Targeted Nuclear Delivery using Peptide-Coated Quantum Dots

Core/shell quantum dots (CdSe/Zns) conjugated with various nuclear localization signaling (NLS) peptides, which could facilitate the transportation of quantum dots across the plasma membrane into the nucleus, have been utilized to investigate the uptake mechanism of targeted delivery. Because of their brightness and photostability, it was possible to trace the trajectories of individual quantum dots in living cells using both confocal and total internal reflection microscopes. We found that, when the quantum dots were added to a cell culture, the peptide-coated quantum dots entered the cell nucleus while the uncoated quantum dots remained in the cytoplasm. At 8 nM, most of the peptide coated quantum dots were found in the cytoplasm due to aggregation. However, at a lower concentration (0.08 nM), approximately 25% of the NLS peptide-coated quantum dots entered the cell nucleus. We also found that some quantum dots without NLS coating could also enter the nucleus, suggesting that the size of the quantum dots may play an important role in such a process

Facile Transfer Method for Fabricating Light-Harvesting Systems for Polymer Solar Cells

In this study, we used a transferring process to fabricate a simple light-harvesting system featuring 2D periodic granular-like electrodes for polymer solar cells (PSCs). This transferring technique, which was based on nanosphere lithography, could be used to fabricate periodic nanostructures on both the photoactive layers and the Al electrodes in the normal PSC device configuration (indium tin oxide glass/PEDOT:PSS/photoactive layer/Al). We investigated the properties of the PSC devices featuring periodic nanostructures in the photoactive layers using reflection UV–vis spectra and in terms of their external quantum efficiency (EQE) and photocurrent–voltage characteristics. In addition, we used numerical simulations to evaluate the electromagnetic field distributions in the devices. The light trapping efficiency in the PSCs featuring periodic nanostructures was enhanced as a result of light scattering and surface plasmon resonance effects. Relative to conventional devices featuring a flat geometry, the power conversion efficiency of a thin (ca. 150 nm) photoactive P3HT/C70 bilayer device increased by 90% when it featured a periodic nanostructure, with up to 20-fold increases in EQE observed at the absorption edge. Furthermore, when we engineered periodic nanostructures into bulk heterojunction devices incorporating a low-bandgap (LBG) photoactive layer (PTPTBT:PC70BM), the photocurrent increased by 20%, suggesting that this facile light-harvesting system is suitable for both thin P3HT and LBG PSC applications in the visible to near-infrared (NIR) region

Synthesis of Tunable and Multifunctional Ni-Doped Near-Infrared QDs for Cancer Cell Targeting and Cellular Sorting

Here, we report the facile preparation of tunable magnetic Ni-doped near-infrared (NIR) quantum dots (MNIR-QDs) as an efficient probe for targeting, imaging, and cellular sorting applications. We synthesized the MNIR-QDs via a hot colloidal synthesis approach to yield monodisperse and tunable QDs. These hydrophobic QDs were structurally and compositionally characterized and further functionalized with amino-PEG and carboxyl-PEG to improve their biocompatibility. Since QDs are known to be toxic due to the presence of cadmium, we have evaluated the <i>in vitro</i> and <i>in vivo</i> toxicity of our surface-functionalized MNIR-QDs. Our results revealed that surface-functionalized MNIR-QDs did not exhibit significant toxicity at the concentrations used in the experiments and are therefore suitable for biological applications. For further <i>in vitro</i> applications, we covalently linked folic acid to the surface of amino-PEG-coated MNIR-QDs through NHS chemistry to target the folate receptors largely present in the HeLa cells to demonstrate the specific targeting and magnetic behavior of these MNIR-QDs. Improved specificity has been observed with treatment of HeLa cells with the folic acid-linked amino PEG-coated MNIR QDs (FA-PEG-MNIR-QDs) compared to the one without folic acid. Since the synthesized probe has magnetic property, we have also successfully demonstrated sorting between the cells which have taken up the probe with the use of a magnet. Our findings strongly suggest that these functionalized MNIR-QDs can be a potential probe for targeting, cellular sorting, and bioimaging applications

MOESM1 of Random and aligned electrospun PLGA nanofibers embedded in microfluidic chips for cancer cell isolation and integration with air foam technology for cell release

Additional file 1. ToF-SIMS characterization of PEGylated biotin-conjugated PLGA nanofibers. Figure S1. Static cell-capture efficiencies of HCT116, MCF7, PC9, HepG2, Huh7, HeLa, and THP1 cell lines on random PLGA nanofiber arrays. HCT116, MCF7: EpCAM-positive cancer cell lines; HeLa, THP1: EpCAM-negative cancer cell lines. Figure S2. Three-dimensional representations of AFM topographic images and root mean square average roughnesses (Rrms) of a random and b aligned PLGA nanofiber arrays. Figure S3. a Cell viability tests for MCF7 cells captured on the control (tissue culture polystyrene, TCPS) and through on-chip (random PLGA nanofiber arrays) and off-chip cell collection (MCF7 cells released from random PLGA nanofiber arrays using the air foam technology). Released cells were washed twice with PBS and incubated for 24 h. Viability was assayed through the fluorescence live/dead staining result, which showed calcein AM (green) for live cells and Eth-1 (red) for dead cells (N = 3). b Live/dead staining image of off-chip cell collection (incubated on TCPS for 3 h)

Table_1_Organic Electrochemical Transistors/SERS-Active Hybrid Biosensors Featuring Gold Nanoparticles Immobilized on Thiol-Functionalized PEDOT Films.doc

In this study we immobilized gold nanoparticles (AuNPs) onto thiol-functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) films as bioelectronic interfaces (BEIs) to be integrated into organic electrochemical transistors (OECTs) for effective detection of dopamine (DA) and also as surface-enhanced Raman scattering (SERS)—active substrates for the selective detection of p-cresol (PC) in the presence of multiple interferers. This novel PEDOT-based BEI device platform combined (i) an underlying layer of polystyrenesulfonate-doped PEDOT (PEDOT:PSS), which greatly enhanced the transconductance and sensitivity of OECTs for electrochemical sensing of DA in the presence of other ascorbic acid and uric acid metabolites, as well as amperometric response toward DA with a detection limit (S/N = 3) of 37 nM in the linear range from 50 nM to 100 μM; with (ii) a top interfacial layer of AuNP-immobilized three-dimensional (3D) thiol-functionalized PEDOT, which not only improved the performance of OECTs for detecting DA, due to the signal amplification effect of the AuNPs with high catalytic activity, but also enabled downstream analysis (SERS detection) of PC on the same chip. We demonstrate that PEDOT-based 3D OECT devices decorated with a high-density of AuNPs can display new versatility for the design of next-generation biosensors for point-of-care diagnostics.</p