle) e avaliadas pelos testes qualitativo (MEV) e quantitativo de adesão e proliferação celular (1 e 7 dias e aos 1, 3, 7, 14 e 21 dias, respectivamente), citotoxicidade celular (1, 3 e 7 dias), corante vermelho de alizarina e formação de mineralização (14 dias) e análise da expressão de genes relacionados à osteogênese por qRT-PCR aos 7, 14 e 21 dias de cultura celular. Os dados foram analisados estatisticamente por variância (ANOVA) e Tukey (p<0,05). Os scaffolds de PBAT e PBAT/nHAp não apresentaram efeito citotóxico e sua arquitetura tridimensional influenciou positivamente na adesão e proliferaçãocelular, formação de matriz mineralizada bem como em alguns períodos na expressão dos genes ALP, Col I, Runx2, OC e OPN em relação ao grupo controle. O efeito osteocondutor e osteoindutor da nHAp promoveu melhor resposta celular nos scaffolds de PBAT/nHAp, independente da concentração. Esses resultados demonstram a efetividade in vitro dos scaffolds de PBAT e PBAT/nHAp, apresentando grande potencial para aplicação biomédica.
The need for the manufacture of new biomaterials that may, in addition to mimic to bone tissue, providing favorable mechanical strength close to natural bone have aroused the interest of researchers in order to improve the quality of life of people who have suffered some kind of injury. Scaffolds polymer nanofibers fabricated by electrospinning have three dimensional features (3D) and interconnected pores that allow the colonization of the entire 3D surface of cells with the consequent formation of tissue. Poly (butylene adipate-co-terephthalate) (PABT) scaffold showed to be a promising biomaterial for bone regeneration, however, has been underexplored to date. Although the use of HA is consecrated to biomedical use, their use in polymers is not well known, especially in association with PBAT. The aim of this study was evaluating in vitro effectiveness of polymeric (PABT) scaffolds with incorporated HA (nHAp) nanoparticles, obtained by electrospinning, through cellular bioactivity and osteoblast-like MG63 gene expression. MG63 cells were grown on PABT; PABT/3%nHAp and PABT/5%nHAp scaffolds and without their presence (control), and evaluated by qualitative (MEV) and quantitative tests of cell adhesion and proliferation (1 and 7 days and at 1, 3, 7, 14 and 21 days, respectively), cell cytotoxicity (1, 3 and 7 days), alizarin red dye and mineralization formation (14 days) and expression of genes related to osteogenesis by qRT-PCR to 7, 14 and 21 days of cell culture. Data were statistically analyzed by variance (ANOVA) and Tukey test (p<0.05). The PBAT and PBAT/nHAp scaffolds showed no cytotoxic effect and its three-dimensional architecture influenced positively in the cell adhesion and proliferation, mineralized matrix formation as well as in some periods the expression of genes ALP, Col I, Runx2, OC and OPN in relation the control group. The osteoconductive and osteoinductive effect of nHAp promoted better cellular response in scaffolds of PABT/nHAp independent of concentration. These results demonstrate the in vitro effectiveness of PABT and PABT/nHAp scaffolds, presenting great potential for biomedical application.
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Anacleto, Pedro Alexandre Marques. „Construção e caracterização de um colector rotatório para produção de nanofibras alinhadas de PCL“. Master's thesis, FCT - UNL, 2008. http://hdl.handle.net/10362/2007.
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GONÇALVES, Gonçalves. „Nanofibras de poli(ε-caprolactona) e poli(óxido de etileno): fabricação pela técnica de eletrofiação e efeitos radiolíticos“. Universidade Federal de Pernambuco, 2015. https://repositorio.ufpe.br/handle/123456789/16683.
