Synthesis of Biotinylated α-d-Mannoside or N-Acetyl β-d-Glucosaminoside Decorated Gold Nanoparticles: Study of Their Biomolecular Recognition with Con A and WGA Lectins

Engineering Carbohydrate-Based Particles for Biomedical Applications: Strategies to Construct and Modify

Carbohydrate-based micro/nanoparticles have gained significant attention for various biomedical applications such as targeted/triggered/controlled drug delivery, bioimaging, biosensing, etc., because of their prominent characteristics like biocompatibility, biodegradability, hydrophilicity, and nontoxicity as well as nonimmunogenicity. Most importantly, the ability of the nanoparticles to recognize specific cell sites by targeting cell surface receptors makes them a promising candidate for designing a targeted drug delivery system. These particles may either comprise polysaccharides/glycopolymers or be integrated with various polymeric/inorganic nanoparticles such as gold, silver, silica, iron, etc., to reduce the toxicity of the inorganic nanoparticles and thus facilitate their cellular insertion. Various synthetic methods have been developed to fabricate carbohydrate-based or carbohydrate-conjugated inorganic/polymeric nanoparticles. In this review, we have highlighted the recently developed synthetic approaches to afford carbohydrate-based particles along with their significance in various biomedical applications.

Exploitation of polyphenols and proteins using nanoencapsulation for anti-viral and brain boosting properties - Evoking a synergistic strategy to combat COVID-19 pandemic

The world is currently under the threat of COVID pandemic and has focused every dimension of research in finding a cure to this novel disease. In this current situation, people are facing mental stress, agony, fear, depression and other associated symptoms which are taking a toll on their overall mental health. Nanoencapsulation of certain brain boosting polyphenols including quercetin, caffeine, cocoa flavanols and proteins like lectins can become new area of interest in the present scenario. Besides the brain boosting benefits, we have also highlighted the anti- viral activities of these compounds which we assume can play a possible role in combating COVID-19 given to their previous history of action against certain viruses. This review outlines the nanoencapsulation approaches of such synergistic compounds as a novel strategy to take the ongoing research a step ahead and also provides a new insight in bringing the role of nanotechnology in addressing the issues related to COVID pandemic.

One-step synthesis of cellooligomer-conjugated gold nanoparticles in a water-in-oil emulsion system and their application in biological sensing

Monodisperse gold nanoparticles (GNPs) were synthesized in a water-in-oil emulsion system (reverse micelles) composed of 80% N-methylmorpholine N-oxide (NMMO)/20% H₂O and dodecane, stabilized with an anionic surfactant: bis(2-ethylhexyl)sulfosuccinate sodium salt. Cellooligomers with a degree of polymerization of 6 or 15 (βGlc6 or βGlc15, respectively), which were labeled at each reducing end group with thiosemicarbazide (TSC) and dissolved in the aqueous NMMO phase, were successfully conjugated to the surfaces of GNPs in situ during spontaneous NMMO-mediated gold reduction. As-synthesized βGlc6-GNPs and βGlc15-GNPs had average diameters of 11.3 ± 2.1 and 10.5 ± 0.7 nm, respectively, while their surface sugar densities were 0.21 and 0.51 chains nm^-2, respectively. Concanavalin A (ConA), a lectin that recognizes non-reducing end groups of glucose residues, aggregated with βGlc15-GNPs with higher sensitivity than it did with βGlc6-GNPs, possibly as a result of the sugar density on the GNP surfaces. The aggregates were rapidly re-suspended by adding methyl-β-d-glucopyranoside as a binding inhibitor. Other lectins and proteins showed no interaction with βGlc-GNPs. Therefore, clustering of glucose non-reducing ends on the GNP surfaces via strong intermolecular association of cellooligomers, possibly led to high affinity for ConA. This facile synthesis route to structural carbohydrate-decorated GNPs has potential applications in carbohydrate-nanometal conjugate nano-biosensor development.

