Nanosprits for cells
A group of scientists from Harvard University offers a new universal method of introducing various molecules into cells. Silicon nanoeedles coated with the test substance, like a syringe, pierce the membrane of growing cells, releasing molecules into the cytoplasm. The new development promises to greatly facilitate the work of many researchers.
The bulk of experimental work in modern biology is reduced to various manipulations with the cell: the introduction of genes, proteins or chemicals in order to study their effect on cellular processes. Often, the introduction of a new component into a cell is like the siege of a medieval fortress due to the need to overcome the cell membrane and numerous defense systems. In addition, such interference is fraught with unpredictable side effects, such as viral infection of the cell or the action of other molecules penetrating through the cell membrane. Many of these methods are suitable only for certain types of cells and only for certain molecules. The authors of the study in their article in the Proceedings of the National Academy of Sciences (Vertical silicon nanowires as a universal platform for delivering biomolecules into living cells) propose a new, unique in simplicity and principle alternative: the use of nanoscale needles to inject molecules into the cell.
The author of the development, Professor Hongkun Park, claims that their method allows you to introduce any molecules into almost any cell. If the new method proves its effectiveness, it will be able to significantly reduce the time spent on a variety of studies, including stem cell reprogramming and testing of new drugs.
Scientists from Professor Park's laboratory have found that most cells are able to grow on substrates dotted with vertical silicon nanoeedles without much harm to their condition. Growing cells are "impaled" on needles and within an hour they are literally pierced by the thinnest peaks. Even on such an inquisitorial bed, the cells feel great, continuing to grow and multiply normally. Penetrating through the membrane, nanoeedles open direct physical access to the cell, which allows you to introduce any molecules into the cell without worrying about the limitations of traditional methods.
The picture above shows neurons grown on a substrate covered with nanoeedles, fibroblasts at the bottom
Professor Park notes that although most of the cell types they tested easily adapt to nanoeedles without noticeable negative consequences, further research is still needed to establish whether such an intervention affects important cellular processes.
Before the nanoeedles are ready to perform the function of a cellular syringe, they must undergo special treatment. To begin with, their surface is treated with a reagent that promotes the fragile binding of the test substance with the nanoeedle material, and then coated with a targeted drug or a combination of drugs. When the nanoeedles pierce the cell membrane, the drug molecules are released into the cell. Various methods of chemical processing of nanoeedles make it possible to regulate the rate of release of molecules depending on the binding strength. By varying the length of the nanoeedles, it is possible to selectively deliver molecules to specific parts of the cell.
Nanoeedle substrates can be made in the form of special microchips designed for complex research. Such chips can be "printed" with a given sequence or combination of drugs, which makes it possible to test the effect of several different substances on one type of cell at once. According to the authors, this method allows testing up to 20,000 different proteins or other substances on a single chip.
Ruslan Kushnir
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Technology Review: Needling Molecules
21.01.2010