Biological applications of colloidal nanocrystals

Parak, Wolfgang J.; Gerion, Daniele; Pellegrino, Teresa; Zanchet, Daniela; Micheel, Christine; Williams, Shara C.; Boudreau, Rosanne; Gros, Mark A. Le; Larabell, Carolyn A.; Alivisatos, A. Paul

doi:10.1088/0957-4484/14/7/201

Cited by 755 publications

(526 citation statements)

References 212 publications

(290 reference statements)

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“…QD properties include high quantum yield, broad absorption spectra, large achievable Stokes shifts, narrow symmetric, size-tunable emission spectra and exceptional resistance to photo-and chemical degradation (2)(3)(4)(5)(6). These properties are particularly appealing for the visualization of cellular processes as they can potentially facilitate long-term and multi-color labeling of both fixed and living cells.…”

Section: Introductionmentioning

confidence: 99%

Self-Assembled Quantum Dot−Peptide Bioconjugates for Selective Intracellular Delivery

et al. 2006

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We demonstrate the use of self-assembled luminescent semiconductor quantum dot (QD) -peptide bioconjugates for the selective intracellular labeling of several eukaryotic cell lines. A bifunctional oligoarginine cell penetrating peptide (based on the HIV-1 Tat protein motif) bearing a terminal polyhistidine tract was synthesized and used to facilitate the transmembrane delivery of the QD bioconjugates. The polyhistidine sequence allows the peptide to self-assemble onto the QD surface via metal-affinity interactions while the oligoarginine sequence allows specific QD delivery across the cellular membrane and intracellular labeling as compared to non-conjugated QDs. This peptidedriven delivery is concentration-dependent and thus can be titrated. Upon internalization, QDs display a punctate-like staining pattern in which some, but not all, of the QD signal is co-localized within endosomes. The effects of constant versus limited exposure to QD-peptide conjugates on cellular viability are evaluated by a metabolic specific assay and clear differences in cytotoxicity are observed. The efficacy of using peptides for selective intracellular delivery is highlighted by performing a multicolor QD labeling, where we found that the presence or absence of peptide on the QD surface controls cellular uptake.

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Section: Introductionmentioning

confidence: 99%

Self-Assembled Quantum Dot−Peptide Bioconjugates for Selective Intracellular Delivery

et al. 2006

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“…1) For the undoped bioactive glass known as B58S: 58%SiO 2 When the final reagent was added, the obtained sols were allowed to complete hydrolysis for 1 hour at room temperature. The resultant sols were poured into capped PTFE vessels and then stored for 10 days at room temperature in order to transform from homogenous sol to gel.…”

Section: Preparation Of the Bg Powdersmentioning

confidence: 99%

“…Furthermore, as biological phenomena develop at the nanoscale and because nanoparticles are highly biocompatible, they are increasing being used in the in vivo/in vitro medical research field, mainly in targeted drug delivery, imaging, sensing, and artificial implants (2,3). Their antimicrobial activity has been found to be a function of the surface area in contact with the microorganisms, and metal nanoparticles have many applications due to the antimicrobial activity when embedded and coated onto surfaces (4).…”

Section: Introductionmentioning

confidence: 99%

Bactericidal Activity of Copper Oxide Nanocomposite/Bioglass for in Vitro Clindamycin Release in Implant Infections Due to Staphylococcus aureus

