Given the wide variety of potential applications of graphene oxide (GO), its consequent release into the environment poses serious concerns on its safety. The future production and exploitation of graphene in the years to come should be guided by its specific chemical-physical characteristics. The unparalleled potential of single-cell mass cytometry (CyTOF) to dissect by high-dimensionality the specific immunological effects of nanomaterials, represents a turning point in nanotoxicology. It helps us to identify the safe graphene in terms of physical-chemical properties and therefore to direct its future safe production.

Here we present a high-dimensional study to evaluate two historically indicated as key parameters for the safe exploitation: functionalization and dimension. The role of lateral dimension and the amino-functionalization of GO on their immune impact were here evaluated as synergistic players. To this end, we dissected the effects of GO, characterized by a large or small lateral size (GO 1.32 μm and GO 0.13 μm, respectively), and its amino-functionalized counterpart (GONH₂ 1.32 μm and GONH₂ 0.13 μm, respectively) on fifteen cell types of human primary peripheral blood mononuclear cells (PBMCs).

We describe how the smallest later size not only evokes pronounced toxicity on the pool of PBMCs compared to larger GOs but also towards the distinct immune cell subpopulations, in particular on non-classical monocytes, plasmacytoid dendritic cells (pDCs), natural killer cells (NKs) and B cells. The amino-functionalization was able to improve the biocompatibility of classical and non-classical monocytes, pDCs, NKs, and B cells. Detailed single-cell analysis further revealed a complex interaction of all GOs with the immune cells, and in particular monocyte subpopulations, with different potency depending on their physicochemical properties. Overall, by high-dimensional profiling, our study demonstrates that the lateral dimension is an important factor modulating immune cells and specifically monocyte activation, but a proper surface functionalization is the dominant characteristic in its immune effects. In particular, the amino-functionalization can critically modify graphene impact dampening the immune cell activation. Our study can serve as a guide for the future broad production and use of graphene in our everyday life.

鉴于氧化石墨烯 (GO) 的广泛潜在应用，其随后释放到环境中对其安全性构成严重关注。未来几年石墨烯的生产和开发应以其特定的化学物理特性为指导。单细胞质量流式细胞术 (CyTOF) 具有无与伦比的潜力，可通过高维分析纳米材料的特定免疫效应，这代表了纳米毒理学的一个转折点。它有助于我们从物理化学性质方面识别安全的石墨烯，从而指导其未来的安全生产。

在这里，我们提出了一项高维研究，以评估两个历史上被认为是安全利用的关键参数：功能化和维度。横向尺寸的作用和 GO 的氨基功能化对其免疫影响的作用在这里被评估为协同作用。为此，我们剖析了以大或小的横向尺寸为特征的 GO（分别为 GO 1.32 μm 和 GO 0.13 μm）及其氨基官能化对应物（分别为 GONH ₂ 1.32 μm 和 GONH ₂ 0.13 μm）的影响十五种细胞类型的人原代外周血单核细胞 (PBMC)。

我们描述了与较大的 GO 相比，最小的后期尺寸如何不仅在 PBMC 池中引起明显的毒性，而且对不同的免疫细胞亚群，特别是对非经典单核细胞、浆细胞样树突状细胞 (pDC)、自然杀伤细胞 (NK) ) 和 B 细胞。氨基功能化能够提高经典和非经典单核细胞、pDC、NK 和 B 细胞的生物相容性。详细的单细胞分析进一步揭示了所有 GO 与免疫细胞的复杂相互作用，特别是单核细胞亚群，其效力取决于其物理化学性质。总体而言，通过高维分析，我们的研究表明横向维度是调节免疫细胞特别是单核细胞活化的重要因素，但适当的表面功能化是其免疫作用的主要特征。特别是，氨基官能化可以严重改变石墨烯对免疫细胞活化的影响。我们的研究可以为我们日常生活中未来广泛生产和使用石墨烯提供指导。