62 / 2018-07-30 13:00:50

Light-Induced Anisotropic Cell Sheet Technology for The Construction of Vascularized Tissue

light induced,cell alignment,TiO2 nanodot film,Tissue engineering

全体主题 > ii. Biomaterials and formulation of novel “bioinks” for tissue-specific applications

Introduction
Cell sheet technology has been applied in cell nondestructive harvest, thin-layer tissue replacement and cell-dense three-dimensional (3D) tissue construction1. However, well-organized orientation of cells and anisotropic extracellular matrix (ECM) are crucial in engineering biomimetic tissues, such as muscles, arteries, and nervous system, and so on2-4. Light-induced anisotropic cell sheet technology has been developed here to build functionalized vascularized bionic tissues.
Materials and methods
We demonstrated a light-induced cell alignment and harvest for anisotropic cell sheets (ACS) technology using light-responsive TiO2 nanodots film (TNF) and photo-cross-linkable gelatin methacrylate (GelMA). SEM, XPS and BSA absorption assay were used to characterize the substrates and anisotropic Fibroblasts sheets and mesenchymal cell sheets were obtained by proper UV light treatment. The properties of ACS were evaluated by immunofluorescence staining, cell viability assay and qPCR. Endothelia cells were sandwich between two layers of ACS to induce the formation of capillary-like networks.
Results
Micropatterned photofunctionalizaiton was obtained via photomask, and cells would display directional extension and arrangement on these micropatterned TiO2 nanodots film surfaces (Fig.1). Surface hydroxyl group features controlled by TiO2 photofunctionalization initiated a hierarchical signal processing thus guided the selective protein adsorption as well as the subsequent cell behaviors. Further UV treatment allowed ACS detachment from TNF surface while simultaneously solidified the GelMA. Two anisotropic cell sheets could further induce HUVECs to form anisotropic capillary-like networks via upregulating VEGFA and ANGPT1 and producing anisotropic ECM.
Conclusions
In this article, light-induced cell alignment, light-induced anisotropic cell sheet harvest and photo-crosslinkable hydrogel have been integrated into the technology, and related material and biological mechanisms have been explored. This developed integrated-functional ACS technology therefore provides a novel route to produce complex tissue constructs with well-defined orientations and may have a profound impact on regenerative medicine.