|Articles about Biomaterials|
|First Page||Previous Page||Next Page||Last Page|
| [Advances in apoptosis induced by biomaterials]
Wu, K., Y. Wang, et al. (2005), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 22(2): 413-9.
Abstract: Biomedical materials are the biomaterials that, used in physiological system for diagnosis, treatment, plerosis or replacement of tissues and organs. Apoptosis, also known as PCD or ACD, is a normal physiological mechanism of cell in organism and a process of automatic cell death in which multicell organism modulates the development of organism and maintains the stability of internal environment. The human beings are able to understand the interaction between the material and organism at the molecular level due to the widely-used biomedical material and the development of material science, life science and biological technology. The research of that interaction is mainly focused on biocompatibility, while much attention has been drawn to the apoptosis induced by biomaterial concerning that apoptosis could be caused by inducing factor, and many therapies of diseases are closely related to inducing apoptosis. Based on the recent research advances of apoptosis in life science and the development of biomaterials, the pathways of apoptosis induced by biomaterials were reviewed; from the different views, the pathways of signal transduction of apoptosis include traditional pathway of signal transduction, the pathway of death receptor, and the pathway through mitochondrion. By the other way, the pathways of apoptosis caused by reactive oxygen species induced by biomaterials and apoptosis by affecting cell adhesion to biomaterials and so forth were discussed also. It indicates that the pathways to apoptosis due to biomaterials possess the characteristics of variety, intercrossing and multiplicity. It is essential for a research to inquire into the mechanism of apoptosis that is induced by biomaterials, and further into the manufacturing of biomaterials. This review is devoted to shedding light on the wide application of biomaterials in the therapy of human diseases, especially in the therapy of cancer that is closely related to apoptosis.
| [Advances in tracheal prothesis]
Shi, H. (2005), Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 19(4): 326-9.
Abstract: OBJECTIVE: To review the research advances of the tracheal prosthesis. METHODS: The articles concerned in recent years were extensively reviewed. RESULTS: There were still many arguments about the use of tracheal substitutes. A variety of artificial trachea had been designed and assessed, but so far none of them had been satisfactory for clinical use. The failures were mainly due to their high mortality and incidence of complication such as prosthetic defluvium, granuloma formation, local infection, air leakage, anastomotic stenosis or obstruction. CONCLUSION: The major causes of the poor effectiveness by the use of tracheal prosthesis are closely related to its biological compatibilities. The selected biomaterials and the design of prosthesis hold the key to a breakthrough in research and clinical use of tracheal prosthesis.
| [Alginate gel microchip for real-time monitoring of intracellular processes in bacterial and yeast cells]
Fesenko, D. O., T. V. Nasedkina, et al. (2005), Mol Biol (Mosk) 39(1): 96-102.
Abstract: A method of alginate-based hydrogel cell microchip manufacturing is proposed. The development of mild conditions for cell immobilization in microvolumes of non-toxic alginate gel allows extending the range of microorganisms used. Different approaches to cell analysis using microchip have been approved in pilot studies. By the example of Escherichia coli, Bordetella bronchiseptica and Saccharomyces cerevisiae it is shown that cell microchip can be successfully applied for monitoring of nucleic acid and protein synthesis in growing cells simultaneously using two fluorescent dyes. The influence of chloramphenicol on the nucleic acids and protein synthesis in five bacterial strains has been studied on the microchip. The microchip was also applied for the analysis of inducible fluorescent protein EGFP synthesis in E. coli cells, the correlation between the level of EGFP synthesis and concentration of the inductor in the medium has been established.
| [Alumina ceramic, a new biomaterial. Properties of the material and possible clinical range of application]
Heimke, G., P. Griss, et al. (1974), Arch Orthop Unfallchir 78(3): 216-26.
| [An experimental study of biomaterials resistant to calcinosis and thrombosis]
Krasovskaia, S. M., L. D. Uzhinova, et al. (1991), Grud Serdechnososudistaia Khir(7): 41-4.
