Penetration of Oxidized Carbon Nanospheres through Lipid Bilayer Membrane: Comparison to Graphene Oxide and Oxidized Carbon Nanotubes, and Effects of pH and Membrane Composition

Abstract

Here we show that the ability of oxidized carbon particles to penetrate phospholipid bilayer membrane varies with the particle shapes, chemical functionalities on the particle surface, lipid compositions of the membrane and pH conditions. Among the similar surface charged oxidized carbon particles of spherical (oxidized carbon nanosphere, OCS), tubular (oxidized carbon nanotube, OCT), and sheet (oxidized graphene sheet, OGSh) morphologies, OCS possesses the highest levels of adhesion to lipid bilayer membrane and penetration into the cell-sized liposome. OCS preferably binds better to the disordered lipid bilayer membrane (consisting of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine) as compared to the ordered membrane (consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine and cholesterol). The process of OCS-induced leak on the membrane is pH responsive and most pronounced under an acidic condition. Covalently decorating the OCS's surface with poly(ethylene oxide) or (2-aminoethyl)trimethylammonium moieties decreases its ability to interact with the membrane. When used as carriers, OCSs can deliver curcumin into nucleus of A549 human lung cancer and human embryonic kidney cells, in contrast, curcumin molecules delivered by OCTs remain in the cytoplasm. OGShs cannot significantly enter cells and cannot induce noticeable cellular uptake of curcumin.

Synthesis, characterization, and interactions of single-walled carbon nanotubes modified with doxorubicin with Langmuir–Blodgett biomimetic membranes

“…Since the shape of the isotherm in the presence of carbon nanotubes is altered mostly in the range of larger areas per molecules and at lower values of surface pressures, it may be supposed that in this region, the influence of SWCNTs is the most significant. These conclusions are also consistent with the results obtained by Seemork et al ( 2016 ), who showed that carbon nanotubes and other carbon materials bind much easier to the disordered lipid bilayer membrane of liposomes consisting of DOPC as compared to the ordered membrane consisting of DMPC/cholesterol. Upon the further compression of the barriers and the formation of more ordered thiolipid layer, the nanotubes cannot be squeezed out from the monolayer into the subphase because they are not enough water-soluble.…”

Oxidized Carbon Black: Preparation, Characterization and Application in Antibody Delivery across Cell Membrane

“…It should be noted here that, comparing to the previously reported membrane penetrating agent OCNs 15 – 17 , which can be synthesized from graphite and graphene, the preparation of OCBs demonstrated here not only gives more than double the yield but also produces neither tube nor sheet by products, thus the multi-step centrifugation process is not needed. With such a simpler OCB preparation process, we investigated whether this newly prepared material would have an ability to bring macromolecules across lipid bilayer membrane.…”

“…After mixing, the suspension was dropped onto the glass slide with a silicon chamber. Then the liposomes in the suspension were observed by CLFM at the λ ex /λ em of 488/520 nm 16 , 17 .…”

“…Our involvement in this area started from our preparation of the oxidized carbon nanospheres (OCNs) that possess excellent ability to bring macromolecules into cells 15 – 17 . Although the previously reported OCN can be effectively used as a delivery reagent to bring matters into cells, there are many limitations on the OCN preparation.…”

Lateral Tension-Induced Penetration of Particles into a Liposome

“…Nano/submicron particles have been actively studied because of their potential for controlling living cells, such as for drug delivery [ 1 , 2 , 3 , 4 , 5 ], local heating [ 6 ], and the visualization of proteins [ 7 ]. To express these functions, particles need to be transported into cells, and this process normally involves cellular uptake functions that are controlled by proteins [ 8 ].…”