There has been a large amount of advancement over the last ten years in the arena of interventional medical devices (IMDs). This is especially true when it comes to their use in neurovascular, cardiovascular, and peripheral vascular procedures. An overwhelming trend is that the vast majority of these interventional medical devices are becoming smaller and more complex in their design. They are also advancing in terms of their capability to perform highly precise tasks within very delicate anatomical structures (higher functionality).
The quality and efficacy of these advancements will make it possible to treat additional types of conditions. They will also allow improved clinical outcomes.
With that being said, the increasing complexity of the devices is creating a tremendous number of engineering and procedural challenges1,2.
One of the major challenges associated with the use of interventional medical devices is the interaction of their surface with the biological environment. This interaction also causes challenges in performing the procedures using the devices. The increasing complexity of these devices is bringing about an increasing risk of frictional-related tissue trauma, micro-particle generation, and the occurrence of adverse biological reactions.
Therefore, it is critical that solutions are created to ensure that a interventional medical device is safe for patients and will facilitate a successful procedure. Hydrophilic medical coatings by companies such as Hydromer®, Inc. are playing a large role in helping OEMs overcome these challenges.
In this article we will dive deep into the increasing complexity and functionality of interventional medical devices (IMDs). And we will also discuss how advanced hydrophilic coatings are being formulated to help OEMs meet these challenges. For medical device engineers, mastering surface technologies is essential for next-generation designs. So make sure you read until the end in order to find out how you can utilize these coatings to achieve advanced devices.
The Impact of Surface Friction on Device Safety and Performance
The surfaces of a medical device are critical to its safety and effectiveness. The surfaces affect the device’s overall navigability, efficiency of procedure and the biocompatibility of the device.
When performing minimally invasive procedures, such as placement of catheters, guidewires or stents, the surface plays a critical role in the device’s ability to navigate through very tortuous vascular pathways without damaging the vascular wall.3,4
The presence of high surface friction creates:
- Increased resistance during navigation of the device in the body. This results in friction, trauma, and increased time to complete the procedure. The last consequence also results in increased fatigue for the operator.
- Trauma to the delicate walls of the vessels. This causes a potential inflammatory response and/or vasospasm.
- Shedding of micro-particles of debris that will travel downstream and create complications.
Traditional bare-metal devices or uncoated devices typically are unable to satisfy the challenges being posed as device design continues to evolve.
Hydrophilic Coatings Help OEMs Overcome Increasing Complexity and Functionality Requirements
Hydrophilic medical device coatings (coating that attracts water) have been developed by companies such as Hydromer, Inc. in various ways to overcome these challenges. These coatings are applied to the surfaces of the medical device. They are compatible with a very wide range of substrates. Upon contact with body fluids, the hydrophilic coating creates a thin, highly lubricated layer on the medical device surface. 5-7
How Hydrophilic Medical Coatings Enable Advanced Interventional Medical Devices
Hydrophilic coatings provide many advantages to medical devices, including interventional medical devices. These include:
1. Decreased Friction with Increased Navigation ability
Hydrophilic coatings allow devices to glide freely through the small or winding passageways of tissues and fluids. They do this by providing a smooth surface on the device that minimizes friction between the device and the surrounding tissue/fluid. This reduces the amount of time it takes to perform a procedure and minimizes the possibility of trauma occurring during the procedure.
2. Long-Lasting Performance
Hydromer coatings are designed to endure the rigors of long procedures and multiple device usages without degrading. As a result, they are able to provide consistent performance from the moment of insertion until after deploying the device. This is vital for complex interventions.
3. Limited Generation of Particles (Low Particulate)
High-quality, advanced hydrophilic coatings limit the particulate generation during the use of medical devices. This decreases possible embolic events. This is critically important when performing neurovascular procedures, because small embolus can result in serious health issues.
