Dyed DNA vaccine coated onto a microneedle array using the novel electrospray deposition technique. Photo: Sarah H. Park/Rutgers School of Engineering.
Dyed DNA vaccine coated onto a microneedle array using the novel electrospray deposition technique. Photo: Sarah H. Park/Rutgers School of Engineering.

Researchers at Rutgers University have devised a highly accurate method for creating coatings of biologically active materials for a variety of medical products. Such a technique could pave the way for a new era of transdermal medication, including shot-free vaccinations.

In a paper in Nature Communications, the researchers describe a new approach to electrospray deposition, an industrial spray-coating process. Essentially, Rutgers scientists have developed a way to better control the target region within a spray zone, as well as the electrical properties of the microscopic particles that are being deposited. The greater command of those two properties means that more of the spray is likely to hit its microscopic target.

Electrospray deposition involves applying a high voltage to a flowing liquid, such as a biopharmaceutical, converting it into fine droplets. Each of those droplets evaporates as it travels to a target area, depositing a solid precipitate from the original solution.

“While many people think of electrospray deposition as an efficient method, applying it normally does not work for targets that are smaller than the spray, such as the microneedle arrays in transdermal patches,” said Jonathan Singer, an associate professor in the Department of Mechanical and Aerospace Engineering at the Rutgers School of Engineering and an author of the paper. “Present methods only achieve about 40% efficiency. However, through advanced engineering techniques we’ve developed, we can achieve efficiencies statistically indistinguishable from 100%.”

Coatings are increasingly critical for a variety of medical applications. They are used on medical devices implanted into the body, such as stents, defibrillators and pacemakers. And they are beginning to be used more frequently in new products employing biologicals, such as transdermal patches.

Advanced biological or ‘bioactive’ materials – such as drugs and vaccines – can be costly to produce, especially if any of the material is wasted, which can greatly limit whether a patient can receive a given treatment.

“We were looking to evaluate if electrospray deposition, which is a well-established method for analytical chemistry, could be made into an efficient approach to create biomedically active coatings,” Singer said. Higher efficiencies could be the key to making electrospray deposition more appealing for the manufacture of medical devices using bioactive materials.

“Being able to deposit with 100% efficiency means none of the material would be wasted, allowing devices or vaccines to be coated in this way,” said Sarah Park, a doctoral student in the Department of Materials Science and Engineering, who is first author of the paper. “We anticipate that future work will expand the range of compatible materials and the material delivery rate of this high-efficiency approach.”

In addition, unlike other coating techniques used in manufacturing, such as dip coating and inkjet printing, the new electrospray deposition technique is characterized as ‘far field’, meaning that it doesn’t need highly accurate positioning of the spray source. As a result, the equipment necessary to employ the technique for mass manufacturing would be more affordable and easier to design.

This story is adapted from material from Rutgers University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.