4D printed microneedles offer painless solution for shots
Rutgers University engineers drew inspiration from parasites and honeybees
A team of engineers from Rutgers University – New Brunswick is developing 4D printed needles which could take the pain out of drug injections, vaccinations and blood sampling. The innovative microneedles were inspired by certain types of parasites that attach themselves to the hosts skin.
If you got chills reading that last part, so did I. But the benefits presented by the parasitic-inspired microneedles far outweigh the initial discomfort. By utilizing 3D printing and smart materials that change shape after printing, the Rutgers team has created a pain-free and less invasive way of administering injections than existing hypodermic needles.
Today, hypodermic needles are the main medical instrument used to extract blood samples and inject drugs or vaccinations. Anyone who has received a shot will know that they are uncomfortable at best. Conventional microneedles are gaining traction in the medical sector because they offer practitioners a way to reduce the pain of injections and minimize the risk of infection. However, they have presented challenges in term of adhesion to tissues for controlled drug delivery. The 4D printed microneedles could offer a solution.
“We think our 4D printed microneedle array will allow for more robust and sustained use of minimally invasive, pain-free and easy-to-use microneedles for delivering drugs, healing wounds, biosensing and other soft tissue applications,” explained senior author Howon Lee, an assistant professor in the Department of Mechanical and Aerospace Engineering in the School of Engineering at Rutgers University–New Brunswick.
The innovative 4D printed microneedles were inspired by the natural world, and the research team drew from the features of certain creatures, like the microhooks of parasites, honeybee stingers and porcupines’ scaled quills. Based on these, the research team devised a microneedle that interlocks with skin tissue when it is inserted.
According to the Rutgers engineers, they used a combination of micro 3D printing and 4D printing to create the “backward-facing barbs” on the microneedles to achieve better skin adhesion. The 4D printed microneedles were tested with a muscle tissue sample from a chicken and demonstrated promising results: the printed microneedle was 18 times stronger than a non-printed microneedle, and outperformed previously reported samples.
Down the line, the adhesive microneedles could come to play an important role in biosensing applications, as they could detect DNA, enzymes, antibodies and other health indicators. For patients with diabetes, who must undergo many blood samples to monitor blood sugar levels, the microneedles could offer a less invasive technique.
A research study about the 4D printed needles was published in Advanced Functional Materials.