Preparation and\nCharacterization of Zein-Metformin/Gelatin\nNanofibers by Coaxial Electrospinning

Metformin is a drug commonly used for the treatment of\ntype 2 diabetes.\nHowever, it has been associated with damaging side effects when used\nover a long period of time. A potential solution to this problem is\nthe implementation of a prolonged-release system for metformin, which\nwould enhance the efficiency of the doses administered to patients.\nTo achieve this, it is necessary to use materials compatible with\nhumans. Electrospinning is an efficient technique that can be employed\nfor this purpose, utilizing solvents that are safe for human use.\nTherefore, the objective of this study was to prepare and characterize\na system for the prolonged release of metformin from zein and gelatin\nthrough coaxial electrospinning as well as to investigate its in vitro\nrelease. Metformin-loaded zein/gelatin coaxial nanofibers were prepared\nusing the coaxial electrospinning technique and then characterized\nby morphological, structural, and thermal analysis. Morphologically,\nmetformin-loaded zein/gelatin coaxial nanofibers were obtained with\nan average diameter of 322.6 ± 44.5 nm and a smooth surface.\nFourier transform infrared spectroscopy (FTIR) analysis showed band\nshifts at a higher wavenumber due to drug–protein interactions\nby hydrogen bonding between N–H and CO groups. Thermal\ngravimetric analysis (TGA) results suggested a possible interaction\nbetween materials due to an increase in the degradation temperatures\nof zein and gelatin when metformin was included. The transition of\nthe crystallinity of metformin to the amorphous form was also confirmed\nby differential scanning calorimetry (DSC). Coaxial nanofibers exhibited\nan encapsulation efficiency of 66% and a profile release that showed\nan initial release of metformin (40%) in the first hour, followed\nby a gradual release until it reached equilibrium at 60 h and a cumulative\nrelease of 97% of metformin. It was concluded that using the coaxial\nelectrospinning technique, it is possible to obtain nanofibers from\npolymeric solutions of zein and gelatin to encapsulate metformin,\nwith a potential application as a prolonged-release system.