Effects of Cordyceps militaris extract and its mixture with silica nanoparticles on burn wound healing on mouse model

Cordyceps militaris extract (CM) has been widely applied in folk and modern medicines due to the content of various therapeutic compounds. However, the administration of CM to promote wound healing has not been elucidated. Herein, we first evaluate the healing efficacy of CM and the potential of improving its efficiency through small silica nanoparticles (SiO2NP). SiO2NP was synthesized using a micelle formation approach and characterized by TEM and FTIR. CM was dissolved in SiO2NP (roughly 20 nm) suspension, evaluated the cytotoxicity in human fibroblasts, and further applied to second-degree skin burn in mice. The wound closure rate was kinetically recorded and the histopathological recovery was evaluated. The results showed that CM and its CM-SiO2NP mixture at small concentrations (0-160 mu g/mL) were not toxic to human dermal fibroblasts. They showed similar effects on proliferating cells, accelerating wound closure, and recovering the skin structure. After 7 days of treatment, the wound closure rate in the CM group was approximately 2.4 times faster than the commercial form of sulfadiazine group and 4.1 times faster than the untreated group. The CM-SiO2NP mixture promoted the highest recovery of the epidermis and collagen deposition, resulting in the complete heal of skin structure after 15 days of treatments. These findings revealed the wound healing efficacy of the CM extract and the possibility of improving its therapeutic benefits through the combination with SiO2NP.