Nanoparticles and metastases
Nanoparticles can be part of processed foods (for example, food additives), consumer goods (for example, sunscreens) and even medicines. While these particles have a huge unexplored potential and scope, according to data obtained by scientists at the National University of Singapore, they can have undesirable side effects on the human body.
In particular, the authors found that an antitumor nanopreparation designed to destroy malignant cells can accelerate the process of metastasis. Using a mouse model of breast cancer, they demonstrated that widely used nanoparticles made of gold, titanium dioxide, silver and silicon dioxide, including those included in medicinal nanopreparations, expand the gaps between blood vessel cells. This makes it easier for other cells, including malignant ones, to move from such "leaking" vessels to tissues and back.
A 30-minute exposure of titanium dioxide nanoparticles to the walls of blood vessels (left) causes the formation of cell-sized pores (right).
The phenomenon, which the authors called "nanomaterial-induced endothelial permeability" (NanoEL), facilitates the movement of cancer cells separating from the primary tumor, and also allows circulating malignant cells to leave the bloodstream and penetrate into tissues. This leads to the rapid formation of larger secondary tumors (metastases), as well as their appearance in places previously inaccessible to primary tumor cells.
According to the authors, for cancer patients, this means that long-term contact with nanoparticles, for example, included in everyday items or environmental pollutants, can accelerate the progression of cancer, even if they do not undergo therapy with nanopreparations. When developing such drugs, it is necessary to take into account the interaction between the nanoparticles included in their composition and the biological systems of the body.
Fortunately, the described mechanism can be used to benefit patients. The authors are already trying to use the effect of NanoEL in the development of more effective anticancer drugs. For example, nanoparticles inducing this effect can potentially be used to enhance vascular permeability, which will facilitate the access of drugs or stem cells to the affected tissue, which may initially be unavailable for therapy.
According to one of the leaders of the work, associate Professor David Leong, today his group is studying the possibility of using the NanoEL effect to destroy immature tumors that have few or no blood vessels with increased permeability of the walls, which would ensure the penetration of drugs into the tumor. This approach should be developed very carefully, choosing the optimal duration of the period of exposure of nanoparticles to the tumor. This will allow you to act directly on the source of the disease before the cancer cells spread through the body and create a very serious problem.
In addition to oncology, this phenomenon can find application in the treatment of other conditions in which a violation of vascular permeability is a key point. For example, organ damage, such as liver fibrosis, can lead to massive scarring of tissue. This is accompanied by a decrease in vascular permeability and a violation of the intake of nutrients from blood vessels into tissues. Currently, the authors are looking for ways to use the NanoEL effect to restore normal blood supply to scarred tissues.
Article by Fei Peng et al. Nanoparticles promote in vivo breast cancer cell intravasation and extravasation by inducing endothelial leakiness is published in the journal Nature Nanotechnology.
Evgenia Ryabtseva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of the National University of Singapore: NUS study: Nanoparticles may promote cancer metastasis.