A team of engineers at the Massachusetts Institute of Technology (MIT) has discovered a way to deliver drugs that allow immune cells to divide. Scientists smuggled them in with nanoparticles added to cells sent to fight the tumor.
As a result, the drug acts only for a specific purpose by stimulating immune cells. Thus, the risk for the patient is reduced, informs Nature Medicine and the medical portal Physorg.com.
Clinical trials to use patients’ own immune cells to destroy cancerous tumors have produced promising results. However, this approach only works if patients are receiving high doses of drugs that allow the cells to divide rapidly, causing life-threatening side effects.
This new approach to this issue has greatly increased the success of an immune cell-based therapy that promises treatment for many types of cancer, said Dr. Darrel Irvine, research team leader.
What we saw (as a result of the research – PAP) is an additional impulse which, due to the effects of immune cell therapy only in certain patients, allows it to work in almost all patients. This puts us closer to treating the disease rather than just slowing its progression, he added. The new method could also be used to deliver other types of anti-cancer drugs and to increase the rate of maturation of blood cells in the bone marrow in people who underwent bone marrow transplant, the researchers said.
To enable cell therapy, doctors remove immune cells – T cells and inject them back into the patient, targeting the tumor. They find the tumor and slowly destroy it. Clinical trials are underway in patients with ovarian and prostate cancer and melanoma.
Immune cell therapy is a promising approach to cancer treatment, but there are major obstacles to its implementation. The biggest limitation concerns getting enough T cells, specific to fight the cancer cells and making them work properly in the patient. To circumvent these limitations, researchers tried to inject patients with an adjuvant that stimulated the production and spread of T cells. Interleukins – naturally occurring proteins that help develop T cells – have shown good results in human clinical trials, but interleukin therapy also had serious side effects. including cardiac or pulmonary arrest, when they have been introduced into the patient’s blood in large amounts.
Dr. Irvine and his colleagues took a new approach: to avoid toxic side effects, they turned to lipid-based nanoparticles to which they added sulfur-containing compounds normally present on the surface of T lymphocytes. nanoparticles and injected T-lymphocyte-nanoparticle complexes of mice with bone marrow and lung cancer. Once the cells reached the surface of the tumor, the nanoparticles degraded and began releasing the drug for a week. The drug molecules got to the surface receptors of the same cell that transferred them, stimulating its growth and division.
After approximately 16 days, all tumors in the drug-carrying T-cell treated mice had disappeared. These mice survived to the end of the 100-day experiment, while the untreated mice died after 25 days, and mice treated with T cells alone or T cells with interleukin injections died after 75 days.
Dr. Irvine and his colleagues also demonstrated what can happen if nanoparticles are added to the surface of immature blood cells found in the bone marrow, which is usually used to treat leukemia. Patients who undergo bone marrow transplantation must have their own bone marrow destroyed with radio- or chemotherapy before the transplantation itself, which makes them susceptible to infection, within 6 months after transplantation, before the new bone marrow begins to produce blood cells. Providing drugs that accelerate the production of blood cells along with bone marrow transplantation reduced the period of immunosuppression, which makes this process safer for the patient – says Dr. Irvine. In the publication Nature Medicine, his team also reported success in increasing the maturity of blood cells in mice that received the drug along with the cells. (PAP)