Wijesundera Samurdhi A, Jayawardana Kalana W, Yan Mingdi
Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States.
ACS Appl Nano Mater. 2022 Aug 26;5(8):10704-10714. doi: 10.1021/acsanm.2c02047. Epub 2022 Jul 19.
Silver nanoparticles (AgNPs) are potent antimicrobial agents, but their utility is limited due to their relatively high cytotoxicity. In this work, we used trehalose as the ligand to reduce the cytotoxicity of AgNPs without affecting their antimicrobial activities. Trehalose is a disaccharide that is unique to mycobacteria. We showed that trehalose-functionalized AgNPs, AgNP-Tre, drastically increased the viability of A549 cells, especially at high concentrations, for example, from 4% for AgNPs to 67% for AgNP-Tre at 64 g/mL. The trehalose ligand slowed down the release of silver, and the amount of silver released from AgNP-Tre was less than half of that from AgNPs in the culture medium. Intriguingly, while the maltose (Mal) or tri(ethylene glycol) (TEG) ligand reduced the antibacterial activity of AgNPs against (minimal inhibitory concentration (MIC) of AgNP-Mal and AgNP-TEG: 4 g/mL for 7 nm AgNPs), the activity of AgNP-Tre was similar to that of AgNPs (MIC of AgNP-Tre: 1 g/mL for 7 nm AgNPs). Uptake experiments revealed that the intracellular concentration of AgNP-Tre was 87 and 114% higher than those of AuNP-Mal and AgNP-TEG, respectively. The increased uptake was attributed to the enhanced interactions of AgNP-Tre with mycobacteria promoted by the trehalose ligand.
银纳米颗粒（AgNPs）是强效抗菌剂，但其应用因相对较高的细胞毒性而受到限制。在本研究中，我们使用海藻糖作为配体来降低AgNPs的细胞毒性，同时不影响其抗菌活性。海藻糖是一种分枝杆菌特有的二糖。我们发现，海藻糖功能化的AgNPs，即AgNP-Tre，显著提高了A549细胞的活力，尤其是在高浓度时，例如，在64 μg/mL时，AgNPs处理后的细胞活力为4%，而AgNP-Tre处理后的细胞活力为67%。海藻糖配体减缓了银的释放，培养基中AgNP-Tre释放的银量不到AgNPs释放量的一半。有趣的是，虽然麦芽糖（Mal）或三甘醇（TEG）配体降低了AgNPs对[具体细菌]的抗菌活性（AgNP-Mal和AgNP-TEG的最低抑菌浓度（MIC）：7 nm AgNPs为4 μg/mL），但AgNP-Tre的活性与AgNPs相似（7 nm AgNPs的AgNP-Tre的MIC：1 μg/mL）。摄取实验表明，AgNP-Tre的细胞内浓度分别比AuNP-Mal和AgNP-TEG高87%和114%。摄取量的增加归因于海藻糖配体促进了AgNP-Tre与分枝杆菌之间更强的相互作用。
