Department of Life Sciences, University of Trieste, Via Giorgieri 1, Trieste I-34127, Italy.
Colloids Surf B Biointerfaces. 2011 Apr 1;83(2):331-9. doi: 10.1016/j.colsurfb.2010.12.002. Epub 2010 Dec 7.
A nanocomposite hydrogel based on natural polysaccharides and gold nanoparticles (ACnAu) has been prepared and its biological effects were tested in vitro with both bacteria and eukaryotic cells. Antimicrobial tests showed that AC-nAu gels are effective in killing both gram+ (Staphylococcus aureus) and gram- (Pseudomonas aeruginosa) bacteria. LDH assays pointed at a toxic effect towards eukaryotic cell-lines (HepG2 and MG63), in contrast with the case of silver-based hydrogels; cytofluorimetry studies demonstrated an apoptosis-related mechanism induced by increase of ROS intracellular level which leads to cell death after 24 h of direct contact with AC-nAu gels. In vivo biocompatibility has been evaluated in a rat model, investigating the peri-implant soft tissue reaction after 1 month of implantation. The results show that silver-containing samples induced a fibrotic capsule of the same average thickness of the control sample (devoid of nanoparticles) (∼50 μm), while in the case of gold containing materials the fibrotic capsule was thicker (∼100 μm), confirming a higher biocompatibility for silver-based samples than for gold-based ones.
一种基于天然多糖和金纳米粒子的纳米复合水凝胶（ACnAu）已经被制备出来，并在体外对细菌和真核细胞进行了生物效应测试。抗菌试验表明，AC-nAu 凝胶对革兰氏阳性（金黄色葡萄球菌）和革兰氏阴性（铜绿假单胞菌）细菌均有杀灭作用。LDH 测定表明，与银基水凝胶相比，该水凝胶对真核细胞系（HepG2 和 MG63）具有毒性作用；细胞荧光法研究表明，细胞内 ROS 水平升高诱导细胞凋亡相关机制，导致与 AC-nAu 凝胶直接接触 24 小时后细胞死亡。在大鼠模型中进行了体内生物相容性评价，研究了植入后 1 个月时种植体周围软组织的反应。结果表明，含银样品诱导的纤维囊厚度与不含纳米颗粒的对照组样品（∼50 μm）相同（∼50 μm），而含金材料的纤维囊较厚（∼100 μm），证实银基样品比金基样品具有更高的生物相容性。
