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Graphene microsheets enter cells through spontaneous membrane penetration at edge asperities and corner sites
Journal article   Open access   Peer reviewed

Graphene microsheets enter cells through spontaneous membrane penetration at edge asperities and corner sites

Yinfeng Li, Hongyan Yuan, Annette von dem Bussche, Megan Creighton, Robert H. Hurt, Agnes B. Kane and Huajian Gao
Proceedings of the National Academy of Sciences - PNAS, v 110(30), pp 12295-12300
23 Jul 2013
PMID: 23840061
url
https://doi.org/10.1073/pnas.1222276110View
Published, Version of Record (VoR)Open Access (License Unspecified) Open

Abstract

Multidisciplinary Sciences Science & Technology Science & Technology - Other Topics
Understanding and controlling the interaction of graphene-based materials with cell membranes is key to the development of graphene-enabled biomedical technologies and to the management of graphene health and safety issues. Very little is known about the fundamental behavior of cell membranes exposed to ultrathin 2D synthetic materials. Here we investigate the interactions of graphene and few-layer graphene (FLG) microsheets with three cell types and with model lipid bilayers by combining coarse-grained molecular dynamics (MD), all-atom MD, analytical modeling, confocal fluorescence imaging, and electron microscopic imaging. The imaging experiments show edge-first uptake and complete internalization for a range of FLG samples of 0.5- to 10-mu m lateral dimension. In contrast, the simulations show large energy barriers relative to k(B)T for membrane penetration by model graphene or FLG microsheets of similar size. More detailed simulations resolve this paradox by showing that entry is initiated at corners or asperities that are abundant along the irregular edges of fabricated graphene materials. Local piercing by these sharp protrusions initiates membrane propagation along the extended graphene edge and thus avoids the high energy barrier calculated in simple idealized MD simulations. We propose that this mechanism allows cellular uptake of even large multilayer sheets of micrometer-scale lateral dimension, which is consistent with our multimodal bioimaging results for primary human keratinocytes, human lung epithelial cells, and murine macrophages.

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Collaboration types
Domestic collaboration
International collaboration
Web of Science research areas
Materials Science, Multidisciplinary
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