In vitro apatite formation on organic polymers modified with a silane coupling reagent

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Organic polymers such as high-density polyethylene, polyamide, and silicone rubber lack inherent bioactivity.
• Enhancing the in vitro apatite-forming ability of polymers is crucial for developing advanced biomaterials.
• Surface modification techniques are essential for imparting new functionalities to existing polymer substrates.

Purpose of the Study:

• To functionalize high-density polyethylene, polyamide, and silicone rubber with gamma-methacryloxypropyltrimethoxysilane (gamma-MPS).
• To evaluate the impact of gamma-MPS grafting on the surface properties, specifically hydrophilicity.
• To assess the in vitro apatite-forming capability of the modified polymer substrates in a simulated body fluid.

Main Methods:

• Gamma-methacryloxypropyltrimethoxysilane (gamma-MPS) was grafted onto polymer substrates using emulsion polymerization.
• Contact angle measurements with distilled water were performed to assess surface hydrophilicity.
• In vitro apatite formation was evaluated using a simulated body fluid (Kokubo solution).

Main Results:

• Gamma-MPS grafting significantly reduced the water contact angles of the polymer substrates, indicating increased hydrophilicity.
• The gamma-MPS-grafted specimens exhibited enhanced in vitro apatite formation when immersed in simulated body fluid.
• Successful functionalization was confirmed for high-density polyethylene, polyamide, and silicone rubber substrates.

Conclusions:

• Surface grafting of gamma-methacryloxypropyltrimethoxysilane (gamma-MPS) effectively enhances the hydrophilicity of organic polymers.
• The modified polymers demonstrate promising in vitro apatite-forming ability, suggesting potential for biomedical applications.
• This surface modification strategy offers a viable route to improve the biocompatibility of common polymeric materials.