Type I collagen can function as a reservoir of basic fibroblast growth factor

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Extracellular matrix (ECM) growth factor storage is crucial for tissue homeostasis and regeneration.
• Heparan sulfate proteoglycans are a known model for basic fibroblast growth factor (bFGF) interaction.
• The role of type I collagen in bFGF binding was previously considered biologically insignificant.

Purpose of the Study:

• To investigate the interaction between basic fibroblast growth factor (bFGF) and type I collagen.
• To evaluate the therapeutic potential of type I collagen as a sustained release system for bFGF.

Main Methods:

• In vitro and in vivo studies of bFGF interaction with type I collagen solutions and sponges.
• Assessment of bFGF protection from proteolysis by collagen.
• Evaluation of sustained bFGF release from collagen sponges in mouse subcutis.
• Analysis of angiogenic activity and blood flow increase in murine ischemic hindlimb models.

Main Results:

• bFGF spontaneously interacts with type I collagen under physiological conditions, gaining protection from degradation.
• Collagen sponges sustainedly released incorporated bFGF, demonstrating dose-dependent local angiogenic activity.
• Collagen microsponges with bFGF significantly increased blood flow in ischemic hindlimbs, outperforming bolus bFGF injection.

Conclusions:

• Type I collagen possesses significant, previously underestimated, biological significance as a reservoir for bFGF.
• Collagen-based delivery systems offer therapeutic utility for sustained bFGF release and enhanced angiogenesis.
• This finding opens new avenues for regenerative medicine strategies utilizing collagen-bFGF interactions.