Rajendran R, Sreekumar Sweda, Sudhakar Asa, Sreekumar Soumya
Department of Microbiology and Bioinformatics, CMS College of Science and Commerce, Coimbatore, India.
Pak J Biol Sci. 2011 Mar 1;14(5):336-43. doi: 10.3923/pjbs.2011.336.343.
Biomaterial-centred bacterial infections present common and challenging complications with medical implants like ureteral stent which provide substratum for the biofilm formation. Hence the purpose of this study is to make antibacterial stent surface with biodegradable polymer (tocopherol acetate) and anti-infective agents (norfloxacin and metronidazole) using a modified dip-coating procedure. This is done by impregnating the stent pieces in the anti-infective solution (a mixture of norfloxacin-metronidazole and polymer) for uniform surface coating (drug-carrier-coated stents). After coating, agar diffusion test was performed as qualitative test to find out the sensitivity of coated stents against the clinical isolates, Staphylococcus epidermidis and Escherichia coli. Quantitative test was measured by calculating the numbers of adhered bacteria on coated and uncoated stents by incubating the stent pieces in artificial urine. Difference in the number of viable bacteria adhered on the surface of coated and uncoated stents were statistically calculated using chi square test with p < 0.05 considered significant. The stent colonising ability of Staphylococcus epidermidis and Escherichia coli in a controlled environment chamber was determined using two-challenge dose of the isolates by in vitro challenge test. In qualitative test, the zone of inhibition around the coated stents showed sensitivity against the clinical isolates. In quantitative test, the number of adhered bacteria on the surface of coated stents was reduced to a significant level (p < 0.05). The polymer, tocopherol acetate is highly biodegradable in nature. Due to its degrading ability in body tissues, it releases the anti-infective drugs at a constant and sustained rate.
以生物材料为中心的细菌感染是医学植入物（如输尿管支架）常见且具有挑战性的并发症，这些植入物为生物膜形成提供了基质。因此，本研究的目的是使用改良的浸涂工艺，用可生物降解聚合物（醋酸生育酚）和抗感染剂（诺氟沙星和甲硝唑）制作抗菌支架表面。这是通过将支架片浸渍在抗感染溶液（诺氟沙星 - 甲硝唑和聚合物的混合物）中以进行均匀的表面涂层（药物载体涂层支架）来实现的。涂层后，进行琼脂扩散试验作为定性试验，以确定涂层支架对临床分离株表皮葡萄球菌和大肠杆菌的敏感性。通过将支架片在人工尿液中孵育，计算涂覆和未涂覆支架上附着细菌的数量来进行定量试验。使用卡方检验统计计算涂覆和未涂覆支架表面存活细菌数量的差异，p < 0.05被认为具有统计学意义。通过体外挑战试验，使用两种挑战剂量的分离株在受控环境室中确定表皮葡萄球菌和大肠杆菌在支架上的定殖能力。在定性试验中，涂层支架周围的抑菌圈显示出对临床分离株的敏感性。在定量试验中，涂覆支架表面附着细菌的数量显著减少（p < 0.05）。聚合物醋酸生育酚在本质上具有高度的生物可降解性。由于其在身体组织中的降解能力，它以恒定且持续的速率释放抗感染药物。
