Electrically Conductive and 3D‐Printable Oxidized Alginate‐Gelatin Polypyrrole:PSS Hydrogels for Tissue Engineering

Abstract

Electroactive hydrogels can be used to influence cell response and maturation by electrical stimulation. However, hydrogel formulations which are 3D printable, electroactive, cytocompatible, and allow cell adhesion, remain a challenge in the design of such stimuli‐responsive biomaterials for tissue engineering. Here, a combination of pyrrole with a high gelatin‐content oxidized alginate‐gelatin (ADA‐GEL) hydrogel is reported, offering 3D‐printability of hydrogel precursors to prepare cytocompatible and electrically conductive hydrogel scaffolds. By oxidation of pyrrole, electroactive polypyrrole:polystyrenesulfonate (PPy:PSS) is synthesized inside the ADA‐GEL matrix. The hydrogels are assessed regarding their electrical/mechanical properties, 3D‐printability, and cytocompatibility. It is possible to prepare open‐porous scaffolds via bioplotting which are electrically conductive and have a higher cell seeding efficiency in scaffold depth in comparison to flat 2D hydrogels, which is confirmed via multiphoton fluorescence microscopy. The formation of an interpenetrating polypyrrole matrix in the hydrogel matrix increases the conductivity and stiffness of the hydrogels, maintaining the capacity of the gels to promote cell adhesion and proliferation. The results demonstrate that a 3D‐printable ADA‐GEL can be rendered conductive (ADA‐GEL‐PPy:PSS), and that such hydrogel formulations have promise for cell therapies, in vitro cell culture, and electrical‐stimulation assisted tissue engineering.

Collagen Hydrogels Loaded with Silver Nanoparticles and Cannabis Sativa Oil

“…A broad range of biomaterial scaffolds has been developed to facilitate the restoration of the skin tissue favoring cellular attachment, proliferation, and differentiation [ 1 , 2 , 3 ]. The goal is to restore the functional and structural properties of the wounded tissue to the before injury levels.…”

Smart and Biomimetic 3D and 4D Printed Composite Hydrogels: Opportunities for Different Biomedical Applications

“…As a result, they show potential in in vitro cell culture and tissue engineering using electrical agitation. Dister and colleagues described the 3D-printability of hydrogel precursors to build cytocompatibility and electrically conductive hydrogel scaffolds using pyrrole and a high gelatin-content oxidized alginate-gelatin (ADA-GEL) hydrogel [ 288 ]. The electrical/mechanical characteristics, 3D-printability, and cytocompatibility of the hydrogels are also evaluated.…”

Wound Healing with Electrical Stimulation Technologies: A Review

“…Nevertheless, the composite of CPs with other biodegradable polymers was shown to be biocompatible [117], providing an opportunity for the fabrication of a biodegradable CPbased scaffold in the field of tissue engineering [118]. The incorporation of other insulating polymers such as silk [119], gelatin [120], chitosan [121][122][123], PLLA [124], polycaprolactone (PCL) [125], and others into CPs can improve the shortcomings.…”

“…The fabrication of silk fibroin composite scaffold incorporated with PEDOT:PSS crosslinked with polyvinyl alcohol (PVA) has been shown to have increased electrical conductivity with the increasing concentration of PEDOT:PSS. The 0.1-0.2% PEDOT:PSS is the optimal concentration, whereas 0.3% is cytotoxic to the corneal epithelial cells [119]. Meanwhile, the excellent conductivity of PEDOT was seen in a study of electroconductive hydrogel with iota-carrageenan (CRG), PVA, and PEDOT:PSS with a conductivity of 0.01 S cm −1 in both dry gel and distilled water conditions [132].…”