Dual-drug delivery system based on the hydrogels of alginate and sodium carboxymethyl cellulose for colorectal cancer treatment

To improve the efficacy of chemotherapy and relieve the pain associated with colorectal cancer, a dual-drug delivery system (DDDS) is proposed. In this system, methotrexate (MTX) loaded CaCO3 (CaCO3/MTX) and aspirin (Asp) are co-entrapped in the hydrogels of alginate (Alg) and sodium carboxymethyl cellulose (CMC) crosslinked with Ca2+. The hydrogels can protect the anti-cancer drug of MTX from being absorbed in stomach and small intestine and ensure their efficacy at the target site of colorectum. More importantly, dual pH-responsive drug delivery can be achieved by the DDDS. Because the pH varies at small intestine and colorectum of human body, dual pH-responsive delivery of Asp and MTX can be achieved at the two organs, respectively, in response to ambient pH. These finding are of significant importance for medical science and pharmaceutics. [Display omitted] •A dual pH-sensitive DDDS based on CaCO3 microspheres-entrapped hydrogels is designed.•The hydrogels can protect MTX from being absorbed in stomach and small intestine.•Kinetic release curves reveal that dual pH-responsive drug delivery can be achieved.•The developed DDDS exhibits excellent biocompatibility on normal cells.