Researchers at the Korea Institute of Science and Technology have developed a technique to coat implantable materials, such as stents, with extracellular matrix components and cells. The new approach could lead to implantable devices that suffer fewer adverse events, such as fibrosis, inflammation, and clotting, because of the foreign body response. Implantable devices all suffer the same limitation – the foreign body response. It is difficult to make the body accept a foreign object, and the foreign body response is behind the majority of failures of implants, especially in devices intended for long-term stay within the body. The body typically reacts to foreign objects through fibrosis and inflammation, and this can spill over into other effects such as blood clotting. In long-term implants such as stents, these phenomena can lead to device failure or unacceptable safety concerns, resulting in the need for additional procedures and treatments. Researchers have developed a variety of device coatings in an attempt to reduce or prevent the foreign body response, and these have met mixed success. This latest technology relies on coating devices with extracellular matrix and then therapeutic cells, in an attempt to both reduce the foreign body response and provide therapeutic benefit at the same time. “This technology can be used to improve various materials that are inserted into the human body,” said Yoon Ki Joung, a researcher involved in the study, in a press release. “Therefore, it is expected to provide a universal platform for the development of implantable diagnostic and treatment devices (that can potentially dictate the future of technology in the field) and medical devices such as stents and implants that require long-term implantation.” The technique involves coating a material with polydopamine and fibronectin, and then preculturing it with cells which deposit a layer of extracellular matrix onto the material surface. Then the researchers remove the cell layer and replace it with a layer of therapeutic cells. In the case of a stent, they experimented with a surface layer of endothelial progenitor cells, which can help to regenerate the endothelium. Calcein stained live outgrowth endothelial cells adhered on bare metal stent (BMS) and pDA /FN/ECM coated stent, respectively. So far, the stent has been tested in a pig model. It demonstrated endothelial regeneration in situ, and compared favorably with other tested stents. With further work, such cell loaded surfaces may help to improve the long-term prospects of implanted materials. Source
