Desenvolvimento de Redes Semi-Interpenetrantes de PCL-pHEMA-copaíba para potencial uso com scaffolds na Engenharia de Tecidos

Abstract

Tissue engineering is an alternative to replace organs and tissues in the biological system affected by an illness. Therefore, it is necessary to study the material used as a scaffold in depth. Among the materials in this area, polymers and hydrogels stand out, such as poly (ε-caprolactone) (PCL) and poly (2-hydroxyethyl methacrylate) (PHEMA), respectively. PCL is a bioresorbable, biodegradable, and biocompatible polymer. However, it is hydrophobic.On the other hand, pHEMA is a biocompatible and hydrophilic hydrogel but does not show good degradability. Furthermore, it is possible to intersperse bioactive compounds through the use of Amazonian vegetable oils in these structures to further enhance tissue regeneration and combat possible infections by microorganisms. Therefore, this work aimed to obtain and characterize PCL-PHEMA-copaíba semi-IPN networks for scaffolds in tissue engineering using the rotospinning technique. The results successfully demonstrated the processing of PCL fibers (with and without copaiba oil) and the formation of PCL-C-PHEMA semi-IPN networks. Gas chromatography confirmed the presence of bioactive components in copaiba essential oil, the majority being (β)-caryophyllene (40.75%). The FTIR spectrum showed interactions of the materials' functional groups, confirming the incorporation of the oil into the PCL structure and the formation of semi-interpenetrating networks. Micrographs and topographies revealed tangled and disorganized microfibers in all samples, with different diameters, porosities, and roughness. The PCL, PCL-C, and PCL-C-PHEMA samples presented fiber diameters ranging from 18.40 to 19.50 μm, 3.11 to 24.44 μm, and 6.29 to 8.14 μm, respectively. Contact angle analyses (PCL: 86.96°, PCL-C: 93.99°, PCL-PHEMA: 29.42°, and PCL-C-PHEMA: 56.02°) and swelling test (PCL: 4.49%, PCL-C: 2.73%, PCL-PHEMA: 21.57%, and PCL-C-PHEMA: 10.11%) demonstrated that the addition of the hydrogel to the PCL structure optimized the hydrophilic properties of material. The sol-gel tests indicated that the PCL-PHEMA and PCL-C-PHEMA materials presented 73.5 74.3% gel fractions. Thermograms confirmed that the material did not significantly change in thermal stability with the addition of the hydrogel and oil. Microbiological tests confirmed the antimicrobial action of copaiba oil, PCL-C-PHEMA, and PCL-C scaffolds against the gram-positive bacterium Staphylococcus aureus, with an inhibition halo of 9, 7, and 5 mm, respectively. Moreover, the cytotoxicity tests concluded that the PCL, PCL-PHEMA, and PCL-C scaffolds showed good cell viability. However, optimizing the photopolymerization process of the semi-IPN network is necessary, given that the PCL-C-PHEMA materials were moderately toxic. Finally, a new biomaterial is expected to be developed for use in tissue engineering, valuing the use of natural Amazonian resources.