Abstract: Creation of hemocompatible materials resistant to calcinosis for plastic cardiosurgery call for employment of combined methods of their evaluation in experiment. The present study deals with some biochemical and physico-chemical aspects of biomaterial calcification inhibition on reduction of their porosity by means of N-vinylpyrrolidone, and also on immobilization of diphosphonates, phosphonates, and anti-aggregants. The method of radiation copolymerization was employed for immobilization of active agents. The effects of different biotissue specimens of varying modifications (pig aortal valves and cattle pericardium) and of Lavsan (polyethyleneterephthalate) on coagulation factor activation were studied in vivo (in goat) and in vitro. The specimen surface was inspected prior to and after the contact with blood and plasma using the techniques of scanning electron microscopy and photoelectron spectroscopy. The influence of the modifications on the calcium and phosphorus accumulation were studied after subcutaneous implantation of the specimens to rats, and the aggregating capacity of blood platelets was determined in incubation of Lavsan treated with an anti-aggregant. Combined studies revealed the optimal modification routine and the most active agents enabling one to obtain biomaterials that not only are resistant to calcification but also possess good hemocompatibility.
| [An experimental study on the implantation of a biomaterial with electro-activity for replacement of hard tissue in bone]
Chen, L., Z. Chen, et al. (2001), Hua Xi Yi Ke Da Xue Xue Bao 32(4): 526-8, 554.
Abstract: OBJECTIVE: To assess the effects of a piezoelectric biological ceramic on osteogenesis. METHODS: Hydroxyapatite (HA) and piezoelectric biological ceramics (hydroxyapatite and barium titanate, HABT) were implanted in the jawbones of 5 dogs, and for sample collection, the dogs were killed separately at 1 week, 2 weeks, 1 month, 2 months and 3 months after implantation. The samples from a rhesus monkey and a blank control were collected 34 months after implantation. The implanted samples and surrounding tissues were subjected to histological observations using light microscopy (LM) and scanning electronmicroscopy (SEM) were made. RESULTS: Compared with the control groups, the HABTs promoted osteogenesis significantly. One week after implantation, new bone tissues were found on the surface vertical to the longitudinal direction of HABT; more bone tissues were found after 2 weeks. HABTs induced the bone tissues to arrange orderly. After two years and ten months of implantation, the piezoelectric bioceramic and bone became monolithic, and the structure of bone was normal. CONCLUSION: HABTs could promote osteogenesis.
| [Animal experiments and cell culture studies on stapes reconstruction with diverse biomaterials]
Dost, P. (2000), Laryngorhinootologie 79(3): 193.
| [Application and characteristics of biomaterials commonly used in plastic surgery--current status and prospects]
Zou, L., D. Zhang, et al. (1998), Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi 14(4): 303-5.
| [Application of a stand-alone interbody fusion cage based on a novel porous TiO2/glass ceramic--2: Biomechanical evaluation after implantation in the sheep cervical spine]
Korinth, M. C., T. Hero, et al. (2005), Biomed Tech (Berl) 50(4): 111-8.
Abstract: Animals are becoming more and more common as in vivo models for the human spine. Especially the sheep cervical spine is stated to be of good comparability and usefulness in the evaluation of in vivo radiological, biomechanical and histological behaviour of new bone replacement materials, implants and cages for cervical spine interbody fusion. In preceding biomechanical in vitro examinations human cervical spine specimens were tested after fusion with either a cubical stand-alone interbody fusion cage manufactured from a new porous TiO2/glass composite (Ecopore) or polymethylmethacrylate (PMMA) after discectomy. Following our first experience with the use of the new material and its influence on the primary stability after in vitro application we carried out fusions of 20 sheep cervical spines levels with either PMMA or an Ecopore-cage, and performed radiological examinations during the following 2-4 months. In this second part of the study we intended the biomechanical evaluation of the spine segments with reference to the previously determined morphological findings, like subsidence of the implants, significant increase of the kyphosis angle and degree of the bony fusion along with the interpretation of the results. 20 sheep cervical spines segments with either PMMA- or Ecopore-fusion in the levels C2/3 and C4/5 were tested, in comparison to 10 native corresponding sheep cervical spine segments. Non-destructive biomechanical testing was performed, including flexion/extension, lateral bending and axial rotation using a spine testing apparatus. Three-dimensional range of motion (ROM) was evaluated using an ultrasound measurement system. In the native spine segments C2/3 and C4/5 the ROM increased in cranio-caudal direction particulary in flexion/extension, less pronounced in lateral flexion and axial rotation (p < 0.05). The overall ROM of both tested segments was greatest in lateral flexion, reduced to 52% in flexion/extension and to 16% in axial rotation. After 2 months C2/3- and C4/5-segments with PMMA-fusion and C2/3-segments with Ecopore-interposition showed decrease of ROM in lateral flexion in comparison to the native segments, indicating increasing stiffening. However, after 4 months all operated segments, independent from level or implanted material, were stiffer than the comparable native segments. The decrease of the ROM correlated with the radiological-morphological degree of fusion. Our evaluation of the new porous TiO2/glass composite as interbody fusion cage has shown satisfactory radiological results as well as distinct biomechanical stability and fusion of the segments after 4 months in comparison to PMMA. After histological analysis of the bone-biomaterial-interface, further examinations of this biomaterial previous to an application as alternative to other customary cages in humans are necessary.
