Design, synthesis and characterization of artificial extracellular matrix proteins for tissue engineering

Artificial extracellular matrix proteins were synthesized using recombinant DNA technology. These proteins were meant to mimic the internal elastic lamina of the tunica intima of muscular arteries for use in the design of small diameter ($\u3c$6 mm) vascular prostheses. These proteins are composed of two blocks, an elastin-like block made up of repeats of the pentapeptide (VPGIG) and a cell binding segment which is composed of the CS5 region of fibronectin. Proteins of the following sequence were designed, synthesized and characterized: (CS5 (VPGIG)$\sb{40})\sb3$ and (CS5(VPGIG)$\sb{20})\sb5$. Successful synthesis and purification were confirmed by NMR spectroscopy and amino acid analysis. These artificial extracellular matrix proteins were designed with both controlled structural integrity and endothelial cell binding ability. The presence of a lower critical solution temperature (LCST) for both proteins suggests that the properties of the elastin like blocks were maintained. The endothelial cell binding ability of the CS5 region of fibronectin was also retained, as demonstrated through human umbilical vein endothelial cell (HUVEC) adhesion and spreading on the proteins, as well as through inhibition of this adhesion through preincubation of the HUVECs with soluble GREDVDY peptide which is known to inhibit $\alpha\sb4\beta\sb1$ integrin binding to CS5. Equivalent numbers of HUVECs adhered to (CS5(VPGIG)$\sb{20})\sb5$ and to fibronectin, although the number of cells well spread on the former was only approximately 55% of the number of those well spread on fibronectin