Pennsylvania is gearing up to become a global center for cannabis research. Yet for more than a decade, Philadelphia has been on the forefront of investigations into the medicinal uses of marijuana.

Sara Jane Ward has built a reputation exploring marijuana's effects on pain and addiction using animals at Temple University's Lewis Katz School of Medicine.

Ward and her colleague Ronald Tuma, a professor of physiology and neurosurgery, lead a  team of 10 researchers at Temple's Center for Substance Abuse in North Philadelphia.

Ward and Tuma conduct well-regarded research on cannabinoids, the molecular compounds produced by the marijuana plant. THC, the best known of the more than 100 compounds, is the psychoactive chemical that induces the feeling of being high. CBD, the second-most prevalent cannabinoid, is not psychoactive but has been shown to reduce inflammation and may have dozens of other health applications.

The lab recently investigated the so-called entourage effect, the theory that when multiple cannabinoids are administered together, the therapeutic effects are magnified.

"We found that, yeah, there was a 10-fold increase in how potent the drugs were when we gave them together," Ward said of the study funded by the National Institute on Drug Abuse. "That was really shocking. "

Ward and Tuma are beginning to explore the use of cannabinoids to treat chronic traumatic encephalopathy (CTE), a type of brain injuries suffered by athletes — football players in particular — after repeated head trauma.

Ward will be a featured panelist Tuesday, May 1, during the second day of the CannabisLearn Conference and Expo at the Convention Center. She'll also lead a program of lightning talks on Wednesday focusing on cannabis research, technology, and its commercial applications.

The Inquirer spoke with Ward last week. This interview has been edited for length and clarity.

What is your lab working on now?

One Temple-funded project is exploring cannabinoids and traumatic brain injury, something that has been pushed by the athletes for a long time. What's been missing is the basic scientific research. We'll use several brain-injury models to see which  might be best treated by different cannabis-based medicines.

We've made the most headway on a chemotherapy-induced pain project, and have seen very exciting results in our animal model. Clinical trials have begun in Canada based on these results.

Do you ever work on human subjects?

No. I don't have the expertise to do human studies.

What are the advantages to doing cannabinoid research with mice?

I have notably fewer challenges as an animal researcher than folks who are doing human studies.

For instance?

We want to build on the research we did with THC and CBD and we're also looking at terpenes [marijuana's fragrant oils] and other minor cannabinoids in the plant. Animal models let us do that in a very systematic way.

You need a sample size of eight to 10 individuals in each group to test each compound alone. In a year, for $250,000, I can tell you which cannabinoids do what alone and which in combination are effective. In a human study, that would take 10 years and thousands of patients.

The closest labs that do human work right now are at Columbia and Johns Hopkins. I'm looking forward to Temple becoming involved with clinical studies under Pennsylvania's research program. That's what we'll be trying to figure out at this CannabisLearn conference: What we can do in our medical schools with our patient populations, what are our research options, and what do we need to navigate the legal space to do the best work we can do within the medical guidelines?

How common are cannabinoid investigations in the U.S.?

There are many. Temple is one of the top research institutes in the country, and we have a reputation for getting the top researchers in the field. There are about 10 labs on the East Coast, but many may have only one or two researchers doing the work. Temple and Virginia Commonwealth University have the concentrations of talent, but work is spread across the country and around the world.

Commercial CBD products for dogs and cats already are for sale in Pennsylvania. What are your thoughts on them?

Because they aren't federally regulated products, we don't know what's in them. I think cannabis-based medicines for companion animals is a very exciting idea. It seems like a no-brainer, and research is going to go in that direction. It doesn't make sense to make the leap from rat to human and not think of our companion animals. But if you're not getting product from a regulated state dispensary, it's hard to have faith in it.