| [Application of biomaterials in the treatment of osteosarcoma]
Kotoura, Y., T. Yamamuro, et al. (1987), Gan To Kagaku Ryoho 14(5 Pt 2): 1423-9.
Abstract: Eight patients with osteosarcoma was treated with an endoprosthetic replacement in combination with chemo- and radiotherapy. Among the 8 patients, 5 died because of lung metastasis but no local recurrence was observed. The functional evaluations of the surgical treatment were 3 excellent, 2 good and 2 poor and the device evaluations were: 4 good and 4 fair. For treatment by prosthetic replacement, the distal femur is the best site, while in proximal tibia, there is difficulty in attachment of the patellar ligament. Usually a hingeless prosthesis is better than a hinge type, but if the tumor resection is wide, a hinge type is better because it can give more stability. Among metals used, titanium alloy is better, while among ceramic materials alumina is good the type of material depending on the location and size of tumor resection. New biomaterials are being used more often in the treatment of osteosarcoma and in the future biomaterials will be not only applied in artificial joint but also in the repair or replacement of soft tissue and for various other purposes.
| [Application of elemental microanalysis for estimation of osteoinduction and osteoconduction of hydroxyapatite bone implants]
Dawidowicz, A., S. Pielka, et al. (2005), Polim Med 35(1): 3-14.
Abstract: Hydroxyapatite (HAp) ceramics based on calcium phosphates, chemical compounds being natural constructive element of bones is now regarded to be one of better implantation materials in osseous surgery and stomatology. HAp is poorly soluble and slowly resorbing in tissues material. Easiness of connecting of hydroxyapatite ceramics with other materials creates possibilities to produce new composites of chemical compounds containing calcium and easier resorbing. An important and till now not fully known problem is influence of hydrodroxyapatite grafts on the processes leading to production of calcium and phosphorus ions responsive for mineralization of bone tissue around the graft. Proliferation of osteoblasts and rate of osseous trabeculas production depends, among others, concentration of calcium and phosphorus ions. The main target of this study was the comparative analysis of the bone mineralisation rate after implantation of hydroxyapatite (HAp) and composites hydroxyapatite + beta tricalcium phosphate (HAp + TCP) and hydroxyapatite + calcium hydrosulfate (HAp + gypsum), on the basis of elemental microanalysis. Implantation studies were carried out on 24 rabbits. Sections were carried out 5, 9, 11 and 14 weeks after implantation of the tested materials. The carried out punctual analysis of the occurring elements and their topographic location (mapping) in bones after implantation showed essential differences among the tested grafts. Those differences were most significant after 5 and 14 weeks and depended on the rate of the tested materials resorption. On the basis of conducted macroscopic evaluation and scanning microscope assessment we can stated that the composite of HAp+TCP showed the best osteocunductive properties, while the best osteoinductive influence was shown by the composite HAp + gypsum.
| [Application research on dextran-based hydrogel and its drug controlled release]
Chen, F., Z. Wu, et al. (2005), Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 19(11): 919-22.