Telechelic polymers from reversible-deactivation radical polymerization for biomedical applications

Strategies for the synthesis of telechelic polymers by reversible-activation radical polymerization for biomedical applications are covered spanning from drug delivery and targeting to theranostics and sensing.

One-Pot Multicomponent Synthesis of Glycopolymers through a Combination of Host-Guest Interaction, Thiol-ene, and Copper-Catalyzed Click Reaction in Water

There is a common phenomenon that the heterogeneity of natural oligosaccharides contains various sugar units, which can be used to enhance affinity and selectivity toward a specific receptor, so the synthesis of heterogeneous glycopolymers is always an important issue in the glycopolymer field. Herein, this study conducts a one-pot method to prepare polyrotaxane-based heteroglycopolymers anchored with different sugar units and fluorescent moieties via the combination of host-guest interaction, thiol-ene, and copper-catalyzed click chemistry in water. Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography, X-ray diffraction, and Ellman's assay test are used in the paper to characterize the compounds. Quartz crystal microbalance-dissipation (QCD-D) experiments and bacterial adhesion assay are utilized to study the interactions of polyrotaxane-based heteroglycopolymers with Con A and Escherichia coli. The results reveal that polyrotaxanes (PRs) with mannose and glucose present better specificity toward Con A and E. coli than PRs with glucose due to synergistic effects.

RAFT polymerization to form stimuli-responsive polymers

Stimuli-responsive polymers respond to a variety of external stimuli, which include optical, electrical, thermal, mechanical, redox, pH, chemical, environmental and biological signals. This paper is concerned with the process of forming such polymers by RAFT polymerization.

Glyconanomaterials for biosensing applications

Nanomaterials constitute a class of structures that have unique physiochemical properties and are excellent scaffolds for presenting carbohydrates, important biomolecules that mediate a wide variety of important biological events. The fabrication of carbohydrate-presenting nanomaterials, glyconanomaterials, is of high interest and utility, combining the features of nanoscale objects with biomolecular recognition. The structures can also produce strong multivalent effects, where the nanomaterial scaffold greatly enhances the relatively weak affinities of single carbohydrate ligands to the corresponding receptors, and effectively amplifies the carbohydrate-mediated interactions. Glyconanomaterials are thus an appealing platform for biosensing applications. In this review, we discuss the chemistry for conjugation of carbohydrates to nanomaterials, summarize strategies, and tabulate examples of applying glyconanomaterials in in vitro and in vivo sensing applications of proteins, microbes, and cells. The limitations and future perspectives of these emerging glyconanomaterials sensing systems are furthermore discussed.

Surface decorated nanoparticles as surrogate carriers for improved transport and absorption of epirubicin across the gastrointestinal tract: Pharmacokinetic and pharmacodynamic investigations

Epirubicin (EPI) is a P-gp substrate antracycline analogue which elicits poor oral bioavailability. In the present work, EPI loaded poly-lactide-co-glycolic acid nanoparticles (PLGA-NPs) were prepared by double emulsion approach and superficially decorated with polyethylene glycol (EPI-PNPs) and mannosamine (EPI-MNPs). Average hydrodynamic particle size of EPI-PNPs and EPI-MNPs was found 248.63 ± 12.36 and 254.23 ± 15.16 nm, respectively. Cytotoxicity studies were performed against human breast adenocarcinoma cell lines (MCF-7) confirmed the superiority of EPI-PNPs and EPI-MNPs over free epirubicin solution (EPI-S). Further, confocal laser scanning microscopy (CLSM) and flow cytometric analysis (FACS) demonstrated enhanced drug uptake through EPI-PNPs and EPI-MNPs and elucidated dominance of caveolae mediated endocytosis for NPs uptake. Cellular transport conducted on human colon adenocarcinoma cell line (Caco-2) showed 2.45 and 3.17 folds higher permeability of EPI through EPI-PNPs and EPI-MNPs when compared with EPI-S (p<0.001) while permeability of EPI was found 5.23 and 5.67 folds higher across rat ileum, respectively. Furthermore, pharmacokinetic studies demonstrated 4.7 and 5.57 folds higher oral bioavailability through EPI-PNPs and EPI-MNPs when compared with EPI-S. In addition, both, EPI-PNPs and EMNPs showed tumor suppression comparable to indicated route (i.v. injection). EPI-MNPs showed 1.18 folds higher bioavailability and better tumor suppression than EPI-PNPs.

