Rice bran extract-assisted synthesis of PMO/ZnO nanocomposites for enhanced gemcitabine loading and anticancer efficacy

This study investigates the green synthesis and detailed characterization of PMO/ZnO nanocomposites, using rice bran extract as a sustainable reducing agent to produce ZnO nanoparticles in-situ on periodic mesoporous organosilica (PMO). TEM analysis confirmed the uniform distribution of spherical ZnO nanoparticles, approximately 100 nm in size, within the PMO framework. BET measurements showed a significant decrease in surface area from 1087 m²/g to 498 m²/g after ZnO loading, along with a reduction in pore volume following the encapsulation of gemcitabine. This indicates efficient drug loading, with an efficiency of 49.7 %–54.7 %. Drug release experiments showed pH-responsive behavior, with faster release at acidic conditions (pH 5.6), similar to the tumor microenvironment. MTT cytotoxicity tests on HT-29 colon cancer cells, known for their sensitivity to gemcitabine, displayed enhanced antiproliferative effects with the drug-loaded nanocomposites compared to the free drug. These results underscore the potential of this green-synthesized nanocomposite system as a multifunctional platform, combining biocompatibility, targeted drug delivery, and environmental sustainability, thereby advancing prospects for effective cancer treatments.