Can Hydrophilic Coatings Reduce Issues in Medical Procedures?

Medical procedures involving catheters, guidewires, and implants have revolutionized modern healthcare. However, these procedures come with inherent risks. These include infections, thrombosis, and tissue damage. A smart way to reduce these problems is to use hydrophilic medical device coatings on the devices used in the procedure. These “slippery-when-wet” coatings create a smooth, biocompatible surface. This boosts patient safety, comfort, and leads to better medical outcomes. They also help reduce complications. This article explores real-world clinical examples and scientific research demonstrating the positive impact of hydrophilic coatings in medical procedures.

The Science Behind Hydrophilic Medical Coatings

Hydrophilic coatings use water-attracting polymers. The coatings absorb moisture and create a slippery surface. This property lowers friction when medical devices contact human tissues. This helps reduce trauma and cuts the risk of complications. 

Common materials for hydrophilic coatings are polyvinylpyrrolidone, polyethylene glycol, and hyaluronic acid. These chemistries all have great biocompatibility, which reduces complications.

If you are new to this topic you can read our in-depth guide on hydrophilic coatings for medical devices, which covers what they are, where they are used, and their benefits. .

Below we list four ways these coatings are being used to help reduce issues in medical procedures.

1. Hydrophilic Coatings Help Reduce Catheter Associated Urinary Tract Infections

Catheter-associated urinary tract infections are a common problem. This is especially true for patients using intermittent catheters.

Hydrophilic-coated catheters help reduce these infections by lowering friction during use. This minimizes the infection risk factors such as urethral trauma and irritation. Studies show that hydrophilic-coated catheters significantly reduce infection rates compared to uncoated ones.¹ Patients using hydrophilic-coated catheters have fewer symptomatic urinary tract infections. This of course helps to improve both patient comfort and clinical outcomes.²

2. Antimicrobial Coatings Can Help Reduce Infections

Next-generation, hydrophilic, antimicrobial catheter coatings use advanced surface modifications to prevent infections. Strategies to reduce infections include: 

• Surface-Bonded Non-Leaching Antimicrobial Coating
• Low-fouling surfaces to resist bacterial adhesion
• Contact-killing materials like antimicrobial peptides
• Coatings that release antibiotics or nanoparticles 

New innovations like biofilm-disrupting enzymes and nanostructured surfaces can make these technologies even more effective. Recent advancements have added antimicrobial features to hydrophilic coatings.³ Embedded agents such as silver and chlorhexidine are demonstrating promising reductions in bacterial adherence and biofilm formation.⁴ 

Surface-bonded, non-leaching antimicrobial coatings are another advancement. These do not release active agents into the environment. The coatings remain indefinitely effective for continued use. This class of hydrophilic, antimicrobial coatings are designed to kill or inhibit the growth of microorganisms upon contact. They prevent any further formation of biofilm and with it the possibility of infection.

Learn more about Surface-bonded, non-leaching antimicrobial coatings. 

These strategies provide alternative approaches to combat catheter-associated urinary tract infections. At the same time they combat the growing concern of antibiotic resistance. As a result, they are creating safer and more effective urinary catheter technologies.⁵

3. They Can Help Prevent Thrombosis in Cardiovascular Stents

Preventing thrombosis (the formation of blood clots) in cardiovascular stents is key. It helps avoid problems like stent thrombosis and restenosis (the recurrence of narrowing of an artery or valve). 

