Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA 02134, USA.
Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, T. H. Chan School of Public Health, Harvard University Boston, MA 02115, USA.
NanoImpact. 2022 Apr;26:100401. doi: 10.1016/j.impact.2022.100401. Epub 2022 Apr 20.
Engineered nanomaterials offer the benefit of having systematically tunable physicochemical characteristics (e.g., size, dimensionality, and surface chemistry) that highly dictate the biological activity of a material. Among the most promising engineered nanomaterials to date are graphene-family nanomaterials (GFNs), which are 2-D nanomaterials (2DNMs) with unique electrical and mechanical properties. Beyond engineering new nanomaterial properties, employing safety-by-design through considering the consequences of cell-material interactions is essential for exploring their applicability in the biomedical realm. In this study, we asked the effect of GFNs on the endothelial barrier function and cellular architecture of vascular endothelial cells. Using micropatterned cell pairs as a reductionist in vitro model of the endothelium, the progression of cytoskeletal reorganization as a function of GFN surface chemistry and time was quantitatively monitored. Here, we show that the surface oxidation of GFNs (graphene, reduced graphene oxide, partially reduced graphene oxide, and graphene oxide) differentially affect the endothelial barrier at multiple scales; from the biochemical pathways that influence the development of cellular protrusions to endothelial barrier integrity. More oxidized GFNs induce higher endothelial permeability and the increased formation of cytoplasmic protrusions such as filopodia. We found that these changes in cytoskeletal organization, along with barrier function, can be potentiated by the effect of GFNs on the Rho/Rho-associated kinase (ROCK) pathway. Specifically, GFNs with higher surface oxidation elicit stronger ROCK2 inhibitory behavior as compared to pristine graphene sheets. Overall, findings from these studies offer a new perspective towards systematically controlling the surface-dependent effects of GFNs on cytoskeletal organization via ROCK2 inhibition, providing insight for implementing safety-by-design principles in GFN manufacturing towards their targeted biomedical applications.
工程纳米材料具有系统可调理化特性（例如尺寸、维度和表面化学）的优势，这些特性高度决定了材料的生物活性。迄今为止，最有前途的工程纳米材料之一是石墨烯家族纳米材料（GFNs），它是具有独特的电学和力学性能的二维纳米材料（2DNMs）。除了设计新型纳米材料的特性外，通过考虑细胞-材料相互作用的后果来采用安全设计至关重要，这对于探索它们在生物医学领域的适用性至关重要。在这项研究中，我们研究了 GFNs 对血管内皮细胞的内皮屏障功能和细胞结构的影响。使用微图案化细胞对作为内皮的简化体外模型，定量监测了细胞骨架重排随 GFN 表面化学和时间的进展。在这里，我们表明 GFNs（石墨烯、还原氧化石墨烯、部分还原氧化石墨烯和氧化石墨烯）的表面氧化在多个尺度上差异地影响内皮屏障；从影响细胞突起发育的生化途径到内皮屏障完整性。更氧化的 GFNs 会导致更高的内皮通透性和更多细胞质突起（如丝状伪足）的形成。我们发现，这些细胞骨架组织的变化以及屏障功能，可以通过 GFNs 对 Rho/Rho 相关激酶（ROCK）途径的影响而增强。具体来说，与原始石墨烯片相比，具有更高表面氧化的 GFNs 会引起更强的 ROCK2 抑制行为。总的来说，这些研究结果为通过 ROCK2 抑制系统地控制 GFNs 对细胞骨架组织的表面依赖性影响提供了新的视角，为在 GFN 制造中实施安全设计原则以实现其靶向生物医学应用提供了见解。
