Green synthesis of pH-sensitive magnetic bio-nanocomposite hydrogel based on galactomannan and sodium alginate for targeted colorectal cancer drug delivery

This study presents the development and characterization of pH-sensitive bio-nanocomposite hydrogel beads designed for the targeted delivery of doxorubicin (DOX) in colorectal cancer (CRC) therapy. The hydrogels were synthesized using galactomannan (GM) and sodium alginate (SA) matrices, reinforced with Fe 3 O 4 magnetic nanoparticles (MNPs) to enhance drug release control and therapeutic efficacy. The MNPs were functionalized through a green synthesis approach, utilizing copper oxide nanoparticles (CuO NPs) reduced and stabilized by orange peel extract (OPE) and carbon quantum dots (CQDs) derived from tea leaves. Characterization techniques (FTIR, XRD, SEM, VSM, PL) confirmed the successful synthesis of the carrier components. In vitro drug release studies demonstrated pronounced pH-sensitive behavior, with minimal release (<14 %) observed at pH 1.2 and substantial release (>88 %) at pH 7.4, indicating potential for targeted delivery to the colorectal region. The carrier exhibited significant antioxidant and antibacterial activity effects against Gram-negative Escherichia coli (>94 % inhibition) and Gram-positive Staphylococcus aureus (>99 % inhibition). Moreover, MTT assays revealed significant cytotoxicity effects of drug-loaded carriers against HT-29 CRC cells. These findings showed the promising potential of synthesized materials for targeted CRC therapy, offering a synergistic combination of controlled drug release, antioxidant properties, and antibacterial activity.