Dissolving Microneedles Take a Stab at Zero-Waste, Painless Shots
Administering vaccines with a small patch covered in numerous microscopic needles instead of a hypodermic needle could lead to more effective vaccinations that anyone can give, with no harmful waste.
After hypodermic needles are used, they are considered biomedical waste and have to be disposed of in special containers. If tossed in the trash or intentionally reused, they pose a danger to anyone coming into contact with them.
An alternative to hypodermic needles being worked on is a small patch that is covered in microscopic needles (650 microns, to be specific) that contain a vaccine. When the patch is pressed into the skin, piercing only the top skin layers, the needles dissolve into the body, leaving only a backing that can dissolve in water.
Researchers at Emory University and Georgia Institute of Technology used microneedle patches to give influenza vaccines to mice, finding that mice that were vaccinated with patches responded to the flu as well as mice vaccinated with hypodermic needles. When exposed to the flu again after three months, the mice that had been vaccinated with patches cleared the infection from their lungs more effectively than the other group of mice.
In addition to providing improved immunization and painless injection, the simplicity of the patch and its lack of hazardous waste created would allow anyone to administer vaccines to themselves or others, and to even receive patches in the mail. Vaccines that are part of large-scale programs could also be distributed more quickly without the need to collect leftover waste. The researches noted that the patches would prevent the reuse of needles that happens in areas with poor medical infrastructure.
The researches said that the patches would cost the same as conventional needle and syringe techniques, and would possibly lead to lower personnel and waste disposal costs.
Further clinical studies will need to be done to assess the safety and effectiveness of using the patches on humans, and researchers may also study using other vaccinations.
To make the vaccine part of the needles, the researchers took poly-vinyl pyrrolidone, a polymer material they say is safe for use in the body, and mixed it will freeze-dried vaccine, then placed in microneedle molds and polymerized at room temperature with ultraviolet light.