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FACEPE
O poli(ε-caprolactona) (PCL) é um poliéster biocompatível, biodegradável e semicristalino utilizado na confecção de artefatos médico-farmacêuticos, especialmente como suporte para cultivo de células e tecidos. Por outro lado, sua hidrofobicidade e baixas taxas de hidrólise in vivo impedem a expansão do uso destes polímeros em aplicações biológicas. Nesta pesquisa, empregamos três estratégias na tentativa de aumentar a taxa de hidrólise da PCL: a) preparação do material em morfologia fibrilar, para aumentar a superfície de contato com o meio; b) irradiação com raios gama, para induzir dano molecular e acelerar a hidrólise; e c) blenda com o polímero hidrofílico e lixiviável poli(óxido de etileno) (PEO), para aumentar a molhabilidade e permitir maior percolação da água. Tapetes de PCL, apresentando nanofibras com diâmetros menores que 100nm e de microfibras com diâmetros entre 1,9 e 7,5μm da blenda PCL/PEO 10% m/m foram preparados pela técnica de eletrofiação, irradiados com raios gama em doses de 25 e 50kGy e submetidos à hidrólise por submersão em tampão fosfato salino (PBS) pH 7,4 a 37 0C. Para comparação, filmes de PCL e da blenda de PCL/PEO foram confeccionados por derrame em solução (film casting) e submetidos ao mesmo tratamento. Nada se pode afirmar sobre as mudanças de Massa Molar Viscosimétrica Média (Mv) em filmes de PCL irradiados, pois não foi possível observar nem o efeito de cisão, nem reticulação da cadeia principal. A irradiação gama não influenciou nas propriedades térmicas dos filmes de PCL e os cálculos de energia de ativação para reações de decomposição térmica evidenciaram que filmes de PCL têm boa estabilidade térmica. Ensaios espectrométricos no Infravermelho com Transformada de Fourier (FTIR) e difratométricos de raios X dos filmes de PCL não foi possível observar mudanças significativas de estrutura molecular ou cristalinidade com a irradiação gama. As estratégias adotadas para melhorar a degradação hidrolítica do PCL funcionaram. Blendas de PCL/PEO (10% m/m) apresentaram taxa de degradação hidrolítica maiores do que as amostras de PCL, tanto na forma de tapetes microfibrilares eletrofiados como na forma de filmes espessos. Sendo a primeira com taxa de degradação mais acentuada. A irradiação gama exerce influência significativa na degradação hidrolítica apenas em blendas PCL/PEO na forma de filmes. A degradação hidrolítica dos filmes de PCL se mostrou muito lenta, não sendo possível observar diferenças significativas entre amostras irradiadas e não irradiadas.
Poly (ε-caprolactone) (PCL) is a biocompatible, biodegradable, semicrystalline polyester used in medical-pharmaceutical devices, specially as scaffolds in cell and tissue culture. Nevertheless, its hydrophobicity and low in vivo hydrolysis rates are obstacles to the expansion of its use in biological applications. In this work, we designed three strategies to address PCL hydrophobicity issues: a)prepare electrospun fibers to enhace contact surface with aqueous media; b)irradiation with gamma rays to induce molecular damage and increase hydrolysis rate; and c) blending with the hydrophilic, leacheble polymer poly(ethylene oxide) (PEO), in order to increase wettability and allow larger water percolation rates. Mats of PCL electrospun nanofiber with less than 100nm in diameter; and of electrospun PCL/PEO (10%wt) blend microfibers presenting diameters in the range of 1.9 - 7.5 μm were irradiated with gamma rays in 25 and 50 kGy dose and submitted to in vitro hydrolysis in phosphatebuffered saline (PBS) solution, pH 7,4 at 37 0C. PCL and PCL/PEO (10%wt) films were also prepared by film casting and treated in the same way, for comparison. Nothing can be said about mass changes Viscosity Average Molar Mass (Mv) in irradiated PCL films because it was not possible to observe nor the effect of spin-off, or crosslinking of the backbone. Good thermal stability was also evidenced by calculations of activation energy for thermal degradation of PCL. Fourier Transform Infrared espectrometry and X-ray difractometry data did not evidence significant changes in molecular structure or crystallitiny of PCL after irradiation. Strategies to improve PCL in vitro hydrolysis degradation rate were successful. Blends of PCL/PEO (10% wt) presented higher hydrolysis rates than PCL samples, either in mat fibers or film forms. Hydrolysis degradation of PCL films was very slow, and no differences between non irradiated or irradiated samples were observed.
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Brito, Talita Almeida Vida de 1985. „Preparação e caracterização de nanofibras da blenda PLLA/PCL obtidas pelos processos de eletrofiação e rotofiação“. [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263530.
