Development of Poly(sorbitol adipate)-<i>g</i>-poly(ethylene glycol) Mono Methyl Ether-Based Hydrogel Matrices for Model Drug Release.

Abstract

Hydrogels were prepared by Steglich esterification and by crosslinking pre-synthesized poly(sorbitol adipate)-<i>graft</i>-poly(ethylene glycol) mono methyl ether (PSA-<i>g</i>-mPEG) using different-chain-length-based disuccinyl PEG. PSA and PSA-<i>g</i>-mPEG were investigated for polymer degradation as a function of time at different temperatures. PSA-<i>g</i>-mPEG hydrogels were then evaluated for their most crucial properties of swelling that rendered them suitable for many pharmaceutical and biomedical applications. Hydrogels were also examined for their Sol-Gel content in order to investigate the degree of cross-linking. Physical structural parameters of the hydrogels were theoretically estimated using the modified Flory-Rehner theory to obtain approximate values of polymer volume fraction, the molecular weight between two crosslinks, and the mesh size of the hydrogels. X-ray diffraction was conducted to detect the presence or absence of crystalline regions in the hydrogels. PSA-<i>g</i>-mPEG hydrogels were then extensively examined for higher and lower molecular weight solute release through analysis by fluorescence spectroscopy. Finally, the cytotoxicity of the hydrogels was also investigated using a resazurin reduction assay. Experimental results show that PSA-<i>g</i>-mPEG provides an option as a biocompatible polymer to be used for pharmaceutical applications.