Isolation of Human Ventricular Cardiomyocytes from Vibratome-Cut Myocardial Slices

Area of Science:

• Cardiovascular Biology
• Cellular Biology
• Biomedical Engineering

Background:

• Cardiac myocyte isolation is crucial for research but challenging for human samples due to limited perfusion.
• Existing methods for human cardiomyocyte isolation yield poor cell viability and require on-site cardiac surgery.
• Translating findings from animal to human cardiac research is hampered by isolation technique disparities.

Purpose of the Study:

• To develop a reliable and efficient protocol for isolating ventricular cardiac myocytes from both human and animal myocardium.
• To overcome limitations of current methods, particularly for human tissue, enabling broader research applications.
• To enhance the yield and viability of isolated cardiomyocytes for downstream functional studies.

Main Methods:

• Myocardial tissue slices (300 µm) were generated using a vibratome to maximize surface-to-volume ratio.
• Tissue slices underwent digestion with protease and collagenase.
• Yields of viable, calcium-tolerant myocytes were quantified using flow-cytometric cell counting and compared to the tissue-chunk method.

Main Results:

• The vibratome slicing method yielded significantly higher percentages of rod-shaped cardiomyocytes from rat myocardium compared to the tissue-chunk method (41.5 ± 11.9% vs. 7.89 ± 3.6%).
• The protocol successfully translated to human myocardium (failing and non-failing), showing markedly higher yields than the tissue-chunk method (45.0 ± 15.0 vs. 6.87 ± 5.23 cells/mg).
• Viable human cardiomyocytes (9-200 cells/mg) were isolated from minimal tissue amounts (<50 mg), and cells remained viable after 36h storage in cardioplegic solution.

Conclusions:

• A vibratome-based tissue slicing and enzymatic digestion protocol provides an efficient method for isolating viable cardiac myocytes from human and animal hearts.
• This protocol overcomes limitations of traditional methods, offering improved yields and applicability to rare human myocardial specimens, even without on-site cardiac surgery.
• The method facilitates research by enabling isolation of functional cardiomyocytes from diverse cardiac tissues, supporting the translation of findings across species.