Study finds spray technique for bioactive materials

Scientists developed a highly accurate method for creating coatings of biologically active materials for a variety of medical products.

According to the researchers, such a technique could pave the way for a new era of transdermal medication, including shot-free vaccinations.

Researchers described a novel approach to electrospray deposition, an industrial spray-coating process, in Nature Communications.

Essentially, Rutgers researchers devised a method to better control the target region within a spray zone as well as the electrical properties of microscopic particles being deposited. The greater command of these two properties, the more likely it is that the spray will hit its microscopic target.

Manufacturers used electrospray deposition to convert a flowing liquid, such as a biopharmaceutical, into fine particles by applying a high voltage to it. Each droplet evaporates as it travels to its destination, 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 in the Rutgers School of Engineering and an author on the study.

“Present methods only achieve about 40 per cent efficiency. However, through advanced engineering techniques we’ve developed, we can achieve efficiencies statistically indistinguishable from 100 per cent.”

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 – 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, researchers said.

“Being able to deposit with 100 per cent 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 the first author on the paper.

“We anticipate that future work will expand the range of compatible materials and the material delivery rate of this high‐efficiency approach.”