Cytotoxicity of the Hydrogel Formulations
Cytotoxicity of XµM[AgNPs-PVP]-18%[P407] with Ag concentration ranging from 0 µM to 100 µM was evaluated using human dermal fibroblast (hFBs), a common cell line used to assess cytotoxicity of topical formulations. All formulations of XµM[AgNPs-PVP]-18%[P407] showed negligible cytotoxicity (Figure 7A), indicating excellent biocompatibility. The cell viability results were further quantified by counting live cell numbers using ImageJ, demonstrating >90% viability for all hydrogel formulations tested. Cytotoxicity was markedly improved for 50µM[AgNPs-PVP]-18%[P407] and 100µM[AgNPs-PVP]-18%[P407] compared to the aqueous solutions of 50 µM and 100 µM AgNPs-PVP (Figure 5C). This phenomenon could be attributed to the sustained release and thus controlled dosing of AgNPs-PVP from the hydrogel formulations, effectively reducing the concentration of AgNPs-PVP to which hFBs cells were exposed. The formulations of 50 µM and 100 µM[AgNPs-PVP]-18%[P407] were selected for further assessment of in vitro release studies given their excellent biocompatibility.