Treating drug addiction relapse and overdose are the primary goals of The University of Chicago researchers in a study published in Nature. Using CRISPR-Cas9, Ming Xu and colleagues edit the butyrylcholinesterase (BChE) gene in mice skin stem cells, which were used as skin patches to deliver BChE to mice injected with cocaine.

BChE is a natural enzyme that degrades cocaine into harmless and inactive components in humans. However, its usage for therapy is hampered by difficulty in delivery and making sure the enzyme maintains its function. Thus, using skin to produce modified BChE to continuously supply the body with the enzyme is a promising tool. The researchers find that skin-grafted mice injected with lethal doses of cocaine were able to live compared with control samples. Preference for cocaine is also low, and relapse is not observed after 25 days of withdrawal.

The researchers also test the expression of the enzyme in human skin cells. They find high expression of BChE in these cells, proving the promising effectiveness of the method. Further studies on possible side effects of the treatment is being considered by the group. If proven effective, this technology may be used in other types of drug and alcohol addiction in humans.

For more information, read the article in The Conversation and the study in Nature.