Biological molecule-impregnated polyester: an in vivo angiogenesis study

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Vascular Biology

Background:

• Angiogenesis, the formation of new blood vessels, is crucial for tissue regeneration and the integration of medical implants.
• Biomaterials can be functionalized with extracellular matrix molecules and growth factors (GFs) to improve their angiogenic potential.
• Porous scaffolds, like Dacron meshes, require vascularization for successful tissue ingrowth.

Purpose of the Study:

• To investigate the efficacy of composite fibrin matrices containing various angiogenic molecules adsorbed onto Dacron meshes for enhancing angiogenesis.
• To determine the in vivo release and tissue distribution of implanted growth factors (GFs).
• To quantify the impact of specific molecules on microvessel formation within the scaffold.

Main Methods:

• Composite fibrin matrices incorporating hyaluronic acid (HA), fibronectin (FN), fibroblast growth factor-1 (FGF-1), FGF-2, and endothelial cell growth supplement (ECGS) were prepared.
• Matrices were adsorbed onto Dacron meshes and implanted subcutaneously in mice.
• In vivo GF release and distribution were tracked using radiolabeled FGF-2.
• Angiogenesis was quantified by counting capillaries in histological sections.

Main Results:

• Radiolabeled GF was rapidly released from matrices, absent by day 28, with minimal systemic distribution.
• Significant increases in microvessel formation were observed with HA and ECGS at 14 days.
• Enhanced vascularization was noted with FN and ECGS or FGF-2 at 28 days.
• FGF-1 did not show a direct angiogenic effect in this model.

Conclusions:

• Fibrin matrices effectively support angiogenic molecules for promoting vascularization within porous scaffolds.
• Combinations of HA, FN, and FGFs with ECGS show promise for enhancing tissue ingrowth in Dacron prostheses.
• This approach offers a strategy for improving the integration of engineered tissues and medical implants.