Nanocellulose-assisted mechanically tough hydrogel platforms for sustained drug delivery.

The controlled delivery of the desired bioactive molecules is required to achieve the maximum therapeutic effects with minimum side effects. Biopolymer-based hydrogels are ideal platforms for delivering the desired molecules owing to their superior biocompatibility, biodegradability, and low-immune response. However, the prolonged delivery of the drugs through biopolymer-based hydrogels is restricted due to their weak mechanical stability. We developed mechanically tough and biocompatible hydrogels to address these limitations using carboxymethyl chitosan, sodium alginate, and nanocellulose for sustained drug delivery. The hydrogels were cross-linked through calcium ions to enhance their mechanical strength. Nanocellulose-added hydrogels exhibited improved mechanical strength (Young's modulus; 23.36 → 30.7 kPa, Toughness; 1.39 → 5.65 MJm) than pure hydrogels. The composite hydrogels demonstrated increased recovery potential (66.9 → 84.5 %) due to the rapid reformation of damaged polymeric networks. The hydrogels were stable in an aqueous medium and demonstrated reduced swelling potential. The hydrogels have no adverse effects on embryonic murine fibroblast (3 T3), showing their biocompatibility. No bacterial growth was observed in hydrogels-treated groups, indicating their antibacterial characteristics. The sustained drug released was observed from nanocellulose-assisted hydrogel scaffolds compared to the pure polymer hydrogel scaffold. Thus, hydrogels have potential and could be used as a sustained drug carrier.