Fluorescent gold nanoparticles with chain-end grafted RAFT copolymers: influence of the polymer molecular weight and type of chromophore

Fluorescence of gold nanoparticles functionalized with chain-end grafted RAFT copolymers increases with polymer corona thickness.

Carbohydrates in Supramolecular Chemistry

Carbohydrates are involved in a variety of biological processes. The ability of sugars to form a large number of hydrogen bonds has made them important components for supramolecular chemistry. We discuss recent advances in the use of carbohydrates in supramolecular chemistry and reveal that carbohydrates are useful building blocks for the stabilization of complex architectures. Systems are presented according to the scaffold that supports the glyco-conjugate: organic macrocycles, dendrimers, nanomaterials, and polymers are considered. Glyco-conjugates can form host-guest complexes, and can self-assemble by using carbohydrate-carbohydrate interactions and other weak interactions such as π-π interactions. Finally, complex supramolecular architectures based on carbohydrate-protein interactions are discussed.

Targeted superparamagnetic iron oxide nanoparticles for early detection of cancer: Possibilities and challenges

Nanomedicine, the integration of nanotechnological tools in medicine demonstrated promising potential to revolutionize the diagnosis and treatment of various human health conditions. Nanoparticles (NPs) have shown much promise in diagnostics of cancer, especially since they can accommodate targeting molecules on their surface, which search for specific tumor cell receptors upon injection into the blood stream. This concentrates the NPs in the desired tumor location. Furthermore, such receptor-specific targeting may be exploited for detection of potential metastases in an early stage. Some NPs, such as superparamagnetic iron oxide NPs (SPIONs), are also compatible with magnetic resonance imaging (MRI), which makes their clinical translation and application rather easy and accessible for tumor imaging purposes. Furthermore, multifunctional and/or theranostic NPs can be used for simultaneous imaging of cancer and drug delivery. In this review article, we will specifically focus on the application of SPIONs in early detection and imaging of major cancer types.

FROM THE CLINICAL EDITOR

Super-paramagnetic iron oxide nanoparticles (SPIONs) have been reported by many to be useful as an MRI contrast agent in the detection of tumors. To further enhance the tumor imaging, SPIONs can be coupled with tumor targeting motifs. In this article, the authors performed a comprehensive review on the current status of using targeted SPIONS in tumor detection and also the potential hurdles to overcome.

Oriented Immobilized Sialyloligo-macroligand Microarray

Silaic acid is the most common terminal glycan on cell surface glycoproteins and glycolipids, involving in many biological processes. Studying interactions between multivalent sialic acid scaffolds and proteins binding to it will give incredible information in understanding the biological process the sialic acid is involved in. Here we describe chemoenzymatic synthesis of chain-end functionalized sialyllactose-containing glycopolymers with different linkages and their oriented immobilization for glycoarray and SPR-based glyco-biosensor applications.

Enhancement of photothermal toxicity and lung targeting delivery of Au nanorods via heparin-based nanogel

The scheme of preparation of heparin–PEI–LA nanogel used for the adsorption of Au nanorods.

Tetravalent glycocyclopeptide with nanomolar affinity to wheat germ agglutinin

A series of tetravalent glycocyclopeptides functionalized with GlcNAc was synthesized using copper(i)-catalysed alkyne-azide cycloaddition, oxime ligation and thiol-ene coupling. The binding ability of these compounds towards wheat germ agglutinin was studied by a competitive ELLA test and ITC experiments. While all compounds were able to inhibit WGA binding to GlcNAc-polymer coated surfaces at low concentrations, derivative 17 having an aliphatic spacer and thioether linkage was 4.9 × 10(6) times more potent on a per sugar basis than GlcNAc. This remarkably strong effect was confirmed by ITC experiments as these revealed an association constant of 9 nM for this compound, therefore presenting a gain of 200,000 times over GlcNAc. These results for compound 17 represent the highest binding properties reported for WGA.

