In nature, many creatures have the ability of regeneration and repair. When the sea cucumber is attacked by the enemy, it will gut out and then take the opportunity to escape. Soon, it will grow new internal organs. Lizards can regenerate their tails after their tails are cut off; Cut an earthworm into two sections from the middle, and its head (with chest section) can regenerate new earthworm; People's skin can heal to some extent after being scratched or damaged. Think about it, if you can't heal yourself, it would be terrible. And our self-healing ability is limited (for example, if the wound on the skin is cracked, we must sew needles to help the wound heal). For a long time, people have been working hard to study materials and devices that can perfectly regenerate and repair damaged and diseased tissues and organs. Since 1980s, the research on this kind of materials has begun to rise. It can regulate and induce the self-repair and regeneration ability of human tissues, so that regenerated natural healthy tissues and organs can replace diseased tissues and organs.

For the repair of diseased and damaged tissues and organs, we are familiar with the transplantation of tissues and organs, such as skin transplantation for patients with extensive burns and kidney replacement for patients with renal failure and uremia. However, due to the rejection of transplanted organs by human organs, the transplantation technology is limited. In fact, many patients died of rejection of this operation. In addition, not all organs can be transplanted. Therefore, to completely solve the problem of repairing damaged tissues and organs, we must find another way, such as using biomaterials to cultivate healthy tissues and organs.

The use of biomaterials can be carried out in the following two aspects:

The first one is to use a small piece of healthy human tissue or cells that need to be transplanted for in vitro propagation and culture, and then send them back to human tissues and cells for culture. For example, by inoculating fibroblasts from our human skin cells onto a porous membrane called "collagen-chondroitin sulfate", we can obtain a vibrant artificial skin. However, this kind of cell culture and reproduction takes a long time, and it is difficult for patients to wait, and the culture technology is not perfect. This technology is similar to the grafting technology of plants. For example, if we want to cultivate a pear seedling, we can graft it on other fruit trees and then take it down for planting.

The second is to select suitable carrier materials and substances that regulate cell growth and differentiation, and to locate and regulate their functions. We know that the basic unit of the human body is the cell, and a primitive fertilized egg cell can develop, multiply, grow and gradually differentiate into various tissues and organs. Now biotechnology can regulate the differentiation, reproduction and growth of these cells. What the patient needs, we will control the direction of cell development.