Hydrophilic, thromboresistant coatings can boost biocompatibility and help with endothelialization (rebuilding/repairing inner walls of blood vessels). This may lower the need for dual antiplatelet therapy (DAPT). A study on flow diverter stents (FDS) found that a hydrophilic polymer coating significantly reduced platelet adhesion compared to uncoated surfaces. Electron microscopy confirmed minimal platelet building. This highlights the potential of hydrophilic coatings to enhance hemocompatibility and lower DAPT dependence.⁶ 

A study developed a functional coating for polycaprolactone (PCL) vascular scaffolds using hyaluronic acid (HA), dopamine (DA), and heparin. The DA-grafted HA was polymerized onto fibrous PCL, integrating heparin during the process. This coating made things more water-attracting (hydrophilic). It boosted strength, helped endothelial cells grow, and supported blood vessel formation. Also, it lowered platelet sticking and clotting. These findings show that it could improve how well vascular grafts work and last over time.⁷

Moreover, a study on a non-elutable low-molecular-weight heparin (LMWH) stent coating showed strong thromboresistance. The nanoscale coating (320 nm) maintained its ability to bind antithrombin. It reduced platelet deposition by 95% compared to stents without a coating. This innovation could help lower stent thrombosis risk, especially in patients with complex lesions.⁸

4. Hydrophilic Coatings Reduce Tissue Damage in Endoscopic Procedures

Hydrophilic medical coatings play a crucial role in endoscopic procedural outcomes. They enhance the performance and safety of endoscopic instruments. These coatings are designed to reduce friction, improve maneuverability, and increase patient comfort during endoscopic procedures. 

A clinical study looked at a short guide wire for therapeutic endoscopic retrograde cholangiopancreatography (ERCP). This guide wire is a fully hydrophilic Terumo Glidewire, measuring 0.035 inches and 260 cm long. In a study of 223 catheter exchanges using a hydraulic technique, wire loss happened in just 5% of cases. All patients successfully accessed their ducts or strictures. These findings suggest that hydrophilic guide wires with hydraulic exchange provide a fast and reliable ERCP method.⁹

Key Benefits of Hydrophilic Medical Device Coatings

This class of medical coatings offer many benefits in terms of medical devices used for procedures. These include: 

• Reduced resistance when passing through tortuous or narrow arteries  
• Minimized trauma to blood vessels and tissues
• Hydrophilic coatings can be combined with antithrombotic agents (e.g., heparin) to lower the risk of clot formation 
• In drug-eluting stents (DES), hydrophilic coatings can regulate the release of antiproliferative drugs to prevent restenosis
• Hydrophilic coated endoscopes, catheters, and guidewires can navigate complex anatomical pathways easier
• The coatings help prevent biological material from sticking to the device. This helps produce clearer imaging and reduce the risk of contamination 
• Hydrophilic coatings are designed to be non-toxic and compatible with bodily fluids. This helps to reduce inflammation
• Smoother operation and easy handling during surgical procedures

Future Directions: Innovations in Hydrophilic Coating Technologies

The field of hydrophilic coatings is continuously evolving. New developments are further improving their effectiveness. Some emerging innovations in the area include:

• Smart Hydrophilic Coatings: These coatings can respond to environmental stimuli, releasing therapeutic agents when needed.
• Nanotechnology-Based Coatings: This technology uses nanomaterials to create ultra-thin, highly durable hydrophilic layers. This can further improve medical device performance.

Hydromer® Advanced Hydrophilic Medical Device Coatings

Hydromer®, Inc. is recognized as a leading medical device coating manufacturer. We offer a complete range of custom coatings and contract services to medical device companies. From contract R&D and regulatory consulting to contract manufacturing and technology transfer our team can aid your product development and production efforts. 

Hydromer medical device coatings include but are not limited to:

