Biosten, a Skolkovo resident startup, presented the technology of radiopaque coating based on lanthanum-containing microparticles at the Fundamental Research and Innovations for Endovascular Surgery 2018 conference on April 12. The event, organized by the N.I. Pirogov National Medical and Surgical Centre with the support of the Skolkovo Foundation, was attended by more than 100 specialists: leading interventional cardiologists from Russia and other countries, researchers, and representatives from the medical industry.

For an interventional cardiologist who places coronary scaffolds or implants other medical devices under fluoroscopy control, it's important to see their position and condition in the body. For example, the clinical outcome of stent implantation depends on how tightly a stent fits the artery wall (this is called stent apposition). New-generation implants made from bioresorbable polymers however pose the greatest radiopacity issue.  

Developers of medical devices use a few workarounds to solve the problem of bioresorbable implant visualization in different ways: some implant metal markers in the polymer, while others develop new iodine-containing polymers. However, the markers do not provide full-body visibility for an implant, and the new polymers require many years of laboratory and preclinical testing to discover possible problems of new polymers, such as increased resorption times. The physical inclusion of common radiopaque agents, such as iodine compounds or barium sulfate, into the polymer impairs the mechanical properties of the implants or leads to adverse biological reactions. 

At the conference, Biosten proposed a new solution for polymeric implant x-ray visibility: a radiopaque coating based on lanthanum-containing microparticles. Lanthanum in the form of a salt was chosen for its radiopacity in a combination with anti-inflammatory, membrane-stabilizing and spasmolytic properties, unlike inert barium sulphate or iodine which is unfavorable for the endothelium. The radiopacity of the coating can be adjusted over a wide range, achieving good visualization even with a layer thickness of several microns, which is unattainable for chemically modified polymers. In other words, a radiographic contrast coating comparable in thickness to the drug coatings of polymeric scaffolds can provide full visualization of the implant. Microparticles made from polymers similar to the parent polymer provide uniform distribution of radiopaque agent and isolate it from the other coating active ingredients such as drug substance.

The Biosten technology can be used not only in bioresorbable polymeric scaffolds, for which it was originally intended, but also to enhance the radiopacity of neurovascular devices made from thin nitinol wire, orthopedic implants, polymeric microspheres for embolization and other medical products. Biosten's original concept of the radiopaque composition with lanthanum-containing microparticles is protected by an international patent, which is currently being transferred into national phases.

Biosten welcomes collaboration from developers who would like to improve the radiopacity of medical devices. The company also provides access to its equipment within the Centre for Collective Use.  

“The biomedical cluster of the Skolkovo Foundation has been a partner of the Fundamental Research and Innovations for Endovascular Surgery conference for three years,” said Ruslan Altaev, development and key partners director of Skolkovo’s biomed cluster.

“This area of medical science has a great capacity for innovation, and we are pleased to note that the number of developments presented at the conference, as well as high-tech services provided by the Skolkovo community centres, grows every year.”