Cell-based detection of microbial biomaterial contaminations

Area of Science:

• Biomaterials Science
• Microbiology
• Immunology

Background:

• Microbial contamination, including endotoxins (lipopolysaccharides, LPS), poses a significant challenge in biomaterial synthesis and functionalization.
• The conventional Limulus amebocyte lysate (LAL)-test has limitations in detecting material-bound LPS and other microbial contaminants like fungi or Gram-positive bacteria.

Purpose of the Study:

• To introduce and validate a novel cell-based assay for detecting both soluble and material-bound microbial contaminations.
• To evaluate the sensitivity of the cell-based assay towards different LPS species and heat-inactivated microbes.

Main Methods:

• Development of a cell-based assay using genetically engineered RAW macrophages.
• Investigation of assay sensitivity using various LPS species and heat-inactivated microbes.
• Proof-of-principle study using a deliberately contaminated poly(n-butyl acrylate) (cPnBA) network.

Main Results:

• The cell-based assay demonstrated sensitivity to different LPS species and heat-inactivated microbes.
• The LAL-test failed to detect microbial contamination on a deliberately contaminated cPnBA biomaterial.
• The cell-based assay successfully detected material-bound microbial contamination on the cPnBA network.

Conclusions:

• A cell-based assay offers a superior method for detecting a broader range of microbial contaminations compared to the LAL-test.
• Routine use of cell-based detection systems alongside the LAL-test is recommended for comprehensive biomaterial safety evaluation.