Novel copper complexes-polyurethane composites that mimics anti-inflammatory response

Abstract

Copper is a trace element of biological significance that can form complexes with several thiol containing compounds which can be used as filler in biomedical polyurethanes. In this work, segmented polyurethanes (SPUs) were synthesized with thiol containing compounds as chain extenders including d-penicillamine (DP), l-penicillamine (LP), l-cysteine (LC) and reduced glutathione (GR). Then, the synthesized polyurethane was filled with copper chelates based on the same chain extenders. Evidence of free thiol containing chain extender in polyurethane was not observed by FTIR and Raman but EDX provided evidence of sulfur in the unfilled polyurethane and copper and sulfur in their composite. DSC and DRX showed the semi-crystalline nature of the polyurethanes which provided good mechanical properties, especially to those prepared with DP. The Tg of the PCL determined by DMA shifted toward higher temperatures by the addition of copper complexes while TGA studies showed that the thermal degradation was slightly improved when LCCu and GRCu complex were added. Macrophage viability was observed in all composition studied after longer times of extraction (72 h) and dilutions (1:2 to 1:32) but remarkably high in those prepared with LCCu and GRCu. The anti-inflammatory response was proved in LC and GR copper complex filled polyurethanes as IL-4 and IL-10 increased with time while IL-1β and TNF-α were reduced.