Fabrication of 3D Controlled in vitro Microenvironments

Area of Science:

• Biotechnology
• Materials Science
• Cell Biology

Background:

• Microfluidics-based lab-on-a-chip devices offer physiologically relevant settings for cell biology.
• There is a growing demand for advanced fabrication techniques for these devices.

Purpose of the Study:

• To develop and optimize a fabrication method for creating three-dimensional (3D) Controlled in vitro Microenvironments (CivMs).
• To mimic in vivo microenvironments for enhanced cell biology experiments.

Main Methods:

• Optimized SU-8 photoresist (SU-2075) processing (ramp, dwell time, spin speed, bake, UV exposure, development) to achieve SU-8 master heights from 40 to 600 μm.
• Room temperature molding of polydimethylsiloxane (PDMS) for at least two days to prevent defects in stamps and masters.
• Inverted device orientation during gel polymerization to ensure the 3D structure of CivMs.

Main Results:

• Achieved fabrication of SU-8 masters with tunable heights (40–600 μm) using optimized processing parameters.
• Prevented tears, bubbles, and cracks during PDMS molding and SU-8 master fabrication by using room temperature curing.
• Successfully created 3D CivMs by maintaining inverted orientation during gel polymerization.

Conclusions:

• The optimized fabrication method enables versatile production of SU-8 masters for various lab-on-a-chip designs.
• Room temperature PDMS molding improves the quality and integrity of microfluidic devices.
• The developed technique facilitates the construction of 3D CivMs, advancing in vitro cell culture models.