Exploring the potential of a thermosensitive in situ gel with Periplaneta americana extracts for efficient wound healing

The primary aim of this study was to fabricate a wound healing thermosensitive <i>in situ</i> gel containing <i>Periplaneta americana</i> extract (PAE), which is widely utilized clinically due to its anti-inflammatory and skin regeneration effects. The thermosensitive <i>in situ</i> gel was prepared using F127 and F68 at concentrations of 17.5% (w/v) and 3.75% (w/v) respectively. The physicochemical properties of the PAE-loaded gel was characterized by DSC, scanning electron microscopy, and FTIR. Additionally, the <i>in vitro</i> release behavior and the <i>in vivo</i> wound healing effects were also investigated. It was observed that the thermosensitive <i>in situ</i> gel exhibited a sol-gel transition temperature of approximately 32.5 °C ± 0.4 °C, and the PAE existed in an amorphous state within the lyophilized gel. FTIR spectra indicated the formation of hydrogel bonds between PAE and F127/F68, signifying a sustained release profile. Further <i>in vivo</i> wound healing and inflammatory cytokine experiments revealed that the drug-loaded hydrogel demonstrated superior wound healing activity compared to other counterparts, by accelerating the reduction of endogenous inflammatory mediators such as TNF-α, MMP9, and IL-6, and inhibiting the MAPK/NF-κB pathway. The PAE-loaded thermosensitive <i>in situ</i> gel represents a promising pharmaceutical candidate for local wound healing applications, owing to its prolonged retention time.