On June 23, 2022, Japan's A&M University (A&M University) announced that they had developed a simple method to generate nanofog. This kind of nanomist can replace the traditional needle syringe to inject drugs. It enters the bloodstream through transdermal absorption without puncturing the skin, and the drug absorption efficiency is higher than needle injection; this technology can also be used to make high-penetration products. cosmetics. The details of this invention were published in the British online comprehensive academic journal "Scientific Reports". The authors of the paper belong to a research team. They are Ryosuke Watanabe, a master's student in the Department of Physics and Engineering, Faculty of Engineering, Graduate School of Agriculture and Technology University, and Biology. Shiori Tanaka, a master's student in the Department of Food and Energy in the Department of Applied Science, Daisuke Yoshino, an associate professor, and Satoru Miyachi, an associate professor in the Department of Advanced Physics and Engineering of the Graduate School.
In the medical field in recent years, the "transdermal drug delivery" method of penetrating drugs from the skin surface into the human body has attracted much attention. It is said that using this method of drug administration can slowly enter the blood vessels under the skin, achieving the effect of maintaining the drug concentration in the blood at the same value for a long time, with little fluctuation, so it can effectively reduce the side effects of the drug.
In order for the drug to effectively penetrate through the skin, the nanometer size of the drug becomes very important; and the drug solution needs to be atomized to increase the surface area of the unit drug solution, that is, to increase the probability of contact between the drug solution and the skin. . In order to achieve the best nano-atomization effect, this research team developed an atmospheric pressure plasma liquid atomization technology. The electron microscope photo of the drug particle effect after atomization is shown in the figure below.
Scanning electron microscope photo of the effect of drug particles produced by the atmospheric pressure plasma atomization technology of medicinal liquid for needle-free injection developed by Japan Agricultural University
The invention team of this technology said that they used it in a machine with a jet opening (so it is atmospheric pressure ), a borosilicate glass tube with an outer diameter of 8 mm and an inner diameter of 6 mm is provided with 16 needle-shaped electrodes with the front ends ground into a 90-degree cone angle; a spiral ground electrode is wound around the outside of the borosilicate glass tube; an electrode is placed inside the glass tube Applying a medium frequency AC high voltage of 12.5kV and 10kHz can generate atmospheric pressure plasma in the tube through dielectric shielding discharge; use an injection needle to inject and replenish the liquid into the glass tube, and then spray nanometers from the nozzle of the glass tube Atomized liquid medicine.
used electron microscopy observation and found that when the liquid is transported at a rate of 10~100μL per minute, the particle size of the nanomist is effectively adjustable, and the maximum size is also below 400nm.
can promote transdermal absorption through nanometer-sized atomization; while constantly replenishing the medicinal solution into the glass tube, the medicinal solution can be continuously delivered to the target part. Compared with traditional electrostatic spraying methods, the nanomist generation mechanism is located in an electrically closed circuit between the electrodes inside the borosilicate glass tube and the spiral ground coil outside the glass tube, so it is highly safe.
The liquid that can be atomized by this method can not only be aqueous liquid (solution), but also oily liquid (solution) can be used to produce nanomist of oily liquid with relatively high viscosity.
So far, this study has verified three types of liquids for nano-mist generation: ultrapure water, phosphate buffered saline, and sesame oil. In addition to confirming that nano-mist is possible, most of the generated mist particles can pass through the skin. The size of the barrier function. In addition, by elucidating in detail the transdermal absorption properties of the chemical nanomist produced by this method, the company stated that this technology can also be used to promote the development of technologies such as drug inhalation, transdermal absorption, and high-penetration cosmetics.
