|Articles about Biomaterials|
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| [Cartilage tissue engineering: state-of-the-art and future approaches.]
Galois, L., A. M. Freyria, et al. (2005), Pathol Biol (Paris) 53(10): 590-8.
Abstract: Lesions of the articular cartilage have a large variety of causes among which traumatic damage, osteoarthritis and osteochondritis dissecans are the most frequent. Returning damaged cartilage in articular joints back to a functionally normal state has been a major challenge for orthopaedic surgeons. This interest results in large part because cartilage defects cannot adequately heal themselves. Current techniques used in orthopaedic practice to repair cartilage give variable and unpredictable results. Bone marrow stimulation techniques such as abrasion arthroplasty, drilling and microfracture produce mostly fibrocartilage. Autologous osteochondral transplant systems (mosaicplasty) have shown encouraging results. Autologous chondrocyte transplantation has led to a hyaline articular cartilage repair but little is known about the predictability and reliability of the procedure. The rapidly emerging field of tissue engineering promises creation of viable substitutes for failing cartilage tissue. Current tissue engineering approaches are mainly focused on the restoration of pathologically altered tissue structure based on the transplantation of cells in combination with supportive matrices and molecules. Among natural and synthetic matrices, collagen and polysaccharidic biomaterials have been extensively used with promising results. Recently, interest has switched to the use of mesenchymal stem cells instead of chondrocytes. Tissue engineering offers the possibility to treat localised cartilage lesions. Genetic engineering techniques using genetically modified chondrocytes offer also the opportunity to treat diffuse cartilage lesions occurring in osteoarthritis or inflammatory joint diseases. Electroporation is specially a reliable and inexpensive technique that shares with electrochemotherapy an ability to target the chondrocytes despite the barrier effect of the extracellular matrix without viral vectors. The authors review recent research achievements and highlight the potential clinical applications of new technologies in the treatment of patients with cartilage injuries.
| [Cell and cell sheet manipulation by utilizing biomaterials--development of cell sheet engineering]
Yamato, M., M. Hirose, et al. (2000), Tanpakushitsu Kakusan Koso 45(13 Suppl): 2156-61.
| [Cell culture and orthopedic surgery. II. Medical applications. Diagnosis, biomaterials evaluation, therapy]
Anselme, K. and P. Hardouin (1996), Rev Chir Orthop Reparatrice Appar Mot 82(8): 724-36.
Abstract: Currently, cell cultures are used for 3 kinds of applications in orthopaedics: diagnosis: they can help to diagnose hereditary diseases like Marfan syndrome, osteogenesis imperfecta, or some osteochondrodysplasia. biomaterial evaluation: cell cultures bring information to ensure safety and efficacy of medical devices following the European Community's directive concerning medical devices. Results of in vitro biomaterial evaluation must be related to cell types (osteoblasts or fibroblasts), cell species (human or rat) and methods used (primary cell line or immortalised cell line). therapy: first clinical applications of cell cultures have been published recently. They concern cultured autologous chondrocytes reimplantation. Bone cells cultured on biomaterials have been tested in animal reimplantation experiments. Animal cells mediated gene therapy experiments are now developed on muscle cells. Cell cultures allow also to determine the best therapeutic way to cure bone tumors. For the moment, these applications are still limited but in the next years, they could develop considerably. Therefore, orthopaedic surgeons must keep interest in this new field.
| [Cell cultures of human osteoclasts for testing biomaterials]
Lambrecht, J. T. (1990), Dtsch Zahnarztl Z 45(2): 82-6.
Abstract: A method for isolating and culturing osteoclast-like cells from cancellous bone material collected from external iliac crest bone of patients is described. Aseptic techniques were used for comminution of the bone material, treatment with collagenase and separation of the bone cells from the bulk bone through a nylon filter. The bone cells were cultured on various surfaces for ten days. Cell motility, mobility and fusion was be observed along with tartrate-resistant acidic phosphatase activity in a majority of the cells soon after they had been cultured. These large cells attached to human cortical bone fragments, where they produced resorption lacunae in vitro. These morphologic and functional characteristics indicate that the cells we had isolated were, in fact, human osteoclasts. SEM studies of these cells on various biomaterials (titanium, hydroxyl apatite, tricalcium phosphate) revealed different morphologic characteristics varying with the substrate used and allowing conclusions as to substrate acceptance. Large areas of cell contact and cell proliferation suggest a favorable response to the materials applied.
| [Cell proliferation and cellular activity of primary cell cultures of the oral cavity after cell seeding on the surface of a degradable, thermoplastic block copolymer]
Rickert, D., A. Lendlein, et al. (2005), Biomed Tech (Berl) 50(4): 92-9.
