Combining oligothiophene with oligo-(D,L-lactide) into a complex, branched topology toward a functional interface aimed at biomedical applications

The last decades have witnessed an increasing interest in advanced electroactive biomaterials based on conducting, π-conjugated polymers for use in different biomedical applications. Recently, we reported about synthesis of an oligothiophene grafted with oligo-(D, L-lactide) (OTh-PDLLA) that has been thought to function as a biolectronic interface, biocompatible and bioerodible.

The present report focuses on the study of those properties of OTh-PDLLA that allow to establishing its suitability as a biomaterial. Thus, its capability for forming thin films, on either rigid or flexible supports, using for processing solvents with different polarities and variable concentrations and films surface properties were explored employing dynamic laser-scattering (DLS), contact- angle measurement and atomic force microscopy (AFM). The obtained results, referring to change in particle’s size, in wettability and films surface topography, have shown that OTh-PDLLA offer several ways to modulate films surface topography properties in order to adjust their interactions with biological entities as proteins or cells. Notably, keeping constant the nature of solvent but varying solution’s concentration the films roughness can be varied, while solvent polarity has more influence in films morphology than in their wettability.The biocompatibility of the OTh-PDLLA films deposited on rigid or flexible substrates was assessed by normal human gingival fibroblasts (NHGF) cells interaction. The obtained results confirm the oligomer’s biocompatibility, advocate for OTh-PDLLA potential as electroactive biointerface or as active layer in flexible and/or implantable transient electronics.