An Alternative Carbon Source from Cassava Residue Saccharification Liquid for In-Situ Fabrication of Polysaccharide Macromolecule/Bacterial Cellulose Composite Hydrogel: A Comparative Study

Bacterial cellulose (BC) is a biopolymer with vast application prospects, and its production demands culture media rich in carbon sources. Here, we researched a modified in situ strategy for preparing composite hydrogels comprising BC and sodium alginate (SA) or sodium hyaluronate (SH), termed as SA-BC and SH-BC, respectively. A new carbon source for BC generation was successfully developed from cassava residue saccharification liquid (CSL), in an attempt to better exploit the residue and decrease the costs of BC production. SA or SH was mechanically hydrogen-bonded with BC nanofibers to form porous nanostructures. Compared to the native BC, the mechanical strength of SH-BC with 1% SH was 61% higher and the thermal stability was also improved. A considerable difference in the cumulative drug-release rate of 93% in 66 h revealed that SA-BC with 0.5% SA exhibited a higher pH sensitivity due to its abundant fibrous layers, the -COO - -electrostatic repulsion, and the weakened hydrogen-bonding at pH 7.4. Such in situ-derived composite hydrogels could provide insights for BC functionalization and advance understanding of polysaccharides’ conversion to biomaterials with favorable biocompatibility and sustainability.