Biomaterials for Cell-Based Therapeutic Angiogenesis - Mechanical and Chemical Signaling in Angiogenesis - page 252

neighboring tissues at the implantation site. Further implantation of these cell-
dispatching hydrogels into a mouse's ischemic hindlimb greatly improved the
recovery of blood perfusion as a result of significant increases in the number of blood
vessels [ 29 ].
3 Conclusion and Future Directions
Cell-laden polymeric biomaterials in forms of porous scaffold, fibrous scaffold,
and hydrogels are increasingly being studied to enhance efficacy of cell-based
revascularization therapies. These biomaterials are designed to release cell-
secreted angiogenic factors, render the cells to form endothelial lumen in the
matrix, or deploy the cells to the target tissue following implantation. In the past,
the design of biomaterials used in this application focused on localizing trans-
planted cells in a target site and also retaining cell viability in order to sustain
cellular production of angiogenic factors and also endothelial differentiation.
These biomaterials are being further evolved as a device to regulate the cellular
phenotypic activities essential to revascularization with chemical and mechanical
properties of the matrix in concert with other supplemental soluble factors.
In addition, biomaterials, specifically fibrous scaffold, were also assembled to
control growth direction and spacing of new blood vessels at micrometer scale, but
there have not been a significant success in recreating functional vascular network
in vivo using the biomaterial. We expect that current efforts to integrate bioma-
terial design with various microfabrication technologies would resolve these
challenges and further elevate the quality of revascularization therapies.
References
1. Sieveking, D.P., Ng, M.K.: Cell therapies for therapeutic angiogenesis: back to the bench.
Vasc. Med. 14(2), 153-166 (2009)
2. Kim, S., Recum, H.V.: Endothelial stem cells and precursors for tissue engineering: cell
source, differentiation, selection, adn application. Tissue Eng. Part B 14(1), 133-147 (2008)
3. Laschke, M.W., Harder, Y., Amon, M., Martin, I., Farhadi, J., Ring, A., et al.: Angiogenesis
in tissue engineering: breathing life into constructed tissue substitutes. Tissue Eng. 12(8),
2093-2104 (2006)
4. Yancopoulos, G.D., Davis, S., Gale, N.W., Rudge, J.S., Wiegand, S.J., Holash, J.: Vascular-
specific growth factors and blood vessel formation. Nature 407(6801), 242-248 (2000)
5. Schmidt, J.J., Rowley, J., Kong, H.: Hydrogels used for cell-based drug delivery. J. Biomed.
Mater. Res. 87A(4), 1113-1122 (2008)
6. Fadini, G.P., Agostini, C., Avogaro, A.: Autologous stem cell therapy for peripheral arterial
disease: meta-analysis and systemic review of the literature. Atherosclerosis 209(1), 10-17 (2010)
7. Coutu, D.L., Yousefi, A.-M., Galipeau, J.: Three-dimensional porous scaffolds at the
crossroads of tissue engineering and cell-based genetherapy. J. Cell. Biochem. 108(3),
537-546 (2009)