Facile development, characterization, and optimization of new metformin-loaded nanocarrier system for efficient colon cancer adjunct therapy

Purpose: Metformin hydrochloride (MF) repurposing as adjuvant anticancer therapy for colorectal cancer (CRC) proved effective. Several studies attempted to develop MF-loaded nanoparticles (NPs), however the entrapment efficiency (EE%) was poor. Thus, the present study aimed at the facile development of a new series of chitosan (CS)-based semi-interpenetrating network (semi-IPN) NPs incorporating Pluronic (R) nanomicelles as nanocarriers for enhanced entrapment and sustained release of MF for efficient treatment of CRC. Methods: The NPs were prepared by ionic gelation and subsequently characterized using FTIR, DSC, TEM, and DLS. A full factorial design was also adopted to study the effect of various formulation variables on EE%, particle size, and zeta-potential of NPs. Results: NPs had a spherical shape and a mean particle size ranging between 135 and 220 nm. FTIR and DSC studies results were indicative of successful ionic gelation with the drug being dispersed in its amorphous form within CS-Pluronic (R) matrix. Maximum EE% reaching 57.00 +/- 12.90% was achieved using Pluronic (R)-123 based NPs. NPs exhibited a sustained release profile over 48 h. The MF-loaded NPs sensitized RKO CRC cells relative to drug alone. Conclusion: The reported results highlighted the novel utility of the developed NPs in the arena of colon cancer treatment.