|Articles about Biomaterials|
|First Page||Previous Page||Next Page||Last Page|
| [Effect of different shape and material of intraocular lens on posterior capsule opacification]
Szalinski, M., J. Oficjalska-Mlynczak, et al. (2005), Klin Oczna 107(1-3): 156-8.
Abstract: In this paper we compare 4 groups of intraocular lenses: PMMA, silicone, hydrogel, acrylic and their influence on posterior capsule opacification is discussed. The possible clinical consequences of different shape in optic part of intraocular lens is also described. This article contains also a short presentation of posterior capsule opacification mechanism and intraocular lens materials biocompatibility in in-vivo and in-vitro experiments.
| [Effect of RGD peptide on adhesive stability of human umbilical vein endothelial cell on polyethylene terephthalate surface]
Wu, Z., K. Dian, et al. (2005), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 22(3): 456-8.
Abstract: In this study for exploring the effect of RGD peptide on adhesive stability of endothelial cells biomaterial surface, all materials were divided into three groups, RGD group (PET covalently grafted synthetic RGD peptides), control group (PET precoated with fibronectin) and blank group (Non-coated surface). Cultured human umbilical vein endothelial cells (HUVECs) were seeded on the materials, then adhesive stability of HUVECs on the varied PET surfaces was observed under steady flow condition, and effects of shear stress and shear time on adherent cells were compared. The results showed that the resistance adherent endothelial cells to detachment by flow was shear stress and shear time dependent. Comparison three groups under the same condition revealed that the ECs retention rates of RGD-grafted or fibronectin-coated group were much higher than that of the non-coated group. Under 8.19 dyne/cm2 shear stress after 4h, retention rates were 13.73% (blank group), 43.33% (RGD group) and 40.75% (control group) respectively. These data indicated that RGD peptide can improve the adhesive stability of endothelial cell on biomaterial and the effect of RGD in vivo needs further studies.
| [Effectiveness of hernioplasty with using a polypropylene mesh implant in treatment of postoperative ventral hernias]
Sedov, V. M., S. D. Tarbaev, et al. (2005), Vestn Khir Im I I Grek 164(3): 85-7.
Abstract: A new method of operative treatment of postoperative ventral hernias is proposed which provides reliable fixation of the implant along the whole line of the primary scar. It excludes its migration due to profound integration into all layers of the abdominal wall and reliable fixation at different levels and with sufficient distance from the hernia hilus. The method can be used for any size of the hernia hilus. This method of plasty of the anterior abdominal wall is especially indicated for great, inreducible hernias, for great defects of the abdominal wall and incarcerated postoperative hernias when continuous preoperative preparation is impossible. Long-term results of the operative treatment were analyzed in terms from 1 year to 3 years in 16 patients aged from 40 to 73 years of age (mean age 58+/-2.6 years) with great and giant postoperative hernias. No recurrences were noted.
| [Effects of biomaterials on immunoglobulins and biochemistry in serum of extracoporal circulation]
Zhu, M., Z. Wu, et al. (1998), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 15(1): 22-5.
Abstract: The polyvinyl chloride(PVC) tube coated with cellulose acetate(CA), polyether suffone(PES), polyurethane(PU), silicon rubber(SR) and polyester fibre(PETF) were put in contact with circular serum at 37 degrees C. According to different time-periods of exposure, the immunoglobulins (G.A.M), albumin(ALB), total protein (TP) and total cholesteral(Tch) in serum were measured by an IL-Monarch biomedical analyser. The results showed that the levels of immunoglobutins significantly decreased after the serum came in contact with CA, PETF, SR and that the levels of ALB, TP and Tch were significantly lower in the serum exposed to PETF while those in the serum exposed to other materials were normal. These changes may relate to the complement activation induced by different materials.
| [Effects of surface modification of intraocular lenses on foreign body reaction]
Okajima, Y., S. Saika, et al. (2005), Nippon Ganka Gakkai Zasshi 109(5): 267-73.
