Picture: WPI
Coronary artery disease is among the common triggers of heart attacks. When a coronary vessel is narrowed by deposits, coronary bypass surgery is often used: a patient’s own vein or an artificial tube bridges the constricted section and restores blood flow. However, synthetic small-diameter grafts in particular often integrate poorly into the surrounding tissue, which can limit their long-term function.
A team led by Yonghui Ding, Assistant Professor at Worcester Polytechnic Institute (WPI), describes in Advanced Healthcare Materials a 3D-printing method for implantable, tubular scaffolds made from a biodegradable polymer. The researchers call the approach MµCLIP and combine layer-by-layer deposition of a liquid, citrate-based polymer formulation with projected UV light patterns. As the printer builds the tube layer by layer, it exposes defined structures directly into the surface. The polymer is then cured, forming a flexible, resorbable tube intended to serve as a temporary scaffold.
“The goal of this research is to regenerate arteries, not just replace them,” says Ding. “To achieve that goal, it will be important to develop grafts that temporarily provide the structure for tissue growth and enable new cells to grow into healthy and functional blood vessels.”
The technical focus is on micro-grooves and micro-channels that serve as guidance structures for cells. Endothelial cells and smooth muscle cells—both central to building functional vessel walls—are expected to migrate and align along these pathways. In a direct comparison, endothelial cells migrated and oriented themselves better on the textured scaffolds than on smooth samples.
“I’m really excited about translational research that breaks ground scientifically but also has the potential to improve peoples’ lives,” Ding says. “Many people need bypass surgery, and our research could result in better grafts that lead to better health outcomes for patients.”
Further steps are needed before clinical use, such as tests of durability under pulsatile pressure, degradation kinetics, and blood compatibility. The work, which involved Rao Fu (WPI) as well as Guillermo Ameer and Cheng Sun (Northwestern), shows how surface architectures from 3D printing can be used as a tuning parameter in vascular regeneration.
