Produção e caracterização de quitooligossacarídeos, avaliação da sua toxicidade aguda e ação cicatrizante

Abstract

The skin integrity is essential for human life. When a rupture occurs in this physical barrier, the purpose of the repair mechanism is to induce a quick and efficient response to avoid complications such as keloid formation or progression to a chronic wound. Thus, the demand for the substances search that can help the healing process has increased rapidly. In this scenario, chitooligosaccharides (COS) are promising biomolecules, with anti-inflammatory and immunostimulating action attested in the literature, which may contribute to the biological repair mechanism. Therefore, this study aims to produce COS, in two times of hydrolysis (1 and 5 minutes) by chitosanases derived from Bacillus toyonensis, to carry out structural characterization, to evaluate biocompatibility in acute toxicity models in vivo and cytotoxicity, and healing action in cell migration models (“scratch”) in vitro and in vivo wound repair. The chitosan enzymatic degradation process produced oligosaccharides with hexamers predominance attributed through the gel permeation technique chromatography (GPC) and proven in the analysis mass spectrometry. The acute toxicity test confirms the nontoxicity of these substances and cytotoxicity indicates the oligosaccharides biocompatibility on murine fibroblasts. The COS ability to stimulate fibroblast migration in vitro was observed in all tested tools (100; 250; 500 µg/mL), with a reduction up to 100% in the groove size 12 hours after adding a concentration of 500 µg/mL COS obtained with 5 minutes hydrolysis. The oligosaccharides in vivo healing effect was confirmed in the surgical wound-induced model, where these molecules reduced for the groups tested with COS1 30 mg/kg (89.25% ± 2.2), COS1 300 mg/kg (82% ± 10.6), COS5 30 mg/kg (89.25% ± 1.7) and COS5 300 mg/kg (93% ± 0.8) when compared to saline group (61.25% ± 8.1) on the seventh day of the experiment. Despite having no known mechanism of action, the hexamers presence may be related to the COS biological effects. Thus, the selected results indicate the COS potential use as a healing for the pharmaceutical field.