Emulsion electrospinning is a flexible and promising technique for encapsulating various drugs into nanofibers. In this work, nanofibrous scaffolds were produced by emulsion electrospinning of either metformin hydrochloride (MH) or metoprolol tartrate (MPT) with poly(ε-caprolactone) (PCL) or poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV). The influence of preparation processes and emulsion compositions (polymer/drug/surfactant Span 80) towards the drug release behaviour of the scaffolds, together with their morphology, surface and thermal properties were evaluated. In vitro release studies indicated that the emulsion electrospun nanofibers significantly alleviated the burst release and produced a sustained release of drugs compared to the blended electrospun nanofibers. Between the two polymers studied, PCL demonstrated a better drug delivery carrier compared to PHBV, and MPT incorporated nanofibers showed less burst release than the others. The emulsion electrospun nanofibers were evaluated for their cytotoxicity using human mesenchymal stem cells and the cytotoxicity results showed that the emulsion electrospun MPT/PCL scaffold favoured cell growth compared to other tested scaffolds. Our study shows that emulsion electrospinning could be a better technique than normal blend electrospinning, especially in modulating the drug release properties by regulating the oil phase and water phase of the emulsions to obtain the desired drug release for the drug delivery systems. And PCL may be a better drug delivery carrier than PHBV.

Peripheral nerve injury is a serious clinical problem to be solved. There has been no breakthrough so far and neural tissue engineering offers a promising approach to promote the regeneration of peripheral neural injuries. In this study, emulsion electrospinning technique was introduced as a flexible and promising technique for the fabrication of random (R) and aligned (A) Poly(ε-caprolactone) (PCL)-Nerve Growth Factor (NGF)&Bovine Serum Albumin (BSA) nanofibrous scaffolds [(R/A)-PCL-NGF&BSA], where NGF and BSA were encapsulated in the core while PCL form the shell. Random and aligned pure PCL, PCL-BSA, and PCL-NGF nanofibers were also produced for comparison. The scaffolds were characterized by Field Emission Scanning Electron Microscopy (FESEM) and water contact angle test. Release study showed that, with the addition of stabilizer BSA, a sustained release of NGF from emulsion electrospun PCL nanofibers was observed over 28 days. [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt; MTS] assay revealed that (R/A)-PCL-NGF and (R/A)-PCL-NGF&BSA scaffolds favored cell growth and showed no cytotoxicity to PC12 cells. Laser scanning confocal microscope images exhibited that the A-PCL-NGF&BSA scaffold increased the length of neurites and directed neurites extension along the fiber axis, indicating that the A-PCL-NGF&BSA scaffold has a potential for guiding nerve tissue growth and promoting nerve regeneration.