TiO₂ Nanoparticles Loaded with Polygonum cuspidatum Extract for Wound Healing Applications: Exploring Their...

The dry roots of Polygonum cuspidatum contain resveratrol, a compound known for its antimicrobial and protective effects against oxidative stress, which is associated with impaired wound healing. In this study, titanium dioxide nanoparticles (TiO₂NPs) were loaded with a P. cuspidatum extract (TiO₂-loaded extract NPs), and the resveratrol release profile, hemocompatibility, antioxidant, cytotoxic, and antimicrobial activities were evaluated. The results demonstrated that TiO₂-loaded extract NPs exhibited antioxidant activity for DPPH (Inhibitory Concentration 50 (IC₅₀) = 62.31 mg Trolox Equivalent (TE)/mL) and ABTS⁺ (IC₅₀ = 4.8 mg TE/mL) assays, along with suitable hemocompatibility (3.02% at 10 mg/mL), in comparison with bulk TiO₂ NPs. Additionally, temperature influenced the resveratrol release over time. The P. cuspidatum extract alone showed strong antibacterial activity, with a Minimal Inhibitory Concentration (MIC) of 5 µg/mL, TiO₂-loaded extract NPs showed MIC values about 50 mg/mL, while bulk TiO₂ NPs exhibited no antibacterial effect against the tested strains. In contrast, the P. cuspidatum extract, the TiO₂-loaded extract NPs, and the bulk TiO₂ NPs did not demonstrate antifungal activity against Candida albicans and C. glabrata. Moreover, TiO₂-loaded extract NPs showed no cytotoxicity against the L-929 cell line at concentrations ranging from 1.5 to 150 µg/mL, unlike TiO₂ NPs, which exhibited high cytotoxic concentrations between 9.4 and 300 µg/mL. These findings suggest that TiO₂-loaded extract NPs effectively control the release of resveratrol and hold promises for applications in skin management and wound healing.