The number of patients requiring vascular grafting surgeries is growing. In addition, vascular diseases are one the leading causes of tissue and organ ischemic necrosis. These facts highlight the need for effective and reliable vascular implants, such as grafts and stents that can replace or repair damaged blood vessels. These types of implants act as artificial channels that have the ability to restore blood flow or prevent aneurysms.
However, the use of synthetic vascular implants can lead to issues. These include infection and thrombosis, as well as durability issues. The reason is because they are continuously exposed to the biological environment and bodily fluids. That’s why, medical device manufacturers prioritize surface treatment in addition to careful material selection when designing these devices.
Keep reading if you want to learn about how surface modification can improve the overall effectiveness and safety of vascular implants. Our focus will be on medical coatings applied to vascular grafts and stents in order to reduce the risk of potentially serious complications. Specifically we will highlight Hydrophilic Vascular Implant Coatings due to their many benefits and ability to be customized.
Related: Learn how to improve other types of medical implants in our comprehensive guide on Hydrophilic Implant Coatings.
What is Surface Treatment?
Surface treatment is a process of modifying a device’s natural surface in order to change its properties. This modification is intended to improve the performance, safety, and reliability of medical devices that are either inserted or implanted within the body.
Most medical implants are made from:
- Metals like titanium and stainless steel
- Polymers such as polyethylene and PEEK
- Bioceramics like hydroxyapatite
Surface modification can enhance the device’s ability to adhere to and seamlessly integrate and co-exist with biological tissues.
Types of Surface Modification Techniques
Surface modification is a tried and tested way to improve the performance and safety of implantable medical devices. Below is a quick list of the most commonly used surface modification methods used:
- Coating-based Techniques: A variety of medical device coatings are available on the market. The most popular ones include hydrophilic, hydrophobic, and antimicrobial coatings. Medical coatings are applied to and modify the device’s surface. They ensure that the medical device meets strict performance, safety, and regulatory requirements.
- Physical Techniques: Such techniques have been in use for a long time. They employ mechanical or thermal methods to modify the surface properties of the device. The most common physical surface modification techniques are laser-blasting, sandblasting, and plasma treatment.
- Chemical Techniques: In this technique, chemical agents are deposited on the surface of medical implants. This creates a thin, uniform layer to enhance biocompatibility, osseointegration, and antimicrobial properties.
Among all these types, coating-based surface modification techniques have become very popular in recent years. This is due to the fact that they are more versatile. They can be used to enhance multiple properties through custom formulation.
Types of Vascular Implant Medical Coatings
Most vascular implants are made of synthetic materials. These include polyethylene terephthalate (Dacron) and polytetrafluoroethylene (Teflon). This is due to their availability, mechanical strength, and ease of use.
However, when their surface is left untreated, it may lead to life-threatening complications. These include complications such as restenosis (re-narrowing of arteries) and thrombosis (blood clotting).
As a result, surface modification is critically important when it comes to these devices.
Below are the five most common types of medical coatings applied to vascular grafts and stents to enhance their surface properties:
1. Anti-thrombogenic Coatings
Thrombosis (blood clotting) is one of the major complications associated with all types of medical implants, including vascular implants. It can lead to strokes and heart attacks.
Polymer-based, thromboresistant medical coatings are considered the best choice to prevent blood clotting on the surface of vascular implants. The coating ensures a safe flow interaction between the blood and graft surface inside the body. Such coatings are beneficial in preventing life-threatening disorders, such as cardiac arrest.
2. Drug-Eluting Coatings
Medical, drug-eluting coatings are applied to cardiovascular implants to ensure localized drug delivery.
The most common example is Drug-Eluting Stents (DES) that have the ability to release therapeutic agents slowly. Their main purpose is to prevent restenosis and thrombosis. Such coatings have revolutionized the treatment of coronary artery disease (CAD). The key to their success is the careful selection of the drug and the polymeric matrix.
3. Antimicrobial Coatings
Healthcare-associated infections (HAIs) are one of the major complications during and after vascular implantation. Antimicrobial coatings can help reduce HAIs. They do this by preventing microbial growth and creating a physical barrier that avoids bacterial colonization.
Such coatings significantly improve the long-term success, and complications of vascular grafts and stents.
4. Metallic Coatings
Vascular implants are continuously exposed to corrosive and dynamic biological environments. This environment has a huge impact on their long-term success and reliability. That’s why they are coated with metallic formulations made up of titanium nitride (TiN) or hydroxyapatite (HA). Such metals are both biocompatible and reliable because they provide wear and corrosion resistance to the implants.
5. Polymer Coatings, Including Hydrophilic Medical Coatings
Polymer-based medical coatings offer versatile benefits for vascular implants. These coatings are made up of polymers such as PLGA, polyurethane, polyethylene glycol (PEG), and chitosan.
In this category, hydrophilic medical coatings have gained widespread popularity. Due to their popularity we will discuss these coatings in detail in the following sections.
What are Hydrophilic Coatings?
Hydrophilic coatings are “water-attracting” surface modifications. The term “hydro” means water, and “philic” means affinity or love for. As such, these coatings can attract and hold water or liquid molecules to the medical device’s surface.
