Authored by Sophia Trapani
Art by Michelle Choi
Connie Teevan was a healthy 44 year-old woman when, seemingly out of nowhere, she found five odd lumps on her breast, turning her life completely upside down. A subsequent biopsy revealed late stage breast cancer. After a mastectomy and the discovery of 14 more cancerous lymph nodes, her surgeon told her to live everyday like it was her last (7). Connie’s story, unfortunately, is not unfamiliar. The rate of early onset cancers, specifically for women in their 30s, is rising by 0.67% each year (2). But imagine if Connie’s cancer could have been cured with a medical grade laser. The emerging scientific field of photocatalysis empowers this sort of sci-fi-esque treatment to become a very real possibility.
Photocatalysis is a subspeciality of chemistry which uses specific wavelengths of light to power chemical reactions (6). Using light as an energy source for the catalysis of reactions has numerous applications such as waste-water treatment, energy production, and antibacterial coatings. Its most promising application, however, would be a new class of cancer treatments that targets exact tumor locations (5). The process would involve using photocatalysis to activate reactive oxygen species in the chemotherapy drugs that ultimately kill cancer cells by attacking their cellular structure (1). Consequently, in medicine, photocatalytic molecules have potential to be used as advanced drug delivery systems. To carry this out, pharmaceuticals, specifically chemotherapy type drugs, would be secured to a photocatalyst, and the mixture would be given intravenously to patients. Then, once the doctor is ready to activate the drug, they simply shine light on the cancer specific area to release the drugs from the photocatalyst (1). By only targeting cancerous areas, this treatment could make profound differences in a physician's capability to precisely treat patients. These patients would no longer have to endure the intense side effects of active chemotherapy agents coursing through their veins, thus greatly improving their overall quality of life.
Even though the use of light as a medical treatment is not new — in 1903, the Nobel Prize in Medicine was awarded to a team using ultraviolet light to treat skin lesions induced by tuberculosis — the field of photocatalysis is a relatively recent subspecialty (6). Nevertheless, early research has produced promising results: a study conducted by Lagopati et al. in 2010 found that using photocatalysis proved to be an effective treatment for epithelial breast cancer cells. The researchers were able to kill a highly malignant strain of breast cancer cells known as MDA-MB-468 using a mixture of TiO2 (titanium dioxide) and photocatalytically activated titania molecules. TiO2-based catalysis has also been shown to exhibit antimicrobial properties demonstrated by its ability to inactivate microbial toxins, inhibit the ability of a bacterium to reproduce, and decompose toxic cancerous cells (5).
As with any area of new research, though, there are an array of challenges that stand in the way of implementing photocatalysis as a viable cancer treatment, specifically, the lack of adequate testing, concerns around production and scalability, issues with design efficacy in vivo, and lengthy procedural development for treatments (6, 1). However, if photocatalysis is able to overcome this and become a widespread form of treatment, the potential impact on patients could be astounding. First, using light as the catalyst for the release of cancer drugs allows doctors to highly regulate and specialize the location of the drug’s activation. This could help preserve as much healthy tissue around the tumor as possible (6). Moreover, photocatalysis will hopefully reduce the long term impacts and burdens of cancer and cancer treatment. Research shows that because photocatalysis based treatment involves a lower amount of active chemotherapy drugs in a patient’s system, it can greatly decrease the overall toxicity required to eliminate the disease while still maintaining a high efficacy (8). The toxic components of chemotherapies have long lasting consequences including reproductive dysfunction, nerve damage, loss of taste/appetite, and other problems that deeply impact a patient’s quality of life (4). Hence, a treatment option that greatly reduces exposure to toxic chemotherapies could comprehensively improve the quality of life during and after therapy.
Ultimately, the research into photocatalysis as a cancer treatment is rapidly developing. The goal is to reach a day that if someone like Connie Teevan gets diagnosed with late stage cancer, they can go back to living a long and healthy life instead of being told that their days are numbered.
References
Teevan, Connie. One in a Million. Stanford Medicine. Patient Stories. https://med.stanford.edu/survivingcancer/inner-fire/section-4-the-power-of-love--family-and-friends/one-in-a-million.html
Goodman, B. (2023, August 16). Cancer diagnosis rates are going up in younger adults, study finds, driven largely by rises in women and people in their 30s. CNN. https://www.cnn.com/2023/08/16/health/early-onset-cancer-increase/index.html#:~:text=The%20study%20found%20that%20overall
Rapp, T. L., & DeForest, C. A. (2021). Targeting drug delivery with light: A highly focused approach. Advanced drug delivery reviews, 171, 94–107. https://doi.org/10.1016/j.addr.2021.01.009
Qurashi, A. (n.d.). Photocatalysis Types, Mechanism And Applications. Chemistrydocs.com. https://chemistrydocs.com/photocatalysis-types-mechanism-and-applications/#f_Antibacterial_and_Cancer_Treatment
Fooladi, S., Nematollahi, M. H., & Iravani, S. (2023). Nanophotocatalysts in biomedicine: Cancer therapeutic, tissue engineering, biosensing, and drug delivery applications. Environmental Research, 231, 116287. https://doi.org/10.1016/j.envres.2023.116287
Zhao, B., Wang, Y., Yao, X., Chen, D., Fan, M., Jin, Z., & He, Q. (2021). Photocatalysis-mediated drug-free sustainable cancer therapy using nanocatalyst. Nature communications, 12(1), 1345. https://doi.org/10.1038/s41467-021-21618-1
Mayo Clinic Staff. (2019). Managing the lingering side effects of cancer treatment. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/cancer/in-depth/cancer-survivor/art-20045524
Lagopati, N., Kitsiou, P. V., Kontos, A. I., Venieratos, P., Kotsopoulou, E., Kontos, A. G., Dionysiou, D. D., Pispas, S., Tsilibary, E. C., & Falaras, P. (2010). Photo-induced treatment of breast epithelial cancer cells using nanostructured titanium dioxide solution. Journal of Photochemistry and Photobiology A: Chemistry, 214(2-3), 215–223. https://doi.org/10.1016/j.jphotochem.2010.06.031