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

Abstract

Regulatory macrophages (Mreg) are a special cell type that present a potential therapeutic strategy for various inflammatory diseases. In vitro, Mreg generation mainly takes 7–10 days of treatment with chemicals, including cytokines. In the present study, we established a new approach for Mreg generation using a three-dimensional (3D) micropatterned polydimethylsiloxane (PDMS) surface coated with a natural biopolymer adhesive polydopamine (PDA) and the common cell adhesion peptide motif arginylglycylaspartic acid (RGD). The 3D PDMS surfaces were fabricated by photolithography and soft lithography techniques and were subsequently coated with an RGD+PDA mixture to form a surface that facilitates cell adhesion. Human monocytes (THP-1 cells) were cultured on different types of 2D or 3D micropatterns for four days, and the cell morphology, elongation, and Mreg marker expression were assessed using microscopic and flow cytometric analyses. The cells grown on the PDA+RGD-coated 3D micropatterns (20-µm width/20-µm space) exhibited the most elongated morphology and strongest expression levels of Mreg markers, such as CD163, CD206, CD209, CD274, MER-TK, TREM2, and DHRS9. The present study demonstrated that PDA+RGD-coated 3D PDMS micropatterns successfully induced Mreg-like cells from THP-1 cells within four days without the use of cytokines, suggesting a time- and cost-effective method to generate Mreg-like cells in vitro.

Human Regulatory Macrophages Derived from THP-1 Cells Using Arginylglycylaspartic Acid and Vitamin D3

“…We did not use M-CSF and IFN-γ, which are commonly used to generate human Mregs [ 11 ]. Our Mregs had an elongated morphology, which was in line with other findings [ 15 , 40 ], and were phenotypically characterized as CD11b hi , CD14 lo , CD16 + , CD33 + , CD80 lo , CD86 + , iNOS - , CD163 hi , CD206 + , CD209 + , CD274 +/hi , TREM-2 + , MER-TK hi , and DHRS9 +/hi . Most of the markers evaluated herein were expressed in the Mregs generated by others, including CD14, CD80, CD86 [ 15 , 21 , 41 ], CD163, CD206, CD274 [ 15 , 42 ], CD209, MER-TK [ 15 ], and DHRS9 [ 22 ].…”

“…Similarly, in an M2-favorable environment, the RGD motif facilitated the M2 polarization of the macrophages [ 53 , 54 ]. In our recent study, we demonstrated that THP-1 cells cultured on RGD- and polydopamine-coated micropatterns were able to induce their differentiation into Mregs-like cells, even in the absence of cytokines [ 40 ]. Additionally, integrin (which is a counterpart to RGD) was also involved in M2 polarization.…”

Electrospun fibers modified with polydopamine for enhancing human mesenchymal stem cell culture

“…It can improve cell attachment from cell-incompatible surfaces. The PDA-coated surfaces have shown enhanced cell compatibility and viability as described in our previous studies [14][15][16]. Similarly, PDA surface modification of PCL nanofiber can reduce their low cell adhesion [17][18][19].…”

Potential effects of biomaterials on macrophage function and their signalling pathways

“…This regulatory phenotype was characterized by elongated fiber-like morphology and high expression of CD163/206/209/274, MER-TK, TREM2 and DHRS9. 63 Chen and colleagues investigated the effects of biomimetic calcium phosphate (BioCaP) coating, with or without bone morphogenetic protein 2 (BMP2), on the polarization of pre-stimulated M1 macrophages. 64 The mRNA expression of TNF-α was upregulated in M1 macrophages co-cultured with BioCaP and BioCaP + Inc.BMP2 coatings on day 1, followed by its downregulation on days 3 and 5.…”