Smart design for a flexible, functionalized and electroresponsive hybrid platform based on poly(3,4-ethylenedioxythiophene) derivatives to improve cell viability

Abstract

Development of smart functionalized materials for tissue engineering has attracted significant attention in recent years. In this work we have functionalized a free-standing film of isotactic polypropylene (i-PP), a synthetic polymer that is typically used for biomedical applications (e.g. fabrication of implants), for engineering a 3D all-polymer flexible interface that enhances cell proliferation by a factor of ca. three. A hierarchical construction process consisting of three steps was engineered as follows: (1) functionalization of i-PP by applying a plasma treatment, resulting in i-PP_f; (2) i-PP_f surface coating with a layer of polyhydroxymethy-3,4-ethylenedioxythiophene nanoparticles (PHMeEDOT NPs) by in situ chemical oxidative polymerization of HMeEDOT; and (3) deposition on the previously activated and PHMeEDOT NPs coated i-PP film (i-PP_f/NP) of a graft conjugated copolymer, having a poly(3,4-ethylenedioxythiophene) (PEDOT) backbone, and randomly distributed short poly(ε-caprolactone) (PCL) side chains (PEDOT-g-PCL), as a coating layer of ∼9 μm in thickness. The properties of the resulting bioplatform, which can be defined as a robust macroscopic composite coated with a “molecular composite”, were investigated in detail, and both adhesion and proliferation of two human cell lines have been evaluated, as well. The results demonstrate that the incorporation of the PEDOT-g-PCL layer significantly improves cell attachment and cell growth not only when compared to i-PP but also with respect to the same platform coated with only PEDOT, constructed in a similar manner, as a control.