As societies around the world age, the prevalence of vascular diseases among older populations is increasing, highlighting the growing need for therapeutic stents. These devices, which help maintain blood flow by expanding narrowed or blocked blood vessels, are essential in treating various vascular conditions. However, traditional metal stents can lead to restenosis—re-narrowing of the artery—caused by excessive smooth muscle cell proliferation within a month after implantation. While drug-eluting stents are commonly used to address this issue, they can inhibit the re-endothelialization of blood vessels, which raises the risk of thrombosis and requires the use of anticoagulants. To overcome these challenges, research is ongoing to coat stent surfaces with bioactive molecules like proteins or nucleic acids. However, these coatings often fail to adequately promote endothelial cell proliferation. A new stent surface treatment, developed using laser patterning, has shown promise in encouraging endothelial cell growth while inhibiting smooth muscle cell dedifferentiation in blood vessels. By leveraging nanostructured patterns to control cellular responses, this approach could enhance vascular recovery, particularly when combined with chemical coatings.

A research team at Korea Institute of Science and Technology (KIST, Seoul, South Korea) has utilized nanosecond laser texturing technology to create micro- and nano-scale wrinkle patterns on nickel-titanium alloy surfaces. These wrinkle patterns prevent smooth muscle cell migration and morphological changes induced by stent-related vascular injury, thus reducing restenosis. Additionally, the patterns enhance cellular adhesion, aiding in re-endothelialization to restore the vascular lining. The team validated this technique through in vitro vascular cell studies and ex vivo angiogenesis assays using fetal animal bones. The laser-textured surfaces provided an environment conducive to endothelial cell proliferation while effectively suppressing smooth muscle cell dedifferentiation and excessive growth.

The study revealed that smooth muscle cell growth on the wrinkled surfaces was reduced by approximately 75%, while angiogenesis more than doubled, according to findings published in the international journal Bioactive Materials. This surface patterning technology holds promise not only for metal stents but also for biodegradable stents. When applied to biodegradable stents, the patterns could help prevent restenosis and promote endothelialization before the stent dissolves, potentially improving treatment outcomes and minimizing the risk of complications. The research team plans to conduct animal testing and clinical trials to further assess the long-term safety and effectiveness of this innovative laser patterning technology.

“This study demonstrates the potential of surface patterns to selectively control vascular cell responses without drugs,” said KIST’s Dr. Hojeong Jeon who led the research team. “Using widely industrialized nanosecond lasers allows for precise and rapid stent surface processing, offering significant advantages for commercialization and process efficiency.”

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