Photothermal Effect-based Cytotoxic Ability of Melanin from Mytilus edulis Shells to Heal Wounds Infected with Drug-resistant Bacteria in vivo.

Owing to antibiotic abuse and the subsequent development of antibiotic resistance, bacterial infection has become one of the most persistent unresolved problems. New antibacterial agents, especially those that are environmental-friendly, are urgently needed. Melanin extracted by filtration centrifugation and acid and proteolytic hydrolysis was characterized using UV, FTIR, TEM, and XPS. Photothermal conversion was calculated, and the bacteriostatic effects, in vitro and in vivo , were assessed by plate counting and ratios (%) of wound areas. Natural melanin hydrolyzed by trypsin had good photothermal conversion effects, which resulted in superior bacteriostatic activities. The extracted melanin along with laser NIR irradiation at 808 nm promoted the healing of wounds infected by drug-resistant bacteria in vivo and was biocompatible according to toxicity tests in vivo and in vitro. The present findings indicated a safe and efficient method of developing natural antibacterial agents. [ABSTRACT FROM AUTHOR]