Nanoparticles to treat drug overdoses

Researchers have discovered that using nanotechnology could help reduce fatalities from drug overdoses, as nanoparticles can act as potential antidotes.

Scientists from Columbia University in New York have developed polymeric-based nanoparticles that have the ability to act as scavengers for overdosed drugs.

Drug intoxication, developed as a result of accidental overdosing, undesirable side effects, or suicide attempts, is a serious health problem. In the US alone, almost 20,000 people die of drug overdoses and accidental poisoning every year, according to the National Centre for Health Statistics.

For example, amitriptyline, a member of tricyclic antidepressants when consumed in excess amount, as in a suicide attempt, causes cardiotoxicity, leading to death.

"Hence there is a need to treat such intoxication by reducing free drug concentrations in the body in a short period of time," said the researchers.

"Nanoparticles, owing to their porous structure and submicron size can be considered as potential antidotes to reverse the fatal effects."

The research team has therefore developed poly(acrylic acid) (PAA) and alkyl modified poly(acrylic acid) (AMPAA) nanoparticles which have the ability to extract drugs such as amitriptyline and bupivacaine from bulk fluid in just a few minutes.

"It is assumed that nanoparticules could effectively extract drugs from bulk media and serve as scavengers for overdosed drugs," added the scientists.

According to the researchers, in recent years, significant effort has been devoted towards the development of nanotechnology for delivery of drugs and other biopharmaceuticals such as proteins, peptides and genes, since such systems allow controlling the release of agents to achieve the desired therapeutic level in target tissues for the required duration and for optimal therapeutic efficacy.

This new research shows that these advantages of nanoparticles can now be also used the other way around, i.e. towards the attenuation of the adverse effects caused by overdosing on amitriptyline and bupivacaine.

Microemulsions and other devices such as liposomes have already been explored for sequestration of overdosed drugs but the world of nanoparticles for such application still remains unexplored, the researchers said.

"Nanoparticles are expected to maintain better structural integrity once introduced inside the body due to their cross-linked structure," said Ponisseril Somasundaran, director of the Langmuir Centre for Colloids and Interfaces at Columbia University.

The extractions of the drugs from bulk media were monitored at pH 7.4 and at 37 degrees Celsius in saline solution.

The average size of the PAA nanoparticles was 80 to 100 nm. The researchers observed that in five minutes the nanoparticles managed to extract 81 per cent of amitriptyline and 62 per cent of bupivacaine.

According to the research team, the extraction capability of PAA is due to the electrostatic interaction between the negatively charged nanoparticles and positively charged drug molecules at pH 7.4.

The research was recently published in Soft Matter.