Developing multifunctional zwitterionic-xanthan gum-anchored network copolymers for biomedical applications

Herein, mucoadhesive and biocompatible network hydrogels were developed by grafting zwitterionic polymer poly(2-[(methacryoyloxy)ethyl]dimethyl (3-sulfopropyl) ammonium hydroxide (poly(MEDSAH)) onto bacterial-derived polysaccharide xanthan gum (XG) via free radical graft polymerization, followed by crosslinking with N,N'-methylene bisacrylamide (NNMBA). The developed polymeric hydrogels were characterized using XRD, FTIR, ¹³C-NMR, TGA-DSC, FESEM, EDX and AFM analyses. FESEM and AFM analyses of these hydrogels demonstrated morphological heterogeneous features with surface roughness. Augmentation in the atomic percentages of sulfur and nitrogen atoms in the EDX spectrum of the polymers and the appearance of the characteristic spectral peaks (FTIR and ¹³C-NMR) of the sulfonic and quaternary ammonium groups of poly(MEDSAH) confirmed the grafting of zwitterionic polymer on the XG backbone. The crosslinked product exhibited modified XRD and thermal degradation (TGA-DSC) patterns, as compared to native XG polysaccharide. The slow and gradual release of ertapenem was observed through supra-molecular interactions and occurred more frequently under neutral to slightly basic conditions. The drug release from the network hydrogels followed non-Fickian type diffusion and was best defined by the Higuchi model. The developed hydrogel-based drug delivery (DD) carriers were found to be bioadhesive with 100.0 ± 5.0 mN force of adhesion, biocompatible with 1.078 ± 0.073% haemolytic index and antioxidant in nature by displaying 28.384 ± 0.963% inhibition during DPPH assay. The physicochemical and biomedical properties of XG-based hydrogels are indicative features for their utilization in gastrointestinal DD applications.