Chitosan-based Bi-nanocomposites for oral drug overdose remediation: A critical review of polysaccharide properties, adsorption mechanisms, and clinical translation pathways.

Chitosan, a pH-sensitive cationic biopolymer possessing reactive amino groups (pKa 6.3), good biocompatibility, and functionalizability, makes an excellent adsorbent for biomedical application. Its combination with water hyacinth activated carbon through cross-linking provides synergistic adsorption that could be used in the treatment of drug overdose in oral medication. A systematic literature of Web of science, Scopus, PubMed and Google Scholar between January 2000 to April 2025, consisting of 59 original research papers and 41 non research papers. In this review, synthesis methods maintaining chitosan functional groups, adsorption mechanisms including electrostatic interactions, hydrogen bonding, hydrophobic effects, pore diffusion mechanism, relationship between structure and properties of nanocomposites, and their comparative environmental and biomedical performances will be discussed with the emphasis on challenges and translational strategies including in vitro physiological studies. The proposed review for the first time comprehensively discusses the field related to detoxification therapy and is distinct from other environment-oriented reviews.