Дисертації з теми "Biomaterials for orthopedic applications"
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Vidal, Girona Elia. "Development of metallic functionalized biomaterials with low elastic modulus for orthopedic applications." Doctoral thesis, TDX (Tesis Doctorals en Xarxa), 2021. http://hdl.handle.net/10803/671888.
Повний текст джерелаEl titani (Ti) i els seus aliatges s'han emprat durant dècades per a implants i pròtesis òssies a causa de la seva fiabilitat mecànica i bona biocompatibilítat. Tanmateix, les infeccions relacionades amb els implants, la manca d'osteointegració amb l'os circumdant i el desajust de les propietats mecàniques entre l'implant i l'os, continuen sent els principals motius de fallida de l'implant En la present tesi doctoral, s'han estudiat dues estratègies per augmentar la viabilitat de l'implant fabricació d'estructures poroses de Ti i funcionalització superficial. El desajust de la rigidesa entre l'implant de titani i l'os pot causar una reabsorció òssia important, que pot provocar complicacions greus com la fractura periprotètica durant o després de la cirurgia de revisió . La superfície del titani té un paper important en les interaccions os-pròtesi, no només per promoure l'adhesió inicial de les cèl·lules, sinó també per evitar l'adhesió bacteriana. Una estratègia estudiada a la tesi ha estat el desenvolupament i fabricació d'estructures poroses de Ti. S'ha preparat un andamiatge amb una porositat del 75% mitjançant Direct lnk Writing, amb l'objectiu de reduir l'elasticitat del mòdul aparent de les pròtesis de Ti. En aquest treball, s'han fabricat estructures poroses de Ti amb una rigidesa i resistència a la compressió de 2,6 GPa i 64,5 MPa respectivament. Per això, es va dissenyar una nova formulació de tinta basada en la barreja d'un hidrogel termosensible amb partícules de pols irregulars de Ti amb una mida mitjana de partícula de 22,45 µm. Es va optimitzar un tractament tèrmic per assegurar l’eliminació completa de l'aglutinant abans del procés de sinterització, per evitar la contaminació de les estructures de titani. La lluita contra les infeccions està estretament lligada al concepte de "carrera per la superfície". El guanyador d'aquesta carrera (cèl·lula contra bacteris) decideix si s'aconseguirà un ancoratge sòlid entre l'implant i l'os o si el creixement bacterià conduirà a una infecció periprotètica. Una altra estratègia estudiada en aquesta tesi se centra en la funcionalització de la superfície de Ti. En primer lloc, la superfície d'andamiatges de Ti es va funcionalitzar amb un fragment recombinant fibronectina d'adhesió cel·lular per optimitzar l’adhesió cel·lular. A més, també es va estudiar un recobriment multifuncional basat en l'ús de recobriments de fosfat de calci com a portadors per a l'alliberament de medicaments per aconseguir un equilibri entre la adhesió cel·lular i la reducció de l'adhesió bacteriana. Les estructures poroses de Ti s'han recobert amb èxit amb un procés d'electrodeposició polsada d'un pas, aconseguint una capa uniforme de fosfat de calci tant a la superfície interna com exterior de les estructures, amb resistències d’adhesió superiors a 22 MPa. La co-deposició d'un agent antibacterià amb una electrodeposició polsada i polsada inversa es va aconseguir tant a les superfícies de Ti d'estructura oberta coma les llises. La velocitat de l'agent antibacterià es pot modular en un terminí d'hores o dies ajustant les condicions de recobriment i sense alterar el potencial antimicrobià del propi agent antibacterià carregat. Els recobriments biofuncionalitzats van mostrar una notable activitat antibacteriana in vitro contra les soques de bacteris S. aureus i E. coli, amb una disminució significativa de bacteris adherits viables a les superfícies tractades. Les proves de cultiu cel·lular també van demostrar que les estructures de Ti carregades de l'agent antimicrobià presentaven una millor adhesió cel·lular en comparació amb la Ti no tractat. Per tant. les estratègies proposades poden millorar els implants ortopèdics de manera eficient en termes de millora de la biointegració la resistència a l'adherència microbiana.
Ciència i enginyeria de materials
Clem, William Charles. "Mesenchymal stem cell interaction with nanonstructured biomaterials for orthopaedic applications." Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2009r/clem.pdf.
Повний текст джерелаAdditional advisors: Yogesh K. Vohra, Xu Feng, Jack E. Lemons, Timothy M. Wick. Description based on contents viewed July 8, 2009; title from PDF t.p. Includes bibliographical references.
Smith, Michael E. "Method Development for On-Site Air Quality Analysis and Design of Hydrogen Sensors for Orthopedic Applications." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1583999801696302.
Повний текст джерелаRaghuraman, Kapil. "Synthesis and Evaluation of a Zn-Bioactive Glass Series to Prevent Post-Operative Infections in Craniofacial Applications." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525241500626456.
