In medical procedures, medical tubes that come into contact with delicate internal tissues play a critical role in patient quality of life and treatment outcomes. In particular, hydrophilic coating applied to tube surfaces has gained attention as a technology that enables smooth insertion and safe operation.
This article explains the purpose of hydrophilic coating for medical tubes using dip coating and the key technical points.
Purpose of Hydrophilic Coating for Medical Tubes
Friction Reduction During Insertion
When medical tubes are inserted and moved inside the body, friction generated between the tube surface and biological tissues can cause pain and discomfort for the patient.
Hydrophilic coating forms a thin water layer on the tube surface, which significantly reduces this friction. As a result, the insertion and manipulation of devices such as catheters become smoother, contributing to reduced physical burden on the patient.
Improvement of Biocompatibility and Safety
Hydrophilic coating can also enhance compatibility with biological tissues. The coating suppresses the adsorption of biomolecules such as proteins on the surface. It also reduces the risk of thrombus formation and infection.
As a result, the biocompatibility and safety of medical tubes are improved. This enables safer and more stable medical procedures.
Hydrophilic Coating Technology for Medical Tubes by Dip Coating
Two-Layer Coating Process
Hydrophilic coating by dip coating generally adopts a two-layer structure. First, a primary polymer layer is formed on the tube surface. This layer dissolves in a polar liquid and contains specific reactive functional groups. Next, a hydrophilic second polymer layer is applied on top. This layer has reactive functional groups that react with those of the first polymer layer.
This two-layer structure enables chemical bonding between the polymer layers, which improves coating adhesion and durability.
Durability Enhancement by Crosslinking Agents
Crosslinking agents are sometimes used to further enhance the durability of the coating. These agents chemically bond polymer chains within the coating layer, forming a crosslinked network.
In particular, crosslinking agents may contain latent reactive functional groups. These groups are activated by external stimuli such as light, allowing precise control of polymer bonding during the coating process. This improves coating strength, wear resistance, and resistance to delamination.
Resistance to Sterilization Processes
Medical tubes must undergo sterilization before use to ensure a sterile condition. Sterilization methods using ethylene oxide gas are commonly employed, but depending on the coating material, such processes may degrade performance or cause damage.
However, hydrophilic coating technologies are designed to maintain key properties such as hydrophilicity and lubricity even after sterilization treatment by enhancing resistance to these processes.
Summary
Hydrophilic coating for medical tubes primarily reduces friction during insertion. This helps lower patient burden and improves biocompatibility and safety. In dip coating-based technologies, a two-layer polymer structure is commonly used. Durability is enhanced by crosslinking agents, and the coating is designed to withstand ethylene oxide sterilization.
These approaches support safer and more comfortable medical procedures while maintaining stable coating performance.