Synthesis, toxicity and activity of carboxymethyl chitosan on biofilm formation by Candida sp.

Abstract

Increasing incidence of infections caused by Candida sp. and its resistance to antifungals justify the research of novel compounds with antimicrobial activity. Carboxymethylchitosan is a derivative of chitosan with properties such as biocompatibility, biodegradability and solubility in a wide range of pH and for these reasons is interested in medical and pharmaceutical areas. In this study, carboxymethylchitosan was obtained by carboxymethylation of chitosan and then purified and characterized by analysis of solubility degree, solubility at different pH ranges and infrared spectroscopy. The toxicity of the compound was determined by brine shrimp lethality assay, and its activity was subsequently evaluated in biofilm formation by Candida yeasts. The results showed an initial weight gain, after purification, a loss of the total weight of the polymer, the degree of substitution was influenced by the reaction conditions and the reaction time, the compound was soluble in a wide pH range including groups acid-neutral-base. It was found that the carboxymethylchitosan was non-toxic against Artemia salina in the evaluated concentrations and showed no significant inhibitory activity against biofilm formation by Candida sp. The lack of toxicity increases the prospect of further applications of the compound, for example, as a carrier and a complexing agent with proven antifungal compounds.