The University of Hull researchers have developed a method of loading nanoparticles with numerous light-sensitive molecules, which can help to establish an effective type of photodynamic therapy (PDT) for cancer treatment.
The PDT utilizes molecules, which when illuminated with light damages cells and generates oxygen in toxic forms known as reactive oxygen species. PDT utilizes single light-sensitive molecules whereas it is possible for the nanoparticles to transport hundreds of molecules to a cancerous area.
The PDT uses several light-sensitive molecules called photosensitisers. Each molecule absorbs specific portions of the light spectrum. The research team from the University of Hull placed one type of photosensitiser within and another type on the outside of each nanoparticle, which resulted in the creation of a highly reactive oxygen species using the same amount of light. The recent issue of Molecular Pharmaceutics published the research findings.
Dr Ross Boyle, lead researcher, stated that the nanoparticles have been specially designed with the right dimensions to penetrate the tumor with ease. He added that minute cancer tumors receive oxygen and nutrients by the process of diffusion. When tumors reach a particular size, they have to develop blood vessels to continue their growth, he says.
He also explained that these newly formed blood vessels are permeable and not as stable as normal blood vessels. The nanoparticles have been designed such that the blood vessel pressure will enable them to traverse through the gap between the cells and to enter into the tumor tissue.
The nanoparticles are formed from a material that prevents leaching of its contents in the blood. Light activates the nanoparticles at the tumor area causing the toxic reactive oxygen species to diffuse out of the nanoparticles limiting the damage of the cells to the cancer sites alone.
The nanoparticles were tested on colon cancer cells and though they were able to penetrate the cells, researchers found that nanoparticles were more effective when placed adjacent to the cells rather than inside them.