Zhejiang University's Prof. Jijian Ji Team Files Albumin-Based Coating Patent for Cardiovascular Implantable Devices

In September 2023, Professor Ji Jian’s team at Zhejiang University filed a patent for an albumin coating with anticoagulant and/or in situ endothelialization functions.. This patent can be applied to the surfaces of a range of implantable and interventional medical devices, including cardiovascular stents, heart valves, and cardiac occluders, providing them with excellent anticoagulant and/or in situ endothelialization effects, and entered the patent publication stage in the same September.

Existing anticoagulant and cell-selective surfaces are typically fabricated by combining antifouling backgrounds with bioactive molecules, a process characterized by high design and fabrication costs as well as cumbersome procedures. To address this,Professor Ji Jian’s team used albumin as a functional layer, which was stably bound to various substrate materials via covalent grafting, thereby simplifying the coating preparation process and ensuring wide availability of raw materials.。

Cardiovascular implants have been widely used to treat various cardiovascular diseases. However, the contact between the implant surface and blood can lead to thrombosis, significantly increasing the incidence and mortality of thrombotic disorders.To reduce the risk of thrombosis, surface modification of implanted devices with anticoagulant coatings has become a common method for preventing thrombus formation and is widely applied in various fields, including bioprosthetic heart valves, vascular stents, and ventricular assist devices.

First, regarding bioprosthetic heart valves, in 2022, Professor Wang Yunbing’s team at Sichuan University developed an all-in-one surface modification strategy by immobilizing RIVA-loaded nanogels and cleavable PEG onto the valve surface. This approach endows bioprosthetic valves with long-term antithrombotic properties and accelerates glucose-triggered endothelialization. Furthermore, the team achieved excellent material-tissue compatibility by incorporating anti-inflammatory drug coatings combined with RIVA on the bioprosthetic valves.

Vascular stent coating technologies that combine anticoagulant and anti-inflammatory drugs are rapidly advancing. Associate Professor Qiu Fen Tu and Researcher Zhilu Yang from Southwest Jiaotong University, in collaboration with Professor Li Shen from Fudan University, developed an endothelial function-biomimetic stent coating by sequentially grafting nitric oxide (NO)-catalytic active substances and glycocalyx components (heparin) onto a mussel-inspired amino-rich coating. This work was published in the journal Bioactive Materials.

Regarding ventricular assist devices (VADs), researchers are also investigating various anticoagulant coatings to improve the blood compatibility of these devices. Professor Someya’s team at the University of Tokyo modified the blood-contacting surfaces of a centrifugal heart pump called MedTech Dispo with an MPC coating and implanted the pump into seven calves with left heart bypass. In vivo experimental results demonstrated that the MPC coating effectively prevented thrombus formation for at least two weeks.

Anticoagulant coatings are the most effective approach to addressing thrombosis on device surfaces.Currently, anticoagulant coatings are also being commercialized in cardiovascular implantable and interventional devices.

For example, in vascular stents, a series of commercialized heparin-coating technologies have emerged, such asCORLINE^®Heparin Surface, Hepamed™ Coating, and Carmeda Heparin BondingAmong these, the Carmeda heparin coating utilizes a single covalent bond between the reducing end of the heparin molecule and the material substrate to form a stable, non-leaching coating with a thickness of several hundred nanometers. W. L. Gore & Associates’ two approved products, Propaten and Acuseal, both incorporate the Carmeda heparin-bonded anticoagulant coating, significantly enhancing the antithrombotic properties and patency rates of synthetic vascular grafts.

In ventricular assist devices,Japanese firm Yamazaki applies DLC coating to the blood-contacting surfaces of Sun Medical’s centrifugal pump to enhance the product’s hemocompatibilityIn vivo studies have demonstrated that this cardiac pump exhibits excellent long-term blood compatibility and can operate continuously for more than six months without failure. The implantable rotary blood pump manufactured by VentrAssist features a diamond-like carbon (DLC) coating on its blood-contacting surfaces.

With the continuous advancement of cardiovascular implantable and interventional devices, research on their anticoagulant surface coatings has garnered widespread attention. Researchers have made increasing efforts to explore coating and modification technologies for the surfaces of these implants and interventional devices.In 2024, Man Jia’s team at the School of Mechanical Engineering, Shandong University, immobilized heparin onto substrate surfaces via terminal fixation, thereby addressing the loss of bioactivity associated with heparin grafting. This approach holds promise for future applications in cardiovascular implantable and interventional devices.