Design of a novel electrospun PVA platform for gene therapy applications using the CHAT peptide

The electrospinning of polymers has previously shown excellent potential for localised gene therapy. Thus, it was proposed that for the first time, the cell-penetrating CHAT peptide could be utilised to deliver DNA via electrospun nanofibres for localised gene therapy treatment. CHAT is an effective delivery system that encapsulates pDNA to form nanoparticles with the physicochemical characteristics for cellular uptake and protein generation. In this study, the production of smooth, bead-free PVA nanofibres by electrospinning was optimised through a Design of Experiments approach. Bead-free PVA nanofibres were consistently produced using the optimised parameters as follows: applied voltage (8 kV); collector-emitter distance (8 cm); polymer flow rate (4 µL/min); polymer concentration (9 wt% polymer); PVA M_W (146-180 kDa). PVA nanofibres were subsequently crosslinked in 1 vol% glutaraldehyde in methanol to confer stability under aqueous conditions with minimal change to morphology, and no compromise to biocompatibility. Nanoparticles of CHAT/pDNA were synthesised and incorporated into the crosslinked nanofibres via soak-loading. Evaluation studies indicated that 100% of the loaded cargo was released within 48 h from the nanofibres. Furthermore, the released pDNA retained structural integrity and functionality as confirmed by gel electrophoresis and transfection studies in NCTC-929 fibroblast cells. Taken together, this data demonstrates that delivery of CHAT/pDNA nanoparticles from electrospun PVA nanofibres represents a solution for localised gene therapy.