We know that the human body is composed of many organs, such as brain, heart, liver, spleen, stomach, intestine, lung, bones, muscles and skin. Organs are composed of various cells, which are the organizational units of organs, and the combination of cells shows the functions of organs. So what are cells made of? According to the present understanding, the main components of cells are various protein, nucleic acids, lipids and other biomolecules, which can be collectively called biomolecules, and there are hundreds of thousands of kinds of them. Biomolecules are the basic components of the human body, and they each have unique biological activities. It is their different biological activities that determine their division of labor and role in the human body. Because the human body is made up of molecules, all diseases, including aging itself, can be attributed to the changes of molecules in the human body. When molecular machines in human body, such as ribosome for synthesizing protein and enzyme for DNA replication, fails or works abnormally, it will lead to cell death or abnormality. From the molecular microscopic point of view, the current medical technology can not reach the level of molecular repair. Nano-medicine is just to make up for this deficiency. At the molecular level, it can use a series of tiny tools to engage in diagnosis, medical treatment, disease prevention, trauma prevention, pain relief, health care and health improvement. Moreover, at present, some diseases that are difficult to treat will be well treated by nano-medical technology.

With nanotechnology, people will know themselves from the molecular level, create and use nano-devices and nano-structures to prevent and treat diseases and improve the whole human life system.

First of all, we need to understand the molecular basis of life, and then we need to develop from scientific understanding to engineering technology, and design and manufacture a large number of nano-devices with incredible and peculiar effects. The geometric scale of these tiny nano-devices is only about one thousandth of that of hair, and they are assembled by molecules, which can play functions similar to those of tissues and organs, and can play a role more accurately and effectively. They can swim around the human body, even in in and out of cells, and accomplish special missions in the microscopic world of the human body. For example: repair distorted genes, kill budding cancer cells, catch bacteria and viruses that invade the human body, and destroy them before they become sick; Detect the changes of chemical or biochemical components in the body, release drugs and trace substances needed by the human body in time, and improve people's health in time. Nanomedicine in the future will be powerful, and it will be surprisingly small, because the drugs and medical devices that play a role in it are invisible to the naked eye. The ultimate realization of nano-medicine will make human beings have sustained health.

I need to remind you that if you go to the doctor for a nano prescription now, the doctor will be puzzled by you. The nano-medical landscape mentioned above is still in the stage of design and germination, and there are still many unknown fields to explore. For example, what should these nano-devices be made of? Can they be accepted by the human body and play the expected role? Scientists are making every effort to turn the scientific idea of nano-medicine into medical reality.

Some people will ask: Is nanomedicine a science fiction? How far is it from us? How long will it take to see the medical realization? In fact, it has gradually entered our lives and has developed vigorously. Let's take a look at the scientific progress that has been made in this field.