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Orientador: Cecília Amélia de Carvalho ZavagliaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: Este trabalho apresenta a preparação e caracterização de nanofibras da blenda poli (L-ácido láctico) (PLLA)/poli (?-caprolactona) (PCL) através dos processos de eletrofiação e rotofiação destinada à produção de fibras visando futuras aplicações como suporte para a engenharia tecidual. As blendas foram preparadas através da dissolução do polímero em clorofórmio e clorofórmio mais acetona, resultando em uma solução de 6%. A eletrofiação é um processo relativamente simples e de baixo custo, que consiste na aceleração de uma solução polimérica, inicialmente contida em um capilar metálico, pela presença de um campo elétrico externo, para produzir fibras com diâmetro médio reduzido. Apesar da popularidade e da versatilidade, o processo de eletrofiação apresenta algumas desvantagens, tais como o uso de fonte de alta tensão, baixa taxa e longo tempo de produção das fibras. Com a necessidade de encontrar um método de produção de fibras para sanar eventuais obstáculos encontrados na eletrofiação, foi realizado um estudo com um novo processo: a rotofiação. O processo de rotofiação é um processo simples que forma fibras durante o jateamento da solução polimérica através de um orifício central utilizando alta velocidade de rotação e não utiliza campo elétrico de alta voltagem, como na eletrofiação. As fibras obtidas por meio dos dois processos foram analisadas e caracterizadas pelos seguintes métodos: microscopia eletrônica de varredura (MEV), análise termogravimétrica (TGA), calorimetria exploratória diferencial (DSC), e espectroscopia na região do infravermelho por transformada de fourier (FTIR). A análise das fibras por microscopia eletrônica de varredura (MEV) mostrou que é possível a formação de nanofibras da blenda PLLA/PCL através dos dois processos. Verificou-se que ocorreram diferenças significativas no diâmetro médio dos fios entre os processos, onde na rotofiação, os diâmetros foram maiores, os dois processos estudados permitiram a obtenção de fibras porosas, uma característica importante requerida na engenharia tecidual. Os resultados das análises térmicas indicaram o comportamento imiscível das blendas PLLA/PCL. Através da análise de FTIR foi possível demonstrar eliminação completa dos solventes durante o processamento e também a imiscibilidade dos polímeros
Abstract: This work presents the preparation and characterization of nanofibers of poly (L-lactic acid) (PLLA) / poly (?-caprolactone) (PCL) through electrospinning and rotary jet spinning processes for the production of fibers aiming future applications as scaffolds for tissue engineering. The blends were prepared using the two polymers cited above in chloroform and chloroform plus acetone, resulting in a solution of 6%. Electrospinning is relatively simple and low cost process, which consists in the acceleration of a polymer solution initially contained in a capillary, the presence of an external electric field to produce fibers with reduced average diameter reduced. Despite the popularity and versatility, the electrospinning process has some disadvantages such as the use of high voltage supply, low spinning rates and takes time for long fiber production. With the need to find a method of producing fibers to remedy any obstacles encountered in electrospinning, a study was conducted with a new process: rotary jet spinning. The process of rotary jet spinning is a simple process that forms fibers during the blasting of the polymer solution through a central hole using high-speed rotation and does not use high intensity electric fields, as in electrospinning. The fibers obtained by the two processes were analyzed and characterized by the following methods: scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and infrared spectroscopy fourier transform (FTIR). The fiber analysis by scanning electron microscopy (SEM) showed that it is possible to form nanofibers of PLLA / PCL through two processes. It was found that there were significant differences in the average diameter of the fibers between the processes, where higher diameters were observed in rotary jet spinning, the two processes studied allowed to obtain porous fibers, an important feature required in tissue engineering. The results of thermal analysis indicated that it was formed immiscible blends of PLLA / PCL. By FTIR analysis it was demonstrated complete elimination of the solvents during processing and also the immiscibility of the polymers
Mestrado
Materiais e Processos de Fabricação
Mestra em Engenharia Mecânica
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Ferreira, Cristina Lorenski. „S?ntese de nanocompo?sitos polim?ricos PCL/PLGA/nanofibras de polipirrol para aplica??o em conduto biocompat?vel para regenera??o nervosa“. Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2017. http://tede2.pucrs.br/tede2/handle/tede/7591.
