Slow degrading hyaluronic acid hydrogel reinforced with cationized graphene nanosheets.

Graphene possesses a large surface area and offers high loading capacity for aromatic compounds. However, the load is quickly released in the absence of rate limiting diffusion barrier. In this study, we have explored the electrostatic interaction between polyanionic hyaluronic acid (HA) and cationized reduced graphene oxide (rGO) as a means to develop a reinforced hydrogel matrix. We tested if; (i) degradation kinetics of HA matrix can be modulated in the presence of cationized nanosheets, and (ii) reinforced hydrogel can offer controlled release of paclitaxel (PLX) stacked over the sheets. Successful synthesis, cationization and drug loading on graphene sheets were demonstrated using Raman and FT-IR spectroscopy. Reinforcement was confirmed through electron microscopy, neutron scattering and texture profile analyses. While incorporation of sheets enhanced the resistance of HA hydrogel against enzymatic digestion, a significant improvement in the biocompatibility of cationized rGO was obtained through this association. Reinforced gel offered sustained release of PLX up to 104 h which can further be extended by tuning its architecture.