4. Improved Biocompatibility
Hdrophilic medical coatings are constructed to be inserted and be compatible with both blood and living tissues. Hydrophilic coated surfaces decrease inflammation and thrombus-related responses; therefore, they increase safety for patients and have a positive influence on clinical outcomes.
5. Advancement of Device Development
There continues to be a trend towards interventional devices being constructed smaller (e.g. less than 3 mm) and incorporating more and more features (e.g. drug delivery, mechanical movement and/or multi-lumen designs). In turn, device requirements for surface characteristics are becoming more rigorous.
Hydrophilic coatings allow for continued innovation of the devices. They modify the surface so that it can achieve the desired results. This means engineers are able to create new, more complex designs without compromising the safety or effectiveness of the product. Hydrophilic coatings allow this regardless of how complex the geometry of the device is or how much functionality the design incorporates.
Trends Driving the Need for Advanced Hydrophilic Medical Coatings
One of the most prevailing trends in the medical device industry is the trend toward increasing device complexity and functionality. 2 Modern medical interventions demand devices that are:
- Miniaturized, to access previously unreachable regions within the body.
- Highly precise, to perform targeted therapeutic actions.
- Functionally diverse, combining multiple capabilities such as imaging, drug delivery, and/or mechanical manipulation.
So why are hydrophilic coatings critical in creating devices that meet these trends?
The fact is simple. Without the use of advanced hydrophilic surface coatings it would be almost impossible to create medical devices that meet these demands
Hydrophilic coatings present a unique solution that help OEMs bridge the gap between the design of the device and its compatibility with the physiology of the patient. These coatings are enabling next generation devices to meet their intended use. They are also helping OEMs deliver a safe product and be able to do so efficiently and in a timely manner.
Hydrophilic Coatings Clinical Case Examples
Below are just a few examples of how hydrophilic coatings enable complex, highly functional devices.
1. Neurovascular Procedures: hydrophilic coated aneurysm coils
A randomized controlled trial comparing hydrogel-coated coils to bare platinum coils for cerebral aneurysm embolization was done. Hydrogel-coated devices demonstrated lower recanalization rates (3.3% vs. 7.1%) and significantly reduced major recanalization (2.3% vs. 6.6%) at 1 year. These devices also showed increased thrombosis and improved occlusion stability. These findings support the role of hydrophilic-based coatings in reducing aneurysm recurrence.8
2. Cardiovascular Procedures: Intra-Aortic Balloon (IAB) Catheters
A prospective evaluation of patients undergoing intra-aortic balloon catheterization was undertaken. Hydrophilic-coated IAB catheters were associated with significantly improved clinical outcomes compared to uncoated devices. The coating reduced friction during insertion. This resulted in a 72% decrease in ischemic vascular complications. It also demonstrated lower rates of balloon ruptures plus fewer required surgical vascular repairs. This indicates the potential of hydrophilic catheter coatings for improving safety of procedures and will reduce the incidence of complications related to insertion.9
Learn more about .
3. Urological Procedures
Intermittent Catheterization
Urinary catheters with hydrophilic coatings help reduce mucosal injury and urethral friction. They do this by providing a lubricated, aqueous surface when used for intermittent catheterization. They do not require manual lubrication and they maintain a consistent water coating. As a result, these catheters have many beneficial outcomes. They may decrease the chances of contamination. They may lessen occurrences of urinary tract infections (UTIs) , which usually occur because of Escherichia coli. Also, they may decrease the risk of urethral irritation or lesions, which have been reported to occur in 2 to 19% of patients who use intermittent catheters. Because of the above characteristics, hydrophilic-coated urinary catheters have the potential to improve patient comfort, decrease complications, and provide better overall results with intermittent catheterization.10,11
Double J (DJ) Ureteral Stents
A randomized controlled trial evaluated double J stents made from polyurethane with or without a hydrophilic coating. The results showed that stents with a hydrophilic coating provide better outcomes than those without. Patients in the hydrophilic coated group had fewer lower urinary tract symptoms, lower pain scores, and better quality of life than patients with a non-coated stent (60% vs 7.5% of patients experienced no pain at all). The hydrophilic coating reduces surface friction and mucosal irritation to improve patient tolerability and stent-related outcomes for hydrophilic coated double J stents compared to non-coated double J stents.12
Conclusion
As the complexity and functional requirements of medical devices increases, hydrophilic coatings are no longer optional. They are essential for developing the next generation of complex medical devices. Hydromer’s advanced hydrophilic formulations provide a combination of lubricity, durability, biocompatibility, and minimal particulate generation. These, along with advanced functionality, such as drug-delivery, will be critical in addressing the key challenges posed by increasingly complex interventional devices.