Advanced or custom formulated hydrophilic coatings have become the most popular polymer-based coatings nowadays. They are activated in the presence of biological fluids and form a thin, highly lubricious layer on the surface of medical devices. As such, they are referred to as “slippery-when-wet” coatings.
These lubricious coatings are essential for reducing friction between body tissues and the device. They make it possible and less painful to insert and navigate devices throughout tortuous pathways in the body.
They are also biocompatible, which allows them to interact well with the body.
In addition, they can be custom formulated to meet the specific performance and regulatory requirements of a device. For example, they can be formulated to provide thromboresistance, antimicrobial properties, and more.
Why Hydrophilic Coatings are Used for Vascular Implants
The most common causes of a damaged blood vessel or artery include traumatic injuries, cardiovascular defects, and degenerative diseases. Such damage or disease is treated using vascular grafts and stents. But synthetic vascular implants alone can cause issues.
Hydrophilic vascular implant coatings help address these issues, improving these devices.
At their core, hydrophilic coatings are intended to reduce friction and ensure smooth and safe insertion of medical devices during operational procedures. But at Hydromer®, Inc., our custom-formulated coatings offer advanced functionalities. These include wear and corrosion resistance, thromboresistance, antimicrobial properties that help reduce infections, and more.
In addition, our advanced coating equipment can successfully apply our Hydromer® coatings to both the inner (luminal) and outer (abluminal) surfaces of vascular grafts and stents.
Benefits of Multifunctional Hydromer® Hydrophilic Vascular Implant Coatings
Below are some of the benefits of Hydrophilic Vascular Implant Coatings in detail:
- Thromboresistance: Hydrophilic medical coatings prevent protein adsorption and platelet adhesion. This reduces blood clot formation on the surface of vascular grafts and stents. They further enhance endothelial cell adhesion, migration, and growth to promote better compatibility between the implant’s inner surface and blood.
- Reduced Risk of Infections: Hydrophilic Coatings can be custom-formulated with antimicrobial properties. These formulations help reduce the risk of infections associated with the vascular graft and stent implantations. At Hydromer®, we offer surface-bonded, non-leaching, antimicrobial coating technology.
- Enhanced Biocompatibility: Medical implants must not harm the surrounding tissues and bones. They should perform their intended functions without causing any adverse reactions to their surroundings. Hydrophilic coatings ensure a better interaction between vascular implant surfaces and tissues. Their main purpose is to prevent tissue abrasion, micro-tears, and protein adsorption.
- Drug-Eluting Capabilities: Hydromer® Drug-Eluting Hydrophilic Coatings can be formulated to act as active drug delivery platforms. They can be customized to encapsulate and release therapeutic agents, such as antiproliferative drugs at the target location over a desired period. Such localised drug delivery is critical to ensure the safety, effectiveness, and longevity of vascular implants.
- Improved Lubricity: Hydrophilic coatings are at their core lubricious coatings. They have high wettability and reduce the device’s coefficient of friction. This is a crucial property for medical devices that are inserted into and navigate through the body. They create a slippery layer on the surface of vascular implants. This helps to prevent tissue trauma during both the insertion and implantation of vascular devices.
- Durability and Longevity: These coatings are engineered to withstand prolonged exposure to biological environments without compromising the implant’s integrity and stability over time.
Meet Hydromer® – Your Medical Device Coatings Manufacturer
Hydromer®, Inc. is a medical device coatings manufacturer and supplier with 40+ years of experience in the industry. Our goal is to allow our customers to focus on their core strengths while helping them bring advanced medical products to market. We supply high-performance hydrophilic coatings with highly sought-after performance attributes, such as:
- Drug-eluting capabilities
- Antimicrobial properties
- Wettability
- Biocompatibility
- Excellent lubricity (reduced device friction)
- Low particulate
- Enhanced adhesion
- Thromboresistance reduces blood clotting
- Durability
- Compatibility with a wide range of medical devices
- Long-lasting hydrophilicity
We do not just offer off-the-shelf products. Rather, we offer custom-formulated hydrophilic coatings to meet your specific product requirements.
Medical Device Coatings Support Services
What truly sets us apart from our competitors is our range of coating support services we offer our partners. These include:
- In-house contract coating services
- Research and Development (R&D) services
- World-wide supply of high-quality, medical coatings
- Specialized Analytical Testing
- Custom Machine Building
- Turn-key Operations
- Technology Transfer Services
- Technical consulting and support service
Conclusion
An increasing number of patients need vascular grafting surgeries, which highlights the need for effective and reliable vascular implants. However, synthetic implants can cause complications like infection and blood clots. To combat this, medical device manufacturers use surface treatment, which modifies a device’s surface properties to improve its performance and safety. Coating-based techniques, especially hydrophilic coatings, have become popular because they are versatile and provide multiple benefits. Hydrophilic coatings are “water-attracting” and create a slippery surface when wet, which reduces friction and makes implant insertion easier. Additionally, these coatings can be customized to offer other advantages such as thromboresistance, antimicrobial properties, enhanced biocompatibility, and drug-eluting capabilities, all of which contribute to the long-term success and safety of vascular implants.
Create Your Custom Medical Device Coating Today
Do you need to develop a custom medical coating to meet your medical device requirements? If so, we can help regardless of what stage you are at in the product development process.
Contact our team of experts today to learn more about our custom coatings and services.
