In recent years, due to the development of medical technology, scientists continue to explore new ways to treat cancer. Researchers at the Massachusetts Institute of Technology have developed nanoparticles that can carry anti-cancer drugs into the blood-brain barrier into the brain and may be able to treat glioblastoma.
Glioblastoma
It also called malignant glioma, is the most common primary malignant tumor in adults, with an annual incidence of 5/100,000 to 7/100,000. This malignant tumor grows rapidly and lead the patient died.
The average life span of patients with malignant glioma is about 1 year. The current standard treatment for newly diagnosed malignant gliomas is surgical resection followed by adjuvant radiotherapy.
Those with a longer course may evolve from low-malignant astrocytomas. A few cases may have a stroke-like disease due to hemorrhage from the tumor.
Due to rapid tumor growth, extensive cerebral edema, and obvious symptoms of increased intracranial pressure, almost all patients have headaches and vomiting.
Approximately 33% of patients have seizures. About 20% of patients have mental symptoms such as apathy, dementia, and mental retardation.
Nanoparticle Therapy
The nanoparticles developed by MIT are liposomes, which are divided into two layers. They carry the commonly used chemotherapeutic drug temozolomide inside, and the outer shell carries experimental drugs JQ-1, JQ-1 stored in fat droplets.
The two drugs have their own functions. Temozolomide can damage the DNA of cancer cells, while JQ-1 is an inhibitor, which can reduce the tumor’s ability to repair DNA damage.
The next step is to help the nanoparticles to sneak into the blood-brain barrier. The researchers coated the nanoparticles with a protein called transferrin, which also helps the liposomes bind to cancer cells.
Finally, the armed nanoparticles are also wrapped in a polymer called PEG, which protects the nanoparticles from the immune system.
Nanoparticles can smoothly pass through the blood-brain barrier and deliver drugs to cancer cells. The unique combination of drugs also inhibits cancer cells.
What is the blood-brain barrier?
The blood-brain barrier refers to the barrier between brain capillary walls and the plasma formed by glial cells and the barrier between the plasma and cerebrospinal fluid formed by the choroid plexus. These barriers can prevent certain substances from entering the brain tissue from the blood.
Many solutes in the blood enter the brain tissue from the brain capillaries, there are difficulties and easy; some pass quickly, some are slower, and some cannot pass at all.
This selective permeability phenomenon makes people imagine that there may be a certain structure that restricts the penetration of solutes. This structure can make the brain tissue less or even not damaged by harmful substances in the circulating blood, thereby maintaining the internal environment of the brain tissue. The basic stability of the central nervous system has important biological significance for maintaining the normal physiological state of the central nervous system.
Treatment Effect
To confirm this, the researchers conducted experiments on mice. They selected mice with glioblastoma and applied nanoparticles. They found that the tumor really got smaller and stopped growing.
In the treatment process, first, the outer layer dissolves and releases JQ-1, shutting down the cancer cell repair system. About a day later, temozolomide was released into the tumor that had become very fragile.
The research team also found that the transferrin wrapped in the outer layer of the nanoparticles is also important. In the control group, the researchers directly injected temozolomide and JQ-1 into the blood of mice, but the effect was not good.
This is because the transferrin coated with nanoparticles can not only treat tumors, but also greatly reduce side effects,
Temozolomide not only kills tumors but also damages blood cells throughout the body, causing bruising, nausea, weakness, and other symptoms,
The FDA has approved the application of such nanoparticles to humans, which will undoubtedly accelerate the transformation of drugs into clinical trials.
But because the half-life of JQ-1 is too short, researchers may try another inhibitor called bromodomain.
This targeted drug therapy provides new ideas for the treatment of glioma, and its side effects are much lower than chemotherapy.