Optimizing PANi doped electroactive substrates as patches for the regeneration of cardiac muscle

Abstract

In scaffold aided regeneration of muscular tissue, composite materials are currently utilized as a temporary substrate to stimulate tissue formation by controlled electrochemical signals as well as continuous mechanical stimulation until the regeneration processes are completed. Among them, composites from the blending of conductive (CPs) and biocompatible polymers are powerfully emerging as a successful strategy for the regeneration of myocardium due to their unique conductive and biological recognition properties able to assure a more efficient electroactive stimulation of cells. Here, different composite substrates made of synthesized polyaniline (sPANi) and polycaprolactone (PCL) were investigated as platforms for cardiac tissue regeneration. Preliminary, a comparative analysis of substrates conductivity performed on casted films endowed with synthesized polyaniline (sPANi) short fibres or blended with emeraldine base polyaniline (EBPANi) allows to study the attitude of charge transport, depending on the conducting filler amount, shape and spatial distribution. In particular, conducibility tests indicated that sPANi short fibres provide a more efficient transfer of electric signal due to the spatial organization of electroactive needle-like phases up to form a percolative network. On the basis of this characterization, sPANi/PCL electrospun membranes have been also optimized to mimic either the morphological and functional features of the cardiac muscle ECM. The presence of sPANi does not relevantly affect the fibre architecture as confirmed by SEM/image analysis investigation which shows a broader distribution of fibres with only a slight reduction of the average fibre diameter from 7.1 to 6.4 μm. Meanwhile, biological assays--evaluation of cell survival rate by MTT assay and immunostaining of sarcomeric α-actinin of cardiomyocites-like cells--clearly indicate that conductive signals offered by PANi needles, promote the cardiogenic differentiation of hMSC into cardiomyocite-like cells. These preliminary results concur to promise the development of electroactive biodegradable substrates able to efficiently stimulate the basic cell mechanisms, paving the way towards a new generation of synthetic patches for the support of the regeneration of damaged myocardium.

Conductive interpenetrating networks of polypyrrole and polycaprolactone encourage electrophysiological development of cardiac cells

“…Electroactive composites of PCL and polyaniline have been previously shown to support the adhesion and proliferation of H9c2 cells (derived from rat heart tissue) [27] and the differentiation of human mesenchymal stem cells towards cardiogenic outcomes [28], whereas electroactive composites of PCL and PPy were demonstrated to support the adhesion and proliferation of primary rabbit cardiomyocytes and the expression of cardiac-specific proteins (α-actinin, troponin-T, and connexin 43 (Cx43)) [29].…”

Fibers for hearts: A critical review on electrospinning for cardiac tissue engineering

“…One also common method to improve conductivity is the incorporation of conductive biocompatible polymers in the same way as described previously (co-electrospinning). Polyaniline (PANi) and polypyrrole (PPy) are the two most used conductive polymers for coelectrospinning [140][141][142][143] [144]. By using this approach, an electrically active scaffold can be created, which will coordinate the synchronous beating of cultured CMs in the scaffold.…”

Nanomembranes and Nanofibers from Biodegradable Conducting Polymers

“…Composite substrates made of synthesized polyaniline (sPANi) doped with camphorsulfonic acid and polycaprolactone (PCL) electrospun fibers were investigated as platforms for cardiac tissue regeneration [55]. In particular, conductibility tests indicated that sPANi short fibres provided a highly efficient transfer of electric signal due to the spatial organization of the electroactive needle-like phases up to form a percolative network.…”