Alijanian¹,

Talebian²,

Doudi³

2016

Avicenna J Med Biochem

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Background: In recent years, bioactive bioceramics such as bioglass and hydroxyapatite (HA) have been introduced as a remarkable development in the field of medicine due to their bio-adaptability, non-toxicity, and persistence, in vivo. They have many potential applications in the repair of bone defects and hence they have attracted significant interest from scholars. Objectives: The aim of this study was to synthesize inorganic matrix CuO-based bioglasses and evaluate their antibacterial activity against aerobic bacterial infections in bone implants. Methods: Nano-composite samples of silica-based bioactive glass, 60S BG with nano-powder CuO, were synthesized using the sol-gel method and then assessed with regard to their antibacterial properties against Staphylococcus aureus using well diffusion agar. The samples included BG58S (58%SiO2, 36%CaO, 6%P2O5), BG/10CuO (58%SiO2, 26%CaO, 6%P2O5, 10%CuO), and BG/20CuO (48%SiO2, 26%CaO, 6%P2O5, 20%CuO). To evaluate their bioactivity, the prepared samples of BG/20CuO, BG/10CuO, and BG58S were immersed in simulated body fluids (SBF). The surface morphology and structure of the samples before and after immersion in the SBF were characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR), respectively. Then, the BG/20CuO and BG/10CuO samples were loaded in clindamycin, an antibiotic widely used in the treatment of osteomyelitis, and their release profiles were studied in phosphate buffer solution. Results: It was observed that the growth inhibition zone increased through clindamycin release due to the increasing CuO percentage in the nanocomposite of bioactive glass. The bioactivity of the nanocomposite/bioglass with CuO was superior to that of bioglass alone. In this study, the BG/20CuO sample showed a sustained release of clindamycin, which is sufficient for a drug delivery system. Conclusions: Increasing the Cu nanoparticles in bioactive glass samples leads to the release of Cu 2+ , which has a positive effect on the antibacterial mechanism, as well as decreasing the cultured Staphylococcus colonies found on the bioglasses. Therefore, it seems that the nanocomposite/bioglass of CuO is a promising option for aerobic bacterial inhibitor systems in common bone implant infections.

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“…11 These properties together with the ability to functionalize the QD surface with any biomolecule demonstrate high potential usability of QDs in FRET-based bioanalytical 12,13 and medical applications. 14 Most often, Eu 3+ or Tb 3+ are used as central ions in the LLC-based fluoroassays, mainly due to their strong and well-distinguished emission bands within the visible and near-infrared spectral range. These properties also facilitate uncomplicated luminescence detection with the use of standard spectroscopy and microscopy equipment.…”

Section: Introductionmentioning

confidence: 99%

Photophysical evaluation of a new functional terbium complex in FRET-based time-resolved homogenous fluoroassays

Cywiński

Nono²,

Charbonnière³

et al. 2014

Phys. Chem. Chem. Phys.

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A new functional luminescent lanthanide complex (LLC) has been synthesized with terbium as a central lanthanide ion and biotin as a functional moiety. Unlike in typical lanthanide complexes assembled via carboxylic moieties, in the presented complex, four phosphate groups are chelating the central lanthanide ion. This special chemical assembly enhances the complex stability in phosphate buffers conventionally used in biochemistry. The complex synthesis strategy and photophysical properties are described as well as the performance in time-resolved Förster Resonance Energy Transfer (FRET) assays. In those assays, this biotin-LLC transferred energy either to acceptor organic dyes (Cy5 or AF680) labelled on streptavidin or to quantum dots (QD655 or QD705) surfacefunctionalised with streptavidins. The permanent spatial donor-acceptor proximity is assured through strong and stable biotin-streptavidin binding. The energy transfer is evidenced from the quenching observed in donor emission and from a decrease in donor luminescence decay, both associated with simultaneous increase in acceptor intensity and in the decay time. The dye-based assays are realised in TRIS and in PBS, whereas QD-based systems are studied in borate buffer. The delayed emission analysis allows for quantifying the recognition process and for auto-fluorescence-free detection, which is particularly relevant for application in bioanalysis. In accordance with Förster theory, Förster-radii (R 0 ) were found to be around 60 Å for organic dyes and around 105 Å for QDs. The FRET efficiency (Z) reached 80% and 25% for dye and QD acceptors, respectively. Physical donor-acceptor distances (r) have been determined in the range 45-60 Å for organic dye acceptors, while for acceptor QDs between 120 Å and 145 Å. This newly synthesised biotin-LLC extends the class of highly sensitive analytical tools to be applied in the bioanalytical methods such as time-resolved fluoroimmunoassays (TR-FIA), luminescent imaging and biosensing.

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Biological applications of colloidal nanocrystals

Cited by 755 publications

References 212 publications

Self-Assembled Quantum Dot−Peptide Bioconjugates for Selective Intracellular Delivery

Self-Assembled Quantum Dot−Peptide Bioconjugates for Selective Intracellular Delivery

Bactericidal Activity of Copper Oxide Nanocomposite/Bioglass for in Vitro Clindamycin Release in Implant Infections Due to Staphylococcus aureus

Photophysical evaluation of a new functional terbium complex in FRET-based time-resolved homogenous fluoroassays

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