UCLA

Electroactive hydrogels have great potential as a scaffold for tissue engineering. We present the development of choline-based conductive microgels via microfluidics fabrication incorporated in methacrylated gelatin hydrogel backbone, forming a conductive composite hydrogel. The mechanical, swelling, and in vitro degradation properties of the conductive composite hydrogel system demonstrate that the backbone polymer characteristics remain unaffected after incorporation of conductive microgels, making this system modular to be used for engineering different tissue constructs by only tuning the backbone polymer matching the mechanical, swelling, and degradation properties necessary for engineering the target tissue. The conductivity of the resulting composite hydrogel was in the range of electroactive tissue engineering. In addition, the ability of the conductive composite hydrogel to restore electrophysiological communication was confirmed ex vivo allowing this system to restore damaged electroconductive tissue. The non-cytotoxicity of the composite hydrogels was also confirmed via in vitro studies using rat C2C12 myoblast cells and lung fibroblast cells. The conductive composite hydrogel system was injectable and used as a bioink to print cell-laden scaffold structures with high fidelity and complexity using Freeform Reversible Embedding of Suspended Hydrogels (FRESH) Carbopol support bath supporting cell viability, attachment, and spreading. Lastly, the conductive composite hydrogel showed minimal inflammatory responses in vivo when subcutaneously implanted in a rat model. We have shown a novel conductive microgel-based hydrogel that can be used for engineering and regeneration of electroconductive tissue.