In the medical field, technology is making an impact in many forms, especially in the area of medical devices. Hydrophilic coatings are just one of those booming innovations.

Hydrophilic coatings are suitable for vascular catheters, guidewires and a wide range of polymeric and metallic substances. The mechanism through which the hydrophilic coating alters the chemical interaction of medical devices is through a dynamic hydrogen bond with water. These hydrophilic coatings facilitate aqueous interactions and exhibit a very low coefficient of friction.

As a result, when the chemical interaction of the hydrophilic coatings’ properties is combined, they are suitable for biological interactions not otherwise possible – perfect for medical device coatings. For example, the lubricity of hydrophilic coatings decreases severe abrasion between device surfaces and a patient’s vessel walls. This may be better understood as the basis of hydrophilic coatings stemming from hyaluronic acid, a natural lubricant in body tissues, which are biocompatible. This relationship also aids in explaining how guidewires which employ hydrophilic coatings help to reduce or eliminate thrombosis.

Hydrophilic Coating FDA Regulations

Coating vendors do face regulatory challenges from the Food and Drug Administration (FDA). Currently, the FDA is focused on approving material-device combinations for specific indications. Vendors are required to maintain a Master File with FDA regulations as a reference point so they know how to proceed in terms of biocompatibility or clinical testing.

Medical Team Education

A 2009 Medicare rule requires hospitals to cover the cost of nosocomial infections from catheters, giving incentive to hospitals to create better methodology to reduce guidelines. Thus, doctors need to be familiar with the materials used in each of the devices and the environmental conditions in which the devices are manufactured, sterilized, stored, and used.

Health care providers also need to understand the extent to which the device will interact with biological tissue when inserted into the patient. Before using any kind of hydrophilic coating device, medical teams must also be aware of a patient’s allergies and any co-morbid conditions to understand any adverse effects. When the manufacturer issues these medical devices to health care facilities, they must provide facilities with all background information on the device.

Hydrophilic Coating Medical Examples

Fifty years ago, the medical industry began using plastics and realized surface interactions with biological systems were significant. The future of hydrophilic coatings will be multifunctional, i.e. catheters and guidewires; short-term implants up to 28 days will prevent the complications associated with long-term implants. Examples include:

• Hydrophilic-coated catheters reduce trauma to a patient’s urethral surface, enabling easy and comfortable catheterization.
• Hydrophilic coatings can also be used to deliver pharmacological treatments to patients safely.
• Guidewires benefit from the slippery surface by reducing insertion force, allowing them to traverse the vasculature and avoid puncture damage and abrasion between the medical device and vessel walls.
• With hydrophilic coatings, the likelihood of thrombosis decreases with the use of guidewire and stroke catheters.
• Within the field of ophthalmology, intraocular lenses (IOLs) are used to replace for the eye’s natural lens in patients who have experienced degradation from age or trauma. The lubricious hydrophilic coating reduces the incidence of catastrophic bursting of the cartridge during the IOL injection.