Researchers in South Korea have developed a phototherapy technology that can significantly increase efficiency while reducing the pain of chemotherapy and minimizing side effects after treatment.
The research team has developed a cancer-targeted phototherapeutic agent that promises complete elimination of cancer cells without side effects. It involves only one injection and repeated phototherapy.
Phototherapy technology, a cancer treatment modality that uses light, injects a photosensitizer that destroys cancer cells in response to a laser, which accumulates in only cancerous tissues. Further, it shoots light to selectively destroy the cancer cells. It has far fewer side effects than radiation therapy or general chemotherapy (that inevitably damage the tissues surrounding the cancer cells). So, the Phototherapy technology is allowing repeated treatment.
Since the effect of the conventional photosensitizers only lasts for one session, photosensitizers have to be administered each time the treatment procedure is repeated. Moreover, the residual photosensitizer after treatment accumulates in the skin or eyes causing side effects due to light; thus, it is recommended to isolate the patient from sunlight and indoor lighting for some time after treatment. Overall, the patients receiving phototreatment have had to suffer from the pain of the repeated injection and the inconvenience of isolation in the dark each time. Recently, photosensitizers with phototherapeutic effects that get activated only in cancer tissues have been developed; however, they are still toxic and have to be injected for every repeated session of treatment.
The research team used peptides that selectively target cancer tissues and assemble themselves in a specific order to resolve the problems associated with the phototherapy technology. The team developed a peptide-based photosensitizer that activates phototherapeutic effects only in cancer tissues by using the internalizing RGD peptide (iRGD) that can selectively penetrate and target cancer tissues, and by proper design for the modulation of its reaction to light.
When this newly developed photosensitizer is injected into a living body, it is activated by the body temperature and aggregates into a supramolecular arrangement designed by the research team, to be stored around the tumor. The subsequent phototherapy can destroy only cancer cells without affecting surrounding normal cells.
The phototherapeutic agent developed by the researchers was injected into a mouse model implanted with a tumor, and the photosensitizer was stored around the tumor and was continuously released for a long time (2 to 4 weeks), demonstrating the ability of selectively targeting the tumor with just a single injection around the cancerous tissues. Moreover, no toxicity was found to destroy the surrounding tissues and major organs, even with repeated exposure to light. The cancerous tissues were completely removed through repeated procedures.
News Source: Eurekalert
