Visualizing bleb mass dynamics in single cells using quantitative phase microscopy.

Area of Science:

• Biophysics
• Cell Biology
• Optical Imaging

Background:

• Directed energy (DE) exposure necessitates understanding biological responses for personnel safety.
• Cellular membrane blebbing is a key indicator of DE-induced cellular damage.
• Advanced imaging techniques are needed to quantify these biophysical changes.

Purpose of the Study:

• To demonstrate quantitative phase imaging (QPI) for visualizing and quantifying membrane blebs in cells exposed to DE.
• To assess the real-time formation and dry mass changes of blebs post-DE exposure.
• To establish QPI as a tool for studying DE-induced and apoptotic blebbing.

Main Methods:

• Utilized quantitative phase imaging (QPI), an interferometric technique measuring optical path length for label-free contrast.
• Exposed Chinese Hamster Ovary (CHO-K1) and U937 cells to a series of 600 ns, 21.2 kV/cm electric pulses to induce blebbing.
• Quantified the dry mass of cellular blebs relative to the cell body over time in real-time.

Main Results:

• Successfully visualized membrane bleb formation in real-time following DE exposure in both cell lines.
• Quantified the relative dry mass of blebs as a function of time post-exposure.
• Established the sensitivity of QPI to bleb formation and dry mass changes.

Conclusions:

• Quantitative phase imaging is a capable tool for real-time visualization and quantification of DE-induced membrane blebbing.
• This method provides insights into the biophysical dynamics of cellular responses to directed energy.
• The developed QPI system can contribute to improved understanding of DE-induced and apoptotic blebbing mechanisms.