1. Hydrophilic Medical Coatings:
   • Designed to reduce friction and enhance lubricity 
   • Commonly applied to catheters, guidewires, and other devices to improve maneuverability and reduce patient discomfort during insertion
   • These coatings are also effective in minimizing tissue irritation
2. Thromboresistant Coatings:
   • Hydromer, Inc. offers specialized thromboresistant coatings designed to enhance the safety and efficacy of medical devices that come into contact with blood. Hydromer’s Thromboresistant Coatings are “slippery-when-wet” and non-leaching. They minimize blood adhesion to device surfaces, which reduces the risk of clot formation that can lead to conditions such as atrial fibrillation, strokes, or heart attacks. 
   • A range of customizable coatings formulated to prevent blood clot formation on medical devices
   • Hydromer’s new HydroThrombX™ coating further advances this technology by providing superior thromboresistance, ensuring enhanced performance and durability for blood-contacting medical devices.
   • Ideal for cardiovascular implants like stents and vascular grafts 
3. One-Step Coatings:
   • One-step coatings allow for an easier coating application process. These combine multiple functions in a single layer and make it easier to maintain device performance.
4. Cell-Growth Enhancing Coatings:
   • Promote tissue integration and cell growth, particularly useful for implantable devices like orthopedic implants and wound healing products.
5. Antimicrobial Coatings:
   • Permanent or surface-bonded non-leaching antimicrobial coatings 
   • Incorporation of silver nanoparticles or antibiotics to coat surfaces to prevent infection. 
   • Suitable for wound care products, surgical tools, and implantable devices.
6. Customizable Primers and Formulas:
   • Designed to improve the adhesion of coatings to virtually all substrates, including complex geometries.

Hydromer offers custom, tailored solutions and flexibility to meet your unique product requirements. For more information, you can explore their services on the Hydromer Medical Device Coatings page. 

References

1. Plata M, Santander J, Zuluaga L, et al. Hydrophilic versus non-hydrophilic catheters for clean intermittent catheterization: a meta-analysis to determine their capacity in reducing urinary tract infections. World Journal of Urology. 2023/02/01 2023;41(2):491-499. doi:10.1007/s00345-022-04235-5
2. Cardenas DD, Moore KN, Dannels-McClure A, et al. Intermittent catheterization with a hydrophilic-coated catheter delays urinary tract infections in acute spinal cord injury: a prospective, randomized, multicenter trial. PM&R. 2011;3(5):408-417. 
3. Duque-Sanchez L, Qu Y, Voelcker NH, Thissen H. Tackling catheter-associated urinary tract infections with next-generation antimicrobial technologies. Journal of biomedical materials research Part A. Mar 2024;112(3):312-335. doi:10.1002/jbm.a.37630
4. Srisang S, Boongird A, Ungsurungsie M, Wanasawas P, Nasongkla N. Biocompatibility and stability during storage of Foley urinary catheters coated chlorhexidine loaded nanoparticles by nanocoating: in vitro and in vivo evaluation. Journal of Biomedical Materials Research Part B: Applied Biomaterials. 2021/04/01 2021;109(4):496-504. doi:https://doi.org/10.1002/jbm.b.34718
5. Stirpe M, Brugnoli B, Donelli G, Francolini I, Vuotto C. Poloxamer 338 Affects Cell Adhesion and Biofilm Formation in Escherichia coli: Potential Applications in the Management of Catheter-Associated Urinary Tract Infections. Pathogens. 2020;9(11). doi:10.3390/pathogens9110885 
6. Lenz-Habijan T, Bhogal P, Peters M, et al. Hydrophilic Stent Coating Inhibits Platelet Adhesion on Stent Surfaces: Initial Results In Vitro. Cardiovasc Intervent Radiol. Nov 2018;41(11):1779-1785. doi:10.1007/s00270-018-2036-7
7. Jiang Y, Wang H, Wang X, Li Q. Surface modification with hydrophilic and heparin-loaded coating for endothelialization and anticoagulation promotion of vascular scaffold. International Journal of Biological Macromolecules. 2022/10/31/ 2022;219:1146-1154. doi:https://doi.org/10.1016/j.ijbiomac.2022.08.172
8. Zhao J, Falotico R, Nguyen T, et al. A nonelutable low‐molecular weight heparin stent coating for improved thromboresistance. Journal of Biomedical Materials Research Part B: Applied Biomaterials. 2012;100(5):1274-1282. 
9. Papachristou GI, Baron TH, Gleeson F, Levy MJ, Topazian MD. Endoscopic retrograde cholangiopancreatography catheter and accessory exchange using a short hydrophilic guide wire: a prospective study. Endoscopy. 2006/11/17 2006;38(11):1133-1136. doi:10.1055/s-2006-944739