Innovative unsaturated polyurethane for cardiac regeneration: Enhancing cytocompatibility and gene expression through gelatin modification

Developing a biomimetic platform that can effectively support myocardial repair and regeneration after a heart attack remains a major challenge for researchers. Polyurethanes (PU), known for their versatile properties, are increasingly being recognized as promising materials for creating cardiac patches. This research study developed the synthesis of a novel unsaturated chain extender via the Baylis-Hillman reaction for incorporation into the backbone of PU to create the unsaturated bridge for post-modification response. Thiol-ene chemistry performed post-modification of unsaturated hard domains of PU with thiolated gelatin as another reactant. Modification of the hard segment domains of PU with gelatin can have a synergistic effect on fabricating a new platform for repairing cardiac tissue. The films were characterized by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Nuclear Magnetic Resonance (NMR), mechanical tests, in vitro degradation rate, water contact angle measurement, and swelling measurement. Metabolic activity and cytocompatibility of the cells onto the films were assessed by MTT assay. An investigation of cardiac-specific marker expression was conducted using immunofluorescence staining and quantitative real-time PCR. The findings showed that none of the substances were cytotoxic to cardiomyocytes, and that the expression of cadiac-specific genes, such as Troponin T, GATA4, Connexin43, and Alpha-SMA, was higher than that of the control group.