Clinical evidence demonstrates that these coatings have several benefits. They can reduce procedural time, minimize tissue trauma, and improve overall patient safety. They have been shown to do this across neurovascular, cardiovascular, and peripheral vascular applications. By integrating hydrophilic coatings, device manufacturers can expand device functionality, improve procedural outcomes, and meet the growing demands of modern medicine.
In an era of rapid medical innovation, hydrophilic coatings are not just a technical enhancement anymore. They are a critical solution that bridges the gap between sophisticated device design and patient-centric outcomes.
References
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1. Amaral C, Paiva M, Rodrigues AR, Veiga F, Bell V. Global Regulatory Challenges for Medical Devices: Impact on Innovation and Market Access. Applied Sciences. 2024;14(20):9304. doi:10.3390/app14209304
2. Yogev D, Goldberg T, Arami A, Tejman-Yarden S, Winkler TE, Maoz BM. Current state of the art and future directions for implantable sensors in medical technology: Clinical needs and engineering challenges. APL bioengineering. Sep 2023;7(3):031506. doi:10.1063/5.0152290
3. Al-Rumaih M, Al-Jaber F, Batheeb N. Vascular injuries and complications in orthopedic surgery procedures. Journal of Orthopaedic Reports. 2025/06/01/ 2025;4(2):100435. doi:https://doi.org/10.1016/j.jorep.2024.100435
4. Wani ML, Ahangar AG, Ganie FA, Wani SN, Wani NU. Vascular injuries: trends in management. Trauma monthly. Summer 2012;17(2):266-9. doi:10.5812/traumamon.6238
5. Hydromer. Hydrophilic Coatings For Medical Device Substrates. https://hydromer.com/hydrophilic-coatings-for-medical-device-substrates/
6. Hydromer. Hydrophilic Coatings: What They Are and Common Uses. https://hydromer.com/hydrophilic-coatings-comprehensive-guide/
7. Hydromer. Medical Device Coatings. Hydromer. https://hydromer.com/medical-device-coatings/
8. Imamura H, Sakai N, Sakai C, et al. Hydrogel coils in intracranial aneurysm treatment: a multicenter, prospective, randomized open-label trial. Journal of neurosurgery. Jun 1 2025;142(6):1803-1809. doi:10.3171/2024.8.jns232369
9. Winters KJ, Smith SC, Cohen M, Kopistansky C, McBride R. Reduction in ischemic vascular complications with a hydrophilic‐coated intra‐aortic balloon catheter. Catheterization and Cardiovascular Interventions. 1999;46(3):357-362.
10. Stensballe J, Looms D, Nielsen PN, Tvede M. Hydrophilic-coated catheters for intermittent catheterisation reduce urethral micro trauma: a prospective, randomised, participant-blinded, crossover study of three different types of catheters. European Urology. 2005;48(6):978-983.
11. Hydrophilic catheters: an evidence-based analysis. Ontario health technology assessment series. 2006;6(9):1-31.
12. Sharma G, Kumar N, Bai D, et al. A randomized controlled trial comparing hydrophilic coated to uncoated polyurethane double J stents: Does it impact stent-related symptoms? Indian Journal of Urology. 2025;41(3)
