Free of organic solvents and requiring no secondary removal, customizable stents offer a new approach to healing chronic wounds.

Diabetic ulcers, bedsores… these stubborn wounds can take months or even years to heal, casting a long shadow over patients' lives. A research team at the University of Mississippi's School of Pharmacy is responding to this challenge in an unexpected way—3D-printed drug patches. This research has been published in the *European Journal of Pharmaceutics & Biopharmaceutics*.

Unlike ordinary bandages, this patch doesn't simply cover the wound; it's a customizable "wound scaffold." It continuously releases natural antibacterial substances, protecting the wound while promoting tissue regeneration. More importantly, it's gradually absorbed by the skin during the healing process and eventually disappears, requiring no secondary surgery for removal.

“People with limited mobility or diabetes often experience insufficient oxygen supply to their wounds, which slows down the body’s repair process and makes the wounds more likely to remain for a long time and breed bacteria,” explained Sateesh Vemula, a postdoctoral researcher in the study.

The research team was led by Michael Repka, a distinguished professor in pharmaceutics and drug delivery, in collaboration with Vemura and doctoral student Nouf Alshammari. They selected two key materials: chitosan and a plant-derived antibacterial agent. Chitosan, extracted from crustaceans, insects, and fungi, has the ability to promote skin cell growth, reduce inflammation, and prevent infection.

“Many bandages contain organic solvents, which can actually impair the wound healing process, especially in areas close to the wound,” Repka said. “The materials and techniques we use are completely free of organic solvents. At the same time, we avoid the long-term use of traditional antibiotics to reduce the risk of bacterial resistance. This is precisely the advantage of natural products.”

Another possibility brought about by 3D printing is customization. No matter where the wound is located on the body or what its shape is, a structure that fits it can be directly generated through printing, instead of "making do" with standardized products.

“Our material is biodegradable,” Al-Shamari said. “Over time, the scaffold will be absorbed by the skin. And it is an inert material, so we don’t have to worry about side effects or toxic residues.”

This means that medical staff do not need to make another incision to remove the stent—for patients, less trauma means a greater chance of healing.

The research team believes that the application scenarios for this technology extend far beyond chronic wounds. It has the potential to be effective in situations where traditional bandages are unsuitable or inadequate.

“For example, in military applications, if there is a generator to drive a 3D printer, it can print out the appropriate support on the spot according to the type of wound a soldier has,” Repka said.

Of course, this technology still has a long way to go before it can be used clinically. The stent still needs to undergo further testing and review by the U.S. Food and Drug Administration before it can be used on patients.

“Our goal is clear: to bring research findings to patients,” Repka said.

Source: University of Mississippi