Multiphoton fabrication of micro-engineered structures with controllable porosity and mechanical properties

Abstract

One of the challenges in tissue engineering is to fabricate scaffolds which can mimic the natural microenvironments of cells. Given the complexity of natural extracellular matrix (ECM), engineered ECM is appealing both in enhancing the understanding of cell-matrix interaction and in controlling cell fates at ex-vivo devices. Our study is to establish a platform as engineered ECM by applying multi-photon photochemical crosslinking of proteins, which is a novel technique with intrinsic 3D fabrication capability. We have successfully achieved fabrication of proteinous structures varying from submicron lines, 2D micro-patterns and microporous matrices, and 3D micro-pillars. Scanning Electron Microscope was used for morphological characterization and quantitative porosity analysis. Elastic modulus of 3D protein micro-pillars was measured by compression test under Atomic Force Microscope. Dose dependence of fabrication on both protein (bovine serum albumin) and photosensitizer (rose Bengal) was studied. Fabrication parameters including average laser power and scanning speed were also investigated and their effects on porosity and elastic modulus were evaluated. This novel multiphoton-based platform provides a new approach to study cell-matrix interaction in the future.