The chip with "organs" is here! It is also the "universal drug tester" of the future

Recently, the artificial blood vessel chip developed by Gu Zhongze's team at Southeast University was used for on-orbit experiments by astronauts on the Shenzhou 15 spacecraft. This is not only the first organ chip project implemented on-orbit in my country's space station, but also the first artificial blood vessel tissue chip research in the world.

In this palm-sized polymer material, we use 3D printing, nano-processing and other technologies to build a "house" that simulates the human body environment, inject human cells or stem cells into it, and then supply oxygen and culture fluid to the "house". After two or three weeks, you can get a beating heart, a metabolizing liver, and breathing lungs that simulate human organs and tissues in the "house"...

Organ chips developed by Gu Zhongze's team. Source: Science and Technology Daily

In fact, the significance of organ chips goes beyond this. They not only "nourish" human cell tissues, but also carry mankind's hopes for drug development and the pursuit of life and health.

01 The Origin of Organ Chips: Indispensable Animal Experiments

A person will use drugs more or less throughout his life, and the development of a drug requires several steps, including the identification of candidate drugs, research on animal models, human clinical trials, and market approval, which is both time-consuming and costly. The development of a drug often takes more than ten years and is very costly.

If you like to raise small animals, you must know that in order to protect their health and vitality, you need to restore their original environment as much as possible, that is, their living environment in nature. The same is true for cells.

Traditional culture media are difficult to create real cell survival conditions, making it impossible to study the effects of drugs on cells. Therefore, scientists have turned their attention to animals such as mice, rabbits, and monkeys, in an attempt to use their organ structures similar to those of humans to complete pharmacology experiments.

The prototype of organ chips began in the early 21st century. In 2011, the Microphysiological Systems Alliance was established in the United States to start the research and development of organ chips, hoping to use them to replace animals for drug testing.

02 Organ Chips and Their Essential Characteristics

Organ-on-a-chip Organ chips are usually made of bionic materials, with microfluidic chips as the core. They construct bionic systems in vitro that cover the in vivo organ microenvironment factors such as a variety of living cells, tissue interfaces, biofluids and mechanical force stimulation, and even pathological environments.

The appearance of organ chips is not similar to that of organs, but the cell types and structures in the chip can simulate the real organ environment. Such as lung chip, heart chip, brain chip, liver chip, and even multi-organ chip combining multiple chip modules. These different organ chips essentially have the following three characteristics:

First, it has a 3D arrangement structure

Second, have multiple cell types to reflect more physiological balance between cells

Third, use mechanical forces associated with the chip model

03 Microfluidics

The technology used in organ chips is called microfluidics. Microfluidics is a technology that accurately controls trace amounts of fluid in integrated microchannels. It can flexibly prepare functional materials of different configurations according to different needs.

Since the sizes of many microscopic structures in the human body, such as blood vessels and muscle fibers, match those of microfluidics, microfluidics has shown good application potential in the preparation of bionic materials.

04 Advantages of organ chips over animal experiments

Compared with animal experiments, organ chips have obvious characteristics:

First, it usually takes 3 to 6 months, or even several years, to build an animal disease model, but it usually only takes two to three weeks to make an organ chip;

Secondly, a model animal can generally only be used for one drug test, while an organ chip can have hundreds or thousands of independent test units, which can be used for multi-concentration tests of several or dozens of drugs;

In addition, organ chips are made of human cell tissues and are highly consistent with the human body's response to drugs and pathogens.

Due to their human origin, low cost, and short culture cycle, organ chips can serve as a "stand-in" for human tissues to undergo drug experiments, thereby accelerating the drug development process and providing solutions for precision medicine.

In addition, organ chips can not only be used to evaluate the effectiveness of related drugs on the human body, but also to evaluate toxic and harmful substances in the environment.

Comprehensive sources: Science and Technology Daily, EFL, China Mechanical Engineering Society