Molecular Weight, Degree of Deacetylation, and Acute Oral Toxicity Evaluation of Irradiated and Nonirradiated Chitosan Using Mice

Chitosan has been used as antimicrobial, anti‐fungal, anti‐virus, antioxidant, and anti‐cancer agent. As a new biomaterial, chitosan will be required to undergo certain toxicity tests for biocompatibility and safety assessment; one of the requirements is acute toxicity. In this study, nonirradiated and irradiated chitosan is used. The MW of chitosan is analyzed using GPC. The degree of deacetylation (DD) is measured by FTIR. OECD Guideline for Testing of Chemicals No 423 is used for evaluation of acute oral toxicity tests of nonirradiated and irradiated chitosan using mice with body weight (BW) ranging from 20 to 30 g. During 14 days after the dosing of chitosan, there are daily observations of toxic symptoms, death of test animals, changes in weight gain, and manifestations of toxic effects of individual animals. The results show that nonirradiated and irradiated chitosan with 75 kGy have an average MW of 276.0 and 90.0 kDa, respectively. Chitosan has a DD of 92%, which is increased by 4% at 75 kGy irradiation dose. Administration of nonirradiated and irradiated chitosan with a concentration of 300 mg/kg BW and continuous following with 2000 mg/kg BW show no toxic symptoms or death of mice test animals, LD50 > 5000 mg/kg. It is concluded that nonirradiated and irradiated chitosan with 75 kGy are categorized as practically nontoxic with LD50 > 5000 mg/kg. The dose up to a test limit of 5000 mg/kg BW is estimated to be equivalent to the dose of 38.79 mg (≈ 38.79 g) in humans (70 kg).