Amphiphilically engineered sodium deoxycholate based nanocomposite hydrogels with strong bactericidal and water absorption characteristics

Soft naturally occurring biodegradable low molecular weight (LMW) gels with high water absorption capacity and inherent antibacterial properties are significant for applications in wound healing patches, personal hygiene products and soft tissue regeneration. Herein, we report novel naturally occurring bile acid based nanocomposite hydrogels derived from sodium deoxycholate (NaDC) and reduced graphene oxide (rGO) as well as amphiphilic sodium dodecylsulfate (SDS) modified rGO. Introduction of rGO and SDS-rGO in the NaDC hydrogel induces π-π stacking in the nanocomposite hydrogels as well as enhances H-bonding interactions significantly yielding long range order as reflected by FTIR, sol-gel transition temperature, XRD, rheology and SEM studies. Among pure NaDC, rGO-NaDC and SDS-rGO NaDC xerogels, the latter is found to exhibit more than 10 times increased water absorption capacity compared to the pure NaDC gels which is attributed to the amphiphilic modification imparting increased H-bonding in the corresponding gel. Highest viscosity of SDS-rGO-NaDC hydrogels followed by rGO-NaDC and pure NaDC hydrogels further confirm the improved interactions. The emergence of antibacterial activity in SDS-rGO gel unlike its precursors as well as pure NaDC and rGO-NaDC gels is assigned to the dehydration induced bacterial cell death resulting from its high water absorption capacity imparted by its enhanced H-bonding. Thus, SDS-rGO NaDC gel obtained through a facile alteration of physical forces exhibiting antibacterial activity along with appreciable water absorption capacity and stability under applied stress indicates its strong applicability in biodegradable and biocompatible antibacterial wound healing patches.