A non-opioid pain relief

GlycoNet Investigator is developing a gel-based drug delivery system with a massive potential

by Ali Chou

GlycoNet Investigator Dr. Molly Shoichet, a Professor of Chemical Engineering & Applied Chemistry and Biomaterials & Biomedical Engineering at the University of Toronto, is developing a safer way to deliver pain killers for patients who undergo surgeries. This new biomaterial can deliver anesthetics to surgical sites without causing side effects typical of opioids, such as addiction.

“There is a big unmet clinical and societal need,” says Shoichet. “When most people undergo surgeries, they are treated with common anesthetics that don’t last very long. Typically, these patients will then leave the hospital with prescribed opioids.”

In collaboration with AmacaThera Inc.—a company born from the work done in the Shoichet Lab—Shoichet and her team are developing a drug delivery system that could eliminate the need to prescribe powerful opioids to patients after surgery. This gel-based drug is easy to store and to inject, says Shoichet. It can target specific surgical sites and the effects can last up to three days. Common local anesthetics typically wear off four to 12 hours after being administered. The long-lasting effect of this new gel-based drug can be traced back to its composition.

“The gel-based drug comprises a hydrogel and a bioactive molecule. By formulating the drug this way, we can achieve sustained release and thereby keep the bioactive molecule longer at the site to relieve pain,” says Shoichet.

Shoichet uses an analogy to explain how the formulation works. “Imagine injecting a drop of dye into a bowl of water. The dye will diffuse quickly. However, if the dye is mixed together within a gel medium, a drop of the gel-dye mixture will diffuse slower in the bowl.” In Shoichet’s case, the dye is the bioactive molecule that relieves pain, and the gel medium is the proprietary hydrogel.

Another huge advantage of using the gel-based drug is that it is not addictive. Unlike opioids, which block pain signals sent from the brain to the body while releasing large amounts of dopamine —a substance that gives pleasure— local anesthetics obstruct the nerve transmitting signals to the brain without changes in awareness and sense perception in other areas. The gel developed by Shoichet achieves local delivery.

The gel-based drug has also been shown to be safe and efficacious through animal testing.

Yet, several steps still need to occur before the product can be commercialized. The team’s next challenge will be to scale up the production of the gel-based drugs to make it possible to test them in clinical trials. Shoichet remarks that this is the hardest step so far, but remains focused, knowing that when commercialized, the technology will alleviate at least some of the heavy medical burden stemming from the opioid crisis.

Other than post-surgical pain relief, Shoichet mentions that this breakthrough can also be applied to tissue engineering and regeneration. In particular, the hydrogel serves as a carrier for cells and proteins, which can be delivered to sites to treat stroke, traumatic spinal cord injury, and blindness.

“Other than delivering pain killers, we are also using the hydrogel delivery system to carry biologic or small molecule therapeutics to the brain and the spinal cord to promote tissue repair and regeneration. We are also investigating different formulations of the hydrogel to carry cells to the retina and replace those cells that have died due to blindness. This could stop retinal degeneration, and even restore vision,” she says.

The versatile technology platform, as Shoichet describes, is analogous to the “Fedex of drug and cell delivery.”

“Our lab works on the packaging of the drug; we try to figure out how to deliver molecules, where they need to be, and for how long they need to be there,” says Shoichet. “Like Fedex, we don’t invent the contents of the package, rather we ensure that the drugs and cells are delivered in the most efficient way.”

You can see the latest on this project on her website: https://shoichetlab.utoronto.ca/