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Cross – Talk between Fibroblasts and Keratinocytes in 3‐d Fibrin Clots. In Vitro Studies

Abstract

Fibrin Sealant products such as TisseelR have been used over the last 25 years to reach hemostasis during surgery or to seal tissues. Moreover, there were many studies on the use of fibrin sealant in cell and bioactive substance delivery. Our In Vitro and In Vivo studies, over the last 2 years, have focused on the use of fibrin sealant to deliver human fibroblasts or keratinocytes to overcome the healing deficiency in chronic wounds. We have shown that some fibrin formulations supported a high fibroblast proliferation and other fibrin formulations supported a high proliferation of human keratinocytes. In this study, we examined the use of fibrin sealant in the co‐delivery of both human – derived keratinocytes and fibroblasts. The study report examined the cell proliferation of these two cell types in various formulations of fibrin sealant. Fibroblasts and keratinocytes were mixed with various dilutions of the Sealer Protein solution and added to culture plates before adding the Thrombin solution to form fibrin clots containing both cell types. We found that a low to medium sealer protein concentration (1–34 mG/mL) and a very low thrombin concentration (1 U/mL) in the final fibrin clots provided for an optimal cell proliferation for both cell types within these fibrin clots. This profile of proliferation was different from that seen when keratinocytes alone or fibroblasts alone were incorporated in the fibrin clots. Morphologically, it was difficult to determine the cell type from examining cell morphology, thus, it was difficult to determine the cell distribution. In conclusion, we found that various modified formulations of fibrin sealant may be chosen when co‐ delivering fibroblasts and keratinocytes. Moreover, there seems to be a positive feedback between keratinocytes and fibroblasts when they were co – introduced in the fibrin clots. This feedback could be carried by growth factors. Future studies will determine his signaling process.

Fibrin sealant as a delivery vehicle for cells, antibiotics, growth factors, and painkillers

“…This composition of fibrin can then be optimized for controlled release, and various formulations of fibrin sealant can be chosen for co-delivery. 33,[99][100][101] This wound healing model may be a future application for how fibrin sealant can be used to both heal a wound site and act as a delivery system for multiple loaded components. DiD on the surface of the 3D wound healing construct and near the fibrinfilled defect at a concentration of 300,000 cells/mL; B fibroblasts fluorescentlytagged with Vybrant DiO that are encapsulated inside a fibrin bead within the collagen layers of the 3D wound healing construct and near the fibrinfilled defect (20,000 cells/bead); and C a stacked fluorescent image of the keratinocyte-fibroblast bead co-culture with fibroblasts encapsulated inside fibrin beads.…”