An in-situ fabrication of bamboo bacterial cellulose/sodium alginate nanocomposite hydrogels as carrier materials for controlled protein drug delivery

Sodium alginate-bacterial cellulose (SA-BC) is a nanocomposite hydrogel with multi-layered porous surfaces fabricated using an in-situ biosynthesis modification method. The enzymatic hydrolysate (EH) of glycerol-pretreated Moso bamboo (MBEH) was the carbon source for glucose substitution to generate SA-bamboo-BC. SA, a natural biological polysaccharide, was combined with BC at dosages of 0.25%, 0.5%, 0.75% and 1% through hydrogen bonding. Compared to the native BC, the addition of 0.75% SA, termed as SA-bamboo-BC-0.75, enhanced the thermal properties. The dynamic swelling/de-swelling were pH-dependent, with an increased swelling ratio (SR) of 613% observed at pH 7.4 but a lower SR of 366% observed at pH 1.2. These differences were attributable to the electrostatic repulsion of -COO−. Two protein-based model drugs were compared to estimate their drug-release properties. Bovine serum albumin (BSA) was adsorbed on lignin from MBEH through hydrophobic interactions, resulting in poor drug release. Lysozyme (LYZ) exhibited a higher drug release rate (92.79%) over 60 h at pH 7.4 due to the static attraction between LYZ and -COO− of SA-bamboo-BC-0.75. As such, SA-bamboo-BC nanocomposite hydrogel was shown to possess sufficient swelling, drug-release and biocompatibility for substrate use.