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Peripheral nerve injury continues to be an important research topic in the scientific community as it may cause lifelong disability. Biocompatible polymers are materials potentially capable of aiding the regeneration of peripheral nerves being used for the production of biocompatible tubes. The aim of this work is to prepare and characterize polymeric nanocomposites based on polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA) and polypyrrole nanofibers (PPy) capable of acting as a guidewire in the regeneration of peripheral nerves. PPy was synthesized by oxidative chemical polymerization with p-toluenesulphonic acid monohydrate (PTSA) as a doping agent. PCL:PLGA blends films and PCL:PLGA:PPy nanofibers nanocomposites films were prepared by the solvent casting method, in the ratio of PCL:PLGA 100:0, 90:10, 80:20 and 70:30 (m/m); to the films with nanoload were added 10% PPy. In order to characterize the films, the following techniques were used: SEM, DSC, TGA, determination of electric conductivity and contact angle, citotoxicity test and hydrolytic degradation test, in vitro, based on ASTM F1635-11 standards. The PPy nanofibers presented electrical conductivity equal to 2.0.10-1 S.cm-1. The presence of PLGA and PPy did not change, meaningfully, the thermal properties of the films. However, in the degradation process, there was a tendency to a greater loss of mass for the blends with higher percentage of PLGA when submitted to longer incubation periods (150 days); when PPy was added to these blends, mass loss occurred in shorter periods (90 days). The nanocomposites films showed nontoxic and porous morphology surface, with hydrophilic intermediary character, good thermal stability and adequate degradation time for potential use in the treatment of injury in peripheral nerves.
Les?o de nervos perif?ricos continua sendo um importante tema de pesquisas no meio cient?fico, podendo causar defici?ncia no paciente por toda a vida. Pol?meros biocompat?veis s?o materiais potencialmente capazes de auxiliarem a regenera??o de nervos perif?ricos sendo utilizados para a produ??o de tubos biocompat?veis. O objetivo deste trabalho ? preparar e caracterizar nanocomp?sitos polim?ricos baseados em policaprolactona (PCL), poli(?cido l?ctico-co-glic?lico) (PLGA) e nanofibras de polipirrol (PPy) capazes de atuarem como conduto guia na regenera??o de nervos perif?ricos. PPy foi sintetizado via polimeriza??o qu?mica oxidativa com ?cido p-toluenosulf?nico monohidratado (APTS) como agente dopante. Foram preparados filmes de blendas PCL:PLGA e de nanocomp?sitos PCL:PLGA:nanofibras de PPy pelo m?todo de evapora??o de solvente, nas raz?es de PCL:PLGA 100:0, 90:10, 80:20 e 70:30 (m/m); aos filmes com a nanocarga, foram adicionados 10% de PPy. Para caracteriz?-los, foram utilizadas as t?cnicas: MEV, DSC, TGA, determina??o da condutividade el?trica e do ?ngulo de contato, teste de citotoxicidade e de degrada??o hidrol?tica, in vitro, com base na norma ASTM F1635-11. As nanofibras de PPy apresentaram condutividade el?trica igual a 2,0.10-1 S.cm-1. A presen?a de PLGA e de PPy n?o modificou, significativamente, as propriedades t?rmicas dos filmes. Por?m, no processo de degrada??o, houve uma tend?ncia ? maior perda de massa para as blendas com maior percentual de PLGA quando submetidas a maiores tempos de incuba??o (150 dias); ao adicionar PPy ?s blendas, a perda de massa ocorreu em menores tempos (90 dias). Os filmes dos nanocomp?sitos apresentaram superf?cie at?xica e de morfologia porosa, com car?ter hidrof?lico intermedi?rio, boa estabilidade t?rmica e tempo de degrada??o adequado para o potencial uso no tratamento de les?es em nervos perif?ricos.