Abstract: PURPOSE: In order to improve biocompatibility, we investigated the effects of surface modification by 2-methacryloyloxyethyl phosphorylcholine (MPC) on the foreign body reaction of intraocular lens (IOLs). MATERIALS AND METHODS: Materials of the IOLs were polymethylmethacrylate, hydrophobic acryl, and MPC surface-modified hydrophobic IOLs (MPC modified acryl). In an in vitro study, cultured macrophages sampled from mouse intra-abdominal exudate were cultured on a plate for each IOL material. The cell density and morphology of attached cells on the IOL materials were investigated. In an in vivo study, each IOL material was implanted in the peritoneal space of mice and foreign body reaction was investigated with a light microscope and a scanning electron microscope. RESULTS: In the in vitro study, the cells on the MPC modified acryl IOL material were remarkably fewer than those on the plates of the other two IOL materials. Regarding the implanted IOL matrevials, MPC modified acryl IOL material showed more polynuclear giant foreign body cells in the early period than the other two IOL materials. CONCLUSION: MPC surface modification can reduce the foreign body reaction of IOLs and has the potential to improve biocompatibility of IOL materials.
| [Effects on the amount of total hemolytic complement levels(CH50) and immunoglobulin in serum induced by the implantation of biomaterials into rats]
Zhu, M., Y. Zeng, et al. (1999), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 16(3): 275-8.
Abstract: Three kinds of biomaterials, PES, YP and SR, were implanted into the subcutaneous tissue of rats and stayed there for 7, 14, 30, 60 and 90 days. Then using the immunity assaying system (Beckman, ICS) and the standard method of measuring the value of total hemolytic complement levels (CH50), we determined the values of immunoglobulin and CH50 in serum of rats. The results showed the amounts of IgG and IgA of rats with the implanted YP and SR materials were significantly higher than those of the control groups, and their value of CH50 was significantly lower than that of the control group. There was no significant difference between the PES group and the control group.
| [Electrochemical properties of biocompatible material hardness modifications on titanium and steel under mechanical loads]
Braun, W., U. Walter, et al. (2005), Biomed Tech (Berl) 50(4): 100-6.
Abstract: Friction corrosion may appear between different implant components or between implant and hard tissue. The sliding micro movements induce fretting wear corrosion and have been recently reported as a cause of joint prostheses failure. A surface coating is desirable, that retains the mechanical properties of the substrate, offers good biocompatibility and improves the fretting corrosion resistance. In this study it could be demonstrated that tantalum and niobium coatings fulfill the requirements. On titanium substrates the coating decreases the abrasion against PMMA, an orthopedic relevant material. Furthermore, in the case of medical steel substrates the biocompatibility and the corrosion properties are improved. The better abrasion-resistance is minimizing the release of allergological critical particles like nickel and chromium.
| [Elemental analysis of tattoo dyes-is there a potential risk from tattoo dyes?]
Schmitz, I. and K. M. Muller (2004), J Dtsch Dermatol Ges 2(5): 350-3.
Abstract: BACKGROUND: Tattoo dyes in current use can cause foreign body reactions. METHODS: There are no rules regulating the composition of tattoo dyes. We performed elemental analysis on a series of dyes obtained from tattoo studios to determine if any dangerous materials were present. The composition of the dyes was determined using scanning electron microscopy in combination with energy dispersive X-ray microanalysis (EDS). This technique demonstrates bets the presence of elements of the sodium family and proves the presence of various metals. It provides no insight in chemical structures or bonds. RESULTS: Elemental analysis revealed multiple metallic components in the dyes; these materials may be responsible for persistent foreign body reactions even years after being placed in the skin. Silicon, aluminium, titanium and copper were found in various yellow, green and red dyes. The composition of various dyes of the same colour from different sources was highly variable. CONCLUSIONS: The tattoo dyes currently in use contain a number of components which cannot be regarded as "tissue inert". Chronic foreign body reactions can be expected even after many years.
