Painless injections with 4D needles

Photo: Printed microneedles, Riddish Mord, Rutgers University

Scientists at Rutgers University drew inspiration from parasites and bees.

A team of scientists at Rutgers University in New Brunswick is developing 4D needles to help get rid of pain when injecting medicine, vaccinating and taking blood for analysis. The principle of action of innovative microneedles was developed by observing parasites and other living things.

It may seem disgusting, but the benefits that the parasite-inspired microneedles bring will far outweigh this emotional discomfort. Thanks to the use of 3D printing and materials capable of changing shape after printing, a group of scientists from Rutgers invented a painless and less invasive method of injection than using conventional medical needles.

Today, medical needles are the main instrument for taking blood samples, administering drugs or vaccinating. Anyone who has ever dealt with them at least knows that sensations are unpleasant at best.

Conventional microneedles are increasingly used in the medical sector because they reduce pain from injection and minimize the risk of infection. However, due to poor adhesion, there was a problem with the controlled delivery of drugs - used microneedles do not adhere well to the skin, even as part of special plasters, and are not suitable for the gradual administration of drugs (dropper, catheter) or for prolonged studies (taking biomaterial, holding sensors on skin). The solution will be printed 4D microneedles.



“We think that our microneedles created using 4D printing will increase the reliability and quality of injections for delivering drugs, healing wounds, conducting research and other activities with soft tissues,

” explains Ho Won Lee, lead author of the Department of Engineering and Aerospace Engineering Rutgers University.


Photo: Testing 4D microneedles, Riddish Mord, Rutgers University

Innovative 4D microneedles were prompted by nature; a team of scientists gleaned ideas from some of the characteristics of various living things, such as micro-hooks of parasites, stings of bees and porcupine needles. Taking them as a basis, a team of scientists invented a microneedle, which adheres to the skin when introduced.

The thickness and location of the teeth and the curvature of their bending are controlled by the parameters and composition of the material during photopolymer 3D printing, and the desolvation effect, in which the material inside the needles does not harden, was used to create internal channels.

The printed 4D microneedles were tested on a sample of chicken muscle tissue and the results were promising: a printed microneedle has 18 times better adhesion to tissues than a conventional microneedle without hooks, and exhibits a slower release of the drug, which allows more controlled administration of potent drugs .

In conclusion, it is worth saying that adhesive microneedles can play an important role in the diagnosis and monitoring of health, helping to take DNA samples, tests for enzymes, antibodies and other medical indicators. For patients with diabetes who have to take a lot of blood tests to control their sugar levels, microneedles can be a less invasive solution for both glucose testing and insulin use.

A study of printed 4D needles was published in the journal Advanced Functional Materials.