Nanocapsules for the precise transport of drugs

An international team of researchers succeeded in developing a completely new type of drug carrier designed for the targeted transport of drugs to the infected organ - gel nanocapsules with a double shell

[Translation by Dr. Nachmani Moshe]
An international team of researchers succeeded in developing a completely new type of drug carrier designed for the targeted transport of drugs to the infected organ - gel nanocapsules with a double shell.

Despite the fact that the research is in its very basic stage, the scientist Igor Potemkin, a professor in the Department of Physics at the Moscow State University, claims that the development of perfect nanocapsules for the targeted transport of drugs based on this research will be a practical possibility already in the coming years, and that the production itself will be pretty cheap Scientists have been focusing for many years on the development of systems for the targeted transport of drugs. Many laboratories around the world are researching this issue, this is in light of the fact that the potential inherent in such efficient systems is enormous. Many "nanocarriers" designed to transport drugs to a precise target in the body have been created over the years, however, scientists are still facing many challenges. The top challenge is how to prevent the drug from starting its activity before it reaches the right location in the body.

"Many existing carriers store drugs within them with the help of long-term electrostatic interactions - the carrier is attracted to the drug charged with an opposite electric charge. Our method is not based on electrostatic bonds at all - the filling of the nanogel with the active molecules, their "locking" in the niche and their controlled release are all controlled by temperature. Therefore, the drugs themselves can be both electrically charged and neutral," explains one of the researchers. According to the researchers, there are other means to activate the release of the drugs, for example, an external magnetic field and acidity level (pH). In any case, the researchers are still faced with the problem of the drug's release efficiency.

The researchers decided to use nano-gel capsules, which were previously underestimated, as the carrier systems. The main problem with using these systems in the past was their tendency to stick to neighboring molecules while loading the drugs. Such behavior made the transportation of the drugs impossible or completely ineffective. The scientists were able to solve this problem by creating a carrier consisting, like an egg, of two layers of membranes with different chemical structures. The outer porous layer has a protective (stabilizing) role that prevents the aggregation of the nanocapsules, while the pores of the inner layer are able to open and close depending on the temperature. During the filling phase, the pores of the two layers are open and the nanogel absorbs the drug molecules into it, similar to a sponge. In the next step, the temperature is changed and the pores inside the inner layer are closed, thereby locking in the drugs ready for transport without harming their effectiveness. In the next step, the pores open again and the active molecules will be released only in the appropriate locations in terms of temperature. The synthesis of the two layers was performed around a silica core. In the final step, the core is chemically dissolved creating an empty niche ready to be filled with the active compounds.

The main problem in this study was the fact that the researchers acted almost without certainty, when they do not know how the nanocapsule will behave, whether the niche inside it will remain stable after the removal of the silica core or will it collapse, and whether the size of the pore will be sufficient to capture the drug and release it as required during transport inside the body. Fortunately, these concerns turned out to be unfounded - in response to the temperature changes, the pores opened and closed as expected, the contents of the capsule remained intact, and the internal niche not only remained stable in terms of its structure, but it even expanded compared to its original size.

At this stage, the research is completely basic research, and it was originally intended to demonstrate the feasibility of the idea. The experiments themselves were conducted in a temperature range of 42-32 degrees Celsius, a little above the appropriate temperature for biological systems, but the researchers are confident that they will be able to adapt the temperature range to the human body.

Article Summary

A method for preparing drug carriers and their nanometric structure. The capture and release of the drug depends on the temperature surrounding the carrier system. [Courtesy: Igor Potemkin/Scientific Reports]