Abstract: Using standard cell biological and biochemical methods we were able to test the ability of a degradable, thermoplastic block copolymer to support the adhesion, proliferation, and the cellular activity of primary cell cultures of the oral cavity in vitro. The delicate balance between a group of endogenous enzymes, Matrix Metalloproteinases (MMPs), and their inhibitors (Tissue Inhibitor of MMPs, TIMPs) have a decisive function in the remodeling of the extracellular matrix during processes like wound healing or the integration of biomaterials in surrounding tissues after implantation. Recently developed, biodegradable thermoplastic elastomers with shape-memory properties may be the key to develop new therapeutical options in head and neck surgery. Primary cell cultures of the oral cavity of Sprague-Dawley rats were seeded on the surface of a thermoplastic block copolymer and on a polystyrene surface as control. Conditioned media of the primary cells were analyzed for MMPs and TIMPs after different periods of cell growth. The MMP and TIMP expression was analysed by zymography and a radiometric enzyme assay. No statistically significant differences in the appearance and the kinetic of MMP-1, MMP-2, MMP-9 and TIMPs were detected between cells grown on the polymer surface compared to the control. An appropriate understanding of the molecular processes that regulate cellular growth and integration of a biomaterial in surrounding tissue is the requirement for an optimal adaptation of biodegradable, polymeric biomaterials to the physiological, anatomical, and surgical conditions in vivo to develop new therapeutic options in otolaryngology and head and neck surgery.
| [Cellular compatibility of three natural xenogeneic bone derived biomaterials]
Li, Y. L., Z. M. Yang, et al. (2001), Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 15(4): 227-31.
Abstract: OBJECTIVE: To evaluate the cellular compatibility of three natural xenogeneic bone derived biomaterials. METHODS: Three types of natural xenogeneic bone derived biomaterials were made with physical and chemical treatment, composite fully deproteinized bone(CFDB), partially deproteinized bone(PDPB) and partially decalcified bone(PDCB). Three types biomaterials were cocultured with human embryonic periosteal osteoblasts. The cell growth, attachment, cell cycle, alkaline phosphatase activity were detected to evaluate the cellular compatibility to biomaterials. RESULTS: Osteoblasts attached on all three biomaterials and grew well, the effect of three biomaterials on cell proliferation was PDCB > PDPB > CFDB. The cell cycle was not obviously affected by three biomaterials. The effect of three biomaterials on alkaline phosphatase activity of osteoblasts was PDCB > PDPB > CFDB. CONCLUSION: CFDB,PDPB,PDCB have good cellular compatibility without cytotoxic and tumorigenicity, CFDB is the best. The three biomaterials can be used as scaffold materials of bone tissue engineering.
| [Characterization of anticoagulant biomaterial and its development]
Chen, B., D. Huo, et al. (2005), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 22(2): 428-32.
Abstract: Good anticoagulant biomaterials need good surface chemical properties, good mechanics performances and particularly good characteristics of biocompatibility, including tissue compatibility and hemocompatibility. In order to understand with greater clearness the anticoagulant biomaterial, we have to characterize them by different methods. In this paper, the approaches to assessing and displaying the characteristics of anticoagulant biomaterial are reviewed in three aspects, namely the surface chemical properties and structure, the mechanics performances the and the biocompatibility of anticoagulant biomaterial.
| [Characterization of custom-made biomaterials containing antibiotics]
Pfefferle, H. J. and B. Nies (2004), Orthopade 33(7): 817-21.
Abstract: The aim of this study was to evaluate the quality of custom-made antibiotic carriers which are produced for hospitals in a central service laboratory. These sterile products, made according to antibiogram, showed quality parameters which are comparable with commercially available products in terms of antibiotic release and other relevant properties.
| [Chitosan pads vs. manual compression to control bleeding sites after transbrachial arterial catheterization in a randomized trial]
Poretti, F., T. Rosen, et al. (2005), Rofo 177(9): 1260-6.
