Special delivery
Nanoparticles developed under the guidance of Daniel Hayes, Associate Professor of Biomedical Engineering at Penn State University, have specific properties that allow microRNAs to be attached to them. The complexes are destroyed by the action of light of a certain wavelength, releasing an anti-cancer molecule at the right time in the right place.
microRNA is a molecule that interferes with the functioning of matrix RNA (mRNA). microRNA does not allow mRNA b to synthesize certain proteins, in this case – necessary for the survival of a cancer cell.
In a new study, scientists delivered silver nanoparticles with microRNA to the cancer cells of 20 transgenic mice with squamous cell skin cancer by injecting them intravenously. Nanoparticles accumulating in the tumor area were irradiated externally with light of a certain wavelength (415 nm) to separate microRNAs from them. The exogenous miR-148b delivered in this way connected with mRNA in cancer Ras-expressing cells, stopping protein synthesis and inducing apoptosis. In animals, tumors regressed by 92.8% within 24-48 hours and stopped growing. In addition, exogenous microRNAs attracted T lymphocytes to the tumor site and acted as a powerful immunomodulator, shifting the balance towards Th1 cytokines both locally and systemically.
Source: article in Biomaterials.
This delivery method has temporal and spatial specificity: instead of systemic delivery of microRNAs with the risk of side effects associated with it, microRNAs can be injected in combination with nanoparticles and released where needed and when needed. This is very important in the treatment of cancer, as it reduces the toxicity of treatment and the frequency of undesirable side effects. In addition, the delivery and activation of microRNAs only in tumors can increase the overall effectiveness of treatment.
A distinctive feature of the new method is also that the microRNA used can regulate a wide range of genes and is especially effective for the treatment of heterogeneous diseases, including cancer. In other words, the overall anti-cancer effectiveness of therapy is higher, since the treatment affects several points in the target cell. This, in turn, can lead to a decrease in the ability of cancer cells to become resistant to treatment, because microRNA is able to connect with various mRNAs in a cancer cell, diversifying the ways in which it blocks the production of proteins.
One of the disadvantages of the method is that it can only be used when the tumor is exposed to light through a fiber optic cable – cancer of the oral cavity, gastrointestinal tract, skin and other superficial tumors. The group intends to develop the technology to make it applicable for the treatment of tumors of deeper localization, as they are more significant in terms of mortality.
Article Y.Liu et al. Photocontrolled miR-148b nanoparticles cause apoptosis, inflammation and regression of Ras induced epidermal squamous cell carcinomas in mice is published in the journal Biomaterials.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru according to Penn State News: Custom nanoparticle regresses tumors when exposed to light.