With the development of AI technology, "personalized medicine" has been frequently mentioned in recent years, and the "precision", "efficient" and "wisdom" symbolized by "personalized" has made it an effective entry point to change the status quo of the medical industry. For example, intelligent guidance can interact with patients, and intelligent monitoring devices can help track and customize medical services. So, is personalized medicine only defined by AI medical products? I'm afraid not. Today, Intelligent Relativity (aixdlun) wants to talk about another level of personalized medicine technology - "organ on a chip."

Break the whole into pieces, truly "personalized" medicine

When it comes to personalized medicine, the first thing that comes to mind is gene medicine, which is a customized medical model based on personal genome information and combined with relevant internal environment information to design the best treatment plan for patients.

Although genetic testing and treatment can provide the basis for personalized medicine, there are also cases of cancer and diabetes found through genetic testing, and then precision medical means to delay the disease, but from the perspective of the development of genetic medicine, except for a few diseases, the correlation between genes and diseases is difficult to determine, such as "ALS" (ALS), the data shows that, Only a small percentage of ALS is associated with a genetic defect, and the cause of 90% of sporadic cases remains unexplained.

Therefore, it is not very reliable to include the entire genetic program of the human body as a reference for personalized medicine. At this time, the emergence of organ chips has given people a new reference index.

The concept of "organ chip" has a long history and was listed as one of the "Top ten emerging technologies" by the Davos Forum in 2016. According to the Proceedings of the Chinese Academy of Sciences, organ-on-a-chip refers to an organ physiological microsystem built on a chip, With microfluidic chip as the core, it can simulate in vitro the construction of tissue and organ microenvironment containing a variety of living cells, functional tissue interface, biological fluid and mechanical force stimulation and other complex factors by combining with cell biology, biomaterials and engineering methods, reflecting the main structure and functional signs of human tissues and organs.

In simple terms, it is to build a simplified version of the biological tissues and organs in the human body in vitro, retaining only the features of organ function and human pathobiology. The significance of "organ chip" in personalized medicine is to break the human body into pieces, change the accurate diagnosis of "human body" to the accurate diagnosis of "organ", and provide more effective and targeted treatment.

Through the use of patient-derived stem cells, the induced pluripotent stem cell-derived organ model can be engineered to make individualized disease risk prediction, drug efficacy evaluation, toxicological evaluation and prognosis analysis more accurate. At present, there are also scientists using stem cells from specific patients to build functional heart tissue to simulate hereditary heart disease models.

In addition to enabling personalized medicine for humans, there is another obvious benefit of organ chips, which is drug testing. This change to animal testing would be revolutionary.

Drugs have always been tested on animals, regardless of whether it's humane to use animals for drug testing. From the point of view of experimental accuracy, although animals share 99% of their genes with humans, the remaining 1% still creates significant variables, resulting in significant physiological differences between the two species. The same drug may react very differently in animals and humans. Even small differences in expression can be amplified as the drug development process progresses, ultimately leading to the failure of the entire project.

"Organ chips" because closer to the human body, can be more effective for drug testing, on October 11, Science Advances reported a 3D method of making neurons and muscle tissue on a microfluidic chip, with the help of this chip, scientists can test new drugs for "ALS".

Simulation, cost, connectivity... The problem with organ chips

The concept of organ chip has been proposed for a long time, but the process of industrialization is very slow, exploring the reasons can be roughly divided into three points.

First, even the most advanced organ chips cannot fully represent the function of living organs. After all, no organ can exist in isolation from the body. Although it is constructive to break the whole into pieces, the whole is greater than the parts, and it is impossible to copy the disease body by relying on organ chips alone, especially the endocrine environment leads to a series of functional changes.

Therefore, we must consider the interconnectedness of the human body as a whole, in this regard, we can use a single chip to form a highly integrated 3D tissue organ microfluidic chip system. The research team at Dalian University of Technology has developed such a system on a chip, which consists of multiple modules stacked on top of each other, integrating cells or tissues such as intestines, blood vessels, liver, tumor, heart, lung, muscle and kidney, with "digestive juices", "blood" and "urine" running through it.

In this way, the organ chip is like a building block, and all the building blocks can be piled up to create a "human body building" to the greatest extent, restore the functional environment in the human body, and achieve drug testing and other functions.

Secondly, organ chips are still a growing technology, and the immaturity of the industrial chain will lead to increased costs. CNBio, a firm based in Oxford, tests drugs for toxicity on chips containing 12 tiny livers. A unit currently costs 22,000 dollars. In fact, the price is much lower than the animal test, after all, the same test for mice cost $50,000.

However, this so-called "cheap" in the process of industrialization is still a question mark. At present, organ chips are mostly used in scientific research, and scientific research funds are enough to support the use of such tools, but our greater hope for organ chips is to land in the medical treatment of ordinary people, if organ chips want to go to industrialization, still need to control costs. Of course, with the improvement of the industrial chain, its advantages will slowly be highlighted, and the cost problem will be solved accordingly.

Until then, we may be able to use 3D printing technology as an important supplement to the organ-on-a-chip production method. 3D printing technology will have an impact on organ chips in at least two aspects, one is chip preparation, and the other is bioprinting. Especially in chip preparation, 3D printing has been able to produce chips with high resolution and complex structure, and has the advantages of short production cycle, simple unit operation, and low cost. Researchers at Harvard's Wyss Institute for Bioengineering and Harvard's JohnA.Paulson School of Engineering and Applied Sciences have used 3D printing to create the first complete organ-on-a-chip with an integrated sensing system.

Finally, there is a common problem in microfluidic chips, that is, it is not easy to connect macro samples with microchips. At present, the on-chip injection is mostly done manually, with low efficiency and poor reliability, which is very easy to affect the vitality of cells, and then affect the real-time detection of cell processes and biometrics. Therefore, we also need to develop more assisting products, such as continuous injection systems, to ensure that the preparation is automated, miniaturized and integrated.

Conclusion:

So far, personalized medicine has accumulated a lot of technical achievements. With the continuous development of technology, we also put forward more requirements for "personalized" and "accurate", the significance of organ chip for human beings is that people can really "correct medicine", without "damaging" other tissues and organs. With the deepening of people's research, organ chip technology will be widely used in the research of life science, medicine, pharmacy and other fields, and bring more possibilities for personalized medicine.