Characterization of Chitosan Nanocomplexes for the Delivery of Double Stranded MicroRNA to Glioblastoma Cells

Nanoscale drug delivery systems has gained significant traction, particularly for rare diseases still lacking a curative treatment such as glioblastoma. To complete the treating system of glioblastoma employing chitosan (CS) as a potential non-viral gene delivery vehicle, the present study aimed to assess the non-viral delivery of microRNA (miRNA) to glioblastoma cells (U251 cell line) and hence, its potential to inhibit the intracellular synthesis of proteins, while exerting a cytotoxic effect in this cell line. To this end a research, chitosan (molecular weight (Mw): 25 Kg/mol, degree of acetylation (DA): 29%) was used to form polyelectrolyte complexes with double-stranded miRNA (ds-miRNA) of [-NH3+]/[-PO4-] molar charge ratio (N/P = 20), and their transfection efficiency was assessed in vitro. The particle size distribution, ζ potential, stability and electrophoretic mobility of CS-miRNA complexes of varying N/P ratios were characterized. The transfection efficiency was evaluated from the cytotoxicity U251 cells using the MTT assay. A linear dose-response dependence was established and the cell viability upon treating the cells with CS-ds-miRNA complexes (200μM) for 72 hours was reduced up to 55.35%, thus indicating a targeted cytotoxic effect. Neither ds-miRNA nor chitosan applied in free form exerted a cytotoxic effect. The results demonstrate that chitosan (DA of 29%) has the ability to serve as a non-viral gene delivery vector for miRNA in glioblastoma cells. The in vitro proof of concept gained may serve as the basis for future animal and pre-clinical studies, in the roadmap for potential translation to clinical use in cancer therapy.