| [Elucidation of remodeling mechanisms in articular cartilage and cortical bone based on evaluation of mechanical properties, and development of novel artificial joints based on biomechanical evaluation of biocompatibility in materials]
Murakami, T. (2005), Fukuoka Igaku Zasshi 96(6): 271-3.
| [Enamel and dentin structures: the effects of demineralizing agents and the implications for the bonding of biomaterials]
Goldberg, M. (1984), Actual Odontostomatol (Paris)(147): 411-34.
| [Epithelialization of porous biomaterials with isolated respiratory epithelial cells in vivo]
Kaschke, O., H. J. Gerhardt, et al. (1995), Hno 43(2): 80-8.
Abstract: Extensive tracheal defects after prolonged assisted ventilation, trauma or large resections in tumor surgery are a challenge in plastic and reconstructive surgery. Defects which cannot be satisfactorily repaired reguine near of an alloplastic tracheal replacement. Previous experimental and clinical experiences in the development of an alloplastic tracheal prosthesis have demonstrated that the main cause for failure is the lack of an epithelial lining of luminal surfaces and inadequate biophysical properties of the prosthesis. With the use of a cell-seeding technique tested in vitro on biomaterials epithelialization of tracheal prostheses can be tested in vivo. In animal experiments isolated respiratory cells were seeded into implanted tubular prostheses of porous polyurethane or expanded polytetrafluorethylene. Light and scanning microscopic investigations then showed the tendency of epithelialization to occur on the luminal surfaces. Vigorous squamous epithelium cell layers that were single and (predominantly) multiple layers were found. Differentiated cilated or mucous cells were not detected in any case. The present results have shown that epithelialization of incorporated porous implants is possible. The realization of usable tracheal replacement for clinical practice must still be tested in further experiments.
| [Established aspects and current knowledge in biomaterials research]
Griss, P., J. Orth, et al. (1993), Z Orthop Ihre Grenzgeb 131(6): 488-95.
Abstract: A review of the currently clinically established biomaterials UHMWPE, Al2O3-ceramic, CoCr- and Ti-based alloys and HA-coatings is given on the basis of recognized and new insights. Advantages and disadvantages as well as prospectives (PE-disease, Ti wear, HA-resorption in vivo etc.) are discussed and documented with results from experimental and clinical experience. New surface hardening techniques for Ti-based alloys are mentioned. Experimental results and singular experience from clinical retrieval study of new plastics (PAEK, Triazin-resin) are presented. Composite materials as a basis for a new generation of isoelastic hip prosthesis stems are described at the end of this paper.
| [Evaluation of biomaterial surfaces by detection of mechanical and electrical inhomogeneities using scanning probe microscopy]
Ropke, C., B. Kopp, et al. (1998), Biomed Tech (Berl) 43 Suppl: 398-9.
| [Evaluation of tissue response to resorbable osteosynthesis materials in maxillofacial surgery. Prospective randomized clinical trial of therapeutic strategy]
Bouletreau, P., P. Jurdic, et al. (2005), Rev Stomatol Chir Maxillofac 106(5): 316-20.
| [Evidence of osteocalcin expression in osteoblast cells of mandibular origin growing on biomaterials with RT-PCR and SDS-PAGE/Western blotting]
Turhani, D., C. Item, et al. (2003), Mund Kiefer Gesichtschir 7(5): 294-300.
