By Alain Gaillard
Published: November 30th, 2016
When Brooklyn College hired Professor Alexander Greer in 1999 for its chemistry department, it recruited a pioneer in singlet oxygen fiber optics techniques. Dr. Greer’s main interest is photodynamic therapy (PDT), which kills bacteria cells and shrinks tumors by causing harmful oxidative reactions to happen in cells.
“I was trained in photochemistry and oxygen chemistry; I took a liking to it. I decided to look for avenues that can bridge the two worlds,” said Professor Greer. “Seems like there is lot of possibilities when bridging photochemistry and oxygen chemistry.”
Professor Greer’s soft-spoken demeanor belies his gregarious wit and determination to look for ways to help people. With a research group that includes postdoctoral collaborators and graduate and undergraduate students, Professor Greer has already received four collaborative grants. Most recently a company he co-founded with Professor Alan Lyons of the College of Staten Island received a grant from the National Institutes of Health (NIH) last September to continue work on targeted dental photodynamic therapy. Professor Deepak Saxena from New York University is also a collaborator on the project.
“These grants help the research infrastructure on campus,” he said. “It benefits everyone in that regard. It enriches the experience for undergraduate, Masters and Ph.D. students on campus. It also helps looking for avenue to phototherapy and aspect that will help people that have diseases.”
This grant will help fund the design of a device that can make PDT a more precise way to kill bacteria or tumor cells.
Professor Greer explained that PDT is process where light, oxygen, and a dye, which are all nontoxic reagents, come together to compose and form toxic reactive oxygen species. The goal is to get those reagents to a particular site of interest where they can affect just that area and leave healthy areas unaffected.
Listing the advantages of PDT over radiation and chemotherapy, Professor Greer explained that radiation therapy can kill a certain site but that the near-neighbor effect can occur, “so even though a huge quantity of the cell can be removed, if there is any trace left, then they will recur and grow back,” he said. “Certain chemicals can then spread into neighboring cells and kill them as well.” Meanwhile, PDT allows for much more accurate cell killing.
PDT has been around for about 40 years. According to Greer, other countries such as Brazil and Canada use PDT to a greater extent than the United States does. The cost of this procedure, due to expensive equipment and special training required, explains why the United States has not really embraced it. “One of the big problems is not actually scientific; it is policy, at least in the U.S. Many insurance companies don’t cover part of the treatment… They would not cover the cost of the surgeon, which is $15,000 an hour.”
Although he is cautious about the possibility of curing cancer completely, Professor Greer said that photodynamic therapy has been used for foot problems and bladder cancer with great success: “Curing cancer is an ultimate, but it is kind of hard to achieve. There is some semantics to it, whether that means there is no recurrence to it after 5 years, 10 years, 20 years; so there is always a monitoring. The word ‘cure’ is a goal to reach. It is a small increment of effort; hopefully, they will lead to something bigger.”
List of current grants:
1- Phase Separation of Reactive Oxygen with Mutli- compartmented Sensitizers. This project is currently funded by the NSF Chemistry Division.
2- A collaborative grant with Andrés Thomas Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas.
Title: Pointsource photodynamic therapy using Pterins and photosensitizers
3- A collaborative grant with Stefano Protti, Department of Chemistry University of Pavia, Italy
Title: Visible Light Generation of Reactive Intermediates from Azosulfones.
4- Singlet 02 Therapeutics LLC— in Support of NIH for Small Business Technology Transfer, Grant application Submitted (R41 STTR PhaseI, National Institute of Dental and Craniofacial Research)