Researchers at Kyoto University’s Institute for Integrated Cell-Material Sciences (iCeMS) in Japan, recently reported a novel technique with potential therapeutic relevance for the management of pain. The study was recently published in the journal Angewandte Chemie International Edition and is entitled “Thermosensitive Ion Channel Activation in Single Neuronal Cells by Using Surface-Engineered Plasmonic Nanoparticles”.
Nanotechnology corresponds to the manipulation of matter at the molecular scale and it has allowed significant advances in medical diagnosis and treatment. The control of cellular functions using external photoresponsive nanomaterials has a huge potential for the development of cell-engineering technologies and therapies. Gold nanorods in particular, correspond to tiny rods that can absorb light in the near-infrared region generating heat when excited with infrared light; nanorods can also be used as light emitting devices.
In the study, the team developed a technique on which gold nanorods are used to target pain receptors. Researchers coated the gold nanorods with proteins that are able to transport fat within the body – lipoproteins. These particular nanorods where able to efficiently bind to intact neuronal cell membranes containing a thermosensitive pain receptor called TRPV1 (transient receptor potential vanilloid type 1). When these coated nanorods were then exposed to near-infrared light, they heated up, activating pain receptors and allowing an influx of calcium ions through the membrane. A prolonged activation of TRPV1 results in their desensitization, which leads to pain relief. One important aspect of this technique is that the heating of the gold nanorods allowed a safe activation of the TRPV1 pain receptors without having an effect on the membrane in which they are present.
“The gold nanorods can be retained in the body for a prolonged period,” explained the study’s senior author Dr. Tatsuya Murakami in a news release. “Local injection of our gold nanorods might enable repetitive and on-demand treatment for people experiencing intractable pain”
In conclusion, the research team developed a new technique based on lipoprotein-coated gold nanorods that are able to efficiently activate and desensitize pain receptors. This technique is especially relevant for the development of therapies for pain relief in individuals suffering from severe pain. This is often the case of patients with fibromyalgia, a medical disorder characterized by widespread chronic musculoskeletal pain, incapacitating fatigue and stiffness and numbness in certain parts of the body. Fibromyalgia can affect people’s ability to conduct simple daily tasks, compromising their quality of life. It is estimated that 5 to 15 million Americans are affected by this disorder, especially women.