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  • Articles  (5)
  • biocompatibility  (5)
  • Technology  (5)
  • 1
    Electronic Resource
    Electronic Resource
    Flow cytometry for assessing biocompatibility (1998)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 41 (1998), S. 649-656 
    Details
    ISSN: 0021-9304
    Keywords: flow cytometry ; cell culture ; biocompatibility ; biomaterials ; implants ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Flow cytometry (FCM) was examined as a possible procedure for measuring in vitro the biocompatibility of implant materials for orthopedic and dental surgery. The human osteoblast-like cell line MG63 was grown on hydroxyapatite (HA) and P2O5 glass-reinforced HA composite discs and compared with the same cells grown on polystyrene culture dishes. While morphological observation at the light and electron microscopic levels showed no major deleterious effects, FCM indicated that cell size was somewhat reduced, particularly by growth on the HA composite. Moreover, this material also appeared to delay the progression of the cells from the G0/G1 into the S phase of the cell cycle. In addition to this low level of inhibition of cell growth relative to control cultures, FCM analysis also demonstrated that the glass-reinforced HA caused some down-regulation of the expression of osteocalcin and fibronectin, two antigens which play a vital part in the integrity and function of bone and soft connective tissue, respectively. These results thus show, first, that although HA and the HA composite used in these experiments were generally biocompatible, they nevertheless had certain suboptimal effects on the cells; and second, that FCM could be a highly useful procedure for effectively screening and evaluating important biological responses to implant materials. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 41, 649-656, 1998.
    Additional Material: 7 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    Glass peek composite promotes proliferation and osteocalcin production of human osteoblastic cells (1997)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 36 (1997), S. 137-144 
    Details
    ISSN: 0021-9304
    Keywords: PEEK ; composite ; biocompatibility ; cell culture ; osteoblasts ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: An isoelastic intramedullary implant has been developed using a composite of polyetheretherketone and 10% random, chopped E-glass fibers (GPEEK). The effect of this novel material on human bone cells has not been defined. The objective of this study was to test whether GPEEK supported the proliferation of the human bone cell line MG63, which exhibits osteoblastlike characteristics. Cells (1 × 105/mL) were propagated on GPEEK discs with three different surface roughnesses (3, 6, and 9 μm) and on polystyrene plates, for comparison. The reaction of MG63 osteoblastlike cells to the GPEEK polymer composite was analyzed by determination of cell yield, osteocalcin production, and levels of alkaline phosphatase. The viable cells that were retrieved from the GPEEK discs of all three surface roughness had an approximate sixfold increase in number. Osteoblastic function of the cells, indicated by osteocalcin production, was unimpaired after a 5-day culture on the three surfaces of GPEEK. The highest level of osteocalcin was produced by osteoblastic cells propagated on GPEEK with a 9-μm surface roughness. The levels of alkaline phosphatase of these cells were similarly greater for the different degrees of surface roughness. Overall, this study demonstrates that GPEEK supported proliferation of osteoblastlike cells and provided a favorable environment for the continued production of osteocalcin in vitro. © 1997 John Wiley & Sons, Inc. J Biomed Mater Res, 36, 137-144, 1997.
    Additional Material: 6 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Comparative histological evaluation of new tyrosine-derived polymers and poly (L-lactic acid) as a function of polymer degradation (1998)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 41 (1998), S. 443-454 
    Details
    ISSN: 0021-9304
    Keywords: poly(lactic acid) ; subcutaneous implantation ; tyrosine-derived polymers ; poly(DTE carbonate) ; poly(DTE adipate) ; biocompatibility ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Previous studies demonstrated that poly(DTE carbonate) and poly (DTE adipate), two tyrosine-derived polymers, have suitable properties for use in biomedical applications. This study reports the evaluation of the in vivo tissue response to these polymers in comparison to poly(L-lactic acid) (PLLA). Typically, the biocompatibility of a material is determined through histological evaluations as a function of implantation time in a suitable animal model. However, due to changes that can occur in the tissue response at different stages of the degradation process, a fixed set of time points is not ideal for comparative evaluations of materials having different rates of degradation. Therefore the tissue response elicited by poly(DTE carbonate), poly(DTE adipate), and PLLA was evaluated as a function of molecular weight. This allowed the tissue response to be compared at corresponding stages of degradation. Poly(DTE adipate) consistently elicited the mildest tissue response, as judged by the width and lack of cellularity of the fibrous capsule formed around the implant. The tissue response to poly(DTE carbonate) was mild throughout the 570 day study. However, the response to PLLA fluctuated as a function of the degree of degradation, exhibiting an increase in the intensity of inflammation as the implant began to lose mass. At the completion of the study, tissue ingrowth into the degrading and disintegrating poly(DTE adipate) implant was evident while no comparative ingrowth of tissue was seen for PLLA. The similarity of the in vivo and in vitro degradation rates of each polymer confirmed the absence of enzymatic involvement in the degradation process. A comparison of molecular weight retention, water uptake, and mass loss in vivo with two commonly used in vitro systems [phosphate-buffered saline (PBS) and simulated body fluid (SBF)] demonstrated that for the two tyrosine-derived polymers the in vivo results were equally well simulated in vitro with PBS and SBF. However, for PLLA the in vivo results were better simulated in vitro using PBS. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 41, 443-454, 1998.
