Hoque Jiaul, Yadav Vikas, Prakash Relekar G, Sanyal Kaustuv, Haldar Jayanta
ACS Biomater Sci Eng. 2019 Jan 14;5(1):81-91. doi: 10.1021/acsbiomaterials.8b00239. Epub 2018 May 18.
Polymer-silver nanocomposites have emerged as an integral weapon to combat device-related infections. However, synthesis of the nanocomposites still remains a major challenge that often involves two-step process in which silver nanoparticles are synthesized ex situ. Additionally, polymers used in the nanocomposites are commonly not antimicrobial and biodegradable thus often lack bioactivity and biocompatibility. Herein we report highly active dual-function polymer-silver nanocomposites consisting of an inherently antimicrobial and biodegradable polymer in one-pot. A simple method of in situ reduction of a silver salt was employed to synthesize the silver nanoparticles (5-15 nm) from silver -toluenesulfonate in which the intrinsically biodegradable and antimicrobial polymer ,-dimethyl--hexadecyl ammonium chitin tosylate acted as reducing as well as stabilizing agent. The nanocomposite with the water-insoluble and organo-soluble polymer was simply painted onto surfaces via facile noncovalent immobilization. Notably, composite-coated surfaces inactivated both drug-sensitive and drug-resistant bacteria including pathogenic fungi at a much faster rate than polymer alone. The composites released active silver ions over an extended period of time and displayed remarkably long-lasting activity. In addition, surfaces coated with composites effectively inhibited both bacterial and fungal biofilm formation. Further, upon coating on catheter, the nanocomposites reduced methicillin-resistant (MRSA) burden both on catheter (>99.99% reduction) and in tissues surrounding the catheter (>99.999% reduction) in a mice model. These novel nanomaterials that showed negligible hemolysis toward human erythrocytes might be used as safe and effective antimicrobial coatings in biomedical device applications.
聚合物-银纳米复合材料已成为对抗与器械相关感染的一种重要手段。然而，纳米复合材料的合成仍然是一个重大挑战，通常涉及两步法，其中银纳米颗粒是在体外合成的。此外，纳米复合材料中使用的聚合物通常不具有抗菌性和生物可降解性，因此往往缺乏生物活性和生物相容性。在此，我们报告了一种一锅法制备的具有高活性的双功能聚合物-银纳米复合材料，该复合材料由一种具有固有抗菌性和生物可降解性的聚合物组成。采用一种简单的原位还原银盐的方法，以对甲苯磺酸银为原料合成了银纳米颗粒（5-15纳米），其中具有固有生物可降解性和抗菌性的聚合物——对甲苯磺酸-N,N-二甲基-N-十六烷基壳聚糖铵既作为还原剂又作为稳定剂。将这种具有水不溶性和有机可溶性的聚合物的纳米复合材料通过简便的非共价固定方法简单地涂覆在表面上。值得注意的是，复合涂层表面使包括致病真菌在内的药物敏感菌和耐药菌失活的速度比单独使用聚合物快得多。该复合材料在较长时间内释放活性银离子，并表现出显著的长效活性。此外，涂覆有复合材料的表面能有效抑制细菌和真菌生物膜的形成。进一步研究发现，在小鼠模型中，将纳米复合材料涂覆在导管上后，可降低导管上耐甲氧西林金黄色葡萄球菌（MRSA）的负荷（降低>99.99%）以及导管周围组织中的负荷（降低>99.999%）。这些对人类红细胞溶血作用可忽略不计的新型纳米材料，有望在生物医学器械应用中用作安全有效的抗菌涂层。
