Separation of PEGylated Gold Nanoparticles by Micellar Enhanced Electrospun Fiber Based Ultrathin Layer Chromatography

Thin layer chromatography coupled with surface enhanced Raman scattering for rapid separation and on-site detection of multi-components

The separation and detection of multi-component mixtures has always been a challenging task. Traditional detection methods often suffer from complex operation, high cost, and low sensitivity. Surface enhanced Raman scattering (SERS) technique is a high sensitivity, powerful and rapid detection tool, which can realize the specific detection of single substance components, but it must solve the problem that multi-component mixtures cannot be accurately determined. Thin layer chromatography (TLC) technology, as a high-throughput separation technology, uses chromatographic plate as the stationary phase, and could select different developing phases for separation experiments. The advantages of TLC technology in short distance and rapid separation are widely used in protein, dye and biomedical fields. However, TLC technology has limitations in detection ability and difficulty in obtaining ideal signal intensity. The combination of TLC technology and SERS technology made the operation procedure simple and the sample size small, which can achieve rapid on-site separation and quantitative detection of mixtures. Due to the rapid development of TLC-SERS technology, it has been widely used in the investigation of various complex systems. This paper reviews the application of TLC-SERS technology in food science, environmental pollution and biomedicine.

High-Throughput Nanoparticle Characterization via Glow Discharge Optical Emission Spectroscopy Elemental Mapping

Nanoparticle (NP) characterization is critical in many fields due to the use of NPs in numerous applications. Traditional NP characterization techniques, however, are limited by low sample throughput, and few can measure the size and elemental composition. Furthermore, sample throughput limitations are compounded in elemental mapping (EM) techniques for obtaining NP spatial distribution. Glow discharge optical emission spectroscopy (GDOES) EM can provide large area maps directly and cost-effectively from solid samples within tens of seconds. Here, GDOES EM is demonstrated for the first time for NP characterization in terms of mass, elemental composition, and size/structure dimensions. The effects of GD pulsed power, pressure, and sample substrate were studied, and optimized conditions resulted in limits of detection at single pg levels. While this is not at the level of single nanoparticle sensitivity, size differentiation of Ag and Au nanoparticles was successfully demonstrated between 5 and 100 nm, while the internal dimensions of complex core-shell NPs were also identified through the optical emission changes as a function of time.

Monolithic Silica Microbands Enable Thin-Layer Chromatography Analysis of Single Cells

A picoliter thin-layer chromatography (pTLC) platform was developed for analyzing extremely miniature specimens, such as assay of the contents of a single cell of 1 picoliter volume. The pTLC chip consisted of an array of microscale bands made from highly porous monolithic silica designed to accept picoliter-scale volume samples. pTLC bands were fabricated by combining sol-gel chemistry and microfabrication technology. The width (60-80 μm) and depth (13 μm) of each band is comparable to the size of single cells and acted to reduce the lateral diffusion and confine the movement of compounds along the microbands. Ultrasmall volumes (tens of pL) of model fluorescent compounds were spotted onto the microband by a piezoelectric microdispenser and successfully separated by pTLC. The separation resolution and analyte migration were dependent on the macropore size (ranging from 0.3 to 2.3 μm), which was adjustable by changing the porogen concentration during the sol-gel process. For a 0.3 μm macropore size, attomoles of analyte were detectable by fluorescence using standard microscopy methods. The separation resolution, theoretical plate number, and separation times ranged from 1.3 to 2.1, 4 to 357, and 2 to 8 min, respectively, for the chosen model biological lipids. To demonstrate the capability of pTLC for separating analytes from single mammalian cells, cells loaded with fluorescent lipophilic dyes or sphingosine kinase reporter were spotted on microbands, and the single-cell contents separated by pTLC were detected from their fluorescence. These results demonstrate the potential of pTLC for applications in many areas where miniature specimens and high-throughput parallel analyses are needed.

Tumor-specific delivery of a paclitaxel-loading HSA-haemin nanoparticle for cancer treatment

A cancer-targeted chemotherapy could potentially eradicate cancers if anticancer drugs are delivered precisely to the cancers. Although various types of nanoparticles have been developed for cancer-specific delivery of anticancer drugs, the drug delivery capabilities of these nanoparticles were not specific enough to eradicate cancer. Here, we developed a targeting-enhancing nanoparticle of paclitaxel, in which paclitaxel was encapsulated with a human serum albumin-haemin complex through non-covalent bonding. The average diameter of TENPA was approximately 140 nm with a zeta potential of +29 mV. TENPA maintained its structural integrity and stability without forming protein coronas in the blood for optimal passive targeting. These characteristics of TENPA resulted in paclitaxel accumulation that was 4.1 times greater than that of Abraxane, an albumin-bound paclitaxel, in cancer tissue. The dramatic improvement in cancer targeting of TENPA led to reduced systemic toxicity of paclitaxel and eradication of end-stage cancer in a xenografted mouse experiment.