Tannic acid-loaded zinc- and copper-doped mesoporous bioactive glass nanoparticles: Potential antioxidant nanocarriers for wound healing

Polyphenols such as tannic acid (TA) with antibacterial and antioxidant activities have recently attracted significant attention for wound healing applications. Mesoporous bioactive glass nanoparticles (MBGNs) have also garnered considerable interest to be employed as nanocarriers of therapeutic biomolecules. This study focuses on the fabrication of TA-loaded MBGNs which were doped with two well-known biologically active elements, copper (Cu) and zinc (Zn). The effect of TA loading on the antioxidant and biological properties of the nanoparticles was investigated in the context of potential wound healing applications. As proven with various techniques, TA was successfully loaded on CuMBGNs and ZnMBGNs. With increasing TA concentration, the phenolic content in the nanoparticles was found to increase and CuMBGNs-TA and ZnMBGNs-TA were found to possess 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. The nanoparticles not only showed biocompatibility towards normal human dermal fibroblast (NHDF) cells, but they were also found to be hemocompatible. In comparison to CuMBGNs-TA leachates resulting in <i>in vitro</i> wound closure rate of ∼66 %-∼83 %, the dissolution products of ZnMBGNs-TA led to higher wound closure rate (>90 %). Our results demonstrate that CuMBGNs or ZnMBGNs are suitable nanocarriers for antioxidant TA and are candidates to promote wound healing.