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Fabbrici, Simone. „Studio delle proprietà meccaniche e smorzanti dei compositi in fibra di carbonio nano-rinforzati“. Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
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Nella tesi in esame ci si pone come obiettivo principale quello di indagare il comportamento meccanico e dinamico di un materiale composito nano-rinforzato. Il composito posto in esame risulta essere un materiale innovativo in quanto unisce un prepreg in fibra di carbonio con fibre unidirezionali e membrane di nano-fibre in gomma. Negli ultimi anni si è notata una crescente esigenza nel settore industriale volta a diminuire le vibrazione in sistemi meccanici sottoposti a sollecitazioni periodiche, come ad esempio, mandrini per macchine automatiche o rulli per il settore tissue o covering, tutto questo giustifica la ricerca portata avanti in questa tesi che consiste nello sviluppare un materiale composito innovativo in grado di attenuare le vibrazioni senza d’altra parte aumentarne il peso. Sono da tempo riconosciute le alte capacita smorzanti della gomma, ma spesso l’integrazione nei materiali compositi avviene attraverso l’inserimento di una strato spesso di gomma tra due
layer rigidi (struttura a sandwich), questo porta ad un aumento considerevole del peso e dello spessore, caratteristiche che possono rendere un materiale composito meno attraente in alcuni campi di applicazione. Lo smorzamento o damping risulta essere un fenomeno impegnativo da studiare nei materiali metallici perché esso è influenzato da innumerevoli fattori. Per quanto
riguarda i materiali compositi la sfida diventa ancora più impegnativa data la loro natura intrinsecamente eterogenea.
Concludendo, dalle prove sperimentali, è emerso un incremento notevole delle prestazioni smorzanti dei provini nano-modificati, lasciando inalterate le prestazioni meccaniche.
Buchteile zum Thema "PCL nanofibers"
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Sharahi, Melika, Mohaddeseh Sharifi, Sara Labbafi, S. Hajir Bahrami und Nahid Hemmati-Nejad. „Fabrication and Characterization of Hybrid Scaffolds Based on β-TCP/PCL-HAp/Gel Nanofibers for Bone Regeneration“. In Eco-friendly and Smart Polymer Systems, 112–16. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45085-4_28.
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Ngiam, M., T. R. Hayes, S. Dhara und B. Su. „Biomimetic Apatite/Polycaprolactone (PCL) Nanofibres for Bone Tissue Engineering Scaffolds“. In Key Engineering Materials, 991–94. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-422-7.991.
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Smaida, Rana, Henri Favreau, Moustafa Naja, Guoqiang Hua, Florence Fioretti, Nadia Benkirane-Jessel, Dominique Scipioni und Sabine Kuchler-Bopp. „Polycaprolactone Based Biomaterials and Sodium Hyaluronate Nanoreservoirs for Cartilage Regeneration“. In Stem Cells and Regenerative Medicine. IOS Press, 2021. http://dx.doi.org/10.3233/bhr210018.
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Obstacles persist in the treatment and prevention of articular cartilage defects. Polycaprolactone (PCL) and poly(vinyl-pyrrolidone) (PVP) biomaterials were obtained by electrospinning and electrospraying to inspect their potential application for cartilage regeneration. Sodium hyaluronate (SH) was then added into nanofibers of PCL and particles of PVP. The aim of incorporating sodium hyaluronate to this polymer is to enhance the capacity of articular cartilage to regenerate. Human bone marrow-derived mesenchymal stem cells (hBM-MSCs) were seeded onto these tissue engineering (TE) products. The cell viability in vitro and the ability of biomaterials to support the chondrogenic differentiation of hBM-MSCs have been assessed. We report here that hBM-MSCs on these biomaterials were not able to regenerate articular cartilage mainly due to unsuitable culture environment.
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Silva, Ana Neilde Rodrigues da, Neemias de Macedo Ferreira und Maria Lúcia Pereira da Silva. „ROADMAP PROPOSAL: PCB AND NANOFIBERS AS STRATEGY FOR INCREASING PROCESS INTENSIFICATION“. In Impactos das Tecnologias na Engenharia de Materiais e Metalúrgica 2, 49–61. Atena Editora, 2021. http://dx.doi.org/10.22533/at.ed.3142119016.
Der volle Inhalt der QuelleKonferenzberichte zum Thema "PCL nanofibers"
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Rijal, Nava P., Udhab Adhikari und Narayan Bhattarai. „Magnesium Incorporated Polycaprolactone-Based Composite Nanofibers“. In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-53090.
