Autologous stem cells and growth factors provide valuable therapies for a variety of indications. When stem cells and growth factors are co-delivered, they produce a greater therapeutic effect than delivery of either stem cells or growth factors alone. However, the use of growth factors in the clinic is limited by the challenges of retaining the proteins at the site of healing. The use of stem cells is challenging because of the low frequency of cells in autologous tissue. To address these difficulties, Affinergy used its core technology, phage display biopanning, to screen phage libraries containing billions of candidate peptide sequences. From this process, we identified peptides that bind with high affinity and specificity to growth factors and stem cells. In our Phase II project, we developed a biomaterial coated with a growth factor-binding peptide that captures and retains growth factors significantly longer than the commercially available biomaterials. We demonstrated in animal models that this biomaterial has greater therapeutic efficacy than commercially available products when combined with autologous tissue containing the target growth factor. In this Competing Renewal application, we propose to further enhance the efficacy of this product through the addition of a stem cell-binding peptide, also identified by phage display. The combination of the two peptides will increase the capture of stem cells from autologous tissue onto the material and provide a synergistic effect with the capture and retention of growth factors.
Stem cells and growth factors provide valuable therapies for a variety of indications, and co-delivery of stem cells with growth factors produces a greater therapeutic effect than delivery of either stem cells or growth factors alone. In this application, we propose to develop a biomaterial that can bind and retain both growth factors and stem cells.
|Hamilton, Paul T; Jansen, Michelle S; Ganesan, Sathya et al. (2013) Improved bone morphogenetic protein-2 retention in an injectable collagen matrix using bifunctional peptides. PLoS One 8:e70715|