Exploring the magical particles of the material world is related to the most precise theories of physics!

Author: Duan Yuechu

Positronium, also known as positronium, is the simplest bound state. The behavior of positrons and their decay products in a vacuum shows us the charm of quantum electrodynamics (QED). QED is a basic theory for studying the interaction between particles such as electrons and photons, and is also one of the most precise theories in physics. By studying positronium, scientists can verify the accuracy of QED and further explore the basic laws of the material world.

Positron-emitting radionuclides are those that can emit positrons through radioactive decay. In the pharmaceutical field, these radionuclides are often used in the development of radiopharmaceuticals and clinical diagnosis. The following are some common positron-emitting radionuclides, their preparation methods, and their applications in the pharmaceutical field:

1. 18F: 18F is the most common positron-emitting radionuclide in nature, with a half-life of about 109.7 minutes. 18F is mainly used for PET (positron emission tomography) imaging. By preparing 18F-labeled radiopharmaceuticals (such as 18FFDG, which is used to detect glucose metabolism), it can be used for tumor diagnosis, heart disease assessment, etc.

Preparation method: 18F is usually prepared by proton bombardment of 18O and then chemically labeled to the appropriate drug molecule.

2. 11C: The half-life of 11C is about 20.4 minutes. It can be used to label a variety of biomolecules. For example, 11C-labeled acetate can be used to study tumor metabolism. 11C is also commonly used in PET imaging.

Preparation method: 11C can be prepared by proton bombardment of 14N and then incorporated into drug molecules through chemical synthesis.

3. 13N: The half-life of 13N is about 9.97 minutes. It is mainly used to label amine compounds, such as 13N-labeled ammonia, for studying renal function and drug distribution.

Preparation method: 13N can be prepared by proton bombardment of 12C and chemically labeled onto drug molecules.

4. 15O: The half-life of 15O is about 2.05 minutes. It can be used to label water molecules, such as 15O-labeled water, to study cerebral blood flow and metabolism.

Preparation method: 15O can be prepared by proton bombardment of 16O and chemically labeled onto drug molecules.

These positron-emitting radionuclides have a wide range of applications in the pharmaceutical field, including but not limited to:

Tumor diagnosis: PET imaging technology uses specific radioactive drugs (such as 18FFDG) to detect the metabolic activity of tumors.

Heart disease assessment: Use of radioactive drugs (such as 13N-labeled ammonia) to assess blood flow and metabolic status of the heart.

Neurodegenerative disease research: PET imaging technology is used to study the distribution and metabolism of specific radioactive drugs (such as 11C-labeled compounds) in the brain.

In summary, the applications of positron-emitting radionuclides in the pharmaceutical field are multifaceted, involving disease diagnosis, treatment monitoring, and basic research. With the continuous progress of radiopharmaceutical research and development, the application range of these nuclides is expected to expand further.

In the biomedical field, positronium is widely used. The decay process of positronium is very sensitive to the molecular structure and metabolic process in the body, which makes it a powerful tool for studying organisms. In positron emission tomography (PET) technology, positronium plays a key role. PET technology is an advanced medical imaging technology. By observing the decay process of positronium, doctors can clearly see the organs and tissues in the patient's body, thereby diagnosing diseases and evaluating the effectiveness of treatment.

It is worth mentioning that the new generation of high-sensitivity and multi-photon whole-body PET systems have pushed the application of positronium to a new level. This system can not only detect the decay process of positronium more accurately, but also reveal the degree of oxidation in the body through positronium, providing a new perspective for studying human health and disease.

Positronium, this magical particle, not only plays an important role in revealing the mysteries of the universe and promoting the development of medicine, but also has broad application prospects in the fields of materials science and energy. I believe that in the near future, with the continuous development of science and technology, positronium will bring more benefits to our lives and health.

References:

American Physical Society Reviews of Modern Physics
https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.95.021002