Abstract: A new approach to addressing difficult tissue reconstructive or replacement problems in the oral cavity is to engineer new tissue by using selective cell transplantation on polymer scaffolds. The current study characterized the osteoblastic nature of adherent mandibular cells on biomaterials, which could have a potential use as scaffolds for tissue engineering strategies. Cells of mandibular origin from one patient were cultivated on three different biomaterials (PepGen P-15 trade mark, Frios Algipore, and OsteoGraf/LD-700) for 7 and 14 days and osteocalcin expression was demonstrated by RT-PCR and SDS-PAGE/Western blotting. In order to explicitly characterize only the adherent cells on the biomaterials, we first separated the biomaterials with adherent cells from the culture plate before trypsinization. We could demonstrate that cell growth of adherent mandibular osteoblast-like cells was significantly higher on biomaterials with an organic component (PepGen P-15 trade mark) in comparison to Frios Algipore and OsteoGraf/LD-700, respectively. In conclusion, only the explicit study of adherent cells at the gene and protein levels gives information about the osteoconductivity of biomaterials.
| [Experimental comparative study of bioactive composite with polymeric matrix for applications to oculoplastic surgery for tissue replacement]
Franca, V. P., A. R. Figueiredo, et al. (2005), Arq Bras Oftalmol 68(4): 425-31.
Abstract: PURPOSE: To compare two new biomaterials: Composite 10% (Engineering School--Universidade Federal de Minas Gerais-UFMG-Brazil) and Composite 20% (Engineering School--Universidade Federal de Minas Gerais-UFMG-Brazil), with two similar materials as control: Medpor (Porex Surgical Inc.--USA) e Polipore (Homus Com. Ind. Ltda--BRASIL). METHODS: In vivo randomized experimental double blind study: a transconjunctival approach was performed in both cartilaginous superior orbital walls of 28 rabbits for 56 implants divided into 4 groups: GI: Composite 10%/Medpor; GII: Composite 10%/Polipore; GIII: Composite 20%/Medpor; GIV: Composite 20%/Polipore. The mean rate for implant time of permanence was 19.7 weeks. The Student's t test was used for statistical analysis. RESULTS: Revealed similar biocompatibility of all materials and none of the implants was extruded; one Composite 20% had partial exposure. Histomorphometry showed a greater bioactivity of the composites with significantly thicker fibrous encapsulation, with more collagen and fibroblasts, exuberant angiogenesis, and a lower inflammatory cell mean compared to controls. The presence of precipitation of a hydroxycarbonate apatite layer, which acts as an implant-tissue bond was confirmed. Composites presented a smaller tissular invasion index of the pores compared to controls. CONCLUSIONS: The composites showed a good biocompatibility and some additional advantage over the Medpor and Polipore controls.
| [Experimental determination of the wear of biomaterials used in the construction of hip arthroprosthesis]
Gualtieri, G. (1989), Chir Organi Mov 74(3-4): 121-5.
Abstract: The author reports the results of an experimental test using a "hip simulator" to evaluate the wear rate of hip prostheses. The following couplings were tested: Cobalt-Chromium-Molybdenum (CoCrMo)-Ultra High Molecular Weight Polyethylene (UHMWPE), Alumina (Al203)-Ultra High Molecular Weight Polyethylene (UHMWPE) and Alumina (Al203)-Alumina (Al203). The Results obtained emphasize that the tribologic properties of alumina are better than those of the other materials tested.
| [Experimental study of the effect of new bone formation on new type artificial bone composed of bioactive ceramics]
Zhu, M., Y. Zeng, et al. (2005), Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 19(3): 174-7.
