USP develops microneedles that take drug directly to skin cancer tumor

The therapy consists of using dissolvable microneedles that, applied directly to the tumor, take medications to fight skin cancer – Photo: personal file researcher
Research carried out at the São Carlos Institute of Physics (IFSC) at USP, in collaboration with Queen’s University of Belfast (United Kingdom), developed a new way to fight skin cancer. The therapy consists of using dissolvable microneedles that, applied directly to the tumor, deliver drugs to fight the disease, via Photodynamic Therapy (PDT). The method was tested on animal models. The study’s author is Michelle Barreto Requena, of the IFSC Optics Group, who did her sandwich doctorate in the United Kingdom.

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Based on her research done for her doctorate, which set out to investigate mechanical methods to improve the delivery of cancer drugs, Michelle discovered a new dimension to her work when she was in contact with a group of specialists in the development of polymeric microneedles, in the United Kingdom. Based on the partnership established, he directed his work to the area of non-melanoma skin cancer treatment.

Back in Brazil, at IFSC, Michelle tested the new microneedle procedure on animal models. The research was guided by Professor Vanderlei Salvador Bagnato, from IFSC. The results obtained in the tests with mice were superior to those presented in topical applications, which are usually made with cream.

According to the researcher, due to the new experience, the drug was made available more homogeneously and at greater depths in the tumors. The drug concentrations were four times lower than those used in creams. The article Dissolving microneedles containing aminolevulinic acid improves protoporphyrin IX distribution describes the results and was published in the Journal Biophotonics .

Michelle Barreto Requena, PhD student at the IFSC Optics Group at USP and author of the research
The innovation, which fits at the tip of a finger, is made up of an arrangement containing 361 microneedles, pyramid-shaped, 0.5 mm (mm) high. During application, the arrangement is positioned on the tumor surface and pressed for 30 seconds. It remains inserted in the tumor so that the microneedles dissolve for an hour. After that time, the microneedles dissolve and the drug is absorbed by the tumor. From then on, the region is illuminated, initiating the process of photodynamic therapy, explains Michelle.

In her master’s dissertation, defended in 2015, Michelle describes that Photodynamic Therapy (TFD) is characterized by a set of physical, chemical and biological processes that occur after the administration of photosensitizing compounds (FS), a source of light and the oxygen. In this therapeutic modality, energy transfer mechanisms occur between the FS and the molecular oxygen present in the tissues, generating reactive oxygen species capable of leading cancer cells to death.

According to the researcher, the new procedure is minimally invasive and does not cause pain or bleeding during application. The next steps would be clinical studies in humans and, if all goes as the researchers are planning, in the future, this type of procedure could be made available to hospitals, health centers and doctors’ offices, adds Michelle.