Thrombosis is a high-risk clinical challenge when it comes to blood-contacting medical devices (e.g., catheters, grafts, extracorporeal circuits). When these devices come in direct contact with blood, protein adsorption and platelet activation occur within seconds. Without any kind of intervention, the ensuing process leads to fibrin generation, thrombus deposition, device stenosis, and other adverse clinical events. Antithrombogenic heparin coatings are used to address thrombosis without the additional problems associated with systemic anticoagulation.
Hydromer®, Inc. is introducing a new generation of heparin and phosphatidylcholine (PC) antithrombogenic coatings for blood-contacting devices. These coatings are designed to adhere to a wide range of medical device substrates. They provide long-lasting bioactivity, improved hemocompatibility, and ease of processing.
In this article, we will give an overview of heparin and Phosphatidylcholine (PC) medical coatings. We also introduce Hydromer’s new thromboresistant coatings line and how they might be the benchmark for antithrombogenic surfaces in modern medical coating technology.
Why Antithrombogenic Coatings Matter More Than Ever
Every year, millions of medical devices are implanted or used in direct contact with circulating blood. Despite advances in device processing, geometry, and materials, the blood-contact problem remains universal:
- Problem: protein adsorption occurs immediately on unprotected devices after blood contact
- Platelets adhere and activate, recruiting additional platelets and triggering clot propagation
- Coagulation factors convert fibrinogen to fibrin, stabilizing a thrombus
- Consequence: device occlusion or surface-induced thrombosis can compromise therapy or threaten patient safety
This problem becomes especially problematic in:
- Long-term implants (stents, grafts)
- Chronic vascular access devices
- Hemodialysis and extracorporeal membrane oxygenation (ECMO) circuits
- Catheters: central venous and cardiovascular catheters
- Blood oxygenator fibers and extracorporeal membranes
Heparin Coatings vs the Alternative
One alternative to heparin coatings are systemic anticoagulants. These can reduce risk, but they can also introduce bleeding complications, require monitoring, and cannot prevent surface-induced platelet adhesion.
As a result, an effective surface-based, antithrombogenic barrier coatings remain the gold standard for improving device safety and extending functional life of the device.
Heparin, stands out as the most clinically validated candidate for this type of medical device coatings. We discuss heparin and PC coatings in more detail below.
Heparin Coatings: The Proven Anticoagulant for Device Surfaces
What is Heparin? It is a type of sugar molecule. It has a strong negative charge that helps prevent blood clots. It works by binding to a protein called antithrombin (AT-III). This increases its ability to stop another protein, thrombin, from forming clots.
When heparin is attached to a surface (such as a medical device) correctly, it can:
- Keep binding to AT-III and prevent clotting
- Stop fibrin, a protein that forms clots
- Decrease the sticking and activation of platelets, which are cells involved in clotting
- Enhance the device’s long-term compatibility with blood
The success of any antithrombogenic heparin coating depends on:
- Strong attachment to the surface (either through covalent or strong ionic bonds)
- Correct positioning of its sulfate groups to allow AT-III binding
- Ability of coating to keep its biological activity after being sterilized, stored, and used
- Being stable and not washing away, especially when in contact with blood for long durations
Hydromer’s new heparin coating technology solves these issues by using a special polymer matrix. This technology keeps heparin in its active form.
Phosphorylcholine (PC) Coatings Offer Nature-Inspired Protection for Blood-Contact Devices
Phosphatidylcholine (PC) is the dominating phospholipid that forms the outer layer of human cell membranes. PC originates from this phospholipid’s polar head group. Because PC is chemically identical to a structure that the human body typically considers as “self,” PC has excellent biocompatibility. This means it does not cause a negative immune response or inflammation when placed into or exposed to the body.
Moreover, the zwitterionic feature of PC binds water tightly. This forms a very well-hydrated “boundary layer” that prevents protein adsorption and helps to reduce early biological fouling.
These two unique characteristics of PC make it the ideal surface chemistry for a biomimetic surface. This is true in situations that require stable and non-immunogenic interactions with blood and tissue. Here is why:
- PC offers biomimetic design that closely replicates natural cell membrane chemistry
- PC offers exceptional biocompatibility with minimal inflammatory response
- It offers strong resistance to protein adsorption and early biological fouling
- PC is naturally hydrophilic and lubricious, improving device insertion and trackability
Introducing Hydromer’s Heparin Antithrombogenic & Phosphorylcholine Hemocompatible Coatings
At Hydromer, Inc. we have been developing antithrombogenic coatings for over a decade. Our heparin-functional coating technology has been engineered for a range of medical substrates, particularly polyurethane (PU) and electropolished stainless steel (SS316).1
Now, we are proud to introduce our new, customizable coatings made for devices that demand the most robust anticoagulant performance.
Hydromer’s Phosphorylcholine (PC) hemocompatible Coatings us inspired by the phospholipid composition of human cell membranes. This advanced coating delivers unparalleled hemocompatibility, durability, and clinical performance. Our PC coatings reduce protein fouling, inhibit platelet adhesion, and maintain exceptionally low thrombogenicity. Both Hydromer’s heparin and PC coatings support long-term patency, improve hemocompatibility, and deliver clinically meaningful benefits.2
Science Behind Hydromer’s Newest Heparin and PC Coatings
Here is what sets Hydromer’s new heparin and PC coatings apart from others.
