Institute of Composite and Biomedical Materials, National Research Council of Italy, P.le Tecchio 80, 80125 Naples, Italy.
J Mater Sci Mater Med. 2011 Apr;22(4):1053-62. doi: 10.1007/s10856-011-4259-x. Epub 2011 Mar 4.
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.
在支架辅助的肌肉组织再生中，复合材料目前被用作临时基底，通过受控的电化学信号以及连续的机械刺激来刺激组织形成，直到再生过程完成。其中，由导电（CPs）和生物相容聚合物共混而成的复合材料由于其独特的导电和生物识别特性，能够确保更有效地对细胞进行电活性刺激，因此作为心肌再生的一种成功策略而崭露头角。在这里，研究了由合成聚苯胺（sPANi）和聚己内酯（PCL）制成的不同复合基质作为心脏组织再生的平台。初步对具有合成聚苯胺（sPANi）短纤维或与本征态聚苯胺（EBPANi）共混的铸膜进行了比较分析，该分析可研究电荷传输的特性，这取决于导电填料的数量、形状和空间分布。特别是，传导性测试表明，sPANi 短纤维由于形成渗流网络的电活性针状相的空间组织，提供了更有效的电信号传递。在此基础上，还对 sPANi/PCL 静电纺丝膜进行了优化，以模拟心脏肌肉细胞外基质的形态和功能特征。SEM/图像分析研究表明，sPANi 的存在不会显著影响纤维结构，其显示出纤维分布更广泛，只是平均纤维直径从 7.1μm 略微减小到 6.4μm。同时，生物测定——通过 MTT 测定评估细胞存活率和肌球蛋白重链免疫染色——清楚地表明，由 PANi 针提供的导电信号促进了 hMSC 向心肌细胞样细胞的心脏发生分化。这些初步结果表明有望开发出能够有效刺激基本细胞机制的电活性可生物降解基质，为支持受损心肌的再生铺平道路。