Abstract: PURPOSE: Until now, no mechanical closure devices were available to achieve fast and secure hemostasis for vessel closure after catheterization of small arterial vessels. MATERIAL AND METHODS: Eighty patients were randomized to evaluate the effect on hemostasis by use of a chitosan pad (Chito-Seal, Abbott Vascular Devices, Galway/Ireland) in comparison to manual compression after diagnostic transbrachial arterial catheterization. Hemostasis after three minutes and one hour as well as local development of a hematoma after one and twenty-four hours were assessed. RESULTS: The use of chitosan pads significantly decreased the bleeding time in the first three minutes after manual compression time (p < 0.01). Significant decrease in bleeding risk at three minutes by use of the chitosan closure pads was also found in subgroups of patients with hypertension (p < 0.001) or diabetes (p < 0.01) and also in patients under anticoagulation therapy (p < 0.01). In addition, long-term protection from bleeding complications such as the risk of hematoma was decreased by the use of chitosan closure pads one hour (p < 0.01) or twenty-four hours (p < 0.001) after catheter removal. CONCLUSION: The use of an intravascular anchor or suture system is not safely applicable in these vessels due to the small diameter of the brachial artery. Our results document a significant improvement in hemostasis by using chitosan pads in these cases.
| [Chitosan-based polyelectrolyte complexes: a review]
Il'ina, A. V. and V. P. Varlamov (2005), Prikl Biokhim Mikrobiol 41(1): 9-16.
Abstract: The review focuses on the formation of polyelectrolyte chitosan complexes with biologically active compounds and prospects of use thereof. The possibility of obtaining low-molecular-weight, water-soluble batches of chitosan, which differ in their degree of acetylation, is discussed, with emphasis on their use for binding nucleic acids into complexes.
| [Clinical-microbiological evaluation of the efficacy of combined use of chitosan, low intensity laser radiation and photosensitizer in treatment of patients with acute suppurative maxillofacial periostitis]
Shomina, S. A., V. V. Bogatov, et al. (2005), Stomatologiia (Mosk) 84(3): 23-6.
Abstract: Results are presented on treatment of 68 patients with acute suppurative periostitis of maxillofacial region. After surgical interventions in patients of the study group (48 patients) the wounds were cleansed by 1% chitosan on 0.2% HC1 in combination with methylene blue and irradiated by IR laser beam. The wounds healed in 2-3 days. In the control group (20 patients) for wound dressing chlorhexidine as a standard procedure was used, length of the healing process was 5-6 days. After combined treatment the number of microflora in the wound was reduced and microflora did not show the signs of pathogenicity.
| [Clinico-pathological studies of dental biomaterials in endodontic therapy, with special reference to the biocompatibility of the hydroxyapatite on exposed vital human pulp]
Nakagawa, K. I. (1983), Shikwa Gakuho 83(5): 501-27.
| [Clinico-pathological studies of dental biomaterials in endodontic therapy, with special reference to the effect of calcined cementum fragments on exposed vital human pulp]
Nakagawa, K. I. (1983), Shikwa Gakuho 83(5): 475-500.
| [Collagen as a biomaterial]
Adam, M. and M. Stol (1989), Cas Lek Cesk 128(42): 1313-7.
Abstract: The authors discuss the characteristics of different types of collagen, their incidence, structure, chemical composition and physical properties with regard to their use as biomaterial. They also mention the antigenicity, effect on platelet aggregation, cytodifferentiation and cellular proliferation. The authors discuss different biomedical applications of collagen and methods of its sterilization.
| [Coloration of cytologic thick sections containing biomaterials with silver methenamine. Usefulness for scanning electron microscopy]
Frayssinet, P., L. Gineste, et al. (1998), Morphologie 82(256): 13-5.
Abstract: Prostheses implanted in hard tissues cannot be processed for electron microscopic examination or microanalysis in the same way as those in other tissues. For these reasons, we have developed a method allowing light and electron microscopic studies as well as microanalysis of the interface between bone and biomaterials after the sections glycoproteins have been stained with silver methenamine. Silver can be evidenced by SEM in back scattered mode. MATERIALS AND METHODS: Tranverse sections of a human femur containing an HA-coated prostheses were obtained with a diamond saw and ground to a thickness of 50-100 microns. The sections were stained in a microwave oven using a 1% silver methenamine solution. They have been examined by back-scatter SEM operated at 25 KV. EDS has been performed on cellular inclusions and extracellular bone matrix. RESULTS: Type I and III collagen fibers, and reticulin fibers were stained. The mineralized matrix was heavily colored. At the cell level, the nuclear and cytoplasm membranes, the chromatin and ribosomes were shown. The characteristic peaks of the Ag spectrum are distinct from those of the elements used in orthopaedic biomaterials and did not impair their identification.
| [Comparative evaluation of biomaterials use in surgical treatment of periodontitis]
Zietek, M., T. Konopka, et al. (1999), Polim Med 29(3-4): 49-59.