Повний текст джерелаAhn, Edward Sun 1972. "Nanostructured apatites as orthopedic biomaterials." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8627.
Повний текст джерелаIncludes bibliographical references.
Historically, using suitable mechanical replacements for bone has been a priority in designing permanent, load-bearing orthopedic implants. As a result, the biomaterials used in these implants have been largely limited to bioinert titanium-based alloys, as well as to polycrystalline alumina and zirconia ceramics. However, analysis of implants incorporating these traditional biomaterials indicated that most failures involved an unstable implant-tissue interface and/or a mismatch of the mechanical behavior of the implant with the surrounding tissues. As a result, up to 20% of patients receiving permanent, load-bearing implants may undergo a revision operation. The objective of this research was to develop an alternative biomaterial that combined both mechanical resilience and an osteoconductive surface to provide a stable interface with the surrounding connective tissue so that the need for revision operations may be significantly reduced. In the effort to address the issue of mechanical strength and bioactivity simultaneously, hydroxyapatite (HAP) has generated considerable interest. Though a commonly used bioceramic, HAP has been limited by its processability. This material is sensitive to non-stoichiometry and impurities during synthesis and processing due to its complex composition and crystal structure (Ca10(P04)6(OH)2, P63/m).
(cont.) Consequently, conventionally processed HAP materials lack phase purity and homogeneity. Densification of HAP requires high temperatures that result in grain growth and decomposition into undesired phases with poor mechanical and chemical stability. To circumvent densification at high temperatures, glassy additives have been introduced to promote liquid-phase sintering at a lower temperature. However, the presence of a secondary glassy phase gave rise to poor mechanical characteristics. Hence, clinical applications of HAP have been limited to powders, coatings, porous bodies, and non-load-bearing implants. To overcome the deficiencies of conventionally processed HAP, nanostructure processing was applied, which allowed for materials design from the molecular level. By using an aqueous chemical precipitation technique, a fully dense, transparent, nanostructured HAP-based bioceramic that exhibited superior mechanical properties and enhanced tissue bonding was obtained. Processing parameters affecting the molecular and structural development of HAP were used to tailor HAP stoichiometry, crystallite size, morphology and surface chemistry for optimal thermal stability and sinterability. Unlike conventionally processed HAP, the stoichiometric, equiaxed, nanocrystalline HAP powders demonstrated significantly enhanced sinterability by fully densifying at a remarkably low temperature of 900ʻC with pressure-assisted sintering.
(cont.) Furthermore, high-resolution electron micrographs illustrated that the sintered compact possessed a uniform and ultrafine microstructure with an average grain size of -100 nm, with no glassy or amorphous interfaces along the grain boundaries. The crystallinity of the HAP grains and grain boundaries and the minimal flaw sizes could be credited for the superior strength of nanostructured HAP compared to conventional HAP. Compared to polycrystalline HAP, nanocrystalline HAP also provided greater osteoblast function. In vitro experiments indicated that nanocrystalline HAP surfaces enhanced cell attachment, proliferation and mineralization. The larger grain boundary volume resulting from the ultrafine microstructure might have enhanced protein adsorption, ...
by Edward Sun Ahn.
Ph.D.
Devlin, Sean M. "Improving Degradable Biomaterials for Orthopedic Fixation Devices." Diss., Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/394989.
Повний текст джерелаPh.D.
Current degradable orthopedic fixation devices do not typically facilitate tissue integration during healing. Proposed here is a novel combination of processing methods to enhance the tissue integration capability of degradable thermoplastics used in temporary orthopedic fixation devices. The provision of open pores in devices used to affix reconstructed hard tissues would allow for local cells to infiltrate during the healing process. Any openly porous structure is inherently weakened in comparison to its monolithic peers (i.e. decreased relative bulk modulus), such that the matrix materials must be made more resilient in keep the device from becoming friable. These processing methods aim to improve degradable surgical fixation devices at multiple levels of design: both through the inclusion of porous morphology, processing changes, and additives to regain mechanical integrity. Biomimetic pores are added for cellular infiltration by dissolving a porogen’s interpenetrating polymer network. The addition of open pores significantly reduces the bulk stiffness. More uniform phase separation has led to better pores, but the objects still need more resilience. Carbon nanomaterials are used to improve on the mechanics and surface chemistry of the polymer matrix material, composites of polylactide/nanodiamond are produced through cryogenic milling and solid state polycondensation. The addition of minute amounts of functionalized nanodiamond has remedied the brittle failure of the material, by cryogenic milling and solid state polycondensation of poly((D,L)lactide-co-glycolide) and hydroxyl functionalized detonation nanodiamonds. This composite has also demonstrated increased cytocompatability with 7F2 osteoblasts, as analyzed by cellular adhesion through fluorescence microscopy and alamar blue assay.
