Incorporating isosorbide as the chain extender improves mechanical properties of linear biodegradable polyurethanes as potential bone regeneration materials

Abstract

One key limitation to the application of linear biodegradable polyurethanes (LBPUs) in scaffold materials for bone regeneration is their insufficient mechanical properties. In this study, isosorbide (ISO), a rigid two-ring small diol is selected as a chain extender to produce a series of new poly (D,L-lactide)-based polyurethanes (ISO-PUs). It is confirmed that incorporating ISO as the chain extender can significantly reduce the crosslinking degree of ISO-PUs and thus increase their molecular weight and mechanical properties. ISO-PUs with M_n values of 72.09 kDa and 84.79 kDa demonstrate higher tensile strength & modulus (39.87 MPa & 2.19 GPa and 42.68 MPa & 2.57 GPa) than PDLLA with a M_n of 100 kDa (36.15 MPa & 2.07 GPa). All these results, together with the sound cytocompatibility of ISO-PUs with MC3T3-E1 cells based on the morphology observation and cell proliferation, suggest that ISO-PU should be a promising scaffold material for bone regeneration.