Hyaluronic acid-functionalized carboxymethyl dextran-coated melatonin nanoconjugates for targeted etoposide delivery in metastatic colon cancer: Extensive in-vitro investigation in HCT116 cell lines, antimicrobial efficacy, and anti-angiogenic potential in chick chorioallantoic membrane (CAM) assay.

Managing advanced colon cancer is challenging, requiring targeted therapies. This study presents a novel nanoconjugate system, HA-CMD@ETP-MLT-NCs, designed to deliver etoposide (ETP) specifically to colon cancer cells. The system consists of Hyaluronic Acid (HA)-Functionalized Carboxymethyl Dextran (CMD) coated with Melatonin (MLT). The nanoconjugates showed good stability, with a zeta potential of -29.90 mV and a particle size of 199.1 nm. They achieved an 80.3 % yield and a high drug entrapment efficiency of 93.4 %. In vitro release studies demonstrated pH-dependent drug release, with 73.4 % released at pH 5.5 (tumour-like environment) and 42.6 % at pH 7.4 (normal tissue) over 24 h. The nanoconjugates improved cellular uptake, induced apoptosis, and reduced reactive oxygen species (ROS) in HCT116 colon cancer cells. Flow cytometry showed a significant decrease in ROS levels, and lipid peroxidation inhibition increased to 56.67 %. These findings suggest that HA-CMD@ETP-MLT-NCs enhance etoposide delivery and reduce side effects. Further in vivo studies and clinical trials are needed to confirm its therapeutic potential.