Institute of Technical Sciences of the Serbian Academy of Sciences and Arts , 11000 Belgrade, Serbia.
ACS Appl Mater Interfaces. 2013 Sep 25;5(18):9034-42. doi: 10.1021/am402237g. Epub 2013 Sep 9.
The global rise in the resistance of pathogens to conventional antibiotics has created an intensive search for alternative materials with antimicrobial properties. This study is performed with an intention to investigate the combined effects of poly(l-glutamic acid)-capped silver nanoparticles (AgNpPGA) and ascorbic acid (AscH) encapsulated within freeze-dried poly(lactide-co-glycolide) (PLGA) nanospheres to obtain a nanomaterial with simultaneous osteoinductive, antioxidative, and prolonged antimicrobial properties. The influence of PLGA/AgNpPGA/AscH particles on (i) viability and superoxide production of human umbilical vein endothelial cells in vitro, (ii) morphology and expression of osteogenic markers in osteoblastic MC3T3-E1 cells in vitro, and (iii) antimicrobial activity against a Gram-positive bacterium, methicillin-resistant Staphylococcus aureus, and a Gram-negative bacterium, Escherichia coli, was investigated. PLGA/AgNpPGA/AscH nanoparticles showed a superior and extended antibacterial activity against both types of bacteria. The nanoparticles appeared to be capable of delivering ascorbate to the cells, which was evidenced by the significant decrease in the level of superoxides in human umbilical vein endothelial cells and which could have a therapeutic potential in preventing oxidative stress. PLGA/AgNpPGA/AscH nanoparticles had a positive effect on MC3T3-E1 osteoblastic cells in vitro, promoting: (i) an intimate contact with the cells and preservation of their healthy morphologies; (ii) unreduced cell viability; and (iii) multiple-fold upregulation of two osteogenic markers: osteocalcin and type I procollagen. It is concluded that PLGA/AgNpPGA/AscH nanospheres present a promising new material for the treatment of infections and use in wound dressings and other prophylactic applications.
全球范围内病原体对抗生素的耐药性不断上升，促使人们积极寻找具有抗菌特性的替代材料。本研究旨在探索聚（L-谷氨酸）- capped 银纳米粒子（AgNpPGA）和抗坏血酸（AscH）在冻干聚（乳酸-共-乙醇酸）（PLGA）纳米球内的协同作用，以获得一种具有同时成骨诱导、抗氧化和延长抗菌特性的纳米材料。研究了 PLGA/AgNpPGA/AscH 颗粒对（i）人脐静脉内皮细胞体外活力和超氧化物产生的影响，（ii）成骨细胞 MC3T3-E1 细胞体外形态和成骨标志物表达的影响，以及（iii）对革兰氏阳性菌耐甲氧西林金黄色葡萄球菌和革兰氏阴性菌大肠杆菌的抗菌活性。PLGA/AgNpPGA/AscH 纳米颗粒对两种细菌均表现出优越和延长的抗菌活性。纳米颗粒似乎能够将抗坏血酸递送到细胞中，这从人脐静脉内皮细胞中超氧化物水平的显著降低得到了证明，这可能具有预防氧化应激的治疗潜力。PLGA/AgNpPGA/AscH 纳米颗粒对体外 MC3T3-E1 成骨细胞具有积极影响，促进了：（i）与细胞的紧密接触和保持其健康形态；（ii）细胞活力未降低；和（iii）两种成骨标志物：骨钙素和 I 型前胶原的多倍上调。总之，PLGA/AgNpPGA/AscH 纳米球是一种有前途的新材料，可用于治疗感染，并可用于伤口敷料和其他预防应用。
