In February I attended a talk hosted by the Uniclinic Münster from the „Cells in Motion“ initiative. They are know as „Brown Bag lunches“ and provide a forum for young Phd students to present their research to an audience of other Phd students and interested parties over lunch. The talks take up to an hour.
This particular talk was given by A. Galstyan about her research into photo dynamic therapy (PDT). PDT is a method of killing cells by using light. A chemical known as a photosensitizer is introduced into the body and then the part of the body with the cells to be killed is exposed to light. The photosensitizing molecules respond to light by releasing energy. The energy is passed on to oxygen to produce an extremely reactive species of oxygen. Finally, the reactive oxygen causes damage to the cell leading to cell death.
The ability of light to cause dramatic reactions in the body was discovered by Friedrich Mayer-Betz in 1913. He injected a chemical known as a hematoporphyrin into his body and exposed himself to sunlight. It produced intense swelling in his face and body which took months to subside. Current therapies use porphoryin derivatives as a photosensitizer. An example of a porphoryin derivative that occurs naturally in the body is haemaglobin in human blood cells.
A porphyrin molecule
In 1924 Policard discovered that porphyrin molecules accumulated preferentially in hyper proliferating cells. This was a key finding since cancer cells fall into this class of cells. PDT has therefore great potential as a cancer treatment.
The limitation of porphyrin derivatives as photosensitizers is that they have poor water solubility (thereby decreasing the ability to travel in the bloodstream) and poor tumour targeting. Research has focused on synthesizing derivatives that improve these 2 properties.
- Arijit Coondoo, Sujata Sengupta, Serendipity and its Role in Dermatology, Indian J Dermatol. 2015 Mar-Apr; 60(2): 130–135. doi: 10.4103/0019-5154.152504
- Velpula N, Maloth KN, Kodangal S, Chappidi V, Goyal S, Lingam S. Photodynamic therapy: A new modality treatment in pre-cancer and cancer patients. International Journal of Case Reports and Images 2014;5(4):250–257.
- Anzhela Galstyan: Targeted photoinduced killing of bacterial pathogens: from chemical synthesis to photobiological application, [Presentation to Brownbag-Lunch des Exzellenzclusters „Cells in Motion“, Münster], 11.2.16
- SANTOSA, Venny; LIMANTARA, Leenawaty. PHOTODYNAMIC THERAPY: NEW LIGHT IN MEDICINE WORLD. Indonesian Journal of Chemistry, [S.l.], v. 8, n. 2, p. 279-291, jun. 2010