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Updated: Dec 20, 2025

Small Molecule Screening and Toxicity Testing in Early-stage Zebrafish Larvae
Published on: March 7, 2025
Characterization and toxicology evaluation of low molecular weight chitosan on zebrafish
Chih-Ming Chou1, Fwu-Long Mi1, Jiun-Lin Horng2
1Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan; Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
Abstract:
Chitosan is suggested as no or low toxicity and biocompatible biomaterial. Digestion of chitosan to reduce molecular weight and formulate nanoparticle was generally used to improve efficiency for DNA or protein delivery. However, the toxicity of low-molecular-weight chitosan (LMWCS) towards freshwater fishes has not been well evaluated. Here, we reported the toxic mechanism of LMWCS using zebrafish (Danio rerio) liver (ZFL) cell line, zebrafish larvae, and adult fish. LMWCS rapidly induced cytotoxicity of ZFL cells and death of zebrafish. Cell membrane damaged by LMWCS reduced cell viability. Damaged membrane of epithelial cell in zebrafish larvae induced breakage of the yolk. Adult fish exhibited hypoxia before death due to multiple damages induced by LMWCS. Although the toxicity of LMWCS was revealed in zebrafish model, the toxicity was only present in pH < 7 and easy be neutralized by other negative ions. Collectively, these data improved a new understanding of LMWCS properties.

