Zhang Meng, Lo Edward C M
Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong SAR, China.
Front Microbiol. 2022 Sep 8;13:985708. doi: 10.3389/fmicb.2022.985708. eCollection 2022.
Some polymer-functionalized AgNPs (P-AgNPs) have been developed to optimize the biological properties of AgNPs. However, there are no studies in the literature comparing the differences in physicochemical and biological properties of AgNPs caused by various polymer-functionalizations and providing evidence for the selection of polymers to optimize AgNPs.
Two AgNPs with similar nano-size and opposite surface charges were synthesized and functionalized by seven polymers. Their physicochemical properties were evaluated by UV-Visible absorption, dynamic light scattering, transmission electron microscopy and inductively coupled plasma optical emission spectroscopy. Their biological properties against and human gingival fibroblast were investigated by MIC determination, time-dependent antibacterial assay, antibiofilm activity and cell viability assay. Silver diamine fluoride, AgNO and metronidazole were used as positive controls.
Comparative analysis found that there were no significant differences between P-AgNPs and AgNPs in nano-size and in surface charge. Raman spectroscopy analysis provided evidence about the attachment of polymers on AgNPs. For antibacterial property, among the negatively charged AgNPs, only polyvinylpyrrolidone (PVP)-functionalized AgNPs-1 showed a significant lower MIC value than AgNPs-1 (0.79 vs. 4.72 μg/ml). Among the positively charged AgNPs, the MIC values of all P-AgNPs (0.34-4.37 μg/ml) were lower than that of AgNPs-2 (13.89 μg/ml), especially PVP- and Pluronic127-AgNPs-2 (1.75 and 0.34 μg/ml). For antibiofilm property, PVP-AgNPs-1 (7.86 μg/ml, = 0.002) and all P-AgNPs-2 (3.42-31.14 μg/ml, < 0.001) showed great antibiofilm effect against biofilm at 5* to 10MIC level. For cytotoxicity, all negatively charged AgNPs and PVP-AgNPs-2 showed no cytotoxicity at MIC level, but significant cytotoxicity was detected at 2.5 to 10*MIC levels.
Among the polymers studied, polymer functionalization does not significantly alter the physical properties of AgNPs, but modifies their surface chemical property. These modifications, especially the functionalization of PVP, contribute to optimize the antibacterial and antibiofilm properties of AgNPs, while not causing cytotoxicity at the MIC level.
已开发出一些聚合物功能化的银纳米颗粒（P-AgNPs）以优化银纳米颗粒的生物学特性。然而，文献中尚无研究比较各种聚合物功能化导致的银纳米颗粒物理化学和生物学特性的差异，也未为选择优化银纳米颗粒的聚合物提供证据。
合成了两种具有相似纳米尺寸和相反表面电荷的银纳米颗粒，并用七种聚合物进行功能化。通过紫外可见吸收、动态光散射、透射电子显微镜和电感耦合等离子体发射光谱对其物理化学性质进行评估。通过最小抑菌浓度（MIC）测定、时间依赖性抗菌试验、抗生物膜活性和细胞活力试验研究了它们对[具体菌种]和人牙龈成纤维细胞的生物学特性。氟化银氨、硝酸银和甲硝唑用作阳性对照。
对比分析发现，P-AgNPs和银纳米颗粒在纳米尺寸和表面电荷方面没有显著差异。拉曼光谱分析提供了聚合物附着在银纳米颗粒上的证据。对于抗菌性能，在带负电荷的银纳米颗粒中，只有聚乙烯吡咯烷酮（PVP）功能化的AgNPs-1的MIC值显著低于AgNPs-1（0.79对4.72μg/ml）。在带正电荷的银纳米颗粒中，所有P-AgNPs的MIC值（0.34 - 4.37μg/ml）均低于AgNPs-2（13.89μg/ml），尤其是PVP-和普朗尼克127-AgNPs-2（1.75和0.34μg/ml）。对于抗生物膜性能，PVP-AgNPs-1（7.86μg/ml，P = 0.002）和所有P-AgNPs-2（3.42 - 31.14μg/ml，P < 0.001）在5倍至10倍MIC水平对[具体菌种]生物膜显示出强大的抗生物膜效果。对于细胞毒性，所有带负电荷的银纳米颗粒和PVP-AgNPs-2在MIC水平均无细胞毒性，但在2.5倍至10倍MIC水平检测到显著的细胞毒性。
在所研究的聚合物中，聚合物功能化不会显著改变银纳米颗粒的物理性质，但会改变其表面化学性质。这些修饰，尤其是PVP的功能化，有助于优化银纳米颗粒的抗菌和抗生物膜性能，同时在MIC水平不会引起细胞毒性。
