Experimental "nano-analgesics" are more effective than morphine, but have a low risk of addiction, scientists discover
- Due to opiate addiction, more than 70,000 Americans died of overdose in 2017
- Many experts blame prescription painkillers for the onset of the epidemic
- But 1.5 billion people worldwide are living with chronic pain – and there are no treatment options that are as effective as opioids
- Researchers at the University of Delaware and France reviewed a drug that exists in the body to treat lower-risk pain in rats
Natalie Rahhal Deputy Health Editor for Dailymail.com
Scientists believe that an experimental "nano-analgesic" could be a safer, non-addictive alternative to the drugs that fuel the current opioid crisis.
Collaborating researchers at the University of Delaware and Paris-Saclay University in France have given their innovative drug to rats with painful, inflamed feet.
The animals appeared to have less pain, but showed no signs of dangerous side effects – addiction – associated with opioid analgesics.
In 2017, 70,237 Americans died of overdoses due to epidemics. But worldwide, 1.5 billion people suffer from chronic pain that can make them unbearable every day.
We urgently need safe ways to treat pain – and the international team of scientists hopes they may have found a way.
Scientists have reworked a peptide in our body to treat pain longer than morphine, but without the highly addictive properties of opioid analgesics (Figure, File).
The drug OxyContin by Purdue Pharmaceuticals was probably the blockbuster that it did in part because it's so addictive – but also because it worked.
But the scale quickly tilts on the American perception of the drug. It can do more harm than good.
However, this shift is not good for people who are really painkillers. So far, however, few treatments – including anti-inflammatory drugs and cannabis – have proven adequate.
So it's about developing the next generation of painkillers without addiction.
Opioids combine with matching receptors to produce a dull pain signal and activate the reward and pleasure system of the brain.
But there are also natural compounds in the body that act on these receptors, including a small peptide called enkephalin.
We know four different opioid receptor systems – the sets Mu, Delta, Kappan and receptor Like-1.
Current opioid drugs such as OxyContin bind to Mu receptors.
However, encaphalin peptides match the delta systems.
Encaphalin alone struggles to cross the blood-brain barrier, a deficit that effectively curbs pain relief.
So have Dr. Feng Jiao, a chemistry and biomedical engineering graduate from the University of Delaware, and his associates in France reworked the encaphalin with nanoparticles – tiny particles that scientists are increasingly using to ensure that drugs reach their goals as effectively and efficiently as possible.
The researchers fused the peptide and nanoparticles, which ensure that the new combination is "attracted" to the source of pain and able to move around the body better, having been released in a natural type of organic fat.
When they administered the new drug to the rats by intravenous infusion, the animals appeared to be less sensitive to pain, as judged by their reactions when heat was applied near the swollen tender paws.
In addition, the effects of nano-analgesics seemed to take longer than those of morphines, the researchers reported.
Since the drug acts on more peripheral opioid receptors, there is a lower risk of addiction.
If the nano-analgesic has similar effects and is equally safe in humans, this may be a promising option for the future of pain management.