Fabrication of Three-Dimensional Bioactive Composite Scaffolds for Hemostasis and Wound Healing.

Fabrication of 3D composite scaffolds was carried out by lyophilization of variable concentrations of collagen and chitosan gel solutions. Fibrinogen and thrombin aerosol were deposited over the surface of scaffolds to enhance hemostasis and wound healing. Composite scaffolds were characterized using differential scanning calorimetry, thermogravimetric analysis, and Fourier-transform infrared spectrophotometer to ascertain the aerosol deposition and stability. Scanning electron microscope showed multilayered porosity with pore size of ~30 µm and mushroom-like fibril growth of aerosol. A detailed investigation by surface plasmon resonance confirmed higher binding affinity of collagen toward the human blood platelets and erythrocytes in comparison to chitosan and was found to increase with the increase in blood cell concentration from 480.8 to 886.4 RU for erythrocytes. Scaffolds showed higher binding response for platelets than erythrocytes, while fibrinogen and thrombin showed no or limited interaction. Highest blood sorption of 83 ± 4% was observed in case of aerosol deposited scaffolds. Aerosol deposited scaffolds showed minimum clotting time of 20 ± 3 s and bleeding time of 38 ± 4 s, which was significantly lower compared to the scaffolds without aerosol treatment. Aerosol deposited composite scaffolds with 2:1 concentration of chitosan/collagen showed complete wound contraction by day 14, while 50% was observed in case of the control group. In vivo studies revealed that chitosan had a crucial role in the inflammatory phase, while collagen played an important role in the proliferation and maturation phase. The present study suggests that the fabricated 3D composite scaffolds with bioactive moieties may be a potential candidate for enhanced hemostasis and wound healing applications.