Engineered Shape-Tunable Copper-Coordinated Nanoparticles for Macrophage Reprogramming

Abstract

The immune system safeguards as primary defense by recognizing nanomaterials and maintaining homeostasis, gaining a deeper understanding of these interactions may change the treating paradigm of immunotherapy. Here, we adopted copper as the principal component of nanoparticles (NPs), given its features of coordination with different benezenecarboxylate ligands to form metal-organic frameworks and complexes with distinct morphologies. As a result, four types of shape-tunable copper-coordinated NPs (CuCNPs) are developed: cuboctahedron, needle, octahedron, and plate NPs. Biocompatibility of CuCNPs varies across different cell lines (RAW264.7, THP-1, HEK 293 and HeLa) in a shape-dependent manner, with needle-shaped CuCNPs showing pronounced cytotoxicity (IC50:104.3 μg mL^-1 at 24 h). Among different shapes, a notable increase of 8.47% in the CD206⁺ subpopulations is observed in needle-shaped CuCNPs, followed by 77% enhancement at 48 h. Overall, this study underscores the shape-dependent immune-regulatory effects of CuCNPs and sheds light on the rational design of nanoscale metal complexes for potential immunotherapy.

Keywords: Copper coordination nanocomplexes; Immune response; Macrophage reprogramming; Nanoparticles; Shape-tunable.

Scheme 1. Schematic Illustration of Shape-Tunable Copper-Coordinated Nanoparticles (CuCNPs) on Modulating Immune Responses (Created with BioRender.com)

Figure 1

Preparation and characterization of shape-tunable copper-coordinated nanoparticles. (A) The morphology of four shape-tunable CuCNPs was observed via TEM imaging. Scale bar: 1 μm. (B) The surface morphology of shape-tunable CuCNPs was analyzed via SEM imaging. Scale bar: 2 μm. (C) PXRD characterization of shape-tunable CuCNPs for determining the crystalline phase. (D) Size (nm) and E. Zeta-potential were determined using DLS analysis. Data are shown as mean ± SD.

Figure 2

Cytotoxicity of shape-tunable CuCNPs on distinct cell lines. Four shape-varying CuCNPs were incubated with different types of cell lines, including (A) RAW264.7 cells, (B) THP-1 cells, (C) HEK 293 cells and (D) HeLa cells. The working concentrations ranged from 0 to 200 μg mL^–1. Data are shown as mean ± SD. The results were analyzed with two-way ANOVA, followed by Tukey’s post-test within two groups.

Figure 3

Shape-tunable CuCNPs regulate macrophage repolarization. Four shape-varying CuCNPs were incubated with RAW264.7 macrophages at the concentration of 75 μg mL^–1 for 24 h (A, B) and 48 h (C, D). Flow cytometry analysis was performed to analyze the repolarization effects.

Figure 4

Gene expression levels of biomarkers for M2-phenotype macrophages. (A, C) The gene expression levels of CD206 and Arg-1 after treatment with shape-switching CuCNPs for 24 h. (B, D) The gene expression levels of CD206 and Arg-1 after treated with shape-switching CuCNPs for 48 h. Data are shown as mean ± SD *, p < 0.05. The results were analyzed with two-way ANOVA, followed by Tukey’s post-test within two groups.

Figure 5

Comparison of cytokines expression profiles. (A) Experimental illustration of distinct effects of shape-tunable CuCNPs on RAW264.7 macrophages. Cytokine expression levels, including (B) TNF-α, (C) IL-4 and (D) IL-10 were determined by ELISA assay. Data are shown as mean ± SD. The results were analyzed with two-way ANOVA, followed by Tukey’s post-test within two groups.