@article {19121, title = {Synthesis and Characterization of Electroactive Gellan Gum Spongy-Like Hydrogels for Skeletal Muscle Tissue Engineering Applications.}, journal = {Tissue Engineering : Part A}, year = {2017}, month = {2017-03-31 00:00:00}, pages = {1-12}, publisher = {Mary Ann Liebert, Inc. publishers}, abstract = {

Advances on materials{\textquoteright} research for tissue engineering (TE) applications have shown that animal cells respond directly to the material physical, chemical, mechanical, and electrical stimuli altering a variety of cell signaling cascades, which consequently result in phenotypic and genotypic alterations. Gellan gum (GG) spongy-like hydrogels (SLH) with open microstructure, mechanical properties, and cell performance have shown promising results for soft TE applications. Taking advantage of intrinsic properties of GG-SLH and polypyrrole (PPy) electroactivity, we developed electroactive PPy-GG-SLH envisaging their potential use for skeletal muscle TE. Three different methods of in situ chemical oxidative polymerization were developed based on the availability of pyrrole: freely dissolved in solution (method I and III) or immobilized into GG hydrogels (method II). PPy was homogeneously distributed within (method I and III) and on the surface (method II) of GG-SLH, as also confirmed by Fourier Transform infrared spectra. PPy-GG-SLH showed higher conductivity than GG-SLH (p \< 0.05) whereas PPy-GG-SLH (method I and II) showed the best conductivity among the 3 methods (\~{}1 to 2 {\texttimes} 10-4S/cm). The microarchitecture of PPy-GG-SLH (method I) was similar to GG-SLH but PPy-GG-SLH (method II and III) presented smaller pore sizes and lower porosity. PPy-GG-SLH (method I and II) compressive modulus (\~{}450-500 KPa) and recovering capacity (\~{}75-90\%) was higher than GG-SLH, nevertheless the mechanical properties of PPy-GG-SLH (method III) were lower. The water uptake of PPy-GG-SLH was rapidly up to 2500\% and were stable along 60 days of degradation being the maximum weight loss 20\%. Mechanically stable and electroactive PPy-GG-SLH (method I and II) were analyzed regarding cellular performance. PPy-GG-SLH were not cytotoxic for L929 cells. In addition, L929 and C2C12 myoblast cells were able to adhere and spread within PPy-GG-SLH, showing improved spreading in comparison to GG-SLH performance. Overall, PPy-GG-SLH show promising features as an alternative electroactive platform to analyze the influence of electrical stimulation on skeletal muscle cells.

}, keywords = {chemical oxidative polymerization in situ, Gellan Gum, polypyrrole, skeletal muscle cells, soft electroactive spongy-like hydrogels}, issn = {2152-4947}, doi = {0.1089/ten.tea.2016.0430}, url = {http://online.liebertpub.com/doi/abs/10.1089/ten.TEA.2016.0430?url_ver=Z39.88-2003\&rfr_id=ori\%3Arid\%3Acrossref.org\&rfr_dat=cr_pub\%3Dpubmed}, author = {Berti, F. V. and Srisuk, P. and da Silva, L. P. and Marques, A. P. and Reis, R. L. and Correlo, V. M.} }