Desenvolvimento e avaliação de hidrogéis bioativos para a cicatrização de feridas crônicas

Abstract

It is known that chronic wounds represent a clinical challenge that, despite the constant advancement of treatments, presents a gap to fill regarding products that are truly effective, making the development of new products with bioactivity attractive. Therefore, hydrogels of natural polymers become interesting considering their biocompatibility. Among their possible components, collagen offers benefits in wound healing, and its extraction from marine sources is currently being targeted, as well as its hydrolyzed byproduct called peptides, which often exhibit different bioactivities. Furthermore, the application of national natural products becomes interesting, considering the wide range of Brazilian flora; among these, buriti oil stands out due to its healing properties. Thus, the objective of this work is to develop and characterize different formulations of collagen-based hydrogels, incorporating collagen peptides and/or buriti oil as bioactives for chronic wounds. First, enzymatic hydrolysis of collagen with papain was performed, and the peptides obtained were characterized by Bradford and SDS-PAGE electrophoresis. Buriti oil was characterized by GC-MS. Subsequently, the bioactive components were characterized for cytotoxic, antimicrobial, and antioxidant activities. Variations of hydrogels were produced, two dry and two wet, combining collagen, alginate, buriti oil, polysorbate 80, and/or peptides. The success of collagen hydrolysis was verified by electrophoresis, showing a decrease in molecular weight in the sample. In addition, in silico modeling was performed, which indicated the possible resulting peptide composition in terms of frequency and bioactivities, verifying regulatory, inhibitory, antithrombotic, and antioxidant activities, among others. Cytotoxicity analyses were performed for HaCaT and L929 cell lines, demonstrating the best concentration for use of buriti oil (0.13% w/v) and peptides (0.8% w/v) for the hydrogel. Most hydrogels demonstrated good cell viability, especially in the first 24 hours of testing. However, for HaCaT, a decrease in viability was observed after 48 hours, with the best result for A2S at 60.43%, while sample A2U showed the lowest result at 55.58%. These factors may be caused by problems in sterilization or washing. For L929, this problem was only observed in hydrogel A1U (57.25%), while the others showed satisfactory results, with a maximum of 92.84% for A2S. In the cell migration test, the in vitro wound closed within 24 hours for all hydrogels, surpassing the control at some analyzed times. Antimicrobial activity analyses did not demonstrate significant activity for the oil and polysorbate 80 mixture, showing a maximum of 25.45% against S. aureus. This was also observed for the peptides, with a maximum inhibition of 56.47% against P. aeruginosa. Regarding the hydrogels, A2U showed the most significant inhibition with 83.82% against P. aeruginosa. The antioxidant activities of the peptides showed results superior to the positive controls for the FIC and BCB methods with 97.71% (81.7 µg/mL) and 84.15% (163.4 µg/mL), respectively. In conclusion, the results were satisfactory and demonstrated promising results for the application of hydrogels in wound healing, in addition to indicating the viability of using peptides as bioactive material for various applications.