Designing biocompatible xanthan gum hydrogels for pH-responsive vitamin B12 delivery

Vitamin B12 (VB12) plays a crucial role as an enzymatic cofactor in hemoglobin synthesis. Its deficiency can lead to serious neurological disorders. Despite its importance, current methods of VB12 delivery face challenges, including degradation in the gastrointestinal tract. Therefore, the development of a pH-responsive material for the controlled release of VB12 is crucial. This study aimed to synthesize hydrogels using xanthan gum (XG) and N,N-dimethyl acrylamide (DMA) as a pH-responsive system for VB12 delivery. The XG was vinyl-modified with GMA and characterized by FTIR and NMR. The hydrogels were synthesized through polymerization of modified XG with DMA. We evaluated these materials for their fragility, swelling degree in simulated gastrointestinal fluid, transport mechanism, and cell viability. SEM results revealed that the hydrogels had a porous structure with a diameter of 20 μm, sufficient for retaining and releasing VB12. Cytotoxic assay suggests that the hydrogels have no toxicity being considered biocompatible. In drug release tests, the hydrogels exhibited controlled release of VB12, with equilibrium reached within 2 h in gastric fluid and 8 h in intestinal fluid. These findings suggest that the hydrogels are promising candidates for safe and effective VB12 delivery, with good compatibility and responsiveness to pH changes.