Extraction and characterization of hyaluronic acid from the eyeball of Nile Tilapia (Oreochromis niloticus)

Hyaluronic acid (HA) is a biopolymer of enormous value aggregation for in general industry. The vitreous humor of the eyeball from Nile tilapia contains appreciable amounts of hyaluronic acid. In this sense, the aim of this work was to extract and characterize hyaluronic acid from the eyeball of the Nile tilapia for biomedical applications, adding value to fish industry residues. The characterization by infra-red (FTIR), 13C nuclear magnetic resonance (NMR) and high performance liquid chromatography (HPLC) confirmed that hyaluronic acid was obtained. The gel permeation chromatography (GPC) showed that the obtained material presents a low molecular mass (37 KDa). Thermogravimetry (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis showed that the materials present a thermal stability superior to the commercial hyaluronic acid from Streptococcus equi, with a partially crystalline character. The cytotoxicity assay (MTT method) with fibroblast cells (L929) demonstrated that the extracted biopolymer besides not being cytotoxic, was able to stimulate cell proliferation. Therefore, the hyaluronic acid extracted from this source of residue constitutes a product with biotechnological potential, which has adequate quality for wide biomedical applications.