Abstract: OBJECTIVE: To introduce the development of dextran-based hydrogel and its drug delivery system in drug sustained and/or controlled release, and to investigate their application in tissue engineering. METHODS: Related literature was extensively reviewed and comprehensively analyzed. RESULTS: In recent years, great progress was made in the studies of dextran-based hydrogels and study on dextran-based intelligent materials became an investigative hotspot especially in tissue engineering. CONCLUSION: Dextran-based hydrogel is considered to be a good potential material in field of drug delivery and tissue engineering. Endowed with new characteristics, a series of intelligent biomaterials can be derived from dextran-based hydrogels, which can be widely used in biomedicine. Further study should be done on the industrialization of its interrelated production.
| [Applications of sol-gel method in preparation of biomaterials]
Chen, Z. and H. Zou (2001), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 18(4): 629-32.
Abstract: In recent years, there has been a great development in the applications of sol-gel method in preparation of biomaterials. In this article, the sol-gel process and its use in preparation of biomaterials are reviewed, and the authors also introduce their studies to be done. Finally, the future development trend are forecasted.
| [Arsenic in hydroxyapatites in gallstones from actively and passively smoking and non-smoking women]
Ahnert, B., J. Kwapulinski, et al. (2004), Przegl Lek 61(10): 1147-50.
Abstract: The investigation on the arsenic changes carried out in gallstones from 93 women (24 active smoking, 18 passive smoking, 51 no smoking women). The elemental composition of gallstones was determined by ICP-AES method. For smoking women in comparison to men the changes of given elements were different. Negative role of smoking in particular concerned accumulation of Mg, Si, P, As.
| [Arthroplasty for scaphotrapeziotrapezoidal arthrosis using a pyrolytic carbon implant. Preliminary results]
Pequignot, J. P., L. D'Asnieres de Veigy, et al. (2005), Chir Main 24(3-4): 148-52.
Abstract: INTRODUCTION: The authors propose a scaphotrapeziotrapezoidal (STT) arthroplasty using a discoid pyrocarbon implant. The aim of this prosthesis is to restore the scapho-trapezial mobility without destabilising the carpal bones (unlike with a simple resection of the distal scaphoid pole). METHOD: This technique was used in 15 cases from 1994 to 2002. 12 patients (10 females and 2 males), mean age 65 years) have been reviewed with a mean follow-up of 4 years (1 to 8). Surgical indication was pain refractory to medical treatment (average 8.5 on V.A.S.). Pre-operative mobility showed a loss of radial deviation and dorsal flexion. The severity of the pain did not allow evaluation of the pre-operative strength. Post-operative results were assessed with the EVAL computerised system, static and dynamic X rays were performed in all cases. RESULTS: Pain decreased to an average of 2. The mobility compared to the healthy side showed a slight loss of radial deviation (less than 10 degrees) and in wrist extension (less than 15 degrees). Grip strength was similar to the normal side, even during rapid exchanges. Pinch grip evaluation showed a slight decrease (0.8 kg) which did not compromise normal function of the first ray. No implant luxation was observed in the radiological study. Angular measurements did not show any modification in DISI and other static angles remained unchanged. Dynamic sagital and frontal views confirmed the good mobility of the prosthesis which adjusts its position to the scaphoid movements. CONCLUSION: The good results, the simple surgical procedure, the absence of complications, the lack of a need for any fixation or ligamentoplasty all confirm the advantages of this pyrocarbon implant in the treatment of STT arthrosis. Furthermore, in cases of failure, it is possible to use any other revision procedure.
| [Assessment of beta-tricalcium phosphate as a carrier for bone formation promoting agent, TAK-778-SR]
Ueda, K., F. Watanabe, et al. (2005), Nippon Hotetsu Shika Gakkai Zasshi 49(2): 211-20.
