Chitosan-Silica Modified Bio-Nanocomposites: Biocompatible pH-Responsive Nanocarriers for Controlled Doxorubicin Release in Leukemia Treatment

This study presents the synthesis and structural characterization of two novel coordination polymers (CPs). CP 1, [Mn(L)(bipy)(H2O)]n (H2L = 6,6'-disulfanediyldinicotinic acid, bipy = 2,2'-bipyridine), exhibits a monoclinic crystal structure in the P21 space group. CP2, an Eu(III)-based CP with the chemical formula [Eu(L)(DMA)2] (H3L = 5-(2-(4-carboxyphenyl)hydrazinyl)isophthalic acid, DMA = N, N-dimethylacetamide), forms a three-dimensional porous network with a dinuclear structure in the C2/c space group. Additionally, the study explores the encapsulation of CPs 1 and 2 within a CS(Chitosan)-SiO2 composite material for the pH-responsive and targeted delivery of the leukemia treatment drug doxorubicin (DOX). The findings reveal that the CS-SiO2@CP2@DOX nanocarrier exhibits significant drug loading and sustained release properties under varying pH conditions, particularly releasing a large amount of DOX at pH 6.8, effectively targeting tumor cells. In vitro experiments demonstrate that this system significantly inhibits leukemia cell proliferation and enhances apoptosis induction, especially in low pH environments. This study provides valuable insights into the application of metal-organic framework materials for drug delivery and leukemia treatment, highlighting the potential of this nanoplatform in leukemia therapy.