| THE UNIVERSITY OF ADELAIDE |
The studies show that addiction can be blocked via the immune system of the brain, without targeting the brain's wiring.
Image: Sigarru/iStockphoto
In a major breakthrough, an international team of scientists has proven that addiction to morphine and heroin can be blocked, while at the same time increasing pain relief.
The team from the University of Adelaide and University of Colorado has discovered the key mechanism in the body's immune system that amplifies addiction to opioid drugs. Laboratory studies have shown that the drug (+)-naloxone will selectively block the immune-addiction response. The results - which could eventually lead to new co-formulated drugs that assist patients with severe pain, as well as helping heroin users to kick the habit - will be published in the Journal of Neuroscience. "Our studies have shown conclusively that we can block addiction via the immune system of the brain, without targeting the brain's wiring," says the lead author of the study, Dr Mark Hutchinson, ARC Research Fellow in the University of Adelaide's School of Medical Sciences. "Both the central nervous system and the immune system play important roles in creating addiction, but our studies have shown we only need to block the immune response in the brain to prevent cravings for opioid drugs." The team has focused its research efforts on the immune receptor known as Toll-Like receptor 4 (TLR4). "Opioid drugs such as morphine and heroin bind to TLR4 in a similar way to the normal immune response to bacteria. The problem is that TLR4 then acts as an amplifier for addiction," Dr Hutchinson says. "The drug (+)-naloxone automatically shuts down the addiction. It shuts down the need to take opioids, it cuts out behaviours associated with addiction, and the neurochemistry in the brain changes - dopamine, which is the chemical important for providing that sense of 'reward' from the drug, is no longer produced." Senior author Professor Linda Watkins, from the Center for Neuroscience at the University of Colorado Boulder, says: "This work fundamentally changes what we understand about opioids, reward and addiction. We've suspected for some years that TLR4 may be the key to blocking opioid addiction, but now we have the proof. "The drug that we've used to block addiction, (+)-naloxone, is a non-opioid mirror image drug that was created by Dr Kenner Rice in the 1970s. We believe this will prove extremely useful as a co-formulated drug with morphine, so that patients who require relief for severe pain will not become addicted but still receive pain relief . This has the potential to lead to major advances in patient and palliative care," Professor Watkins says. The researchers say clinical trials may be possible within the next 18 months. This study has been funded by the National Institute on Drug Abuse (NIDA) in the United States and the Australian Research Council (ARC).
Editor's Note: Original news release can be found here.
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| THE UNIVERSITY OF NEW SOUTH WALES |
For the first time, engineers at the University of New South Wales have demonstrated that hydrogen can be released and reabsorbed from a promising storage material, overcoming a major hurdle to its use as an alternative fuel source. Researchers from the Materials Energy Research Laboratory in nanoscale (MERLin) at UNSW have synthesised nanoparticles of a commonly overlooked chemical compound called sodium borohydride and encased these inside nickel shells. Their unique "core-shell" nanostructure has demonstrated remarkable hydrogen storage properties, including the release of energy at much lower temperatures than previously observed. “No one has ever tried to synthesise these particles at the nanoscale because they thought it was too difficult, and couldn’t be done. We’re the first to do so, and demonstrate that energy in the form of hydrogen can be stored with sodium borohydride at practical temperatures and pressures,” says Dr Kondo-Francois Aguey-Zinsou from the School of Chemical Engineering at UNSW. Considered a major a fuel of the future, hydrogen could be used to power buildings, portable electronics and vehicles – but this application hinges on practical storage technology. Lightweight compounds known as borohydrides (including lithium and sodium compounds) are known to be effective storage materials but it was believed that once the energy was released it could not be reabsorbed – a critical limitation. This perceived “irreversibility” means there has been little focus on sodium borohydride. However, the result, published last week in the journal ACS Nano, demonstrates for the first time that reversibility is indeed possible using a borohydride material by itself and could herald significant advances in the design of novel hydrogen storage materials. “By controlling the size and architecture of these structures we can tune theirproperties and make them reversible – this means they can release and reabsorb hydrogen,” says Aguey-Zinsou, lead author on the paper. “We now have a way to tap into all these borohydride materials, which are particularly exciting for application on vehicles because of their highhydrogen storage capacity.” The researchers observed remarkable improvements in the thermodynamic and kinetic properties of their material. This means the chemical reactions needed to absorb and release hydrogen occurred faster than previously studied materials, and at significantly reduced temperatures – making possible application far more practical. In its bulk form, sodium borohydride requires temperatures above 550 degrees Celsius just to release hydrogen. Even on the nano-scale the improvements were minimal. However, with their core-shell nanostructure, the researchers saw initial energy release happening at just 50 °C, and significant release at 350 °C. “The new materials that could be generated by this exciting strategy could provide practical solutions to meet many of the energy targets set by the US Department of Energy,” says Aguey-Zinsou. “The key thing here is that we’ve opened the doorway.”
Editor's Note: Original news release can be found here.
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