Multivariate biophysical markers predictive of mesenchymal stromal cell multipotency

Area of Science:

• Stem cell biology
• Biophysics
• Regenerative medicine

Background:

• Therapeutic applications of mesenchymal stromal cells (MSCs) require large quantities, necessitating efficient in vitro expansion.
• Identifying and isolating multipotent MSCs from heterogeneous cell populations remains a significant challenge.
• Novel methods are needed to characterize and separate MSCs and their progenitors for improved therapeutic efficacy.

Purpose of the Study:

• To identify reliable biophysical markers for the robust identification and isolation of multipotent mesenchymal stromal cells (MSCs).
• To correlate biophysical properties with biomolecular markers and functional stem cell characteristics.
• To develop methods for separating MSC subpopulations from other stromal cells.

Main Methods:

• Multivariate biophysical analysis of culture-expanded, bone marrow-derived MSCs.
• Correlation of biophysical measures with gene and protein expression, and in vitro/in vivo functionality.
• High-throughput inertial microfluidics for cell sorting.

Main Results:

• No single biophysical property reliably predicts MSC multipotency.
• A combination of three biophysical markers (small cell diameter, low cell stiffness, high nuclear membrane fluctuations) accurately predicts multipotent subpopulations.
• These identified subpopulations exhibit high clonogenicity and stemness signatures.
• Inertial microfluidics effectively sorted osteoprogenitor cells from MSCs in adult bone marrow.

Conclusions:

• A minimal set of three biophysical markers can identify and isolate multipotent MSC subpopulations from culture-expanded stromal cells.
• These findings offer novel markers of stemness for physical isolation and study.
• The developed methods facilitate the therapeutic use of specific MSC subpopulations.