RESUMO
Objective: To construct an antibacterial peptide controlled release coating for percutaneous implant and to study its release and antibacterial properties. Methods: TiO2 nanotube specimens were prepared by anodizing. PDLLA was used as the retarder and HHC-36 as the antibacterial peptide, PDLLA-HHC-36 were loaded on TiO2 nanotube surface by solvent-casting technology. The surface form of the specimens was observed under SEM. Sustained release was analyzed by the release curves and the antibacterial effect was examined with inhibition zone test. Results: TiO2 nanotube specimens with 80-120 nm diameter were fabricated, the drug coating was observed under SEM. The drug loaded specimens showed 15 days sustained release in vitro and inhibition zone about 15 mm in diameter was found in the test for at least 10 days. Conclusion: TiO2 nanotube specimens with PDLLA-HHC-36 controlled release coating has sustained-release and antibacterial properties.
RESUMO
<p><b>INTRODUCTION</b>The 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.</p><p><b>METHODS</b>Titanium 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.</p><p><b>RESULTS</b>Live, 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.</p><p><b>CONCLUSION</b>Titanium 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.</p>