< Back to previous page

Project

Formation of endothelial networks in human tissue-engineered skeletal muscle

Skeletal muscle is a complex tissue with a capacity to regenerate upon injury. However, when skeletal muscle loss is beyond the regenerative capacity of skeletal muscle, the muscle repair process fails and scar tissue replaces the damaged area with resultant functional impairment. Current treatments have several disadvantages and new strategies are being explored, such as skeletal muscle tissue engineering. The aim is to reproduce the native structure and function of muscle in vitro and transplant this tissue in the damaged area. Besides applications in regenerative medicine, there are many other applications in which tissue-engineered skeletal muscle can be useful. Some examples are the use as an in vitro model for studying myogenesis, myopathology or molecular pathways or implementation as in vitro preclinical model for drug-screening and toxicity testing of compounds.

The main goal of this project is development, characterization and optimization of 3D in vitro tissue-engineered human skeletal muscle tissue. Existing techniques involve culturing and differentiation of myogenic (stem) cells on natural or synthetic scaffolds. These techniques often result in non-aligned myofibers. Alignment of the myofibers is important for directional force generation, the principal function of skeletal muscle. In our lab, human muscle progenitor cells are engineered in a 3D extracellular fibrin matrix and grown in a custom-made mold with 2 attachment points, serving as artificial tendons. The resulting bio-artificial muscle (BAM) is about one millimeter thick and consists of aligned multinucleated myotubes. However, to create tissue-engineered constructs with a thickness exceeding the millimeter size, perfusion of the construct is essential to avoid cell death by lack of oxygen and nutrients. In this project, we have developed two approaches to introduce vascular networks in vitro in the 3D muscle tissue, the so-called prevascularization. In the one-stage approach, human muscle cells were directly cocultured with endothelial cells in 3D. In the two-stage approach, a one week old BAM containing differentiated myotubes was coated with a fibrin hydrogel containing endothelial cells. To prove functionality of in vitro engineered endothelial networks, prevascularized BAMs were implanted subcutaneously in mice for 14 days. In vivo anastomosis and perfusion of engineered endothelial networks with host vessels was shown. In addition, we have discussed how prevascularization in turn influences the survival and integration of a tissue-engineered construct in vivo.  Furthermore, the BAM approach has been evaluated as a preclinical model for intramuscular drug injection. We have shown that the BAM is an adequate model to assess compound toxicity, retention, release and compound metabolism. To conclude, the BAM model is a promising tool, but several challenges need to be addressed in order to translate the BAM model into the clinic for regenerative medicine or towards drug development. 

Date:1 Oct 2014 →  23 May 2019
Keywords:tissue-engineering, prevascularization, bio-artificial muscle
Disciplines:Laboratory medicine, Palliative care and end-of-life care, Regenerative medicine, Other basic sciences, Other health sciences, Nursing, Other paramedical sciences, Other translational sciences, Other medical and health sciences
Project type:PhD project