Histomorphological observations revealed the formation of three-dimensional crosstalk models composed of HMVECs and HDFs or HMVECs and HT-29 cells. In addition, human microvascular endothelial cells (HMVECs) were cultured on one surface of the collagen vitrigel membrane with a nylon frame, and human dermal fibroblasts (HDFs) or HT-29 (a human colon carcinoma cell line) cells were cocultured on the opposite surface. Serum proteins up to a molecular weight >100 kDa also gradually passed through the collagen vitrigel membrane. Glucose penetrated through the collagen vitrigel membrane to the opposite side, and concentrations on each side were found to be equilibrated within 24 h. Here, we investigated the molecular permeability of the collagen vitrigel membrane in a time course-dependent manner using glucose and serum proteins. By encompassing the collagen vitrigel membrane in a nylon frame, it can be easily handled with tweezers, and functions as an excellent scaffold for three-dimensional cell culture models, as cells can be cultured on both sides. This novel stable and transparent gel has been termed ‘vitrigel’. Soft and turbid collagen gel disks were previously converted into strong and transparent gel membranes utilizing a concept for the vitrification of heat-denatured of proteins.

Protein scaffold composed