Temple University--Theses
Ensing, Geert Tone. "Prevention and treatment of biomaterial related infection in orthopedics a study of application of ultrasound and of antibiotic release /." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2006. http://irs.ub.rug.nl/ppn/291344038.
Повний текст джерелаGianforcaro, Anthony L. "Improvement Of Biodegradable Biomaterials For Use In Orthopedic Fixation Devices." Master's thesis, Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/599834.
Повний текст джерелаM.S.
Current orthopedic internal fixation devices, such as pins and screws, are typically made from metals and have a long list of complications associated with them. Most notably, complications such as infection or decreased wound healing arise from revisional surgeries needed to remove the used hardware. A new class of fixation devices is being produced from biodegradable biomaterials to eliminate the need for revisional surgery by being naturally broken down in the body. While currently available polymers lack the necessary mechanical properties to match bone strength, the incorporation of small amounts of hydroxylated nanodiamonds has been proven to increase the mechanical properties of the native polymer to better resemble native bone. Additionally, modern polymers used in biodegradable fixation devices have degradation rates that are too slow to match the growth of new bone. Poly-(D, L)-lactic-co-glycolic acid (PDLG) incorporated with hydroxylated nanodiamonds has not only been proven to start out stronger, but then also helps the polymer degrade faster when compared to the pure polymer in vivo and prevents effusion of the polymer into the surrounding environment. Nanodiamond incorporation is accomplished via solid state polycondensation of PDLG to create a uniform material with increased mechanical properties, faster degradation rates, and enhanced calcification when tested in simulated body fluid.
Temple University--Theses
Wong, Kai-lun, and 黄棨麟. "Strontium-substituted hydroxyapatite reinforced polyetheretherketone biomaterials in orthopaedic implants." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42182505.
Повний текст джерелаWong, Kai-lun. "Strontium-substituted hydroxyapatite reinforced polyetheretherketone biomaterials in orthopaedic implants." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42182505.
Повний текст джерелаLópez, Alejandro. "Injectable Biomaterials for Spinal Applications." Doctoral thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-215606.
Повний текст джерелаLawson, McKinley C. "Structure-function relationships of polymerizable vancomycin derivatives for the antimicrobial surface modification of orthopedic biomaterials." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3315775.
Повний текст джерелаYeung, Che-yan, and 楊芷茵. "Antibacterial properties and biocompatibility of novel peptide incorporated titanium alloy biomaterials for orthopaedic implants." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hdl.handle.net/10722/197133.
Повний текст джерелаLahiri, Debrupa. "Hydroxyapatite-Nanotube Composites and Coatings for Orthopedic Applications." FIU Digital Commons, 2011. http://digitalcommons.fiu.edu/etd/444.
Повний текст джерелаBoroujeni, Nariman Mansouri. "Monetite Cement Composites for Orthopedic and Dental Applications." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1341378401.
Повний текст джерелаGOLOB, SAMUEL. "INNOVATIVE ANTIBACTERIAL SYSTEMS FOR ORTHOPEDIC AND TRAUMATOLOGY APPLICATIONS." Doctoral thesis, Università degli Studi di Trieste, 2016. http://hdl.handle.net/11368/2907984.
Повний текст джерелаCai, Yanling. "Titanium Dioxide Photocatalysis in Biomaterials Applications." Doctoral thesis, Uppsala universitet, Nanoteknologi och funktionella material, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-160634.
Повний текст джерелаHeath, Daniel Edward. "Methacrylic Terpolymer Biomaterials for Cardiovascular Applications." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1276802114.
Повний текст джерелаMiao, Tianxin. "Smart Synthetic Biomaterials for Therapeutic Applications." ScholarWorks @ UVM, 2016. http://scholarworks.uvm.edu/graddis/610.
Повний текст джерелаTARUSHA, LORENA. "Novel nanostructured biomaterials for biomedical applications." Doctoral thesis, Università degli Studi di Trieste, 2016. http://hdl.handle.net/11368/2908088.
Повний текст джерелаChan, Yee-loi. "Surface modification of NiTi for long term orthopedic applications." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B39557406.
Повний текст джерелаChan, Yee-loi, and 陳以來. "Surface modification of NiTi for long term orthopedic applications." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39557406.
Повний текст джерелаBlanquer, Jerez Andreu. "Biocompatibility of new biomaterials for orthopaedic applications." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/386500.