Abstract: PURPOSE: The aim of this study was to evaluate the combination of TAK-778-SR which was sustained-release microcapsules of a bone formation stimulant, TAK-778, and its carrier beta-tricalcium phosphate (beta-TCP) blocks (pore rates 60%, 75% respectively). The difference of their abilities in bone-formation was evaluated histomorphologically by varying the following conditions: with or without TAK-778, pore ratio of carrier and embedding period. METHODS: Nine-week-old female SD rats were used. After removing the parietal bone from the head with a trephine bar, the defects were refilled by beta-TCP blocks immersed with or without TAK-778 under the following conditions: saline solution, release microcapsules only, and release microcapsules with TAK-778 (TAK-778-SR). These rats were sacrificed after 5 and 10 weeks and their histological specimens were prepared. Morphological change was observed and the formation rates of each new bone were compared using an NIH imaging program. RESULTS: A significant amount of new bone was morphologically observed in all beta-TCP samples that were treated with TAK-778-SR. A high rate of new bone formation was confirmed in the 10-week samples (pore rate 75%, with TAK-778-SR) with the NIH imaging. CONCLUSIONS: 1. beta-TCP and release microcapsules did not disturb the recovery process. 2. Five- and 10-week samples (pore rate 60%) were absorbed marginally. 3. Absorption was observed in the 5-week samples (pore rate 75%), and it was accelerated further at 10 weeks. 4. An accelerating bone-formation effect of TAK-778-SR was confirmed and beta-TCP block was proved to be highly useful as a carriage material.
| [Autografts versus biomaterials for ossiculoplasty with normal stapes; a comparative analysis of functional outcome in 100 cases]
Malard, O., G. Daculsi, et al. (2001), Ann Otolaryngol Chir Cervicofac 118(4): 225-31.
Abstract: Ossicular graft is usually considered as the reference for surgical substitution in ossiculoplasties. Nevertheless, according to the infectious risks, nothing but autografts or synthetic prosthetic substitutes should be used nowadays. Authors compare hearing results for 100 patients after ossiculoplasty with either ossicular autograft or calcium-phospathe chain reconstruction. Audiometric results were retreived using both Glasgow Benefit Plot study and post-operative air-bone gap thresholds closure. Significant hearing improvement was statistically demonstrated in both conditions, and 60% of the patients had a post-operative hearing gain. Autograft ossicular reconstructions did not show to provide higher results. Biocompatibility and functionnal properties of calcium-phosphate materials retreived in this study, indicate that those ceramic substitutes should be considered as the best alternative to autografts.
| [Autologous bone grafts, allografts and biomaterials]
Ben Slama, L. (2005), Rev Stomatol Chir Maxillofac 106(3): 133-5.
| [Bioabsorbable osteofixation devices.]
Iera, D., A. J. Haddad, et al. (2005), Ann Chir Plast Esthet 50(6): 723-32.
Abstract: There is continued interest in the development of new biomaterials. The application of new implantable biomaterials requires intense research and thorough evaluation. Much time and effort has been required to overcome the risks and problems associated with the bioabsorbable devices. For surgical bone fixation, these materials were investigated since the 1960's. Different polymer properties were explored to ensure adequate strength and biocompatibility. High-molecular-weight bioabsorbable polymers were initially used, followed by addition of reinforcement materials. The most recent materials are self-reinforced, small yet strong devices. The newer generations contain bioactive substances such as antibiotics and growth factors. Bioabsorbable materials are constantly changing as we try to adopt the principles of tissue engineering. Surgeons are using new techniques to exploit these polymers and their bioabsorbable properties. It is hoped that this multidisciplinary approach of surgery and research will continue to help the further evolution of biomaterial science.
| [Bioactive films for biomaterial coating and intended for tissue engineering: new original methods?]
Schaaf, P. and J. C. Voegel (2002), Pathol Biol (Paris) 50(3): 189-93.
Abstract: Numerous functionalized biomaterials aimed to induce specific cellular or tissular responses have been developed in the last decade. They result often from a specific treatment of the interface of the material. Techniques like physisorption, covalent binding or deposition of a Langmuir-Blodgett film have been employed to modify surface properties. We describe here a novel approach based upon an alternated adsorption of polyelectrolytes (polyanions or polycations) leading to the build-up of a film. These films can be functionalized through protein insertion (ligands) or by covalent peptide bindings able to interact with cellular receptors. Combined with a high affinity for calcium or phosphate complexing properties such functionalized architectures could constitute an original way to favour osseointegration.
|First Page||Previous Page||Next Page||Last Page|