In vivo tissue engineering for neointima formation on vascular prostheses

Neointima formation in vascular prostheses is a product of tissue engineering in vivo. For this purpose, three major factors, the necessary cells, a suitable matrix, and cytokines for cell activation, are required. We found a rapid neointima formation with endothelial cell lining throughout the graft surface using autologous bone marrow transplantation. Bone marrow contains both multi-potential cells and endothelial cells, a biological matrix for cell migration, and the ability to continuously produce cytokines. The key to success is as follows. First, the combination of different cell types is helpful for their survival. The second point is the separation of the cells. Enzymatically separated cells have difficulty surviving in vivo. A certain number of cells is required to start a new colony A clump of cells has an extracellular matrix to aid survival and some can produce cytokines. We transplant a system that slowly releases cytokines and supplies young cells using bone marrow. Such systems an useful not only in vascular prostheses, but also in various hybrid artificial organs and in surgery in general.