Повний текст джерелаThe use of biocompatible materials has attained an increasing importance for medical surgery and orthopaedics due to population aging. Metallic alloys currently used in bone implants have physical and mechanical properties different from those of the bone, which increases the probability of implant loosening. For this reason, new metallic alloys with better properties are being developed. In this regard, the present thesis aims to analyse the biocompatibility of new biomaterials for orthopaedic applications. First, we demonstrated the biocompatibility of TiZrCuPd bulk metallic glass in terms of cytotoxicity, and osteoblast adhesion and differentiation. Second, we assessed the effect of surface modification of TiZrCuPd and Ti-6Al-4V alloys by electrochemical anodization and physical modification on osteoblast behaviour. Differences in topography did not cause changes on osteoblasts adhesion, proliferation and differentiation. Third, we demonstrated that TiZrPdSi and TiZrPdSiNb alloys are also biocompatible and enhance osteoblasts adhesion, spreading, proliferation and differentiation. Fourth, we evaluated the electrostimulation effect of two new ZnO piezoelectric nanogenerators using two cell lines involved in bone regeneration (osteoblasts and macrophages). We observed that both nanogenerators are biocompatible and that their interaction with cells produces a local electric field that stimulate macrophages motility and the increase in intracellular Ca2+ concentration in osteoblasts. Thus, these new smart materials have interesting properties for their use in biomedical devices. Collectively, the results obtained in our studies contribute to the progress in the development of better materials for bone repair and regeneration.
Venturato, Andrea. "2D and 3D applications of polymeric biomaterials." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31045.
Повний текст джерелаKhurshid, Z., S. Najeeb, M. S. Zafar, and Farshid Sefat. "Advanced Dental Biomaterials: Chemistry, Manipulation and Applications." Elsevier, 2019. http://hdl.handle.net/10454/18383.
Повний текст джерелаAdvanced Dental Biomaterials is an invaluable reference for researchers and clinicians within the biomedical industry and academia. The book can be used by both an experienced researcher/clinician learning about other biomaterials or applications that may be applicable to their current research or as a guide for a new entrant into the field who needs to gain an understanding of the primary challenges, opportunities, most relevant biomaterials, and key applications in dentistry.
Zhao, Weiyu. "Development of Functionalized Biomaterials for Biomedical Applications." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1594988786199951.
Повний текст джерелаZhang, Rui. "Converting macroalgal biomass into biomaterials and applications." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/20122.
Повний текст джерелаCostanza, Frankie. "Design, Synthesis and Applications of Polymer Biomaterials." Scholar Commons, 2015. https://scholarcommons.usf.edu/etd/5462.
Повний текст джерелаRUINI, FRANCESCA. "Chitosan based biomaterials: soft tissue engineering applications." Doctoral thesis, Politecnico di Torino, 2015. http://hdl.handle.net/11583/2602188.
Повний текст джерелаRubini, Katia <1966>. "Biomaterials for osteoarticular applications: role of functionalization." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10077/1/Rubini_Katia_submitted-1-140.pdf.
Повний текст джерелаSCOGNAMIGLIO, FRANCESCA. "Nano-engineered adhesive biomaterials for biomedical applications." Doctoral thesis, Università degli Studi di Trieste, 2016. http://hdl.handle.net/11368/2907994.
Повний текст джерелаRivera, Miguel A. "Powder processing of porous polysulfone for orthopedic and dental applications." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/10288.
Повний текст джерелаBenezra, Valarie Ilene 1971. "Electron microscopic investigation of interfaces in materials for orthopedic applications." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9690.
Повний текст джерелаIncludes bibliographical references (leaves 214-230).
About 250,000 people undergo knee and hip arthroplasty each year in North America alone, with hundreds of thousands more receiving joints over the rest of the world. Two factors are key to the success of these implants: first, the quality of attachment of the prosthetic joint to the patient's bone, and second, the low generation of wear particles as the components of the prosthesis articulate against each other. This thesis is a study of both of these factors. First, the mechanism of bone apposition to hydroxyapatite (HA) coatings on Ti-6Al-4V was investigated via transmission electron microscopy (TEM). In this section of the study, Ti alloy cylinders were coated with HA by two different methods to yield three types of coatings - annealed and unannealed plasma-spray (PSHA) coatings and an annealed ion-beam assisted deposited (IBAD-HA) coating. These cylinders were implanted in trabecular bone in dogs from periods ranging from 3 hours to 14 days. Mechanical testing indicated that the bone/implant interface with the PSHA coated implants was significantly stronger than that with the IBAD-HA coated or uncoated Ti alloy implants. However, there were no differences in the degree of bone apposition to the three HA-coated materials; thus indicating that bone apposition is not a sufficient indicator of mechanical integrity of the bone/HA interface. In the second section of this study, the microstructural factors contributing to the observed wear properties of the oxide on Zr-2.5Nb were investigated via TEM. Zr-2.5Nb barstock which had been rotary-forged to impart an anisotropic microstructure was sectioned and oxidized in dry air at 600°C and 635°C for a variety of times ranging from 30 minutes to 40 hours. Cross-sections across the oxide/metal interface were observed via TEM. The oxide scale comprises primarily monoclinic zirconia, with small amounts of tetragonal zirconia. Evidence of a mixed oxide phase, 6Zr02.Nb205, was also observed. The microstructure of this oxide is dependent on oxidation temperature, the microstructure of the underlying metal, and oxide depth. Two oxide microstructures originating from beta-Zr grains in the alloy were also identified. A third study concerned the architecture and microstructure of naturally-derived and synthetic bone substitute materials (BSMs). While BSMs are used clinically to promote healing in large bone defects, they were useful to this study as a control for the organization of mineral in mature bone. Low voltage high resolution scanning electron microscopy (LVHRSEM) enabled observations of the three dimensional architecture of these materials which were then correlated with TEM observations. The crystallites in an anorganic bovine-derived BSM were organized in a hierarchical fashion which paralleled the organization of collagen. In contrast, the synthetic materials were organized in an isotropic network. The difference in organization was attributed to the formation of the mineral matrix of bone on an anisotropic collagen template.
