The research team led by Dr. Hojeong Jeon and Dr. Hyung-Seop Han of the Biomaterials Research Center at the Korea Institute of Science and Technology (KIST, President Oh Sang-Rok), along with Dr. Indong Jun from KIST Europe, has developed a novel stent surface treatment technology using laser patterning. This technology promotes endothelial cell growth while inhibiting smooth muscle cell dedifferentiation in blood vessels. By controlling cellular responses to nanostructured patterns, the technique holds promise for enhancing vascular recovery, especially when combined with chemical coating methods.
As South Korea approaches a super-aged society, the incidence of vascular diseases among the elderly population is rising, increasing the importance of therapeutic stents. These tubular medical devices maintain blood flow by expanding narrowed or blocked blood vessels. However, traditional metal stents may cause restenosis—a re-narrowing of the artery—due to excessive smooth muscle cell proliferation one month after implantation.
Drug-eluting stents are widely used to mitigate this issue but often inhibit vascular re-endothelialization, increasing the risk of thrombosis and necessitating the use of anticoagulants. To overcome these limitations, research into coating stent surfaces with bioactive molecules like proteins or nucleic acids is ongoing. However, these coatings often serve limited functions, falling short in accelerating endothelial cell proliferation.
To address this issue, the research team applied nanosecond laser texturing technology to create nano- and micro-scale wrinkle patterns on nickel-titanium alloy surfaces. The wrinkle patterns inhibit the migration and morphological changes of smooth muscle cells caused by stent-induced vascular wall injury, preventing restenosis. The wrinkle patterns also enhance cellular adhesion, promoting re-endothelialization to restore the vascular lining.
The team validated the effectiveness of this technology through in vitro vascular cell studies and ex vivo angiogenesis assays using fetal animal bones. The laser-textured metal surfaces created favorable environments for endothelial cell proliferation while effectively suppressing smooth muscle cell dedifferentiation and excessive growth. Notably, smooth muscle cell growth on the wrinkled surfaces was reduced by approximately 75%, while angiogenesis increased more than twofold.
The surface patterning technology is expected to be applicable not only to metal stents but also to biodegradable stents. When applied to biodegradable stents, the patterns can prevent restenosis and enhance endothelialization before the stents dissolve, improving treatment outcomes and reducing complication risks. The research team is planning to conduct animal tests and clinical trials to verify the long-term safety and efficacy of this laser patterning technology.
Dr. Jeon stated, "This study demonstrates the potential of surface patterns to selectively control vascular cell responses without drugs. Using widely industrialized nanosecond lasers allows for precise and rapid stent surface processing, offering significant advantages for commercialization and process efficiency."
