Removing Endotoxin from Metallic Biomaterials with Compressed Carbon Dioxide-Based Mixtures

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Microbiology

Background:

• Bacterial endotoxins adhere strongly to metallic biomaterials due to surface energy.
• Conventional depyrogenation methods may damage biomaterials and fail to fully remove endotoxins.

Purpose of the Study:

• To evaluate the efficacy of compressed CO(2)-based mixtures for endotoxin removal from metallic surfaces.
• To assess the impact of water and surfactant Ls-54 in CO(2) mixtures on endotoxin solubilization and removal.

Main Methods:

• Testing endotoxin removal from titanium and stainless steel using compressed CO(2) with water and/or Ls-54.
• Utilizing a CO(2)/water/Ls-54 ternary mixture under specific temperature and pressure conditions (25 °C, 27.6 MPa).
• Employing strong mixing to enhance penetration and dissolution of endotoxins.

Main Results:

• The CO(2)/water/Ls-54 ternary mixture effectively removed E. coli endotoxin from smooth and porous titanium and stainless steel lumens.
• Endotoxin levels were reduced below detection limits, indicating complete removal.
• The mixture demonstrated penetration and solubilization of endotoxins from various metallic substrates.

Conclusions:

• Compressed CO(2)-based mixtures, particularly the ternary CO(2)/water/Ls-54 formulation, offer a viable solution for endotoxin removal from metallic biomaterials.
• This technology shows promise for cleaning reusable medical devices and ensuring the safety of implants.
• The method avoids compromising the biological properties and functionality of metallic instruments.