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Recent advances in developing composite nanofibers are of great interest for scientific community due to their wide range of potential applications in biomedical engineering such as drug delivery, wound healing, tissue engineering and implant coatings. Here, we present a fabrication of Mg incorporated polycaprolactone/low molecular weight chitosan (PCL/LMW-CS) composite nanofiber via an electrospinning technique. PCL, a synthetic polymer, has good mechanical properties, whereas, chitosan, a natural polymer, has good bio-functional properties and good cell adhesion properties. Furthermore, magnesium is the second most abundant intracellular cation in the body and is important to metabolism. These nanofibers were characterized by using Scanning Electron Microscopy (SEM), ImageJ, and Instron Universal Testing Machine.
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Srikar, R., C. M. Megaridis, A. L. Yarin und A. V. Bazilevsky. „Desorption-Limited Mechanism of Release From Polymer Nanofibers“. In ASME 2008 International Manufacturing Science and Engineering Conference collocated with the 3rd JSME/ASME International Conference on Materials and Processing. ASMEDC, 2008. http://dx.doi.org/10.1115/msec_icmp2008-72054.
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This work examines the release of a model water-soluble compound from electrospun polymer nanofiber assemblies. Such release attracts attention in relation with biomedical applications, such as controlled drug delivery. It is also important for stem cell attachment and differentiation on biocompatible electrospun nanofiber scaffolds containing growth factors, which have been encapsulated by means of electrospinning. Typically, the release mechanism has been attributed to solid-state diffusion of the encapsulated compound from the fibers into the surrounding aqueous bath. Under this assumption, a 100% release of the encapsulated compound is expected in a certain (long) time. The present work focuses on certain cases where complete release does not happen, which suggests that solid-state diffusion may not be the primary mechanism at play. We show that in such cases the release rate can be explained by desorption of the embedded compound from nanopores in the fibers, or from the outer surface of the fiber in contact with the water bath. After release, the water-soluble compound rapidly diffuses in water, whereas a release rate is determined by the limiting desorption stage. A model system of Rhodamine 610 fluorescent dye embedded in electrospun monolithic Poly(methylmethacrylate) PMMA or Poly(caprolactone) PCL nanofibers, or in nanofibers electrospun from PMMA/PCL blends, or in core/shell PMMA/PCL nanofibers is studied. Both the experimental results and theory point at the above-mentioned desorption-related mechanism and the predicted characteristic time, release rate, and effective diffusion coefficient agree fairly well with the experimental data. A practically important outcome of this surface release mechanism is that only the compound on the fiber and pore surfaces can be released, whereas the material encapsulated in the bulk cannot be freed within the time scales characteristic of the present experiments (days to months). Consequently, in such cases complete release is impossible. We also demonstrate how the release rate can be manipulated by the polymer content and molecular weight affecting nanoporosity and the desorption enthalpy, as well as by the nanofiber structure (monolithic fibers, fibers from polymer blends and core-shell fibers). In particular, it is shown that by manipulating the above parameters, release times from tens of hours to months can be attained.
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Lor Huai Chong, Mohd Izzat Hassan und Naznin Sultana. „Electrospun Polycaprolactone (PCL) and PCL/ nano-hydroxyapatite (PCL/nHA)-based nanofibers for bone tissue engineering application“. In 2015 10th Asian Control Conference (ASCC). IEEE, 2015. http://dx.doi.org/10.1109/ascc.2015.7244569.
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Jarvis, David, Angela Edwards und Narayan Bhattarai. „Extraction and Production of Keratin-Based Nanofibers for Biomedical Applications“. In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-64501.
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Keratin, a natural biomaterial found within the hair, nails, and epidermis of humans, has shown promise of being a useful material for tissue engineering scaffolds and drug delivery systems, due in part to its favorable biological qualities. The scaffolds generated by electrospinning are useful in proliferating cells, and can even biodegrade over time, reducing the impact on the body and not invoking any adverse tissue response. This research details the extraction process of keratin from human hair, and using electrospinning to weave the keratin into nanofibrous polymers. Using a synthetic polymer solution, for example, polycaprolactone (PCL) in trifluoroethanol (TFE), keratin was easily mixed and successfully electrospun into nanofibers. The fiber formation characteristics and nanofiber morphology was studied under a scanning electron microscope (SEM).
