Collagen-Supplemented Incubation Rapidly Augments Mechanical Property of Fibroblast Cell Sheets

Cell sheet technology using UpCell (TM) (Thermo Fisher Scientific, Roskilde, Denmark) plates is a modern tool that enables the rapid creation of single-layered cells without using extracellular matrix (ECM) enzymatic digestion. Although this technique has the advantage of maintaining a sheet of cells without needing artificial scaffolds, these cell sheets remain extremely fragile. Collagen, the most abundant ECM component, is an attractive candidate for modulating tissue mechanical properties given its tunable property. In this study, we demonstrated rapid mechanical property augmentation of human dermal fibroblast cell sheets after incubation with bovine type I collagen for 24 h on UpCell plates. We showed that treatment with collagen resulted in increased collagen I incorporation within the cell sheet without affecting cell morphology, cell type, or cell sheet quality. Atomic force microscopy measurements for controls, and cell sheets that received 50 and 100 mu g/mL collagen I treatments revealed an average Young's modulus of their respective intercellular regions: 6.6 +/- 1.0, 14.4 +/- 6.6, and 19.8 +/- 3.8 kPa during the loading condition, and 10.3 +/- 4.7, 11.7 +/- 2.2, and 18.1 +/- 3.4 kPa during the unloading condition. This methodology of rapid mechanical property augmentation of a cell sheet has a potential impact on cell sheet technology by improving the ease of construct manipulation, enabling new translational tissue engineering applications. Impact statement We demonstrated that collagen I treatment can rapidly augment the mechanical properties of monolayer fibroblast cell sheets by increasing stiffness in a concentration-dependent manner without affecting cell morphology, cell type, or cell sheet quality. This methodology has a potential impact on cell sheet technology by providing an avenue for matrix stabilization. It can improve the ease of construct manipulation while allowing for rapid harvest of monolayer fibroblast cell sheets. Future investigations should evaluate mechanical property responses of cell sheets that consist of other cell types for broader translational tissue engineering applications.

Automated summary

This study demonstrated that rapid mechanical property augmentation of monolayer fibroblast cell sheets can be achieved by treating them with collagen I in a concentration-dependent manner. This methodology has the potential to improve the ease of construct manipulation in cell sheet technology and enable new translational tissue engineering applications.