Structural characterization and toxicity effect of nano-carboxymethyl chitosan from Uroteuthis (Photololigo) sibogae (Adam, 1954) in the zebrafish model.

Chitin is converted into chitosan by the gladius of the Uroteuthis sibogae (U. sibogae). Chitosan (CH) is then converted into carboxymethyl chitosan (CMC). The structural and functional groups of CH and CMC, respectively, are ascertained using FT-IR and NMR spectroscopy. The molecular weight of the isolated CMC is 731.87 Da. The degree of deacetylation (DDA) is confirmed at about 83%, and the CMC degree of substitution (DS) of 0.8 is determined. Moreover, using the crosslinker sodium tripolyphosphate (TPP), nano-CMC (N-CMC) is synthesized from the obtained CMC. The N-CMC particle size is 146 nm, and 68% of N-CMC is soluble in distilled water. N-CMC is thermostable up to 194.25°C as determined by thermogravimetric analysis (TGA). Zebrafish embryos (ZFE) exposed to N-CMC at a concentration of 4 μg/mL revealed teratogenic effects. The locomotor activity of the N-CMC (1 to 4 mg/L) treated zebrafish was significantly (P<0.05) decreased during the third week of the experiment by using ToxTrac software. [ABSTRACT FROM AUTHOR]