Glycoconjugated amphiphilic polymers via click-chemistry for the encapsulation of quantum dots

Fluorescent Nanoparticles for Super-Resolution Imaging

Super-resolution imaging techniques that overcome the diffraction limit of light have gained wide popularity for visualizing cellular structures with nanometric resolution. Following the pace of hardware developments, the availability of new fluorescent probes with superior properties is becoming ever more important. In this context, fluorescent nanoparticles (NPs) have attracted increasing attention as bright and photostable probes that address many shortcomings of traditional fluorescent probes. The use of NPs for super-resolution imaging is a recent development and this provides the focus for the current review. We give an overview of different super-resolution methods and discuss their demands on the properties of fluorescent NPs. We then review in detail the features, strengths, and weaknesses of each NP class to support these applications and provide examples from their utilization in various biological systems. Moreover, we provide an outlook on the future of the field and opportunities in material science for the development of probes for multiplexed subcellular imaging with nanometric resolution.

Nanotechnology in Glycomics: Applications in Diagnostics, Therapy, Imaging, and Separation Processes

This review comprehensively covers the most recent achievements (from 2013) in the successful integration of nanomaterials in the field of glycomics. The first part of the paper addresses the beneficial properties of nanomaterials for the construction of biosensors, bioanalytical devices, and protocols for the detection of various analytes, including viruses and whole cells, together with their key characteristics. The second part of the review focuses on the application of nanomaterials integrated with glycans for various biomedical applications, that is, vaccines against viral and bacterial infections and cancer cells, as therapeutic agents, for in vivo imaging and nuclear magnetic resonance imaging, and for selective drug delivery. The final part of the review describes various ways in which glycan enrichment can be effectively done using nanomaterials, molecularly imprinted polymers with polymer thickness controlled at the nanoscale, with a subsequent analysis of glycans by mass spectrometry. A short section describing an active glycoprofiling by microengines (microrockets) is covered as well.

Synthesis of D-manno-heptulose via a cascade aldol/hemiketalization reaction

A [4 + 3] synthesis of D-manno-heptulose is described. The cascade aldol/hemiketalization reaction of a C₄ aldehyde with a C₃ ketone provides the differentially protected ketoheptose building block, which can be further reacted to furnish target D-manno-heptulose.

Application of semiconductor quantum dots in bioimaging and biosensing

In this review we present new concepts and recent progress in the application of semiconductor quantum dots (QD) as labels in two important areas of biology, bioimaging and biosensing.

Meta-analysis of cellular toxicity for cadmium-containing quantum dots

Understanding the relationships between the physicochemical properties of engineered nanomaterials and their toxicity is critical for environmental and health risk analysis. However, this task is confounded by material diversity, heterogeneity of published data and limited sampling within individual studies. Here, we present an approach for analysing and extracting pertinent knowledge from published studies focusing on the cellular toxicity of cadmium-containing semiconductor quantum dots. From 307 publications, we obtain 1,741 cell viability-related data samples, each with 24 qualitative and quantitative attributes describing the material properties and experimental conditions. Using random forest regression models to analyse the data, we show that toxicity is closely correlated with quantum dot surface properties (including shell, ligand and surface modifications), diameter, assay type and exposure time. Our approach of integrating quantitative and categorical data provides a roadmap for interrogating the wide-ranging toxicity data in the literature and suggests that meta-analysis can help develop methods for predicting the toxicity of engineered nanomaterials.

Click Chemistry-Mediated Nanosensors for Biochemical Assays

Click chemistry combined with functional nanoparticles have drawn increasing attention in biochemical assays because they are promising in developing biosensors with effective signal transformation/amplification and straightforward signal readout for clinical diagnostic assays. In this review, we focus on the latest advances of biochemical assays based on Cu (I)-catalyzed 1, 3-dipolar cycloaddition of azides and alkynes (CuAAC)-mediated nanosensors, as well as the functionalization of nanoprobes based on click chemistry. Nanoprobes including gold nanoparticles, quantum dots, magnetic nanoparticles and carbon nanomaterials are covered. We discuss the advantages of click chemistry-mediated nanosensors for biochemical assays, and give perspectives on the development of click chemistry-mediated approaches for clinical diagnosis and other biomedical applications.

The role of ROS generation from magnetic nanoparticles in an alternating magnetic field on cytotoxicity

Monosaccharide coated iron oxide nanoparticles were developed to selectively target colon cancer cell lines for magnetically mediated energy delivery therapy. The nanoparticles were prepared using a coupling reaction to attach the glucose functional group to the iron oxide core, and functionality was confirmed with physicochemical characterization techniques. The targeted nanoparticles were internalized into CT26 cells at a greater extent than non-targeted nanoparticles, and the nanoparticles were shown to be localized within lysosomes. Cells with internalized nanoparticles were exposed to an AMF to determine the potential to delivery therapy. Cellular ROS generation and apoptotic cell death was enhanced with field exposure. The nanoparticle coatings inhibit the Fenton-like surface generation of ROS suggesting a thermal or mechanical effect is more likely the source of the intracellular effect, unless the nanoparticle coating is unstable in the cellular environment.

STATEMENT OF SIGNIFICANCE

This is the first study to assess glucose coated MNPs for the delivery of MagMED therapy. With exposure of an AMF, the glucose-coated nanoparticles displayed a significant increase in cellular ROS and apoptotic cell death with no measurable increase in media temperature. To determine the mechanism of toxicity, we investigated the surface generation of ROS through Fenton-like chemistry. The coated systems displayed negligible ROS generation compared to uncoated nanoparticles. These observations suggest the cellular ROS measured is attributed to a thermal or mechanical effect of the internalized nanoparticles. In summary, this manuscript reports on some new insights as to the mechanism of MagMED therapies, which are of high interest to the biomaterials and cancer nanomedicine fields.

Polysaccharide-based nanocomposites and their applications

Polysaccharide nanocomposites have become increasingly important materials over the past decade. Polysaccharides offer a green alternative to synthetic polymers in the preparation of soft nanomaterials. They have also been used in composites with hard nanomaterials, such as metal nanoparticles and carbon-based nanomaterials. This mini review describes methods for polysaccharide nanocomposite preparation and reviews the various types and diverse applications for these novel materials.

Tailoring the ligand shell for the control of cellular uptake and optical properties of nanocrystals

In this short review, the main challenges in the use of hydrophobic nanoparticles in biomedical application are addressed. It is shown how to overcome the different issues by the use of a polymeric encapsulation system, based on an amphiphilic polyisoprene-block-poly(ethylene glycol) diblock copolymer. On the basis of this simple molecule, the development of a versatile and powerful phase transfer strategy is summarized, focusing on the main advantages like the adjustable size, the retained properties, the excellent shielding and the diverse functionalization properties of the encapsulated nanoparticles. Finally, the extraordinary properties of these encapsulated nanoparticles in terms of toxicity and specificity in a broad in vitro test is demonstrated.