by Valarie Ilene Benezra.
Ph.D.
Yang, Xia. "Multi-functional Hyaluronan Based Biomaterials for Biomedical Applications." Doctoral thesis, Uppsala universitet, Polymerkemi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-224371.
Повний текст джерелаBanwell, Eleanor Frances. "Self-assembling fibrous biomaterials for cell-biology applications." Thesis, University of Bristol, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441317.
Повний текст джерелаHodgkinson, Tom. "Silk fibroin biomaterials for skin tissue engineering applications." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/silk-fibroin-biomaterials-for-skin-tissue-engineering-applications(75958c4c-dacf-466f-ae6f-e8c9bb7c20b8).html.
Повний текст джерелаMa, Weili. "Engineered Biomaterials for Human Neural Stem Cell Applications." Diss., Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/594172.
Повний текст джерелаPh.D.
Within the last decade, neurodegenerative diseases such as Alzheimer’s and Parkinson’s have emerged as one of the top 5 leading causes of death globally, and there is currently no cure. All neurodegenerative diseases lead to loss of the functional cells in the nervous system, the neurons. One therapeutic approach is to replace the damaged and lost neurons with new, healthy neurons. Unfortunately, this is a difficult endeavor since mature neurons are not capable of cell division. Instead, researchers are turning to neural stem cells, which are able to self-renew and be rapidly expanded before being differentiated into functional cell phenotypes, such as neurons, allowing for large numbers of cells to be generated in vitro. Controlled differentiation of human neural stem cells into new neurons has been of interest due to the immense potential for improving clinical outcomes. Adult neural stem cell behavior, however, is not well understood and the transplanted stem cells are at risk for tumorigenesis. The focus of this dissertation is the development of engineered biomaterials as tools to study human neural stem cell behavior and neurogenesis (differentiation). A novel cell penetrating peptide was developed to enhance intracellular delivery of retinoic acid, a bioactive lipid known to induce differentiation. A hydrogel platform fabricated from hyaluronic acid, a naturally-occurring polysaccharide found in brain extracellular space, was designed to serve as a biomimetic soft substrate with similar mechanical properties to the brain. The biological behavior of the stem cells was characterized in response to chemical and physical cues.
Temple University--Theses
Curcio, Mariangela. "Thin coatings of biomaterials for hard tissue applications." Doctoral thesis, Universita degli studi di Salerno, 2018. http://hdl.handle.net/10556/3055.
Повний текст джерелаThe goal of the present study is the production of new-generation coatings suitable for hard tissue implants, intended to decrease the healing time, limit infections and rejections and improve patients' life quality. Materials designed for implant coatings are mainly bioactive ceramics. Belonging to this class of biomaterials, hydroxyapatite (HAp), bioglass (BG) and glass-ceramic (BGC) are indicated for application in hard tissue replacement and regeneration. However the use of each one has strengths and weaknesses; therefore the attention has been focused on their peculiarity in the coating of metallic materials, suitable for hard tissue replacement. In particular, in order to overcome their drawback and enhance their strengths, possible solutions, like the adding of helpful component in the basic material or the choice of composites, have been investigated. The main technique used for the coatings production has been the Pulsed Laser Deposition (PLD). Furthermore the Electrophoretic Deposition (EPD) has been performed to produce composite biopolymer/bioceramic coatings, which cannot be accomplished by the conventional PLD. Hydroxyapatite has been deposited with IONPs (iron oxide nanoparticles). The IONPs have been previously obtained by the means of a really "green" technique, the PLAL (pulsed laser ablation in liquid). The obtaining of HAp/IONPs films has demonstrated how PLD is a successful deposition technique for the production of magnetic composite coatings. BG_Cu films have been also successfully deposited trough PLD and their bioactivity has been demonstrated by the hydroxyapatite growth on their surface during the soaking in simulated body fluid (SBF). The use of electrophoretic deposition (EPD) has allowed the coating of SS substrate with polymer/bioglass composite films. Also in this case a Cu-doped bioaglass has been used together with a protein-based polymer, zein, and the films bioactivity has been proved. RKKP (glass-ceramic) pulsed laser deposited has been proved functional coatings for celldelivery implantation and for the reduction of the corrosion of biodegradable implant. Although glass-ceramics show superior mechanical properties than bioglasses, they are still not enough for load-bearing application. Therefore, RKKP&C60 has been used as target for the deposition of composite films with improved hardness. Finally, RKKP has been modified by the adding of another component, manganese, useful for the bone regeneration, and its biocompatibility has been proved. [edited by author]
XVI n.s.
