Fibrin Glue A Scaffold for Cellular-Based Therapy in a Critical-Sized Defect

Purpose: Cartilage-based treatments have vast applications in plastic and reconstructive surgery, especially craniofacial constructs. Current techniques in craniofacial cartilage reconstructions greatly rely on autologous donor site harvest. Whole cartilage grafts are wrought with complications of warping, resorption, extrusion, and donor site morbidity. Percutaneous delivery of expanded chondrocytes would have the potential to expand a small quantity of autologous cells to deliver cell therapy. To deliver chondrocytes effectively, there must be a reliable medium in which chondrocytes can be kept. The purpose of this work is to highlight the utility of fibrin glue sealant, Evicel, as a suitable chondrocyte carrier in the treatment of a critical-sized defect model of nonarticular cartilage previously developed in our laboratory. Methods: Athymic rats were separated into 2 groups: fibrin glue (n = 3) and fibrin glue + rat chondrocytes (n = 6). The animals with an empty defect were used to ensure that they responded normally to the procedure. All animals received a 3-mm full-thickness xiphoid cartilage defect characterized previously as a critical-sized defect in our laboratory (Moyer HR, Wang Y, Farooque T, et al. Tissue Eng Part A. 2010; 16:2321-2330). A control animal received no xiphoid defect creation procedure. The fibrin glue group was treated with 0.5 mL of fibrin glue placed directly into the 3-mm defect. The fibrin glue/rat chondrocyte group received a mixture of 1 x 10(6) resting zone chondrocytes mixed with 0.5 mL of fibrin glue. Rats were euthanized at 5 weeks (35 days) and their xiphoid cartilages harvested. The xiphoids were analyzed with morphometrics through histology and microcomputed tomography. Results: In the fibrin glue vehicle group, there was minimal evidence of wound healing. Xiphoid defects treated with resting zone chondrocytes in a fibrin glue carrier were significantly smaller (P = 0.002) at harvest and had significantly more glycosaminoglycan content on microcomputed tomography analysis. Thus, there was significant healing in the chondrocyte/fibrin glue group. Conclusion: Human fibrin sealant is an effective chondrocyte carrier and retains viable cells. Treatment of a nonarticular critical-size defect with resting zone chondrocytes embedded in a fibrin glue polymer demonstrates tissue healing.