Source: Bio-Exploration (ID: biodiscover)
The cover of the latest issue of Science Translational Medicine magazine recommended a new dosing study that broke the 167-year needle injection history. The creation of this new mode of administration is a romantic imaginary journey. Scientists have created a liquid drug delivery patch that not only allows the patient to withstand less repulsion and pain, but also effectively and quickly The drug is delivered to the skin.
Inspiration for the snake's teeth: rapid penetration of capillaries
Since the invention of subcutaneous injection, pharmaceutical liquids and vaccines have generally been administered by needle. Although this method of injection has been a stable method for the quantitative delivery of drugs for hundreds of years, the pain, rejection and infection problems caused by needles cannot be ignored.
Professor Bae Won-kyu from Songsil University and Professor Jung-Hoon Jung from UNIST Research Source: Korea Research Foundation
So, Professor Bae Won-kyu from Chongshi University in Korea and Professor Jung-Hoon Jung from the National Institute of Science and Technology (UNIST) in Korea, “Deep Brain Hole”, simulated the snake tooth, and jointly developed a liquid drug. The patch is delivered to effectively reduce the repulsion and pain caused by traditional needle injections and deliver the polymer drug to the cells within 15 seconds.
Duvernoy glandular tooth venom in the posterior molar of Venom. Source: References 
Professor Bae Won-gyu introduced: This design is inspired by the process by which snakes secrete venom. We know that some snakes secrete venom through long teeth, while others release venom through the Duvernoy glands in the posterior molars. Glandular venom release is not only fast, but also unaffected by external pressure, acting through capillary osmosis. Inspired by glandular venom, the researchers designed a microneedle syringe with a groove on the top. The microneedle is like the posterior molar of a viper, and the groove containing the liquid is like the Duvernoy gland. Under micro-pressure, the liquid naturally penetrates into the subcutaneous cells through the capillaries.
Mini patch design: get rid of needle fear
The microneedle patch shown on the human thumb delivers a liquid drug when a slight pressure is applied to its surface. Image source: References 
The end of the paper is so shallow that I know that this matter must be carried out. The researchers used a semiconductor process to create a mini-slice of about 1 cm2, which was filled with 100 micro-needles of about two or three hair thicknesses and up to six similar grooves. The liquid penetrates into the body.
Patch action picture Source: References 
To verify their effectiveness, the researchers first performed a dosing simulation on a computer. It was found that, as expected, this approximately 1 cm2 patch allows 100μl liquid to be injected into the skin in less than one second without the need for a complicated drug delivery system. Later, the researchers also experimented with lidocaine preparations or inactivated influenza viruses on mouse and guinea pig models. It was found that the injection was completed in less than 5 seconds, and after a slightly longer drug infiltration, the corresponding immune response was produced in the animal model.
Professor Bae Won-gyu and his team are very excited about this research and development result. He said: “We learned the nature of “singularity” and not only improved the existing hypodermic syringe, but also solved the big needle. And rejection or pain caused by high pressure. In the future, we will conduct more clinical research in large animal models and human volunteers, hoping to complete the development of this new type of syringe faster and to facilitate more doctors.