The Use of Collagen Methacrylate in Actuating Polyethylene Glycol Diacrylate-Acrylic Acid Scaffolds for Muscle Regeneration.

After muscle loss or injury, skeletal muscle tissue has the ability to regenerate and return its function. However, large volume defects in skeletal muscle tissue pose a challenge to regenerate due to the absence of regenerative elements such as biophysical and biochemical cues, making the development of new treatments necessary. One potential solution is to utilize electroactive polymers that can change size or shape in response to an external electric field. Poly(ethylene glycol) diacrylate (PEGDA) is one such polymer, which holds great potential as a scaffold for muscle tissue regeneration due to its mechanical properties. In addition, the versatile chemistry of this polymer allows for the conjugation of new functional groups to enhance its electroactive properties and biocompatibility. Herein, we have developed an electroactive copolymer of PEGDA and acrylic acid (AA) in combination with collagen methacrylate (CMA) to promote cell adhesion and proliferation. The electroactive properties of the CMA + PEGDA:AA constructs were investigated through actuation studies. Furthermore, the biological properties of the hydrogel were investigated in a 14-day in vitro study to evaluate myosin light chain (MLC) expression and metabolic activity of C2C12 mouse myoblast cells. The addition of CMA improved some aspects of material bioactivity, such as MLC expression in C2C12 mouse myoblast cells. However, the incorporation of CMA in the PEGDA:AA hydrogels reduced the sample movement when placed under an electric field, possibly due to steric hindrance from the CMA. Further research is needed to optimize the use of CMA in combination with PEGDA:AA as a potential scaffold for skeletal muscle tissue engineering.

Characterization and optimization of a positively charged poly (ethylene glycol)diacrylate hydrogel as an actuating muscle tissue engineering scaffold.

Hydrogels have been used for many applications in tissue engineering and regenerative medicine due to their versatile material properties and similarities to the native extracellular matrix. Poly (ethylene glycol) diacrylate (PEGDA) is an ionic electroactive polymer (EAP), a material that responds to an electric field with a change in size or shape while in an ionic solution, that may be used in the development of hydrogels. In this study, we have investigated a positively charged EAP that can bend without the need of external ions. PEGDA was modified with the positively charged molecule 2-(methacryloyloxy)ethyl-trimethylammonium chloride (MAETAC) to provide its own positive ions. This hydrogel was then characterized and optimized for bending and cellular biocompatibility with C2C12 mouse myoblast cells. Studies show that the polymer responds to an electric field and supports C2C12 viability.