Three-Dimensional (3D) Fibronectin Nano-Array Presented on Fibrin Matrix Accelerates Mice Skin Wound Healing

Plasma fibrinogen (F1) and fibronectin (pFN) polymerize to form a fibrin clot that is both a hemostatic and provisional matrix for wound healing. About 90% of plasma F1 has a homodimeric pair of γ chains (γγF1) and 10% has a heterodimeric pair of γ and more acidic γ9 chains (γγ9F1). We have synthesized a novel fibrin matrix exclusively from a 1:1 (molar ratio) complex of γγ9F1 and pFN in the presence of highly active thrombin and recombinant Factor XIII (rFXIIIa). In this matrix, the fibrin nanofibers were wrapped with periodic 200-300 nm wide pFN nanobands (termed γγ9F1:pFN fibrin). In contrast, fibrin made from 1:1 mixture of γγF1 and pFN formed a sporadic distribution of pFN droplets (termed γγF1+pFN fibrin). The γγ9F1:pFN fibrin enhanced the adhesion of primary human umbilical vein endothelium cells (HUVECs) relative to the γγF1+FN fibrin. Three dimensional (3D) culturing showed that the γγ9F1:pFN complex fibrin matrix enhanced the proliferation of both HUVECs and primary human fibroblasts. HUVECs in the 3D γγ9F1:pFN fibrin exhibited a starkly enhanced vascular morphogenesis while an apoptotic growth profile was observed in the γγF1+pFN fibrin. Relative to γγF1+pFN fibrin, mouse dermal wounds that were sealed by γγ9F1:pFN fibrin exhibited accelerated and enhanced healing. This study suggests that a 3D pFN nano-array presented on a fibrin matrix can promote wound healing.