Materials and methods for controlling vasculogenesis from endothelial colony forming cells

Abstract

Materials and methods are disclosed for controlling vasculogenesis using building blocks of a collagen matrix and endothelial colony forming cells (ECFC). The building blocks may be isolated by fractionating an acid soluble Type I collagen. The building blocks comprising monomers and/or oligomers may be recombined in desired ratios to alter the matrix microenvironment and to influence ECFC behavior.

We claim: 
     
         1 . A vessel forming matrix comprising:
 a population of endothelial colony forming cells in a polymerized matrix comprising at least one fraction of an acid soluble Type I collagen.   
     
     
         2 . The matrix according to  claim 1 , wherein said at least one fraction of the acid soluble Type I collagen is selected from the group consisting of monomers having an average molecular weight of about 282 kDa and oligomers having an average molecular weight of about 603 kDa. 
     
     
         3 . The matrix according to  claim 1 , wherein said at least one fraction of acid soluble Type I collagen includes a telopeptide reactive aldehyde. 
     
     
         4 . The matrix according to  claim 1 , further comprising a second fraction of the acid soluble Type I collagen that differs from the at least one fraction. 
     
     
         5 . The matrix according to  claim 4 , wherein the at least one fraction is an oligomer-rich fraction and the second fraction is a monomer-rich fraction. 
     
     
         6 . The matrix according to  claim 5 , wherein the matrix comprises more of the oligomer-rich fraction than the monomer-rich fraction. 
     
     
         7 . The matrix according to  claim 1 , wherein said at least one fraction of acid soluble Type I collagen is present in the matrix at a concentration of about 0.5 to about 3.0 mg/ml. 
     
     
         8 . The matrix according to  claim 1 , wherein said population of endothelial colony forming cells is present in the matrix at a concentration of about 5×10 5  to about 2×10 6  cells/ml. 
     
     
         9 . A method of promoting vessel formation comprising the steps of:
 obtaining an engineered collagen matrix from an oligomer-rich fraction of a Type I acid soluble collagen; and   seeding the matrix with a plurality of endothelial colony forming cells to form one or more vessels within the matrix.   
     
     
         10 . The method according to  claim 9 , wherein the matrix is richer in Type I acid soluble collagen oligomers than in Type I acid soluble collagen monomers. 
     
     
         11 . The method according to  claim 9 , wherein the average molecular weight of the collagen in the matrix is about 603 kDa. 
     
     
         12 . The method according to  claim 9 , wherein the average molecular weight of the collagen in the matrix is greater than about 282 kDa. 
     
     
         13 . The method according to  claim 9 , wherein the matrix has a collagen concentration of about 0.5 to about 3.0 mg/ml. 
     
     
         14 . The method according to  claim 9 , wherein the obtaining step comprises isolating oligomers from the Type I acid soluble collagen. 
     
     
         15 . The method according to  claim 9 , wherein the matrix is stiffer than the Type I collagen. 
     
     
         16 . The method according to  claim 9 , wherein the matrix is in an unpolymerized state during the seeding step. 
     
     
         17 . The method according to  claim 9 , wherein the seeding step comprises seeding the matrix with about 5×10 5  to about 2×10 6  cells/ml. 
     
     
         18 . The method according to  claim 9 , further comprising the step of implanting the matrix into a diseased area of a patient. 
     
     
         19 . The method according to  claim 18 , wherein the diseased area of the patient comprises an ischemic limb. 
     
     
         20 . The method according to  claim 9 , wherein the obtaining step comprises independently controlling a stiffness of the matrix and a collagen concentration of the matrix.