β-Cyclodextrin-bearing gold glyconanoparticles for the development of site specific drug delivery systems

Three novel gold nanoparticles containing multiple long, flexible linkers decorated with lactose, β-cyclodextrin, and both simultaneously have been prepared. The interaction of such nanoparticles with β-d-galactose-recognizing lectins peanut agglutinin (PNA) and human galectin-3 (Gal-3) was demonstrated by UV-vis studies. Gal-3 is well-known to be overexpressed in several human tumors and can act as a biorecognizable target. This technique also allowed us to estimate their loading capability toward the anticancer drug methotrexate (MTX). Both results make these glyconanoparticles potential site-specific delivery systems for anticancer drugs.

Immobilized sialyloligo-macroligand and its protein binding specificity

We report a chemoenzymatic synthesis of chain-end functionalized sialyllactose-containing glycopolymers with different linkages and their oriented immobilization for glycoarray and SPR-based glyco-biosensor applications. Specifically, O-cyanate chain-end functionalized sialyllactose-containing glycopolymers were synthesized by enzymatic α2,3- and α2,6-sialylation of a lactose-containing glycopolymer that was synthesized by cyanoxyl-mediated free radical polymerization. (1)H NMR showed almost quantitative α2,3- and α2,6-sialylation. The O-cyanate chain-end functionalized sialyllactose-containing glycopolymers were printed onto amine-functionalized glass slides via isourea bond formation for glycoarray formation. Specific protein binding activity of the arrays was confirmed with α2,3- and α2,6-sialyl specific binding lectins together with inhibition assays. Further, immobilizing O-cyanate chain-end functionalized sialyllactose-containing glycopolymers onto amine-modified SPR chip via isourea bond formation afforded SPR-based glyco-biosensor, which showed specific binding activity for lectins and influenza viral hemagglutinins (HA). These sialyloligo-macroligand derived glycoarray and SPR-based glyco-biosensor are closely to mimic 3D nature presentation of sialyloligosaccharides and will provide important high-throughput tools for virus diagnosis and potential antiviral drug candidates screening applications.

Gold nanoparticles: preparation, properties, and applications in bionanotechnology

Gold nanoparticles (AuNPs) are important components for biomedical applications. AuNPs have been widely employed for diagnostics, and have seen increasing use in the area of therapeutics. In this mini-review, we present fabrication strategies for AuNPs and highlight a selection of recent applications of these materials in bionanotechnology.

Beauty is skin deep: a surface monolayer perspective on nanoparticle interactions with cells and bio-macromolecules

Surface recognition of biosystems is a critical component in the development of novel biosensors and delivery vehicles, and for the therapeutic regulation of biological processes. Monolayer-protected nanoparticles present a highly versatile scaffold for selective interaction with bio-macromolecules and cells. Through the engineering of the monolayer surface, nanoparticles can be tailored for surface recognition of biomolecules and cells. This review highlights recent progress in nanoparticle-bio-macromolecule/cellular interactions, emphasizing the effect of the surface monolayer structure on the interactions with proteins, DNA, and cell surfaces. The extension of these tailored interactions to hybrid nanomaterials, biosensing platforms, and delivery vehicles is also discussed.

Engineering the nanoparticle-protein interface: applications and possibilities

Covalent and non-covalent conjugation of proteins to nanoparticles provides access to functional hybrid systems with applications in biotechnology, medicine, and catalysis. The creation of effective conjugates requires the retention of protein structure and function, a challenging task. In this review we discuss successes, challenges and opportunities in the area of protein-nanoparticle bioconjugation.