(178c) Bioactive Peptides for Mesenchymal Stem Cell Differentiation in Cartilage Tissue Engineering

Osteoarthritis is characterized by degradation of articular cartilage, and there is strong demand for long-lasting and minimally invasive cartilage replacements. One promising approach for cartilage regeneration is to use the patient's own bone marrow-derived stem cells (MSCs) to seed an artificial protein scaffold embedded with bioactive differentiation cues. This method could allow MSCs seeded on the scaffold to be directly implanted, which reduces ex vivo culturing time. In addition, this technique could lead to the development of materials with spatially patterned differentiation cues, which would aid in the development of complex tissues such as osteochondral grafts.

Screening experiments identified bioactive domains that direct or influence human MSC differentiation towards cartilage cell fates. Pellet cultures adapted for a 96-well plate were used to evaluate the efficacy of agonist peptides derived from growth factors. DNA content and production of cartilage-specific extracellular matrix proteins such as sulfated glycosaminoglycans (GAGs) were monitored during differentiation. One promising peptide agonist derived from bone morphogenetic protein-2 stimulated MSCs to produce significantly greater amounts of GAG/DNA than cultures without the peptide. In the future, these peptide sequences will be incorporated within protein-based scaffolds specifically designed for application in cartilage engineering.