Perin, Danilo. "Biomaterials for biotechnological applications: synthesis and activity evaluations." Doctoral thesis, Università degli studi di Trieste, 2010. http://hdl.handle.net/10077/3518.
Повний текст джерелаA biomaterial was defined as any non-living material used in a medical device that interacts with biological systems. Many different applications involve the use of biomaterials: pharmacology, controlled drug release, extracorporeal devices (contact lens, emodialysis devices, cardiopulmonary bypass oxygenators), artificial prostheses. One of the most interesting biomaterials application regards the release of nucleic acids and their derivatives as therapeutic agents. These molecules, defined as “nucleic acid base drugs” (NABDs), allows highly targeted cellular metabolism modifications. The aim of this research project concerns the characterization of biomaterials for biotechnological applications and evaluation of their activities. In particular, because of the great therapeutics and commercial interest and the delivery problems that are largely unresolved, the attention is focused on the study of new delivery systems for siRNA, proposed as model system as they represent the most common and best characterized NABD. SiRNA proved to be useful for what concerns the in-stent restenosis, pathology implying the re-occlusion of the artery due to the iper-proliferation of smooth muscle cells induced by the presence of the stent, a metal prosthesis that is applied to avoid the elastic recoil of the artery wall after balloon angioplasty. In this system, the siRNA should act as an anti-proliferative of smooth muscle cells without interfering with endothelial cells. In order to design an appropriate delivery system, it is crucial a precise structural and dimensional characterization of polymeric mesh. This purpose was achieved by the use of various techniques such as Rheology, low field NMR and Cryoporometry. Rheology allows the evaluation of the macroscopic mechanical properties of the system under investigation (Young's and shear modulus for example). Low field NMR, instead, allows evaluating the microscopic properties and, coupled to the rheology, provides an estimation of the polymeric mesh size distribution. Cryoporometry is another method to assess the mesh size distribution. In vivo release tests represent the final step of the experimental process. The polymeric system ability to carry and deliver the liposome-siRNA complexes, was tested in culture models of smooth muscle cells and endothelial cells. The attention has been focused on polymeric hydrogels, whose biocompatibility and biodegradability is well known: • Alginate (polymeric concentration 1% - 2% - 3%), crosslinked by Ca2+ or Cu2+ water solution • Pluronic™ F127 18% in water • Dextran 5% or 30% methacrylate (respectively D40MA5% and D500MA30%; polymeric concentration 5%) crosslinked by UV • Gel systems derived from benzofulvene And polymeric blends: • Pluronic™-alginate hydrogels respectively at 18% and 2% in water • Dextran methacrylate-alginate respectively at 5% and 3% in water (A3D40MA5% or A3D500MA30%)
Un biomateriale è definito come qualsiasi materiale non-vivente utilizzato in un dispositivo medico interagente con i sistemi biologici. Diverse applicazioni comportano l'uso di biomateriali: farmacologia, sistemi di controllato rilascio di farmaci, dispositivi extracorporei (lenti a contatto, dispositivi per emodialisi, ossigenatori, bypass cardiopolmonari, ecc.), protesi artificiali. Una delle applicazioni più interessanti dei biomateriali riguarda il rilascio di acidi nucleici e loro derivati come agenti terapeutici. Queste molecole, definite come " nucleic acid base drugs " (NABDs), consentono modifiche altamente mirate del metabolismo cellulare. L'obiettivo di questo progetto di ricerca riguarda la caratterizzazione dei biomateriali per applicazioni biotecnologiche e la valutazione delle loro attività. In particolare, dato il notevole interesse terapeutico e commerciale, oltre ai problemi di delivery tutt’ora in gran parte irrisolti, l'attenzione è stata focalizzata sullo studio di nuovi sistemi di somministrazione di siRNA, proposti come sistema modello in quanto rappresentano il più comune e meglio caratterizzato NABD. I siRNA si sono rivelati utili per il trattamento della ristenosi in-stent, una patologia che comporta la ri-occlusione dell'arteria in seguito alla iper-proliferazione delle cellule muscolari lisce indotta dalla presenza dello stent, una protesi di metallo applicata per evitare la contrazione elastica della parete arteriosa in seguito ad angioplastica con palloncino. In questo sistema, il siRNA dovrebbe agire come un anti-proliferativo delle cellule muscolari lisce, senza interferire con le cellule endoteliali. Al fine di progettare un adeguato sistema di rilascio, è di fondamentale importanza una precisa caratterizzazione strutturale e dimensionale delle maglie polimeriche. Questo scopo è stato raggiunto mediante l’utilizzo di varie discipline quali la Reologia, l’NMR a basso campo e la Crioporimetria. La Reologia permette una valutazione macroscopica delle proprietà meccaniche del sistema in esame (ad esempio attraverso il modulo di Young ed il modulo di taglio). L’NMR a basso campo, invece, permette di valutare le proprietà microscopiche e, accoppiato alla reologia, fornisce una stima della distribuzione dimensionale delle maglie polimeriche. La Crioporimetria è metodo alternativo per la valutazione della distribuzione dimensionale delle maglie. I test di rilascio in vivo rappresentano l'ultima fase del processo sperimentale. La capacità del sistema polimerico di trasportare e rilasciare liposomi complessati a siRNA, è stata valutata in modelli di cellule muscolari lisce e cellule endoteliali in coltura. L’attenzione e stato focalizzata soprattutto su sistemi idrogel polimerici la cui biocompatibilità e biodegradabilità è ben nota: • Alginato (concentrazione polimero 1% - 2% - 3%), reticolato attraverso soluzioni acquose di Ca2+ o Cu2+ • Pluronico F127 al 18% in acqua • Destrano 5% o 30% metacrilato (rispettivamente D40MA5% e D500MA30% ad una concentrazione polimerica pari al 5% in acqua), reticolati tramite UV • Sistemi gel derivati da benzofulvene E le miscele polimeriche costituite da: • Idrogel di pluronico-alginato rispettivamente al 18% e 2% in acqua • Destrano metacrilato-alginato rispettivamente al 5% e 3% in acqua (A3D40MA5% o A3D500MA30%)
XXII Ciclo
1980
Flamant, Quentin. "Surface modification of zirconia-based bioceramics for orthopedic and dental applications." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/436899.
Повний текст джерелаDue to their outstanding mechanical properties and excellent biocompatibility, the use of zirconia-based ceramics in dental and orthopedic applications has grown rapidly over the last decades. However, both alumina and zirconia are bioinert, which hampers their implantation in direct contact with bone. Furthermore, infections remain one of the leading causes of implant failure. To address both issues, an improved surface design is required: in particular, an adequate topography can promote osseointegration and limit bacterial adhesion. On the other hand, long-term reliability is a major concern for load-bearing implants, and zirconia-containing ceramics require special attention. As for other ceramics, surface alterations can impair their mechanical properties. Besides, the tetragonal to monoclinic phase transformation, which accounts for their exceptional toughness, can occur spontaneously in the presence of water, potentially deteriorating the material properties. The kinetics of this phenomenon, known as hydrothermal ageing, are highly sensitive to processing changes. Any surface modification of zirconia-containing ceramics should thus be accompanied by a careful assessment of its impact on implant reliability. Based on these observations, the objective of this thesis was to develop processes to modify the surface of zirconia-based implants, in particular the topography, without compromising their mechanical properties and hydrothermal stability. The research effort focused on two materials of particular interest: yttria-stabilized zirconia (3Y-TZP), which is increasingly used for prosthodontic applications (e.g., crowns, implants), and zirconia toughened alumina (ZTA), which is the current gold Standard in orthopedics for the fabrication of load-bearing ceramic components. Accordingly, this work can be divided into two main parts. In the first part, an extensive study of the hydrofluoric acid (HF) etching of zirconia was carried out. It was shown that monitoring etching time allows controlling the roughness and fractal dimension of the surface. Furthermore, the results indicated suitable processing conditions for a fast and uniform roughening of zirconia components, without compromising substantially their strength and ageing resistance. Based on these findings, zirconia samples with roughness gradients were obtained by immersing specimens into an etching solution with a controlled speed. Thanks to this method, which drastically reduces the efforts and resources necessary to study cell-surface interactions, a rapid screening of the influence of HF-induced micro- and nano-topography on mesenchymal stem cell morphology was conducted. Correlations between roughness parameters and cell morphology were evidenced, highlighting the importance of multiscale optimization of topography to induce the desired cell response. In the second part, an integrated strategy was developed to provide both osseointegrative and antibacterial properties to ZTA surfaces. The micro-topography was controlled by injection molding. Meanwhile a novel process involving the selective dissolution of zirconia by HF (selective etching) was used to produce nano-roughness and interconnected Surface nanoporosity. Potential utilization of the porosity for delivery of antibiotic molecules was demonstrated, and it was shown that liposomal encapsulation could improve drug loading. Furthermore, the impact of selective etching on mechanical properties and hydrothermal stability was shown to be limited. The combination of injection molding and selective etching thus appears promising for fabricating a new generation of ZTA components implantable in direct contact with bone.
