Stephen M. Goldman
Ph.D. Dissertation Defense
Friday, October 31, 2014
U.A. Whitaker Building, Room 1103
9:00 a.m.

Advisor:
Gilda Barabino, Ph.D. (BME)

Committee:
Edward Botchwey, Ph.D. (BME)
Robert Guldberg, Ph.D. (ME)
Spero Karas, M.D. (Emory University)
Athanassios Sambanis, Ph.D. (ChBE)
Johnna Temenoff, Ph.D. (BME)

Development & Validation of a Microfluidic Hydrogel Platform
For Osteochondral Tissue Engineering

Due to the inability of intra-articular injuries to adequately self-heal, current therapies are largely focused on palliative care and restoration of joint function rather than true regeneration. Subsequently tissue engineering of chondral and osteochondral tissue constructs has emerged as a promising strategy for the repair of partial and full-thickness intra-articular defects. Unfortunately, the fabrication of large tissue constructs is plagued by poor nutrient transport to the interior of the tissue resulting in poor tissue growth and necrosis. Further, for the specific case of osteochondral grafts, the presence of two distinct tissue types offers additional challenges related to cell sourcing, scaffolding strategies, and bioprocessing. To overcome these constraints, this dissertation was focused on the development and validation of a microfluidic hydrogel platform which reduces nutrient transport limitations within an engineered tissue construct through a serpentine microfluidic network embedded within the developing tissue. To this end, a microfluidic hydrogel was designed to meet the nutrition requirements of a developing tissue and validated through the cultivation of chondral tissue constructs of clinically relevant thicknesses. Additionally, optimal bioprocessing conditions with respect to morphogen delivery and hydrodynamic loading were pursued for the production of bony and cartilaginous tissue from bone marrow derived mesenchymal stem cells. Finally, the optimal bioprocessing conditions were implemented within MSC laden microfluidic hydrogels to spatially engineer the matrix composition of a biphasic osteochondral graft through directed differentiation.