Abstract: Clinical and radiological evaluation of three biomaterials--HA-Biocer, Bio-Gran and Bio-Oss was carried out two years after their grafting in parodontium. The tests were carried out for 91 patients with parodontis. Comparative clinical results (remission of the inflammatory state of parodontium tissues, essential reduction of gingival pockets and rebuilding of alveolar process bone on aimed X-ray pictures) were noted. The carried out observations show that biomaterials application for filling vertical alveoral process bone defects for patients with parodontis gives satisfactory clinical results.
| [Comparison between hemolysis percentage measurement and hemiglobincyanide measurement for standardizing the evaluation of hemolytic properties of biomaterials]
Zhang, L., W. Zhu, et al. (2004), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 21(1): 111-4, 137.
Abstract: In this study, two methods--the supernatant hemoglobin spectrophotometry, i.e. hemolysis percentage measurement(according to ISO/TR 7405) and the hemiglobincyanide measurement(according to ISO 10993-4)--were used to assay the hemolytic properties of hydroxyapatite(bioceramics) and collagen (polymer). The results showed that the conclusions drawn from using the two methods were basically consistent, and the latter was more sensitive, stable and comparable. However, some of the procedures in the hemiglobincyanide method were not defined in details. So based on our experiments we have offered some suggestions and improvements, which do not deviate from ISO and ASTM standards, for hiher practicability of usig it in standardizing the evaluation of the hemolytic properties of biomaterials. Hemiglobincyanide measurement is worthy of wider application.
| [Comparison of infrared spectra of native and esterified beer yeast]
Han, R. P., G. L. Bao, et al. (2004), Guang Pu Xue Yu Guang Pu Fen Xi 24(7): 820-2.
Abstract: The native beer yeast and esterified beer yeast were examined by infrared spectroscopy. The IR spectrum of beer yeast is mainly composed of the adsorption of carbohydrates, protein, etc. The dominating bands near 1652, 1532 and 1240 cm(-1) were assigned to amide I, amide II and amide III, and the characteristic IR absorption of protein could be one of the significant components of cell walls. The peak near 1 454 cm(-1) is attributable to the bending stretching of CH2- and CH3-. A substantial portion of the absorbance at 1160 cm(-1) is attributable to the stretching vibration of C-O on the structure of carbohydrates, the main components of the cell walls. The band present at 1080 cm(-1) was caused by the C-O stretching of carbohydrates and alcohols found in the RNA, the DNA and/or the cell envelop of the yeast. The peaks at 1744 cm(-1) (attributed to the carboxylate stretching) and 1454 cm(-1) confirmed the esterification process of carboxylate groups presented in the cell wall. After esterification with methanol-chloride hydride, the major components and the structures of the biomaterial remained intact.
| [Compatibility research of self-designed scaffold biomaterials of nature extracellular matrix]
Wang, Y., W. Kong, et al. (2004), Lin Chuang Er Bi Yan Hou Ke Za Zhi 18(6): 363-6.
Abstract: OBJECTIVE: Scaffold biomaterials for cell culture of tissue-engineering demand satisfactory biocompatibility. This experiment aimed to evaluate biocompatibility of self-designed scaffold biomaterial of NECM. METHOD: The biocompatibility of self-designed NECM was evaluated both in vivo and in vitro, including cytotoxic test, acute and subacute systemic toxicity test, hemolysis test, pyrogenic test, lymphocyte transformation test and long-term subcutaneous implantation test of NECM. RESULT: Self-designed NECM scaffold biomaterial for cell culture has no cytotoxicity, no acute and subacute systemic toxicity, and it did not cause inflammatory reaction. CONCLUSION: Self-designed NECM has good biocompatibility and may become an ideal biological scaffold material for cell culture of tissue engineering.
| [Component distribution in gradient biomaterial prepared with multi grades energy PIII]
Yin, G., D. Zhou, et al. (2003), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 20(1): 104-6.
Abstract: During the preparation of functional gradient materials (FGM) with plasma immersion ion implantation-ion beam enhanced deposition (PIII-IBED), the combination strength between the coating and the substrate would be greatly affected by the implantation dose and the distribution of implanted ions in substrate. According to the requirements of FGM, an idea of multi grades energy implantation had been suggested, with which the Gauss peak could be moved toward the surface, and the concentration of implanted ions could be maximized at the surface. In this study, the distribution of carbon ions implanted into titanic alloy substrate have been simulated theoretically, and the tentative idea have been confirmed experimentally.
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