Bringing Macromolecules into Cells and Evading Endosomes by Oxidized Carbon Nanoparticles

Abstract

A great challenge exists in finding safe, simple, and effective delivery strategies to bring matters across cell membrane. Popular methods such as viral vectors, positively charged particles and cell penetrating peptides possess some of the following drawbacks: safety issues, lysosome trapping, limited loading capacity, and toxicity, whereas electroporation produces severe damages on both cargoes and cells. Here, we show that a serendipitously discovered, relatively nontoxic, water dispersible, stable, negatively charged, oxidized carbon nanoparticle, prepared from graphite, could deliver macromolecules into cells, without getting trapped in a lysosome. The ability of the particles to induce transient pores on lipid bilayer membranes of cell-sized liposomes was demonstrated. Delivering 12-base-long pyrrolidinyl peptide nucleic acids with d-prolyl-(1S,2S)-2-aminocyclopentanecarboxylic acid backbone (acpcPNA) complementary to the antisense strand of the NF-κB binding site in the promoter region of the Il6 gene into the macrophage cell line, RAW 264.7, by our particles resulted in an obvious accumulation of the acpcPNAs in the nucleus and decreased Il6 mRNA and IL-6 protein levels upon stimulation. We anticipate this work to be a starting point in a new drug delivery strategy, which involves the nanoparticle that can induce a transient pore on the lipid bilayer membrane.

Oxidized Carbon Black: Preparation, Characterization and Application in Antibody Delivery across Cell 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 .…”

“…In order to eliminate anthocyanin at the outside of the liposomes, the liposome suspension was left undisturbed at 37 °C for overnight to allow sedimentation. Then, the aqueous solution above the settled down liposomes was carefully removed, followed by an addition of the same volume of water 16 . Experiment was started by adding OCBs suspension to the anthocyanin-filled liposomes to give the final concentration of lipids and OCBs of 0.25 mM and 100 µg/mL, respectively.…”

Enhancing Passive Transport of Micro/Nano Particles into Cells by Oxidized Carbon Black

“… 21 Distinct superiority of OCSs over oxidized carbon nanotubes and graphene oxide sheets in passing through the phospholipid bilayer membrane has been demonstrated in both artificial cells and real cells. 22 Recently, we have also prepared new OCSs from commercially available carbon black particles and showed that these oxidized carbon black particles (OCBs) can directly deliver big functional proteins across cell membranes via a nonendocytic pathway. 23 Here, we report that these nonimmunogenic, relatively nontoxic OCBs can outstandingly enhance the penetration of both micro- and submicron-sized particles across phospholipid bilayer membranes.…”

A Freeze‐Concentration and Polyampholyte‐Modified Liposome‐Based Antigen‐Delivery System for Effective Immunotherapy

“…Many researchers in this area have recently focused on the development of carriers, which provide additional adjuvant activity for the induction of immune response. Nanocarriers such as nanoparticles, micelles, and nanogels have been developed for the cytoplasmic delivery of antigens, such as proteins, peptides, or genes. However, many of these are toxic and unstable .…”