Drug-loaded PLCL/PEO-SA bilayer nanofibrous membrane for controlled release

The bilayer nanofibrous membrane fabricated via electrospinning technique can be considered as an ideal structure for the treatment of chronic skin diseases and exudative wound dressings. Wound exudate would affect healing and increases the likelihood of infection at the same time. Therefore, it is essential to produce a kind of wound dressing with relatively high hygroscopicity which could absorb wound exudate and provide a relatively dry healing environment. Bilayer nanofibrous membranes of poly(L-lactide-co-ε-caprolactone)/tetracycline hydrochloride- polyethylene oxide/sodium alginate-zinc oxide (PLCL/TCH-PEO/SA-ZnO) with drug delivery potential were prepared by electrospinning for wound healing. Then, a cross-linking which involved soaking the samples in an aqueous solution containing strontium ions for 4 h was conducted. SEM images showed that membranes still maintained the peculiar nanofibrous structure. The spinning aid (PEO) used was removed in the cross-linked alginate without affecting the PLCL/TCH outer layer gave the membrane good mechanical properties and manageability. The hydrophilicity of the mats was tested to evaluate the ability of the bilayer membrane to absorb exudate from the wound. In vitro drug release suggested that antibacterial agents TCH could release continuously more than 10 days. The cross-linked fibrous membrane has improved mechanical properties and fluid repellency, thus representing a barrier to the external environment and effective wound protection. Consequently, the bilayer fibrous scaffold with good hygroscopicity and drug release properties would have wide applications prospects for the treatment of chronic skin diseases and exudative wound dressings.