Hydromer’s Heparin Immobilization Technology
Our newest Heparin Coating employs a proprietary covalent bonding technology. This locks active heparin molecules onto the device surface. This form of immobilization is helpful in the following way:
- Preserves heparin’s native bioactivity
- Ensures long-term stability
- Prevents unintentional drug release
- Maintains a consistent antithrombogenic profile
The coating neutralizes thrombin and prevents fibrin formation. As a result, the coating effectively limits platelet adhesion, reduces clot propagation, and minimizes fibrin network buildup. At the same time it also lowers complement activation. Together, these protective effects help maintain the reliability and safety of both temporary and long-term blood-contacting medical devices. 2
Phosphorylcholine Passive Antithrombogenic Technology
Phosphorylcholine (PC) comes from the polar head group of phosphatidylcholine. This is the most prevalent phospholipid found within the outer layer of human cell membranes. This allows PC to possess biomimetic characteristics, including high biocompatibility, low immunogenicity, and natural resistance towards protein adhesion.
Heparin uses its ability to bind to antithrombin, inhibiting blood coagulation. On the other hand, PC’s antithrombotic mechanism is passive. PC creates a non-adhesive, hydrophilic interface, preventing the initial adhesion of plasma proteins and decreasing the stimuli that cause platelet activation.
Hydromer’s PC coating creates a covalently bonded, durable, high shear force resistant, and long-term stable PC coating on device surfaces. The coating creates a thin, uniform film that replicates the properties of natural cell membranes.
Key Features and Material Advantages of Hydromer’s PC and Heparin Coatings
1. Bioactive Anticoagulation
Hydromer’s heparin coatings maintain active anticoagulant properties at the device–blood interface. This provides immediate and continuous protection.
2. Hemocompatibility
The heparin and PC coatings repel proteins and blood cells, significantly reducing platelet adhesion, suppressing activation of the coagulation cascade, and lowering complement system activation.
3. Surface Uniformity
The coating forms a uniform film on polymers and metals, even on complex geometries. This ensures consistent therapeutic performance across the entire device’s surface.
4. Broad Substrate Compatibility
Compatible substrates include:
- Polyurethane
- Polycarbonate
- Polyethylene
- Silicone
- Stainless steel
- Nitinol
- PVC
This allows versatility across diverse clinical devices.
Durability Under Flow
Heparin coatings are designed to withstand high shear stress in:
- Cardiopulmonary bypass circuits
- ECMO
- Long-term vascular access
- High-pressure injection lines
Phosphorylcholine (PC) coatings offer superior long-term durability. This is in contrast to drug-based coatings that may release or degrade over time. PC coatings can maintain structural integrity, withstand extended implantation, and remain reliable under mechanical stress.
Lubricity
PC is naturally lubricious. This enables coated devices to exhibit lower insertion forces, improved trackability, and reduced tissue trauma during placement or manipulation. Heparin itself is not lubricious. However, it can be incorporated with a suitable hydrophilic material.
Clinical Benefits of PC and Heparin Coatings
- Reduced Clotting on Device Surfaces: The surface-bound heparin and PC inhibits blood clotting at the local site. In addition, a polymer layer prevents platelets from binding. Together, these features significantly decrease the likelihood of clot formation, enhancing patient safety and device performance.
- Lower Risk of Device Occlusion: The coating promotes lower levels of clot formation. This helps keep devices open and functioning. Reduced clot formation is an advantage for medical equipment, such as catheters, stents, and other tubes.
- Higher Safety in High-Flow Blood Situations: Devices used in high blood flow conditions benefit from lower clotting rates. This minimizes interruption and enhances the performance of oxygenators, filters, and pumps.
- Extended Device Longevity: Heparin and PC coatings are stable. The reduced buildup creates longer-lasting devices that require fewer replacements and reduce costs. Example devices include catheters and grafts.
- Decreased Need for Blood Thinners: Anti-coagulant coatings on the device may decrease the need for high-dose blood thinners, which may reduce the incidence of bleeding.
- Improved Patient Outcomes: Reduced clotting leads to fewer device failures and complications. This helps to improve patient comfort and patient outcomes.
- Easy Production and Integration: The coating is specifically designed to work with contemporary production and can easily be upscaled for mass production.
Conclusion
Hydromer’s heparin and phosphorylcholine coatings offer many benefits for blood contacting devices. These coatings greatly reduce thrombus formation on medical devices, create a more biocompatible environment for blood contact devices, and provide improved performance characteristics. They are suitable for coating many devices, from vascular catheters to guidewires, and from extracorporeal devices to implantable devices.
Hydromer’s new line of heparin and phosphatidylcholine (PC) antithrombogenic coatings sets the benchmark for blood-contacting medical devices. These products provide crucial protection against thrombosis and ensure superior hemocompatibility. They leverage proprietary covalent bonding (for active heparin) and biomimetic properties (for passive PC resistance). Doing so they deliver long-term stability, reduced bio-fouling, and enhanced patient safety for blood-contacting devices. The key benefit is the ability to significantly reduce clotting and device occlusion without the risks presented by systemic anticoagulation. They also provide extended device longevity and improved patient outcomes.
Contact Hydromer today to discuss your product needs and how we can develop a custom coating for you.
References
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1. Hydromer. Hydromer Announces Launch of HydroThrombX Medical Device Coating Technology. https://hydromer.com/hydromer-announces-launch-of-hydrothrombx-medical-device-coating-technology/
2. Vicario PP, Lu Z, Wang Z, Merritt K, Buongiovanni D, Chen P. Antithrombogenicity of Hydromer’s polymeric formula F202TM immobilized on polyurethane and electropolished stainless steel. Journal of Biomedical Materials Research Part B: Applied Biomaterials. 2008/07/01 2008;86B(1):136-144. doi:https://doi.org/10.1002/jbm.b.30998
3. Hydromer. Heparin and PC Coating. https://hydromer.com/wp-content/uploads/2025/10/Heparin-and-PC-Coating-Brochure.pdf
