Evaluation of lignin and cellulose nanoparticles from bacterial-deconstructed sugarcane bagasse for effective quercetin delivery.

This study attempts an innovative biorefinery strategy to valorize sugarcane bagasse (SCB), producing nanomaterials for targeted drug delivery for the hydrophobic drug Quercetin. Bacterial strain Ectopseudomonas mendocina NITDDGIFE11 was employed to delignify Sugarcane bagasse (SCB) via batch-submerged fermentation, and analyzed for alteration in its structural and chemical content. The extracted biopolymers lignin and cellulose, characterized via FESEM, XRD, and FTIR, were transformed into their respective lignin (LNPI) and cellulose (CNPI) nanoparticles, found to have size averaging 279.4 and 207.25 nm via DLS and validated by HRTEM (<150 nm), XRD, FTIR, and FT-RAMAN. Both these nanoparticles were found to act as good delivery vehicles for Quercetin, where LNPI-Q demonstrated superior encapsulation (84.413 %) and loading capacity (36.30 %) relative to CNPI-Q and enhanced antioxidant activity compared to their free form. They exhibited sustained Quercetin release over 6 days and followed first-order kinetics. Reduced toxicity in HEK-293 cells revealed the host compatibility of the free LNP and CNP as a delivery system, while Quercetin-loaded forms exhibited significant anticancer activity, as examined in the triple-negative breast cancer cell line MDA-MB-231. Biocompatibility was further validated through haemolytic and phytotoxicity assays, confirming safety. Apart from biopolymer valorisation, a few interesting low molecular weight aromatic compounds (LMWACs) were also noticed in the bacterial-treated liquid fraction of SCB using LC-MS study. The outcome of this study not only provides a development of a drug delivery system from lignocellulosic biomass, but also may help in agricultural waste management and circular bioeconomy.