Selective targeting of green fluorescent nanodiamond conjugates to mitochondria in HeLa cells

Abstract

Fluorescent cellular biomarkers play a prominent role in biosciences. Most of the available biomarkers have some drawbacks due to either physical and optical or cytotoxic properties. In view of this, we investigated the potential of green fluorescent nanodiamonds as biomarkers in living cells. Nanodiamonds were functionalized by attaching antibodies that target intracellular structures such as actin filaments and mitochondria. Then, the nanodiamond conjugates were transfected into HeLa cells. Transfections were mediated by 4(th)-generation dendrimers, cationic liposomes and protamine sulfate. Using fluorescence microscopy, we confirmed successful transfections of the nanodiamonds into HeLa cells. Nanodiamond fluorescence could be easily differentiated from cellular autofluorescence. Furthermore, nanodiamonds could be targeted selectively to intracellular structures. Therefore, nanodiamonds are a promising tool for intracellular assays.

Optimizing nanomedicine pharmacokinetics using physiologically based pharmacokinetics modelling

“…The active targeting of nanoformulations to particular sites in the body further complicates PBPK modelling. Intracellular compartments may be targeted, such as the use of nanodiamonds conjugated to antibodies to target the mitochondria (Mkandawire et al, 2009) and PLGA nanoparticles conjugated to nuclear localization signal peptides to target the nucleus (Misra and Sahoo, 2010). Active targeting could be integrated into PBPK models by including preferential transportation kinetics based on affinity of the nanoformulation for the molecular target, subpopulation of cells or tissue.…”

“…The elimination of nanomedicines can mean both the removal of intact nanoformulation from the body and also the degradation of nanoformulations (and subsequent release of drug) in plasma, tissues and organs. Potential elimination sites may include the reticuloendothelial system (Owens and Peppas, 2006), tissues with specific pH (Kim et al, 2008) and compartments within cells (Misra and Sahoo, 2010) (Mkandawire et al, 2009), as well as other sites. New elimination mechanisms may become important in traditional organs of clearance, for example the destruction of nanoparticles by Kupffer cells in the liver (Sadauskas et al, 2007).…”

Nanodiamonds as novel nanomaterials for biomedical applications: drug delivery and imaging systems

“…141 Immunoconjugated ND complexes were prepared by covalently coupling actin and mitochondrial-targeted antibodies to the surface of oxidized NDs. 141 The actin antibody-ND and mitochondria antibody-ND immunoconjugates were then allowed internalization by HeLa cells using maltotriose-shelled fourthgeneration dendrimers.…”

“…141 Using the green fluorescence of the NDs as a marker, live-cell fluorescence microscopic images of the treated cells, collected at 535/40 nm wavelength, revealed selective targeting of actin and mitochondria by actin antibody-ND and mitochondria antibody-ND immunoconjugates, respectively. 141 With the rational selection of an antibody, NDs could also be designed to image the specific structures of the cells. (Figure 10), a hermaphrodite with an optically transparent body.…”

Nanodiamond delivery circumvents tumor resistance to doxorubicin

“…In Dox-resistant cells, the drug can be actively pumped out by ABC transporters [6] . Nanometer-sized diamonds (NDs) have been used for fluorescent cellular biolabeling [7] , biomedical imaging [8] , and as drug carriers [9] . Chow and colleagues recently developed a biocompatible nanodiamond drug carrier system at 2 to 8 nm in diameter with Dox binding to its surfaces electrostatically, forming NDX complexes with an average size of ~80 nm.…”