Preparation and optimization of polyurethane/crosslinked poly acrylic acid semi-IPNs containing multi wall carbon nanotube applicable for artificial tendon

The tendons and nerves of the body are inextricably linked to each other. That is why the adjacent neural system should also be supported in the most effective treatments for damaged tendons. Hence in designing the tissue engineering tendons, adequate elasticity, good biocompatibility, and relative conductivity must be achieved to stimulate nerve tissue. This study aims to prepare semi-interpenetrating polymer networks (semi-IPNs) based on polyurethane (PU)/crosslinked polyacrylic acid (PAA), using Response Surface Methodology (RSM). Concerning this method, the variables such as the amount of AA, crosslinker, and multi-wall carbon nanotube (MWCNT) were optimized. Notably, the swelling, mechanical strength, tensile strength, and electrical conductivity of the prepared composites were selected as the evaluated responses. The optimal samples had an AA content of 20 wt%, a crosslinking agent of 8.75 and 16.25 mol.%, and an MWCNT content of 1 and 3 wt% Optimal samples were then evaluated by X-ray diffraction analysis (XRD), cyclic mechanical strength, electrical conductivity, biocompatibility and cell adhesion. The promising results of these evaluations demonstrated that the PU/PAA/MWCNT semi-IPN nanocomposites could be a proper biocompatible material for artificial tendons.