Department of Medicine and Surgery, Nanomedicine Center, University of Milano-Bicocca, Piazza dell' Ateneo Nuovo, I-20126, Milan, Italy.
Nanotechnology. 2019 Jul 19;30(29):295702. doi: 10.1088/1361-6528/ab15f9. Epub 2019 Apr 26.
Antibacterial treatment is an essential issue in many diverse fields, from medical device treatments (for example prostheses coating) to food preservation. However, there is a need of novel and light-weight materials with high antibacterial efficiency (preferably due to the physical activation). Utilization of photo-thermally active nanoparticles can lead to novel and re-usable materials that can be remotely activated on-demand to thermally eradicate bacteria and mitigate biofilm formation, therefore meeting the above challenge. In this study polyvinyl alcohol (PVA) hydrogel films containing non-toxic and highly photo-thermally active Prussian blue (PB) nanoparticles were fabricated. The confocal microscopy studies indicated a uniform nanoparticle distribution and a low degree of aggregation. Upon near-infrared (NIR; 700 and 800 nm) light irradiation of PVA-PB films, the local temperature increases rapidly and reaches a plateau (up to ΔT ≅ 78 °C), within ≈6-10 s under relatively low laser intensities, I ≅ 0.3 W cm. The high and localized increase of temperature on the fabricated films resulted in an efficient antibacterial effect on Pseudomonas aeruginosa (P. aeruginosa) bacteria. In addition, the localized photo-thermal effect was also sufficient to substantially mitigate biofilms growth.
抗菌处理在许多不同的领域都是一个重要的问题，从医疗器械处理（例如假体涂层）到食品保鲜。然而，需要新型的、轻便的材料，具有高效的抗菌性能（最好是通过物理激活）。利用光热活性纳米粒子可以制备出新型的、可重复使用的材料，这些材料可以远程按需激活，以热方式消灭细菌并减轻生物膜的形成，从而满足上述挑战。在这项研究中，制备了含有无毒且具有高光热活性普鲁士蓝（PB）纳米粒子的聚乙烯醇（PVA）水凝胶薄膜。共聚焦显微镜研究表明纳米粒子分布均匀，聚集程度低。在近红外（NIR；700 和 800nm）光照射 PVA-PB 薄膜时，局部温度迅速升高并达到平台（高达 ΔT≅78°C），在相对较低的激光强度下，I≅0.3Wcm，约 6-10s 内即可达到。所制备的薄膜上的高温和局部升高的温度导致对铜绿假单胞菌（P.aeruginosa）细菌的有效抗菌作用。此外，局部光热效应也足以大大减轻生物膜的生长。
