Effect of Polyurethane Structure on the Physicochemical, Mechanical, and Biological Properties on their Copper Complexes Composites

Polyurethanes and their composites are versatile materials widely used in numerous medical applications. However, limited information is available regarding their copper composites. Copper is a trace element in the human body that functions as an enzyme cofactor in both normal and pathological angiogenesis, as well as in muscle and brain formation. Considering this, copper complexes of D-penicillamine (DP), L-cysteine (LC), and dopamine (DOP) were incorporated into segmented polyurethanes (SPU) synthesized with either a semi-crystalline (poly-ε-caprolactone, PCL) or an amorphous (polytetramethylene ether glycol, PTMEG) soft segment. FTIR and Raman revealed new absorptions and peak shifts, confirming the presence of the complexes within the matrix of all composites. XPS further corroborated the presence of copper and sulfur. The crystallinity of the PCL-based polyurethanes was influenced by the addition of the filler, as observed through DSC and DRX. Furthermore, TGA analysis indicated the emergence of new decomposition temperatures following the incorporation of copper complexes. In general, no significant reduction in Young's modulus was observed, except for certain composites containing DPENCUII as filler, which exhibited a slight increase compared to pristine SPU´s. Finally, the composites demonstrated neither hemolytic nor procoagulating behavior (hemolysis < 5% and BCI > 20), although they exhibited some degree of impairment in cytocompatibility compared to their respective pristine SPUs. Collectively, these findings suggest that some composites possess promising properties for potential cardiovascular applications.