A new hydrogel to promote healing of bacteria infected wounds: Enzyme-like catalytic activity based on MnO2 nanocrytal

Manganese dioxide (MnO2) nanocrystal, a kind of nanomaterial with excellent enzyme-like catalytic properties, have been widely used in chemical, biological and pharmaceutical fields. It is composed of unique octahedral units that form a variety of tunnels and layered structures, which also lead to the emergence of different crystal forms and properties. In this study, different crystalline types of MnO2 were synthesized by different methods, and different substrates were used to study MnO2 catalytic ability of H2O2. β- MnO2 nanocrystal had nearly 50% oxygen, among which adsorbed oxygen accounted for nearly 65%, so it exhibited the best catalytic performance and could promote oxidation catalytic reaction well. Furthermore, a functional MnO2 hydrogel was prepared using β-MnO2 as antibacterial agent and natural gelatin hydrogel as carrier. The antibacterial performance of the new hydrogel was further studied, and the survival rate of different species of bacteria was<5% after high concentration of MnO2 functional hydrogel. In the end, MnO2 functional hydrogel was applied to the wound treatment of mice infected with antibiotic resistant bacteria, and it was found that the wound healing rate of mice was nearly 100% on the 14th day, indicating that it had the potential of a new antibacterial dressing.