Elucidating in vitro cell-cell interaction using a microfluidic coculture system.

Area of Science:

• Biotechnology
• Cell Biology
• Microfluidics

Background:

• Accurate evaluation of cell-cell interactions is crucial in biological research.
• Existing coculture methods can be limited by direct cell contact or lack of precise control over communication.
• Microfluidic systems offer potential for controlled cellular environments.

Purpose of the Study:

• To develop and validate a novel microfluidic coculture system.
• To improve the accuracy of evaluating interactions between physically separated cocultured cell types.
• To demonstrate the system's capability in modeling inflammatory cytokine-induced bone resorption.

Main Methods:

• Fabrication of a microfluidic coculture chip using CO(2) laser direct-writing on polymethyl methacrylate (PMMA).
• Design of a system with upstream wells for cell activation and downstream wells for target cells, separated by a microchannel.
• Utilizing a microfluidic mixing system to generate linear concentration gradients of inflammatory cytokines (interleukin-1 beta, tumor necrosis factor-alpha).
• Assessing osteoblast response by measuring prostaglandin E2 release and viability via MTT assay.

Main Results:

• The microfluidic system successfully separated two cell types while enabling media transfer.
• Activated macrophages in upstream wells released inflammatory cytokines that induced prostaglandin E2 release in downstream osteoblasts.
• Osteoblast viability was maintained, indicating system compatibility with cellular functions.
• Demonstrated the ability to create controlled concentration gradients of signaling molecules.

Conclusions:

• The novel microfluidic coculture system enhances the accuracy of studying cell-cell interactions.
• This system allows for physical separation of interacting cells, controlling communication pathways.
• It provides a valuable platform for investigating complex biological processes like inflammation-induced bone resorption.