Biocompatibility characterization of vaterite with a bacterial whole-cell biosensor

Area of Science:

• Biomaterials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Biocompatibility is crucial for drug delivery and implantable devices.
• Calcium carbonate (CaCO3) vaterite nanoparticles offer unique properties for biomedical applications.
• Evaluating the toxicity of nanomaterials is essential for safe development.

Purpose of the Study:

• To assess the biocompatibility of differently shaped calcium carbonate (CaCO3) vaterite nanoparticles (toroids, ellipsoids, spheroids).
• To investigate the bacterial toxicity mode-of-action using a whole-cell biosensor.
• To determine the influence of particle shape on cytotoxicity, genotoxicity, and quorum-sensing.

Main Methods:

• Utilized scanning electron microscopy (SEM) and fluorescence microscopy for characterization.
• Employed a bioluminescent assay with multiple Escherichia coli (E. coli) strains.
• Assessed bacterial cell death, aggregation, and bioluminescent signals to determine toxicity.

Main Results:

• Bacterial cell death and aggregation occurred only at the highest vaterite particle concentrations, particularly toroids.
• Vaterite particles induced a toxicity response (induction factor > 1) across all tested E. coli strains.
• Spheroid vaterite nanoparticles showed the lowest induction factor, indicating minimal toxicity.

Conclusions:

• Calcium carbonate vaterite nanoparticles did not significantly affect bacterial cell viability.
• Spheroid-shaped vaterite nanoparticles demonstrated a biofriendly profile, suggesting their suitability for biomedical use.
• Particle shape is a critical factor influencing the biocompatibility of vaterite nanoparticles.