Tan Binbin, Hu Juanmei, Wu Fengmin
Key Laboratory of Optical Field Manipulation of Zhejiang Province, Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, China.
ACS Omega. 2024 Feb 19;9(8):9216-9225. doi: 10.1021/acsomega.3c08236. eCollection 2024 Feb 27.
Graphene nanosheets are highly valued in the biomedical field due to their potential applications in drug delivery, biological imaging, and biosensors. Their biological effects on mammalian cells may be influenced by cholesterols, which are crucial components in cell membranes that take part in many vital processes. Therefore, it is particularly important to investigate the effect of cholesterols on the transport mechanism of graphene nanosheets in the cell membrane as well as the final stable configuration of graphene, which may have an impact on cytotoxicity. In this paper, the molecular details of a graphene nanosheet interacting with a 1,2-dipalmitoyl--glycero-3-phosphorylcholine (DPPC) membrane with cholesterols were studied using molecular dynamics simulations. Results showed that the structure of the graphene nanosheet transits from the cut-in state in a pure DPPC membrane to being sandwiched between two DPPC leaflets when cholesterols reach a certain concentration. The underlying mechanism showed that cholesterols are preferentially adsorbed on the graphene nanosheet, which causes a larger disturbance to the nearby DPPC tails and thus guides the graphene nanosheet into the core of lipid bilayers to form a sandwiched structure. Our results are helpful for understanding the fundamental interaction mechanism between the graphene nanosheet and cell membrane and to explore the potential applications of the graphene nanosheet in biomedical sciences.
石墨烯纳米片因其在药物递送、生物成像和生物传感器方面的潜在应用而在生物医学领域备受重视。它们对哺乳动物细胞的生物学效应可能会受到胆固醇的影响，胆固醇是细胞膜中的关键成分，参与许多重要过程。因此，研究胆固醇对石墨烯纳米片在细胞膜中的转运机制以及石墨烯最终稳定构型的影响尤为重要，这可能会对细胞毒性产生影响。在本文中，使用分子动力学模拟研究了石墨烯纳米片与含有胆固醇的1,2 - 二棕榈酰 - sn - 甘油 - 3 - 磷酸胆碱（DPPC）膜相互作用的分子细节。结果表明，当胆固醇达到一定浓度时，石墨烯纳米片的结构从纯DPPC膜中的切入状态转变为夹在两个DPPC叶之间。潜在机制表明，胆固醇优先吸附在石墨烯纳米片上，这对附近的DPPC尾部造成更大的干扰，从而引导石墨烯纳米片进入脂质双层的核心形成夹心结构。我们的结果有助于理解石墨烯纳米片与细胞膜之间的基本相互作用机制，并探索石墨烯纳米片在生物医学科学中的潜在应用。
