Posts Tagged ‘Post-traumatic stress disorder’

Remote control of hormone release using magnetic nanoparticles

Reporter: Irina Robu, PhD

Depression and post-traumatic stress disorder can increase abnormal levels of stress hormones such as adrenaline and cortisol. Adrenaline and cortisol are steroids hormones, produced in the adrenal glands and is released into the blood stream and serve as chemical mediators. Scientists at MIT invented a way to remotely control the release of these hormones from the adrenal gland, using magnetic nanoparticles.

Magnetic nanoparticles are nanoparticles consist of magnetic elements such as iron, nickel, cobalt, chromium, manganese, gadolinium and their chemical compounds. These nanoparticles are super magnetic due to their nanoscale size and can be selectively attached to a functional molecule and allow transportation to a targeted location under external magnetic field from an electromagnet. In an effort to avert aggregation and minimize the interaction of particles with the system environment.

This method can aid researchers to study more about how hormone release influences mental health and can ultimately bargain a new way to treat hormone-linked disorders. To obtain a control over hormone release Dekel Rosenfeld, an MIT-Technion postdoc has developed specialized magnetic nanoparticles that can be injected into the adrenal gland. When exposed to a weak magnetic field, the particles heat up slightly, activating heat-responsive channels that trigger hormone release. This technique can be used to stimulate an organ deep in the body with minimal invasiveness.

In the new study, the exploration team desired to discover the idea of treating disorders of the brain by manipulating organs that are outside the central nervous system but impact it through hormone release. Hormones secreted by the adrenal gland, including cortisol and adrenaline, play vital roles in depression, stress, and anxiety.

The researchers decided on ion channels that control the flow of calcium into adrenal glands as a target to stimulate hormone release. When calcium flows through the open channels into adrenal cells, the cells begin pumping out hormones. To stimulate these heat-sensitive channels, scientists designed nanoparticles made of magnetite. In rats, they found these particles could be injected directly into the adrenal glands and remain there for at least six months. When the rats were exposed to a weak magnetic field—about 50 millitesla (100 times weaker than the fields used for MRI), the particles heated up by about 6 degrees Celsius, enough to activate the calcium channels to open without damaging any surrounding tissue.

TRPV, the heat-sensitive channel that they targeted found in numerous sensory neurons throughout the body, including pain receptors. TRPV1 channels can be activated by capsaicin as well as by temperature and are found across mammalian species.This stimulation triggered a hormone rush, doubling cortisol production and boosting noradrenaline by about 25 percent which can lead to a measurable increase in the animals’ heart rates.

The investigators are now planning to use this method to investigate how hormone release affects PTSD and other disorders, and this technique would propose a much less invasive alternative to potential treatments that include implanting a medical device to electrically stimulate hormone release, which is not practicable in organs such as the adrenal glands that are soft and highly vascularized.



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