Carbon nanotube-based nanocarriers: the importance of keeping it clean.
Nanotechnology-introduced materials have promising applications as nanocarriers for drugs, peptides, proteins and nucleic acids. Several studies showed that the geometry (shape and size) and chemical properties of nanoparticles affect the kinetics and pathways of cellular uptake and their intracellular trafficking and signaling. Accurate physico-chemical characterization of nanoparticles customarily precedes their use in cell biology and in vivo experiments. However, a fact that is easily overlooked is that nanomaterials decorated with organic matter or resuspended in aqueous buffers can be theoretically contaminated by fungal and bacterial microorganisms. While investigating the effects of extensively characterized PEGylated carbon nanotubes (PNTs) on T lymphocyte activation, we demonstrated bacterial contamination of PNTs, which correlated with low reproducibility and artifacts in cell signaling assays. Contamination and artifacts were easily eliminated by preparing the materials in sterile conditions. We propose that simple sterile preparation procedures should be adopted and sterility evaluation of nanoparticles should be customarily performed, prior to assessing nanoparticle intracellular internalization, trafficking and their effects on cells and entire organisms.
Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Suite 240, Los Angeles, CA 90033, USA.
Lucia G
LG
Delogu
Stephanie M
SM
Stanford
Eugenio
E
Santelli
Andrea
A
Magrini
Antonio
A
Bergamaschi
Khatereh
K
Motamedchaboki
Nicola
N
Rosato
Tomas
T
Mustelin
Nunzio
N
Bottini
Massimo
M
Bottini
D016477:Artifacts; D004337:Drug Carriers; D004340:Drug Contamination; D004705:Endocytosis / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007376:Interleukin-2 / Q000235:genetics / Q000378:metabolism; D019169:Jurkat Cells; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal; D058726:Nanoconjugates / Q000737:chemistry / Q000382:microbiology*; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000382:microbiology*; D010316:Particle Size; D011092:Polyethylene Glycols; D015203:Reproducibility of Results; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D051193:Toll-Like Receptors / Q000378:metabolism
D004337:Drug Carriers; D007376:Interleukin-2; D058726:Nanoconjugates; D037742:Nanotubes, Carbon; D051193:Toll-Like Receptors; D011092:Polyethylene Glycols