Polymers are hydrophobic by nature, so plastic devices like catheters cause friction when they are used on a patient. This friction causes extreme discomfort when in contact with body tissue. Medical scientists have been using a new process that uses aqueous medical device coatings on catheters and other devices. This “slippery when wet” design is hoped to help manage some of the discomfort associated with these medical procedures.
The solution is applied directly to the surface of the medical device, where it is likely to come into contact with skin or blood. The coating renders the device slippery, which also helps expedite the delivery of the device. Scientists hope to create a device soon that will actually help medical devices navigate the body’s twists and turns. That technology is not quite here, but water-based coatings are a step in the proper direction.
There are essentially two types of coatings used in the medical coating market. There are water based lubricants, and solvent based. These solutions are applied through a magnetron sputtering system that uses heat, UV, plasma and corona to help apply a thin coating to medical devices.
Water-based solutions offer a few advantages over solvent based methods. For one, the process is much friendlier to the environment because it relies on fewer chemicals. The lack of these inorganic compounds eliminates residual build up on the device as well, helping to keep medical devices functioning for much longer.
Water-based lubricants covalently bond with a non-water-soluble polymer. The molecules blend, which yields a chain of biocompatible polymers. The polymer chain is incorporated into the coating on the device, which becomes a kind of anchor. The device becomes lubricated as the polymers come into contact with bodily fluids.
When this mixture is applied to catheters, guide wires, balloons and other devices, it virtually eliminates any friction felt by the patient. That means that as soon as the device enters the patient’s blood stream, he or she will barely feel a thing as it is slid into place. Furthermore, it is hoped that these coatings will create a strong adhesive that helps to keep devices in place for a longer life span than current methods.
Water-based coating is an amazing technology that has the promise of delivering medical machinery in minimally invasive procedures. In the future, devices that end up in our bodies will receive these coatings to help us stay healthy without adding more chemicals to our blood stream.
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