Enhanced Human Bone Marrow Mesenchymal Stem Cell Functions in 3D Bioprinted Biologically Inspired Osteochondral Construct

Cartilage defects, which are caused by a variety of reasons such as traumatic injuries, osteoarthritis, or osteoporosis, represent common and severe clinical problems. Each year, over 6 million people visit hospitals in the U.S. for various knee, wrist, and ankle problems. As modern medicine advances, new and novel methodologies have been explored and developed in order to solve and improve current medical problems. One of the areas of investigation that has thus far proven to be very promising is tissue engineering. Since cartilage matrix is nanocomposite, the goal of the current work is to use nanomaterials and nano/microfabrication methods to create novel biologically inspired tissue engineered osteochondral scaffolds for facilitating human bone marrow mesenchymal stem cell (MSC) differentiation. 3D printed polymer constructs were designed to mimic the osteochondral region of articulate joint, and to have enhanced mechanical characteristics when compared to traditional designs. Fabricated scaffolds were also subject to surface modification, both with a chemically functionalized acetylated collagen coating and through absorption via poly-L-lysine coated carbon nanotubes. In vitro proliferation results demonstrated not only that incorporation of the biomimetic carbon nanotubes and poly L-lysine coating and acetylated collagen can induce more proliferation of MSCs than controls, but that more controlled and biomimetically designed features also enhance proliferation of MSCs.