Physics in the News: Physics Applied to Cancer Treatments

Physics in the News: Physics Applied to Cancer Treatments

Being interested in oncology research, I found a recent article on dissolving microneedles that could extend access to skin cancer treatments. In this type of treatment method, drug-infused microneedles are inserted by intradermal injection, which utilize photodynamic therapy (PDT) to treat skin cancers. Researchers use fabricated arrays of 500 micrometer long needles mixed with a water-soluble polymer and a precursor of a PDT photosensitizer. In mice trials, dissolved microneedles were determined, by use of fluorescence confocal microscopy, to be more effective than topical creams at delivering the therapeutic agent to the tumor cells. Compared to mainstream topical creams, mice with microneedles arrays had a 200% increase in uptake of the photosensitizer precursor that was well diffused to the depths of the tumor. Because of this, researchers particularly find this method to be effective at treating thicker skin lesions. Additionally, this approach is quite cost-effective as it requires a lesser concentration of the precursor than the topical creams. This method also provides a non-invasive alternative to surgical procedures, which are currently the standard treatment method for non-melanoma skin cancers.

University of Sao Paulo’s Michelle Barreto Requena leads this PDT research where she is focusing on improving the photosensitizer to have the greatest effect possible. To do this, her team found that using the precursor, aminolaevulinic acid, allowed for greater penetration of tumor cells. ALA is taken up into tumor cells where it is then processed into the photosensitizer protoporphyrin IX form. By using dissolving microneedles, Requena and her colleagues are able to treat past superficial cells, which topical creams are limited to.

PDT works by using certain chemicals that can be activated by irradiation of a certain frequency of light, which is similar to the photoelectric effect discussed in introductory physics classes. The energy from photosensitizing chemicals converts molecular oxygen into reactive oxygen species to damage targeted cells and its DNA. By shining light on the tumor cells, physicians can specifically induce the cell death of cancerous cells while preserving nearby healthy tissue. 

(http://www.facialskincancer.com/html/photodynamic_therapy.php)

Michelle Barreto Requena holds a bachelor’s degree in physics and a Master of Science in biomolecular physics. She most recently finished her PhD program in the biomolecular physics program at the institute of Physics at the University of Sao Paulo in 2019. She now resides at the University of Sao Paulo as a post-doctoral researcher. 

From this article, it is clear to me physics is fundamental in medical research to improving quality of care, effectiveness of care, and healthcare equity.

Works Cited:

Marric, S. (2020, October 30). Dissolving microneedles could extend access to skin-cancer

    treatment. Physics World. Retrieved from https://physicsworld.com/a/dissolving

    microneedles-could-extend-access-to-skin-cancer-treatment/

Requena, M. B., Permana, A. D., Vollet‐Filho, J. D., González‐Vázquez, P., Garcia, M. R., de 

    Faria, C. M. G., Pratavieria, S., Donnelly R. F., & Bagnato, V. S. (2020). Dissolving microneedles containing aminolevulinic acid

    improves protoporphyrin IX distribution. Journal of Biophotonics.