Angiogenesis promoted by caged growth factors

Abstract

The present disclosure relates to controlling the release of growth factors for the promotion of angiogenesis. The growth factors or a polymer matrix are modified by photoactive compounds, such that the growth factors are not released into an active form until they are irradiated with light. The disclosure also relates to tissue engineering scaffolds comprising one or more polymers and at least two growth factors.

1 - 12 . (canceled) 
     
     
         13 . A tissue engineering scaffold comprising:
 one or more polymers and at least two growth factors, wherein a first polymer is configured to release a first growth factor in a bioactive state in response to a first spectral sensitivity range and a second polymer is configured to release a second growth factor in a bioactive state in response to a second spectral sensitivity range.   
     
     
         14 . The tissue engineering scaffold of  claim 13 , wherein the scaffold further comprises collagen. 
     
     
         15 . The tissue engineering scaffold of  claim 13 , wherein the scaffold further comprises elastin. 
     
     
         16 . A method of controlling the release of two or more growth factors at a target site, comprising:
 delivering the tissue engineering scaffold of  claim 13  to a target site;   releasing the first growth factor at the target site by radiation of the target site with a first wavelength of light in the first spectral sensitivity range; and   releasing the second growth factor at the target site by radiation of the target site with a second wavelength of light in the second spectral sensitivity range.   
     
     
         17 . The method of  claim 16 , wherein an amplitude of the radiation of the target site controls a rate of release of the first growth factor, the second growth factor, or both. 
     
     
         18 . A method for tissue engineering in a mammal, comprising:
 applying to a tissue progenitor site of a mammal an effective amount of a scaffold comprising one or more polymers and at least two growth factors, wherein a first polymer is configured to release a first growth factor in a bioactive state in response to a first spectral sensitivity range and a second polymer is configured to release a second growth factor in a bioactive state in response to a second spectral sensitivity range.   
     
     
         19 . The method of  claim 18 , wherein the scaffold further comprises a population of cells. 
     
     
         20 . The method of  claim 19 , wherein the scaffold comprises a population of vascular endothelial cells or cell precursors and wherein application of the scaffold to the tissue progenitor site stimulates vascularization in the site.