Synthesis of hydrogels based on sterculia gum-co-poly(vinyl pyrrolidone)-co-poly(vinyl sulfonic acid) for wound dressing and drug-delivery applications

Much research is currently focused on designing functional materials derived from sterculia gum (SG) for sustainable development. Herein, poly(vinylsulfonic acid) (poly(VSA) and poly(vinyl pyrrolidone) (PVP) was grafted onto SG to form semi-interpenetrating network (semi-IPN) hydrogels for use in a drug-delivery (DD) system for doxycycline and in hydrogel wound dressings (HWDs). The hydrogels were characterized using FESEM, EDS, AFM, FTIR spectroscopy, ¹³C-NMR, and XRD. A range of biomedical properties were assessed by evaluating the interactions of the hydrogels with blood, mucosal tissues, and drugs. In the FTIR analysis, bands were observed at 1288 and 1149 cm⁻¹ due to asymmetric and symmetric stretching of SO₂ of poly(VSA) along, while in the ¹³C-NMR analysis, a peak at 63.21 ppm was noted due to a carbon attached to a sulfonic acid group of poly(VSA), confirming the polymerization reactions. The hydrogels were found to be biocompatible (hemolysis analysis = 2.54 ± 0.02%) and mucoadhesive (detachment force = 91.0 ± 8.0 mN). The semi-IPN HWDs exhibited antioxidant and antimicrobial properties. The dressings were permeable to oxygen and water vapor but impermeable to microbes. The diffusion mechanism of doxycycline from the dressings was found to follow a non-Fickian mechanism. The release profile could be best described by the Higuchi kinetic model. Overall, these properties revealed that the drug-encapsulating hydrogels could be applied as materials for DD and wound dressing.