A microwell pattern for C17.2 cell aggregate formation with concave cylindrical surface induced cell peeling

Area of Science:

• Biomaterials Engineering
• Stem Cell Biology
• Tissue Engineering

Background:

• Developing 3D multicellular aggregates is crucial for neural stem cell research.
• Existing methods for aggregate formation can be inefficient or lack control.

Purpose of the Study:

• To create a polydimethylsiloxane (PDMS) microwell pattern for efficient formation of multicellular aggregates from C17.2 neural stem cells.
• To investigate the role of structural dimensions and mechanical properties in aggregate formation.

Main Methods:

• Fabrication of PDMS patterns with arrays of microwells and channels.
• Culture of C17.2 neural stem cells on the patterned surfaces.
• Microscopy to observe cell attachment, strip formation, and aggregate assembly.
• Finite Element Method (FEM) simulations to analyze cellular prestress and peeling behavior.

Main Results:

• Neural stem cells formed cellular strips on microwell sidewalls, which then peeled to form aggregates.
• Smaller microwell diameters (80 and 100 μm) and narrow channel widths (20 μm) facilitated aggregate formation.
• FEM simulations showed lower critical peeling prestress on curved surfaces compared to flat substrates, suggesting cell growth also influences aggregate induction.

Conclusions:

• The developed PDMS microwell patterning method is a practical approach for generating 3D neural stem cell aggregates.
• Structural dimensions significantly influence the efficiency of aggregate formation.
• Mechanical properties and cell growth behaviors are key factors in this novel patterning method for 3D neural stem cell assays.