"3D Printing with Peptide-Polymer Conjugates to Regenerate the Osteochondral Interface"
Department: Bioengineering
Advisor: Lesley Chow
Abstract:
The osteochondral interface refers to the interface between cartilage and bone, two mechanically and compositionally dissimilar tissues. Damage to this interface is caused by disruption to cartilage, an avascular tissue that has limited ability to self-repair. This can lead to significant pain and immobility that eventually results in total knee replacement, which often requires costly revision surgeries. Tissue engineering offers strategies to prevent or delay this by fabricating biomaterials mimic the body’s native tissues to guide tissue regeneration. Notably, the native extracellular matrix (ECM) in the osteochondral interface is composed of different biomolecules arranged in a complex and hierarchical organization to yield specific functions. To achieve this, we developed a peptide-polymer functionalization approach to control the spatial arrangement of multiple peptides within a single scaffold. Hyaluronic acid (HA)-binding and mineralizing peptides designed to promote human mesenchymal stem cell (hMSC) chondrogenesis and osteogenesis, respectively, were conjugated to poly(caprolactone) (PCL) to form peptide-PCL conjugates. These conjugates were then added to PCL-based inks and 3D printed to control the spatial deposition of each peptide-PCL conjugate. This technique allowed us to organize HA-binding and mineralizing peptides on opposing sides of the same scaffold. The scaffolds were sectioned and labeled with specific fluorophores to visualize the spatial distribution of peptides using confocal microscopy. Future and ongoing work involves in vitro experiments to investigate spatial hMSC differentiation and matrix formation.
