PDMS Micropatterns Coated with PDA and RGD Induce a Regulatory Macrophage-like Phenotype

Area of Science:

• Biomaterials Science
• Cell Biology
• Immunology

Background:

• Regulatory macrophages (Mreg) are crucial for managing inflammatory diseases.
• Current in vitro Mreg generation methods are lengthy, requiring 7-10 days and cytokine treatment.

Purpose of the Study:

• To develop a rapid and efficient method for generating Mreg-like cells in vitro.
• To investigate the use of 3D micropatterned polydimethylsiloxane (PDMS) surfaces coated with polydopamine (PDA) and arginylglycylaspartic acid (RGD) for Mreg generation.

Main Methods:

• Fabrication of 3D PDMS micropatterns using photolithography and soft lithography.
• Coating of PDMS surfaces with a PDA and RGD mixture to enhance cell adhesion.
• Culture of human monocytes (THP-1 cells) on various 2D and 3D micropatterned surfaces for four days.
• Assessment of cell morphology, elongation, and Mreg marker expression via microscopy and flow cytometry.

Main Results:

• THP-1 cells cultured on PDA+RGD-coated 3D micropatterns (20-µm width/20-µm space) showed enhanced elongated morphology.
• These cells exhibited significantly higher expression of key Mreg markers (CD163, CD206, CD209, CD274, MER-TK, TREM2, DHRS9).
• Mreg-like cells were successfully generated within four days without cytokine induction.

Conclusions:

• PDA+RGD-coated 3D PDMS micropatterns provide an effective platform for rapid in vitro Mreg generation.
• This novel approach offers a time- and cost-efficient alternative to conventional methods for producing Mreg-like cells.