Abstract: OBJECTIVE: To investigate the osteogenic potential of four kinds of new bioactive ceramics combined with bovine bone morphogenetic proteins (BMP) and to explore the feasibility of using compounds as bone substitute material. METHODS: Ninety-six rats were divided into 4 groups (24 in each group). BMP was combined with hydroxyapatite (HA), tricalcium phosphate (TCP), fluoridated-HA (FHA), and collagen-HA(CHA) respectively. The left thighs of the rats implanted with HA/BMP, TCP/BMP, FHA/BMP, and CHA/BMP were used as experimental groups. The right thighs of the rats implanted with HA, TCP, CHA, and decalcified dentin matrix (DDM) were used as control groups. The rats were sacrificed 1, 3, 5 and 7 weeks after implantation and bone induction was estimated by alkaline phosphatase (ALP), phosphorus (P), and total protein (TP) measurement. The histological observation and electronic microscope scanning of the implants were also made. RESULTS: The cartilage growth in the 4 experimental groups and the control group implanted with DDM was observed 1 week after operation and fibrous connective tissues were observed in the other 3 control groups. 3 weeks after implantation, lamellar bone with bone marrow and positive reaction in ALP stain were observed in the 4 experimental groups. No bone formation or positive reaction in ALP stain were observed in the control groups. The amount of ALP activity, P value, and new bone formation in the experimental groups were higher than those in the control group(P < 0.05). The amount of ALP activity, P value, and new bone formation in TCP/BMP group were higher than those in HA/BMP, CHA/BMP and FHA/BMP groups (P < 0.05). There was no significant difference in TP between the BMP treatment group and the control groups. From 5th to 7th week, new bone formation, histochemistry evaluation, and the level of ALP, P, TP value were as high as those in the 3rd week. CONCLUSION: New composite artificial bone of TCP/BMP, HA/BMP, CHA/BMP, and FHA/BMP all prove to be effective, but TCP/BMP is the most effective so that it is the most suitable biomaterial replacement of tissue.
| [Experimental study of using acellular dermal dermis instead of donor sclera in orbital implantation]
Chen, T., Y. Min, et al. (2005), Zhonghua Zheng Xing Wai Ke Za Zhi 21(3): 204-7.
Abstract: OBJECTIVE: To evaluate the histocompatability of homologous acellular dermal matrix as a wrapping material for a hydroxyapatite orbital implant and compare the speed of fibrovascular ingrowth in hydroxyapatite orbital implant wrapped with homologous acellular dermal matrix and homologous sclera respectively. METHODS: Twenty four New Zealand rabbits were divided into two groups randomly. One group is implanted with hydroxyapatite orbital implant wrapped with homologous acellular dermal matrix behind the globe, the other group with homologous sclera. The observation included immunological reaction of the globe postoperation. Biposies of implanted material were taken on weeks 1, 4, 8 and 12 postoperation for histopathological and electron microscope examination. RESULTS: Histological examination showed the homologous acellular dermal matrix has no immunological and inflammatory reaction after implanted in orbit. But the speed of fibrovascular ingrowth is a little slower than that of homologous sclera. CONCLUSIONS: The homologous acellular dermal matrix has the better histocompatability as an encapsulating biomaterial, it can be a new material instead of homologous sclera.
| [Experimental study on a novel esophageal prosthesis made of composite biomaterials]
Qin, X., Z. F. Xu, et al. (2003), Zhonghua Wai Ke Za Zhi 41(7): 541-4.
Abstract: OBJECTIVE: To design and develop a novel esophageal prosthesis by selecting appropriate biomaterials, developing special manufacturing techniques, and investigating the feasibility of replacement of cervical esophagus in mongrel dogs. METHODS: In accordance with the requirements of ideal esophageal substitutes, we designed a new type of esophageal prostheses. The inner stent were made with polyurethane of medical grade, and the outer surface of the prosthesis was coated with collagen-chitosan sponge. The silicone tube was used as a control. Thirteen adult mongrel dogs that were divided into two groups were used to establish the experimental models. RESULTS: In the experimental group (n = 8), the esophageal prostheses were completely incorporated with the native esophagus and adherent to the surrounding host connective tissues. Epithelial linings of varying degrees were formed on the luminal surface, and complete epithelization was seen in 1 month postoperatively. The granulation at the sites of the anastomosis in this group was less significant than that of the control group. One dog has been surviving for 12 months up to now without any complications. In the control group (n = 5), esophageal epithelial was not observed on the luminal surface, constriction of the regenerated esophagus progressed and all the dogs died within 2 months after operation. CONCLUSION: These observations suggest that this esophageal prosthesis made of composite biomaterials has high biocompatibility and potential for long-segment esophageal reconstruction, which is promising for the clinical repair of esophageal defects.
|First Page||Previous Page||Next Page||Last Page|