Fabrication and characterization of bamboo shoot cellulose/sodium alginate composite aerogels for sustained release of curcumin

The feasibility of using unmodified bamboo shoot cellulose (BSC) to produce composite aerogels with sodium alginate (SA) in a fast and green way for sustained release of curcumin was explored for the first time, in which calcium ion-induced SA cross-linking could effectively retain the structural stability of aerogel skeleton. The aerogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. The encapsulation and release of curcumin from aerogels were studied while the antioxidant activity of encapsulated curcumin was investigated. Curcumin was evenly encapsulated in the composite aerogels and showed a sustained release behavior, followed the first-order rate expression. Interpenetrating network structures were built between BSC and SA mainly through hydrogen bonding, which could be further reinforced by the cross-linking of CaCO3 on the SA matrix. The original characteristics of BSC in the composite aerogels were well retained. The thermal stability and mechanical properties of the composite aerogels were improved by Ca2+-induced cross-linking, while the uncross-linked composite aerogels exhibited better encapsulation efficiency and in vitro antioxidant activity. Overall, this study was the first to use cellulose from bamboo shoot to develop aerogels for drug delivery purposes. The cellulose/alginate composite aerogels were promising to be used as biocompatible carriers for drug and nutraceutical delivery.