Polydopamine and dopamine interfere with tetrazolium-based cytotoxicity assays and produce exaggerated...

Area of Science:

• Biomaterials Science
• Cell Biology
• Nanotechnology

Background:

• Tetrazolium-based assays, including MTT, are standard for assessing material biocompatibility.
• Polydopamine (PDA) and its precursor dopamine (DA) are widely used in biomedical applications.
• Accurate cell viability assessment is crucial for evaluating the safety and efficacy of biomaterials.

Purpose of the Study:

• To investigate the interference of dopamine (DA) and polydopamine (PDA) with MTT assays.
• To evaluate the accuracy of different cell viability assays in the presence of DA and PDA.
• To determine the impact of DA polymerization methods on assay interference.

Main Methods:

• Comparison of MTT assay results with trypan blue exclusion assay.
• Assessment of cell viability in the presence of varying DA polymerization methods.
• Quantitative analysis of MTT reduction by DA and PDA.

Main Results:

• Dopamine (DA) and polydopamine (PDA) spontaneously reduce MTT, leading to overestimation of cell viability.
• The degree of MTT assay interference is dependent on the method used for DA polymerization.
• The trypan blue exclusion assay demonstrated accurate cell viability determination in the presence of DA and PDA.

Conclusions:

• MTT assays are unreliable for assessing cell viability with DA and PDA due to inherent chemical interference.
• The trypan blue exclusion assay offers a more robust alternative for evaluating cell viability in the context of DA and PDA nanomaterials.
• Careful selection of cell viability assays is essential when working with redox-active biomaterials like PDA.