Much research has focused on developing
vascular endothelial growth factor (
VEGF) delivery systems to enhance angiogenesis in
wound repair and in tissue engineering.
Collagen can be used as a delivery system because of its biocompatibility, but its fast degradation rate and limited affinity with
growth factors are disadvantageous for maintaining a sufficient
growth factor concentration at injury sites. To enhance
VEGF binding to
collagen scaffolds and reduce the
collagen degradation rate we found a simple way to modify porous
collagen scaffolds by chemical addition of sulfhydryl groups, which then allow both cross-linking of the
collagen fibers with each other and the immobilization of more
VEGF in the scaffold
after treatment with
sulfo-SMCC. We demonstrated that cross-linking led to a slower degradation rate of the
collagen scaffolds, while cellularization was improved by both cross-linking and the presence of
VEGF. On the other hand, angiogenesis was increased only moderately by cross-linking, but significantly more by the presence of immobilized
VEGF. We conclude that
collagen scaffolds chemically conjugated to
VEGF by Traut's
reagent and
sulfo-SMCC is an effective delivery system in
wound repair and tissue engineering.