Photodynamic antibacterial application of TiO2/curcumin/hydroxypropyl-cyclodextrin and its konjac glucomannan composite films

Although photodynamic therapy (PDT) has great advantages for the treatment of bacterial infections, photosensitizers (PSs) often have many disadvantages that limit their application. Improving the shortcomings of PSs and developing efficient PDT antimicrobial materials remain serious challenges. In this study, a nanocomposite drug (TiO 2 /curcumin/hydroxypropyl-cyclodextrin, TiO 2 /Cur/HPCD) was constructed and combined with konjac glucomannan to form composite films (TiO 2 /Cur/HPCD films, KTCHD films). The stabilities of TiO 2 and Cur were improved in the presence of HPCD. The particle size of TiO 2 /Cur/HPCD was approximately 33.9 nm, and the addition of TiO 2 /Cur/HPCD enhanced the mechanical properties of the films. Furthermore, TiO 2 /Cur/HPCD and KTCHD films exhibited good biocompatibility and PDT antibacterial effects. The antibacterial rate of TiO 2 /Cur/HPCD was 74.46 % against MRSA at 500 μg/mL and 99.998 % against E. coli at 400 μg/mL, while it was adsorbed on the surface of bacteria to improve the effectiveness of the treatment. In addition, studies in mice confirmed that TiO 2 /Cur/HPCD and KTCHD films can treat bacterial infections and promote wound healing, with a highest wound healing rate of 84.6 % in the KTCHD-10 films + Light group on day 12. Overall, TiO 2 /Cur/HPCD is a promising nano-antibacterial agent and KTCHD films have the potential to be employed as antibacterial and environment-friendly trauma dressings.