In the medical field, material surface properties directly determine biocompatibility, functionality, and safety. Contact angle, as an intuitive and quantitative characterization method, has become an indispensable testing tool in medical research and production. Contact angle measurement can be used to assess a material's wettability, surface energy, and hydrophilic/hydrophobic properties, thereby guiding the design and optimization of medical devices, consumables, and implants.

1. Biocompatibility Assessment

Hydrophilic surfaces (small contact angles) facilitate cell adhesion, protein adsorption, and promote tissue integration;

Hydrophobic surfaces (large contact angles) are often used to reduce cell adhesion and mitigate foreign body reactions.

Applications: Compatibility studies of surfaces such as artificial bones, vascular stents, heart valves, and dental implants.

2. Surface Modification Verification for Medical Devices

Medical materials such as plastics, metals, and ceramics often require plasma treatment, chemical modification, or coating to improve their properties.

Contact angle testing can verify the effectiveness of surface modification. For example, a significant decrease in the water drop angle after surface activation indicates an increase in surface energy, which facilitates adhesive or coating adhesion.
Applications: Surface modification testing of catheters, syringes, and hemodialysis machines.

3. Coating Performance Testing

Medical devices often require functional coatings (such as antibacterial, anti-thrombotic, and hydrophilic lubricating coatings).

Contact angle measurement can quantitatively characterize the hydrophobicity/hydrophilicity of a coating, determining its uniformity and durability. Applications: Coatings for urinary catheters, cardiac stents, and anti-stick coatings for surgical tools.

4. Drug Delivery and Controlled Release Systems

In drug delivery systems (microspheres, films, and stents), the water drop angle is used to assess surface hydrophilicity, which in turn affects the release rate of drug molecules.
Applications: Controlled-release membranes and drug-eluting stents (DES).

5. Medical Membranes and Filter Materials

Contact angle is used to assess the wettability and liquid permeability of medical membranes.

Hydrophilic membranes: Facilitate hemodialysis and filtration;

Hydrophobic membranes: Used for gas exchange or to prevent liquid penetration.

Applications: Hemodialysis membranes, ventilator filters.

6. Quality Control (QC) and Standardization

In medical device production, the water drop angle is a rapid, non-destructive quality control metric.

It is used to confirm the stability of surface treatment processes and ensure batch consistency.

Applications: Implant production and high-volume manufacturing of disposable consumables.

Summary

Contact angle measurement has multiple applications in the medical industry, including biocompatibility assessment, surface modification verification, coating performance testing, drug release studies, and quality control. It not only helps R&D personnel optimize material surface properties but also provides strong assurance for the safety, reliability, and functionality of medical devices.