Rapid Fabrication of Living Tissue Models by Collagen Plastic Compression: Understanding Three-Dimensional Cell Matrix Repair In Vitro

Objective: To produce biomimetic collagen scaffolds for tissue modeling and as tissue-engineered implants. Approach: Control of collagen fibril material parameters in collagen hydrogel scaffolds by using plastic compression (PC), resulting in direct control of cell proliferation, cell migration, and cell-cell interaction. Results: We were able to control the density of collagen in such scaffolds from between 0.2% and 30%, and controllably layer the fibrils in the Z-plane. Cell migration was observed in gels where a gradient of collagen density was present. In these gels, cells preferentially migrated toward the collagen-dense areas. Cell proliferation rates were measurably higher in dense collagen gels. Innovation: The use of PC to control material properties of collagen hydrogels results in collagen scaffolds that are biomimetic. These collagen gels reproduce the relevant matrix-mechanical environment in which behavior is more representative of that found in vivo. Conclusion: The material properties of native collagen type I gels can be engineered to match those found in tissues in vivo to elicit more biomimetic cell behavior.