Growth Factor-Loaded Microparticles Enhance 3D Bioprinted Muscle

Researchers at the Terasaki Institute in Los Angeles have developed a new method to create 3D printed muscle constructs with enhanced muscle cell alignment and maturation. The technique involves creating microparticles loaded with insulin-like growth factor (IGF) using a microfluidic platform. Then, these particles are included in a bioink that also incorporates myoblast cells and a gelatin-based hydrogel. Once 3D printed, the resulting constructs show enhanced cell growth, elongation, and alignment, and in some cases even began to spontaneously contract after a ten day incubation. The Terasaki researchers hope that their innovation will help pave the way for fully functional, lab-created muscle transplants for human patients.

Skeletal muscle is clearly crucial for movement and basic activity. If such muscle becomes injured or has to be removed because of injury or disease, then a patient’s quality of life can change significantly as their ability to move and perform daily activities is affected. Moreover, other closely associated tissues, such as lymph or blood vessels, may also be affected, leading to additional complications. At present, the main treatment option is to remove healthy muscle from elsewhere in the body and transplant it to the region where it is required.  

However, this is not ideal. Not only is this strategy highly invasive, damaging healthy tissue to repair an injury elsewhere, but it can have mixed results, with issues such as incomplete innervation affecting the transplant performance and limiting the activity of the transplanted muscle. These issues have prompted scientists to attempt to create lab-grown alternatives using biomaterials.

3D bioprinting represents a very useful technique in this context, allowing researchers to print constructs in various shapes and sizes very rapidly. These researchers used this approach, but enhanced it with the judicious inclusion of slow-release growth factors to influence cell activity within the construct.

They included microparticles in the bioink that release IGF slowly within the construct over a period of days, helping to steer the included myoblasts cells towards a skeletal muscle phenotype. So far, the method appears to help in encouraging the cells to elongate and align, just like the real thing, and some constructs even demonstrated muscle contractions.   

“The sustained release of IGF-1 facilitates the maturation and alignment of muscle cells, which is a crucial step in muscle tissue repair and regeneration,” said Ali Khademhosseini, a researcher involved in the study. “There is great potential for using this strategy for the therapeutic creation of functional, contractile muscle tissue.”

Study in journal Macromolecular Bioscience: Enhanced Maturation of 3D Bioprinted Skeletal Muscle Tissue Constructs Encapsulating Soluble Factor‐Releasing Microparticles

Via: Terasaki Institute