Caracterização da biocompatibilidade e biodegradação de hidrogéis com associação de colágeno, nanoqueratina e bioapatita provenientes de subprodutos da indústria avícola

Abstract

The search for new osteoconductive biomaterials is desirable to enhance the clinical treatment of bone defects. Hydrogels mimicking the extracellular bone matrix could be a viable and sustainable option for the green biotechnology industry from the economic and environmental point of view. The objective of this research was to characterize in vivo the biocompatibility and biodegradability of collagen (Col), nanokeratin (NQ) and bioapatite (BA) hydrogels from poultry industry by - products. 45 Swiss male mice were divided into three experimental times: 1, 3 and 9 weeks. In the mice that received the test materials, 2 modalities of poultry hydrogels were implanted in the subcutaneous dorsothoracic region: 100% Col (G1), 90% Col: 10% BA (G2), 90% Col: 10% NQ (G3) or 90 % Col: 5% NQ: 5% BA (G4). In the Negative Control (CN) group, biomaterial was not inserted into the formed pockets. Excisional necropsies were collected at the end of each experimental time and histologically processed for qualitative and semiquantitative analyzes of the tissue-biomaterial interaction, following the criteria of ISO 10993-6. The non-parametric data was performed by Kruskal-Wallis test and Dunn post-test, considering significant differences if p <0.05. Results regarding biocompatibility and compared to NC showed high presence of neutrophils for G1, G3 and G4 at 1 week and for G3 and G4 at 3 weeks, from lymphocytes to G3 at 1 week, G3 and G4 at 3 weeks and G2 and G3 at 9 weeks and G2 giant cells at 3 weeks, with no differences in macrophages. Also, there was a low presence of neovascularization for G1 and G3 at 1 week and of connective tissue for G1, G2, G3 and G4 at 1 week. G1 and G2 were considered non-irritant test materials throughout the experimental period, whereas G3 and G4 exhibited little irritation in only 3 weeks. With respect to biodegradability and compared to CN in intergroup analysis, all implanted materials were present at 1 and 3 weeks, but only G2 persisted at 9 weeks. In intragroup analysis, there was a progressive reduction in G1, G3 and G4 throughout the experimental period. The data obtained demonstrate that all test materials based on poultry by-products showed ectopic biocompatibility, however, only G2 maintained its integrity and shows biotechnological potential as a membrane for guided bone regeneration therapies.