RESUMO
Composite collagen gels with hyaluronic acid are developed tissue-engineered structures for filling and regeneration of defects in various organs and tissues. For the first time, phytic acid was used to increase the stability and improve the mechanical properties of collagen gels with hyaluronic acid. Phytic acid is a promising cross-linker for collagen hydrogels and is a plant-derived antioxidant found in rich sources of beans, grains, and oilseeds. Phytic acid has several benefits due to its antioxidant, anticancer, and antitumor properties. In this work, studies were carried out on the kinetics of the self-assembly of collagen molecules in the presence of phytic and hyaluronic acids. It was shown that both of these acids do not lead to collagen self-assembly. Scanning electron microscopy showed that in the presence of phytic and hyaluronic acids, the collagen fibrils had a native structure, and the FTIR method confirmed the chemical cross-links between the collagen fibrils. DSC and rheological studies demonstrated that adding the phytic acid improved the stability and modulus of elasticity of the collagen gel. The presence of hyaluronic acid in the collagen gel slightly reduced the effect of phytic acid. The presence of phytic acid in the collagen gel improved the stability of the scaffold, but, after 1 week of cultivation, slightly reduced the viability of mesenchymal stromal cells cultured in the gel. The collagen type I gel with hyaluronic and phytic acids can be used to replace tissue defects, especially after the removal of cancerous tumors.
RESUMO
Polymer blending is a suitable physical modification method to create novel properties of different polymers. Blending polylactic acid (PLA) and polyethylene glycol (PEG) produces materials with a wide range of properties. This study was the first to investigate the effect of different isomeric forms of PLA and PEG with terminal amino groups to obtain biocompatible films for human mesenchymal stem cell cultivation. It has been shown by scanning electron microscopy that the surface topology changes to the greatest extent when using films obtained on the basis of poly(d,l-lactide) and PEG with high molecular weights (15,000 g/mol). In order to obtain thin films and rapid evaporation of the solvent, PEG is mixed with PLA and does not form a separate phase and is not further washed out during the incubation in water. The presence of PEG with terminal hydroxyl and amino groups in blend films after incubation in water was proven using Fourier transform infrared (FTIR) spectroscopy. Results of fluorescence microscopy demonstrated that blend films formed on PLA and polyethylene glycol diamine (PEG-NH2) are more suitable for cell spreading and focal contact formation compared to cells cultured on the surface of pure PLA films or films made from PLA and PEG.