Novel thermal-regulation and temperature-responsive controlled-release fibermats with porous sheath-core structures

Active regulation of the wound microenvironment as well as on-demand drug delivery have proven to be effective ways to accelerate wound healing, and the development of advanced textiles offers feasibility. A novel fibermat with thermal-regulation and temperature-responsive controlled-release properties was fabricated by using coaxial electrospinning, consisting of porous sheath-core polylactic acid (PLA)/polyethylene glycol (PEG) fibers. The pore generation in the PLA shell of the PLA/PEG fiber was achieved through a phase separation method. The fiber diameter and pore size of the obtained fiber could be controlled by adjusting the flow rate of shell solution during electrospinning. Increasing the flow rate of shell solution form 0.8 mm min⁻¹ to 1.4 mm min⁻¹ resulted in an increase in fiber diameter from 4.8 μm to 15.3 μm, and an increase in pore size from 59.4 nm to 305.6 nm. Due to the high enthalpy and coverage of the PEG core, the PLA/PEG fibermats exhibited excellent thermal-regulation performance, with a surface temperature that was 2.5 °C–5.6 °C lower than that of pure PLA fibermat during heating process. On-demand release was achieved by directly controlling the core layer of the coaxial PLA/PEG fiber through temperature. The hydrophobicity of the PLA shell initially reduced burst release, followed by increased release as the temperature reached the phase transition temperature of PEG. Furthermore, this advanced fibermat demonstrated desirable moisture permeability, appropriate mechanical properties and good thermal stability, indicating broad potential applications in medical and health fields.