New gene therapy via skin can combat cocaine addiction

Scientists have developed a novel approach using skin cell-based gene therapy to stifle the desire for cocaine and to protect against an overdose.

The study, succesfully tested on mice, involved removing a small patch of skin and introducing genes that produce cocaine-degrading enzymes. Finally, grafting it back onto the patient.

"Our results show promise of cutaneous gene therapy as a safe and cost-effective therapeutic option for cocaine abuse in the future," said researchers led by Ming Xu, Professor at the University of Chicago. 

For cocaine addicts or those prone to cocaine abuse, this approach could reduce drug-seeking and protect against cocaine overdose, potentially making them "immune" to further cocaine abuse. 

This skin cell-based approach can potentially be used to treat alcohol, nicotine and opioid abuse and co-abuse, the researchers said.

In the study, the team collected primary epidermal basal progenitor/stem cells from newborn mice and used CRISPR to deliver engineered human butyrylcholinesterase (BChE) -- enzymes that can degrade cocaine -- to the cells.

Then they prepared skin organoids and transplanted them back to the donor animals, where they acted as a depot for robust expression and secretion of hBChE into the blood stream. 

This efficiently protected the mice from cocaine-seeking and cocaine-induced relapse. It even prevented the death of mice exposed to uniformly lethal doses of cocaine, the researchers noted.

Mice who received the skin grafts were able to remove cocaine from the bloodstream much faster than normal mice.

They were able to withstand cocaine overdoses that would be lethal to 100 per cent of unprotected mice and were less likely than untreated mice to enter environments previously associated with cocaine use. 

However, mice exposed to alcohol retained a learned fondness for that drug.

"Our study demonstrates that transplantation of genome-edited skin stem cells can be used to deliver an active cocaine hydrolase long term in vivo," the researchers said, in the paper published in the journal Nature Biomedical Engineering. 

The study showed that epidermal stem cells "can be successfully employed for ex vivo gene therapy, as efficient genetic manipulation is possible with minimal risk."