FREMONT, CA: Implanted medical devices have become an everyday aspect of life-saving treatment. The use of heart valves, vascular grafts, and stents is common and helps restore physical function in thousands of patients every day, as are many other important body support systems. Therefore, the output of these devices is critical.
There may be a significant risk to health and, possibly, life if a system does not work to its optimal level or harms the body in any way, with any device placed inside a human body. Therefore, the coatings that are applied to these devices to reduce possible health hazards, protect the body, or enhance the acceptance of a foreign object by the body are as important as the product design itself. Many choices for coatings are available, but new methods, properties, and applications have a lot of scope for further study.
Bioactive coatings not only have the potential to increase the body’s acceptance of an implanted device but may also have a beneficial effect on the ability of the device to work properly for longer. There is a chance of failure due to the body’s reaction to the implant that might be in contact with the blood, including stents and central venous access catheters that can remain in place for weeks, months, or sometimes even years. It is expensive to repair or replace devices that are damaged by clots or inflammation of the tissues of the body. Therefore, the quest for cost-efficiency has fuelled research into coatings that can mitigate the normal responses of the body. The goal is to find a way to deposit a thin film of bioactive compounds on equipment that will remain stable and functional over a long period of time.
This is, not by any means, a modern field of research. Drug therapies have been integrated into the design of implanted devices for over three decades. For example, the anticoagulant heparin has been used to prevent the development of blood clots in the coating of cardiovascular devices. The scope for better therapies and novel coatings, however, continues to grow.
Many different methods, some with limited results, have been tried, but the ability to have bioactive opioid treatment substances in the coating of a device has improved dramatically over time. There are several new devices that have effective bioactive coatings that can combat inflammatory responses, help heal surrounding tissue, avoid blood clots or have antimicrobial effects.
Laser treatments and microblasting methods are also being studied as ways for implantable devices to provide successful bioactive coatings. These are expected to be studied for several years to come, with the ongoing production of more reliable coatings and application techniques, as well as the ability to prolong their functional life.