Optimization of scanning electron microscope technique for amniotic membrane investigation: A preliminary study

Area of Science:

• Biomaterials Science
• Cell Biology
• Microscopy Techniques

Background:

• Human amniotic membrane (hAM) is a promising scaffold for stem cell applications.
• Scanning Electron Microscopy (SEM) is crucial for visualizing cell morphology and scaffold interaction.
• Standardized SEM preparation protocols are essential for reproducible and high-quality imaging.

Purpose of the Study:

• To compare formaldehyde-based and glutaraldehyde-based SEM preparation protocols.
• To determine the optimal SEM preparation technique for stem cells on hAM scaffolds.
• To enhance the understanding of stem cell behavior on biomaterial surfaces.

Main Methods:

• Comparison of two SEM preparation protocols: formaldehyde-based vs. glutaraldehyde-based.
• Evaluation of SEM image quality for stem cells cultured on hAM scaffolds.
• Optimization of dehydration steps using graded alcohol concentrations.

Main Results:

• The formaldehyde-based protocol yielded clearer topography of the hAM scaffold and better visualization of cell borders.
• Recommended dehydration sequence: 20-90% graded alcohol (1x each), 100% alcohol (2x) for 10 min each.
• Gold sputter-coating was found to be unnecessary and did not improve image quality.

Conclusions:

• Formaldehyde-based protocol is recommended for SEM imaging of stem cells on hAM.
• Preliminary studies are advised to optimize sample preparation for specific cell-scaffold systems.
• Careful optimization of dehydration is critical for preserving sample integrity and improving SEM image clarity.