Drug delivery needles can be 3D printed

Pain-free drug delivery device will allow drugs to diffuse within the body as the biomaterial device degrades

Mechanical engineers in the US have 3D ‘micro-printed’ an array of biodegradable needles capable of drug delivery.

The technique offers a pain-free drug delivery device that will allow drugs to diffuse within the body as the biomaterial device degrades. Treatments could cover a wide range of diseases, including melanoma cancers.

The researchers, based at the University of Akron in Ohio and the University of Texas, produced a drug-loaded array for transdermal delivery of a chemotherapy drug. The array consisted of 25 micro-needles, each having a tip and base diameter of 20µm and 200µm, respectively, and a height of 1mm. 

The micro-needles were 3D printed using a photocurable biomaterial to encapsulate the drugs and a digital micro-mirror device (DMD). This device is a micro-electrical mechanical system which controls light using an array of 780,000 aluminium micro-mirrors.

Jae-Won Choi, assistant professor of mechanical engineering at the University of Akron, said that the technique improves upon current skin-patch drug delivery methods.

He said: “The light emitted from a mercury lamp is reflected on the DMD which creates the same light profile as the DMD pattern. The focused light pattern delivered through several optics is projected and crosslinks a photopolymer.” Dacarbazine, commonly used to treat skin cancer, was blended into the solution before crosslinking. 

Testing confirmed that the needles are able to withstand the stresses and strains they would be submitted to when inserted into the body. The team hopes to improve the process by optimising printing parameters, such as light intensity and exposure energy.