Noninvasive sorting of stem cell aggregates based on intrinsic markers

Area of Science:

• Stem Cell Biology
• Biomarkers
• Flow Cytometry

Background:

• Noninvasive biomarkers are crucial for stem cell characterization and purification.
• Exogenous labels can alter stem cell state.
• Intrinsically fluorescent nicotinamide adenine dinucleotide (NADH) intensity correlates with stem cell viability and differentiation.

Purpose of the Study:

• To utilize multiphoton flow cytometry for noninvasive characterization and purification of stem cell aggregates.
• To assess the differentiation capacity of stem cell populations sorted by NADH intensity.
• To demonstrate the utility of endogenous properties for stem cell purification.

Main Methods:

• Development and application of multiphoton flow cytometry.
• Characterization and purification of stem cell aggregates based on NADH intensity and size.
• Assessment of cardiomyocyte differentiation potential in sorted populations.

Main Results:

• Removing aggregates with low NADH intensity (indicating cell death) increased cardiomyocyte production (26% vs. 8%).
• Isolating aggregates with high NADH intensity (indicating differentiation potential) also increased cardiomyocyte yield (50% vs. 28%).
• Combining NADH intensity with size-based gating further enhanced enrichment for cardiomyocyte-producing aggregates (59% vs. 27%).

Conclusions:

• Endogenous NADH intensity and aggregate size can serve as noninvasive gating parameters for stem cell purification.
• This approach enables the purification of stem cells or progeny without exogenous labels.
• The method holds promise for improving stem cell-based therapeutic applications.