    Additional Material: 8 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New anionic polyelectrolyte hydrogel for corneal surgery (1997)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 37 (1997), S. 548-553 
    Details
    ISSN: 0021-9304
    Keywords: hydrogel ; biocompatibility ; permeability ; complement activation ; AN-69 dialysis membrane ; synthetic biopolymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: A new high-water-content (78%) anionic polyelectrolyte hydrogel was obtained by phase inversion (demixion) of a polymer solution containing 9.0% poly(acrylonitrile sodium methallylsulphonate), 85.0% dimethylformamide, and 6.0% saline solution (0.9% NaCl). The hydrogel is permeable to water, saline, urea, creatinine, glucose, human albumin, and saline-dissolved oxygen. Investigation of the interactions between human serum and surfaces prepared with the new yielded hydrogel, compared to serum interaction with silica-free silicone (RTV), regenerated cellulose (Cuprophan), MMA/PVP copolymer (Lidofilcon), PMMA (Perspex), PTFE (Gore-Tex), and poly(acrylonitrile sodium methallylsulphonate) hemodialysis membrane (AN-69), showed the hydrogel and hemodialysis membrane (both prepared with AN-69 copolymer) to be the only materials devoid of complement (C′)-activating ability. © 1997 John Wiley & Sons, Inc. J. Biomed Mater Res, 37, 548-553, 1997.
    Additional Material: 2 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    The interface of bone microstructure and an innovative coating: An X-ray diffraction study (1998)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 40 (1998), S. 86-91 
    Details
    ISSN: 0021-9304
    Keywords: X-ray diffraction ; ceramic ; external fixation ; coating ; biocompatibility ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The in vivo compatibility and degradation aspects of an innovative coating to be sprayed onto titanium implants were investigated. The surface of fluorinated apatite (fHA), consisting of fluorhydroxyapatite plasma sprayed in a vacuum atmosphere, was treated with carbonate to improve its biological compatibility. fHA coating was compared with titanium implants coated (a) with hydroxyapatite (HA) by the traditional plasma spraying, and (b) with titanium oxide (TiOx). Screw-shaped implants were inserted in the cortical bone of sheep tibiae. X-ray diffraction (XRD) analysis of bone tissue and coatings was carried out at 2, 4, 12 and 36 weeks after surgery. The crystallographic habit of the implant-facing bone, as well as the structural stability of the coating, were evaluated. For each time period and type of ceramic bone apatite lattice at the interface, no significantly different reference apatite lattice and no foreign peak were recorded. Two weeks after implantation, the bone at the interface was strongly unmineralized in all samples; after 4 weeks, poorly mineralized bone microareas decreased. At 12 weeks, the newly formed bone tissue at the interface with both the new coating and HA coating was shown to be fully mineralized; this crystallographic habit was retained at 36 weeks, when particle release from the tested material was lower compared to the controls. The XRD pattern of bone apatite surrounding the coating particles was unmodified. The innovative coating did not alter the mineralization process at the interface. It improved implant osteointegration, mainly due to a limited release of particles. Consequently, clinical performance of external fixation treatment could be improved by modifying the chemical composition of the implant surface. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 40, 86-91, 1998.
    Additional Material: 2 Ill.
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