Thermoresponsive nanofiber dressing for body heat-triggered drug release and exudate management in chronic wounds

This study developed a thermoresponsive PAN/CA/AVE nanofiber dressing through a single-step electrospinning process to address chronic wound challenges. By leveraging the phase transition of capric acid (CA) near body temperature (36.5°C), the dressing facilitated body heat-triggered, biphasic release of Apocynum venetum extract (AVE): an initial minimal burst of less than 23 %, followed by sustained delivery of 89 % by 48 h. The release kinetics, characterized by Fickian diffusion and matrix dissolution, along with swelling, exhibit a strong temperature dependence. Notably, release (89.0 % vs 66.0 %) and swelling (1148 % vs 641 %) are significantly enhanced at 36°C/37°C compared to 32°C, attributed to the melting of CA which disrupts polymer chains. The PAN network demonstrates excellent moisture management, with a water vapor transmission rate of 2780.5 g/(m²·24 h), which is 23 % superior to that of commercial dressings. The optimized dressing showcased uniform fiber morphology, thermal stability below 60°C, and good mechanical strength (15.8 ± 1.5 MPa). AVE exhibited broad-spectrum antimicrobial activity, achieving over 99 % inhibition against Staphylococcus aureus and Escherichia coli via membrane disruption. This single-platform dressing effectively integrates thermo-triggered drug release, swelling-mediated exudate control, and potent antimicrobial functionality, highlighting its significant potential for advanced chronic wound therapy. • The nanofiber dressing realizes two critical challenges including controlled drug release and effective exudate management. • The synergy of CA and PAN retains wound moisture and accelerates healing. • The nanofiber dressing also keeps high thermal stability.