Surface functionalization of dialdehyde cellulose nanocrystals by radical polymerization as a dual pH and temperature...

In this study, cellulose nanocrystals were oxidized with sodium periodate to introduce dialdehyde groups and grafted with polymers to create a pH- and temperature-responsive nanocomposite for docetaxel delivery. The chemical structure, crystallinity, morphology, and thermal behaviors were investigated by FT-IR, XRD, FE-SEM, EDX, and TGA analyses. A central composite design optimized the docetaxel loading efficiency, identifying pH 7, 30 min, and 30 °C as ideal conditions. ANOVA validated the model's reliability with high correlation coefficients (R² = 0.9864, adjusted R² = 0.9711). Assessing the non-linear isotherm and kinetic models showed that the drug adsorption on the carrier was fitted with Langmuir and pseudo-second-order models, respectively. The release of the drug from the carrier showed a dual responsive behavior and released 68.47 % of the drug at high temperature during 6 h at pH = 5.6. The conformity of the drug release kinetics to the Korsmeyer-Peppas model indicated that the non-Fickian diffusion dominated the drug release. The in vitro cytotoxicity assay was performed on human breast cancer cell line (MCF-7), which showed that the carrier had significant biocompatibility, and the drug loaded carrier had outstanding killing capability against breast cancer cells.