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Guler, Zeliha, und A. Sezai Sarac. „BMP-2 immobilized PCL/P3ANA nanofibers for bone tissue engineering“. In 2015 E-Health and Bioengineering Conference (EHB). IEEE, 2015. http://dx.doi.org/10.1109/ehb.2015.7391452.
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Baji, Avinash, Shing-Chung Wong, Todd Blackledge, Darrell Reneker und Sureeporn Tripatanasuwan. „Mechanical Behavior and Toughness of Electrospun Polycaprolactone Nanofibers“. In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41248.
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This study examines the toughness and mechanical properties of biodegradable poly(ε-caprolactone) (PCL) with varying hydroxyapatite (HAP) content (0 – 30 wt%). Fracture toughness of HAP-filled PCL was also examined for the electrospun fibers using the essential work of fracture (EWF) concept. The electrospun fibers exhibited a diameter ranging from 200–500 nm and a combination of HAP particle sizes ranging from (50–100 nm) under the SEM. The tensile stress-strain behavior and fracture toughness of electrospun nanofibers were assessed using a nanoforce tensile tester. The electrospun system showed a substantial increase in plane-stress essential work of fracture in comparison to bulk specimens processed from pellets. Toughness decreased as HAP loading increased. The effect of simulated body fluid (SBF) on the mechanical properties was also studied. Mechanical properties including tensile strength and modulus were found to increase with HAP concentration in general. Compression molded electrospun nanofibers were spatially confined such that the tensile strength and stiffness of molded and spun fibers are remarkably higher than those from molded specimen of pellets.
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Shi, Qiang, Shing-Chung Wong, Kai-Tak Wan, Todd A. Blackledge und John Najem. „Dry Adhesion Based on Electrospun Polymer Nanofibers“. In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37226.
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Dry Adhesion exists between polymer nano/microfibers. An elaborate experiment was performed to directly measure the adhesion between electrospun poly(ε-caprolactone) (PCL) microfibers using a nano force tensile tester. Electrospun nano/microfibers with radius ranging from 0.2 to 1.1 μm were investigated. It was found that the adhesion force depended on the fiber radius following a linear relationship, which complied with the classical Johnson-Kendall-Roberts (JKR) contact mechanics model. The force increased with temperature and decreased with relative humidity between two fibers positioned in orthogonal directions. Our data suggested the van der Waals’ (vdW) interactions are primarily operative between the micro-/nano-fibers.
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Sultanova, Zahida, Gozde Kabay, Gizem Kaleli und Mehmet Mutlu. „Coaxial electrospun PCL/PVA-chitosan nanofibers: A novel non-viral gene delivery scaffold“. In 2015 IEEE International Conference on Plasma Sciences (ICOPS). IEEE, 2015. http://dx.doi.org/10.1109/plasma.2015.7179972.
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Zheng, Zhao-Bin, Chen Li, Yang-Chao Deng, Yang-Lu Qu, Di Wu und Deng-Guang Yu. „The Influence of Sheath Solvent Compositions on the Diameters of Electrospun PCL/PTMC Nanofibers“. In 3rd Annual International Conference on Advanced Material Engineering (AME 2017). Paris, France: Atlantis Press, 2017. http://dx.doi.org/10.2991/ame-17.2017.34.
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Ionescu, Lara C., Brendon M. Baker, Jason A. Burdick und Robert L. Mauck. „A Composite Microsphere/Nanofiber Controlled Release System for Fibrous Tissue Engineering“. In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-205474.
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Fibrous tissues are characterized by a dense, ordered collagenous structure that defines their unique and anisotropic mechanical properties. These properties are critical for tissue function, and are compromised in instances of injury and tissue degeneration. To improve repair, engineering methods based on electrospinning have produced aligned and anisotropic scaffolds composed of biodegradable nanofibers that can serve as templates for new tissue formation [1]. For example, the slow degrading polyester, poly(ε-caprolactone) (PCL) can be formed into aligned arrays that direct cell alignment and ordered ECM deposition, with construct mechanical properties that increase with time [2]. We have further modified these structural templates via the fabrication of multi-polymer composites, with different mechanical properties and degradation profiles provided by different component materials [3]. For example, inclusion of a sacrificial poly-ethylene oxide (PEO) fiber element, followed by its removal (via hydration) increases the porosity of the remaining PCL network and expedites cell infiltration [4].