Koju, Naresh. "Smart Piezoelectric Calcium Phosphates for Orthopedic, Spinal-fusion and Dental Applications." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1524047236280822.
Повний текст джерелаFang, Liming. "Processing of HA/UHMWPE for orthopaedic applications /." View abstract or full-text, 2003. http://library.ust.hk/cgi/db/thesis.pl?MECH%202003%20FANG.
Повний текст джерелаIncludes bibliographical references (leaves 128-138). Also available in electronic version. Access restricted to campus users.
Woo, Gregory Lu-Yuen. "Development of novel biodegradable antimicrobial polymers for biomaterials applications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0001/MQ40915.pdf.
Повний текст джерелаWang, Ling. "Syntheses and applications of bisphosphonate-based biomaterials and nanomaterials /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202007%20WANG.
Повний текст джерелаZheng, Jukuan. "Synthesis and Modification of Biomaterials for Tissue Engineering Applications." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1427581327.
Повний текст джерелаFraioli, Roberta. "Functionalization of titanium with integrin-selective ligands for orthopedic and dental applications." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/404303.
Повний текст джерелаEl objetivo principal de este proyecto de tesis es la instalación de bioactividad en la superficie de titanio para implantes ortopédicos y dentales a través de un proceso de funcionalización superficial. A pesar de ser biocompatible y con buenas propiedades mecánicas para substituir el tejido óseo dañado o ausente, el titanio carece de capacidades osteoinductivas, es decir, soporta pero no favorece los procesos de formación de hueso. Esto puede llevar a la fallida del implante debido a una falta de osteointegración. Las modificaciones superficiales permiten transformar la superficie bioinerte del titanio en una superficie bioactiva que estimula la producción de hueso, sin afectar las propiedades mecánicas del material. Para lograr dicha bioactividad, en este trabajo de tesis se inmovilizaron dos familias de moléculas peptidicas inspiradas en la matriz extracelular de las células que interactúan con las integrinas, los receptores celulares más importantes que transmiten la información entre las células y su matriz. El primer tipo de biomolécula testada es una molécula ramificada, cuyas dos extremidades llevan dos motivos peptídicos distintos: el motivo de adhesión celular RGD (Arg-Gly-Asp) y el motive de sinergia PHSRN (Pro-His-Ser-Arg-Asn), que incrementa la afinidad para la integrina a5ß1, muy relevante en procesos de crecimiento óseo. La segunda familia de biomoléculas abarca dos peptidomiméticos selectivos para la integrina a5ß1 o la integrina avß3, cuyo rol en la formación de hueso es también objeto de discusión en la literatura, y que fueron sintetizados por el grupo del Prof. H. Kessler de la Technische Universität München. Para la inmovilización de las moléculas en el titanio se utilizaron dos técnicas distintas: la fisisorción, que sólo está basada en la formación de enlaces débiles electrostáticos, puentes hidrogeno, etc., y la unión covalente, más estable, mediante la silanización de la superficie metálica. Las superficies de titanio modificadas se testaron con dos tipos celulares relevantes en el contexto de la substitución de material óseo: células de osteosarcoma (SaOS-2) y células mesenquimales (hMSCs), ambas de procedencia humana. La combinación de esos factores originó cuatro estudios, tres de los cuales son reportados como trabajos publicados. Dos de esos estudios incluyen también un análisis in vivo en un modelo animal, que permitió comprobar el efecto de la funcionalización en un escenario clínico real. Finalmente, se llevó a cabo un estudio en colaboración con el Prof. M. Dalby del Centre for Cell Engineering de la University of Glasgow para combinar la funcionalización química y la nanotopografia, obteniendo así una superficie de titanio multifuncional: las nanoestructuras superficiales son bactericidas, pero carecen de propiedades adhesivas, que pueden ser proporcionadas a través de la inmovilización de motivos peptídicos. En conjunto, los resultados de esta tesis demuestran que la funcionalización química es una herramienta poderosa para optimizar la respuesta celular en la superficie del biomaterial e inducir la respuesta biológica deseada.
Nysjö, Johan. "Interactive 3D Image Analysis for Cranio-Maxillofacial Surgery Planning and Orthopedic Applications." Doctoral thesis, Uppsala universitet, Avdelningen för visuell information och interaktion, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-301180.
Повний текст джерелаHassan, S. M. Mahmudul. "Development of Novel High Strength Composite Calcium Phosphate Cement for Orthopedic Applications." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1533212629435654.
Повний текст джерелаFan, Dongmei. "Mesoporous silicon/biopolymer composities for orthopedic tissue engineering and drug delivery applications." [Fort Worth, Tex.] : Texas Christian University, 2008. http://etd.tcu.edu/etdfiles/available/etd-12192008-090502/unrestricted/fan.pdf.
Повний текст джерелаZhang, Xi. "Polymer composites incorporating engineered electrospun fibres : flexible design and novel properties for biomedical applications." Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/30904.
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