Vascularized Tissue Construction Using Specialized 3D Bioprinting Techniques

Tissue engineering technology is of particular import to the Army for the matter of producing tissue replacements for the repair and regeneration of various organ systems (liver, heart, muscle, lung, etc.) for wounded patients. Unfortunately, the production of masses of tissue with thicknesses greater than ~1 mm presents a challenge due to diffusion limits of nutrients into the tissue and waste out of the tissue. This is solved through proper vascularization. Providing vasculature for lab-grown tissues (in addition to providing the correct nutrients, growth factors, etc.) is essential to keeping them alive and functional for any relevant length of time. In order to meet these challenges, Lynntech is proposing the development of a hybrid bioreactor/3D-printing system in order to engineer vascularized tissue. We will demonstrate feasibility through the production of 1 cm thick, vascularized pieces of tissue. The Phase I development process will include fine-tuning the individual components of our system and evaluating the tissue for vascularization, health, and function over weeklong timescales. Testing will include metabolic assays, imaging of the vasculature, and mechanical testing. Methods and materials that meet the Armys objectives will be recommended for further development in Phase II and beyond.