优化纳米银-PMMA 复合涂层，以提供强大的抗菌效果，同时最大限度地降低人骨髓基质细胞毒性。

Nanosilver-PMMA composite coating optimized to provide robust antibacterial efficacy while minimizing human bone marrow stromal cell toxicity.

机构信息

Division of Biology, Chemistry, and Materials Science, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD 20993, USA.

Joint Department of Biomedical Engineering, University of North Carolina-Chapel Hill and North Carolina State University, Raleigh, NC 27695, USA.

出版信息

Toxicol In Vitro. 2017 Oct;44:248-255. doi: 10.1016/j.tiv.2017.07.014. Epub 2017 Jul 21.

DOI:10.1016/j.tiv.2017.07.014

PMID:28739488

Abstract

Porous PMMA is a versatile biomaterial with good biocompatibility but high susceptibility to bacterial colonization, which we mitigated by utilizing immobilized antimicrobial silver nanoparticles (AgNPs). A uniform porous thin film was deposited onto silicon wafers by simultaneously ablating PMMA and silver (Ag) using pulsed laser deposition (PLD) optimized for minimal human cell toxicity and antibacterial efficacy. PMMA without Ag became heavily colonized by E. coli in simulated dynamic conditions, while Ag-containing samples prevented all colonization. ICP-MS analysis demonstrated that the amount of leached Ag after 24h under simulated in vivo conditions (with serum media at 37°C and 5% CO) increased in proportion to film thickness (and total silver content). 10,000, 14,000, and 20,000 laser pulse-deposited films released 0.76, 1.05, and 1.67μg/mL Ag, respectively, after 24h. Human bone marrow stromal cells (hBMSCs) grown directly on 10,000-pulse films (0.76μg/mL Ag released) for 24-h exhibited no cytotoxicity. Exposure to the remaining films produced cytotoxicity, necrosis, and apoptosis detected using flow cytometry. Examining both leachates and direct cell contact allowed us to develop an in vitro cytotoxicity test method and optimize a novel device material and coating to be nontoxic and bactericidal during both potential initial implantation and external use.

摘要

多孔聚甲基丙烯酸甲酯（PMMA）是一种具有良好生物相容性的多功能生物材料，但容易被细菌定植。为了解决这个问题，我们利用固定化抗菌银纳米粒子（AgNPs）来减轻细菌定植的影响。我们通过脉冲激光沉积（PLD）技术，同时将 PMMA 和银（Ag）烧蚀在硅片上，沉积出均匀的多孔薄膜。PLD 技术的优化参数旨在降低对人类细胞的毒性和抗菌效果。在模拟动态条件下，没有添加 Ag 的 PMMA 会被大肠杆菌严重定植，而含有 Ag 的样品则完全阻止了细菌的定植。ICP-MS 分析表明，在模拟体内条件下（37°C 和 5% CO 的血清介质），24 小时后浸出的 Ag 量与薄膜厚度（和总银含量）成正比。在 10000、14000 和 20000 个激光脉冲沉积的薄膜中，分别释放了 0.76、1.05 和 1.67μg/mL 的 Ag。在 10000 个脉冲沉积的薄膜（释放 0.76μg/mL 的 Ag）上直接培养人骨髓基质细胞（hBMSCs）24 小时后，细胞无毒性。暴露于剩余的薄膜会产生细胞毒性、坏死和凋亡，通过流式细胞术可以检测到。通过对浸出液和直接细胞接触的检测，我们开发了一种体外细胞毒性测试方法，并优化了一种新型装置材料和涂层，使其在潜在的初始植入和外部使用过程中均具有无毒和杀菌作用。