OBJECTIVETo investigate the biocompatibility of polyurethane-BaFe(12)O(19) magnetic composite microsphere as a new endovascular embolization material.

METHODSThe biocompatibility of BaFe(12)O(19) particle was evaluated in vitro using Ames test, cell toxicity test, acute and subacute systemic toxicity test, hemolysis test, bleeding time and clotting time test and blood clotting function assay.

RESULTSAmes test showed that the MR values of this particle leaching solution were all less than 2 without mutagenicity. Cell toxicity test showed that leaching solution at different concentrations had grade I toxicity on L929 cells. Acute and subacute systemic toxicity test showed that the experimental animals had good general condition without obvious pathological abnormality. The hemolysis rate of experimental group was 2.43%, which met the ISO standard (no more than 5%). The bleeding time and clotting time in mice were comparable between the experimental group and control group (P>0.05). There were no significant differences in blood clotting function between experimental group and control group (P>0.05).

CONCLUSIONThe material has no obvious toxicity or mutagenicity, and does not cause hemolysis or hemopexis or affect the bleeding time and clotting time. Polyurethane-BaFe(12)O( 19) particle possesses satisfactory biocompatibility.

Animals ; Barium Compounds ; chemistry ; toxicity ; Biocompatible Materials ; Cell Line, Tumor ; Embolization, Therapeutic ; instrumentation ; Ferric Compounds ; chemistry ; toxicity ; Microspheres ; Polyurethanes ; chemistry ; toxicity ; Toxicity Tests

INTRODUCTIONThe risk of surgery-related infection is a persistent problem in orthopaedics and infections involving implants are particularly difficult to treat. This study explored the responses of bone and soft tissue to antimicrobial-coated screws. We investigated whether such screws, which have never been used to fix bony tissues, would result in a cytotoxic effect. We hypothesised that the coated screws would not be toxic to the bone and that the likelihood of infection would be reduced since bacteria are not able to grow on these screws.

METHODSTitanium screws were inserted into the left supracondylar femoral regions of 16 rabbits. The screws were either uncoated (control group, n = 8) or coated with a polyvinylpyrrolidone-polyurethane interpolymer with tertiary amine functional groups (experimental group, n = 8). At Week 6, histological samples were obtained and examined. The presence of necrosis, fibrosis and inflammation in the bony tissue and the tissue surrounding the screws was recorded.

RESULTSLive, cellular bone marrow was present in all the rabbits from the experimental group, but was replaced with connective tissue in four rabbits from the control group. Eight rabbits from the control group and two rabbits from the experimental group had necrosis in fatty bone marrow. Inflammation was observed in one rabbit from the experimental group and five rabbits from the control group.

CONCLUSIONTitanium surgical screws coated with polyvinylpyrrolidone-polyurethane interpolymer were associated with less necrosis than standard uncoated screws. The coated screws were also not associated with any cytotoxic side effect.

Animals ; Bone Screws ; Coated Materials, Biocompatible ; Polyurethanes ; toxicity ; Povidone ; toxicity ; Rabbits ; Surgical Wound Infection ; prevention & control ; Titanium

A polyetherurethane (PU) film containing 0.1% zinc diethyldithiocarbamate (ZDEC) is the international standard reference material for testing the in vitro cytotoxicity of polymer based biomaterials. Nowadays, culturing L929 or BALB/3T3 cells in direct contact or in an extract dilution condition is the most frequently using method for evaluating the cytotoxicity from biomaterials and medical devices. However, the results often vary, because it is directly related to the cellular functions and the mechanism of the toxicity of the contacting cells. In this study, 13 cell lines originating from various tissues were used to detect the cytotoxic activities of a PU film containing 0.1% ZDEC (PU-ZDEC). The correlation between the reactivity zone size and the relative cytotoxicity by quantifying the released total protein from each cell in the direct contact testing method was investigated. Hepa-1c1c7 cells demonstrated the highest sensitivity in the reactivity zone size, while CHO/dhFr(-) cells were the most sensitive in terms of the relative cytotoxicity. A correlation between the two processes in each cell line was not found (r=-0.478). In the extract dilution method, which involved cultivating the cells in the medium with various ZDEC concentrations prepared by diluting the PU incubation, the cytotoxicity increased with increasing ZDEC concentration in all cell lines. The BALB/ 3T3 cells demonstrated the highest sensitivity in the extract dilution method. No correlation in a comparison of the relative cytotoxicity from the direct contact method with the extract dilution method in each cell line, was found (r=-0.445). In this experiment, Hepa-1c1c7, BALB/3T3, CHO/dhFr(-) and L-929 cells among the 13 types of cell lines were the sensitive cell lines according to the two methods. The preliminary results suggest that a comparison of at least one or more cytotoxicity testing methods and many cell lines is necessary for an in vitro cytotoxicity test of biomaterials.
Animal ; Cell Line ; Cell Survival/drug effects ; Ditiocarb/*toxicity ; Hamsters ; Human ; Mice ; Polyurethanes/*toxicity ; Support, Non-U.S. Gov't ; Toxicology/*methods

The one-step method was adopted in this study to synthesize aliphatic polyurethane with 4,4-methylene dicyclohexyl diisocyanate(HMDI), 1,4-butanediol (BDO) and poly (tetrahydrofuran) (PTMG). The tests conducted on this material were: FIR spectrum, mechanical properties test, water contact angles test, hemolysis test and platelet adhesion test. Results showed that this material has a good tensile strength up to 30 Mpa, similar to aromaphatic polyurethane. But its tensile elongation, tensile permanent change, hydrophility are better than those of aromaphatic polyurethane. The hemolysis test and platelet adhesion test showed that it has good blood compatibility.
Animals ; Biocompatible Materials ; chemical synthesis ; chemistry ; toxicity ; In Vitro Techniques ; Materials Testing ; Platelet Adhesiveness ; drug effects ; Polyurethanes ; chemical synthesis ; chemistry ; toxicity ; Rabbits ; Spectroscopy, Fourier Transform Infrared ; Surface Properties ; Tensile Strength