Synthesis, micellization and lectin binding of new glycosurfactants

Accuracy improvement enzyme-linked immunosorbent assay using superparamagnetic/polyethylene glycol) nanoparticles for leishmaniasis diagnostic

Serodiagnosis methods have been used as platforms for diagnostic tests for many diseases. Due to magnetic nanoparticles' properties to quickly detach from an external magnetic field and particle size effects, these nanomaterials' functionalization allows the specific isolation of target analytes, enhancing accuracy parameters and reducing serodiagnosis time. Superparamagnetic iron oxide nanoparticles (MNPs) were synthesized and functionalized with polyethylene glycol (PEG) and then associated with the synthetic Leishmaniosis epitope. This nano-peptide antigen showed promising results. Regarding Tegumentary leishmaniasis diagnostic accuracy, the AUC was 0.8398 with sensibility 75% (95CI% 50.50 - 89.82) and specificity 87.50% (95CI% 71.93 - 95.03), and Visceral leishmaniasis accuracy study also present high performance, the AUC was 0.9258 with sensibility 87.50% (95CI% 63.98 - 97.78) and specificity 87.50% (95CI% 71.93 - 95.03). Our results demonstrate that the association of the antigen with MNPs accelerates and improves the diagnosis process. MNPs could be an important tool for enhancing serodiagnosis.

Sertraline associated with gold nanoparticles reduce cellular toxicity and induce sex-specific responses in behavior and neuroinflammation biomarkers in a mouse model of anxiety

This study aimed to evaluate the effects of sertraline associated with gold nanoparticles (AuNPs) in vitro cell viability and in vivo behavior and inflammatory biomarkers in a mouse model of anxiety. Sertraline associated with AuNPs were synthesized and characterized. For the in vitro study, NIH3T3 and HT-22 cells were treated with different doses of sertraline, AuNPs, and sertraline + AuNPs and their viability was evaluated using the MTT assay. For the in vivo study, pregnant Swiss mice were administered a single dose of lipopolysaccharide (LPS) on the ninth day of gestation. The female and male offspring were divided into five treatment groups on PND 60 and administered chronic treatment for 28 days. The animals were subjected to behavioral testing and were subsequently euthanized. Their brains were collected and analyzed for inflammatory biomarkers. Sertraline associated with AuNPs exhibited significant changes in surface characteristics and increased diameters. Different doses of sertraline + AuNPs showed higher cell viability in NIH3T3 and HT-22 cells compared with sertraline alone. The offspring of LPS-treated dams exhibited anxiety-like behavior and neuroinflammatory biomarker changes during adulthood, which were ameliorated via sertraline + AuNPs treatment. The treatment response was sex-dependent and brain region-specific. These results suggest that AuNPs, which demonstrate potential to bind to other molecules, low toxicity, and reduced inflammation, can be synergistically used with sertraline to improve drug efficacy and safety by decreasing neuroinflammation and sertraline toxicity.

Development of a Novel Lipid-Based Nanosystem Functionalized with WGA for Enhanced Intracellular Drug Delivery

Despite a considerable number of new antibiotics under going clinical trials, treatment of intracellular pathogens still represents a major pharmaceutical challenge. The use of lipid nanocarriers provides several advantages such as protection from compound degradation, increased bioavailability, and controlled and targeted drug release. Wheat germ agglutinin (WGA) is known to have its receptors on the alveolar epithelium and increase phagocytosis. The present study aimed to produce nanostructured lipid carriers with novel glycosylated amphiphilic employed to attach WGA on the surface of the nanocarriers to improve intracellular drug delivery. High-pressure homogenization was employed to prepare the lipid nanocarriers. In vitro, high-content analysis and flow cytometry assay was employed to study the increased uptake by macrophages when the nanocarriers were grafted with WGA. A lipid nanocarrier with surface-functionalized WGA protein (~200 nm, PDI > 0.3) was successfully produced and characterized. The system was loaded with a lipophilic model compound (quercetin; QU), demonstrating the ability to encapsulate a high amount of compound and release it in a controlled manner. The nanocarrier surface functionalization with the WGA protein increased the phagocytosis by macrophages. The system proposed here has characteristics to be further explored to treat intracellular pathogens.

The Protein Corona Conundrum: Exploring the Advantages and Drawbacks of its Presence around Amphiphilic Nanoparticles

The success of targeted drug delivery systems still requires a detailed understanding about the biological consequences of self-developed biomolecular coronas around them, since this is the surface that interacts with living cells. Herein, we report the behavior of carbohydrate-decorated amphiphilic nanoparticles in a plasma environment with regard to the formation and biological consequences of the protein corona. Naked amphiphilic nanoparticles were produced through the self-assembly of azido-PEO₉₀₀-docosanoate molecules, and the coupling of N-acetylglucosamine via click chemistry enabled the fabrication of the corresponding bioactive glyco-nanostructures. Light scattering measurements, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, liquid chromatography-mass spectrometry, and the Pierce BCA protein assay all confirmed the presence of protein coronas around the self-assembled nanoparticles, regardless of the presence of the sugar residues, although it reduces the amount of adsorbed proteins. The protein coronas were formed mainly by human serum albumin, complement proteins, apolipoproteins, immunoglobulins, and proteins involved in the coagulation cascade (fibrinogen and prothrombin). While the presence of these protein coronas significantly reduced cellular uptake of the amphiphilic assemblies, they also notably reduced the cytotoxic and hemolytic effects that result from the contact of the nanoparticles with living cells. Accordingly, we highlight that protein coronas should not always be treated as artifacts that have to be avoided because they can also provide beneficial effects.

Sweetness Reduces Cytotoxicity and Enables Faster Cellular Uptake of Sub-30 nm Amphiphilic Nanoparticles

Glycoconjugates are versatile entities used for the manufacturing of targeted drug delivery nanocontainers because of their outstanding capability to bind to lectins, which are proteins that can be found overexpressed in the membranes of unhealthy cells. The assisted attachment to pathological cells can further enable a more efficient intracellular delivery of loaded active agents, thereby reducing side effects that commonly compromise chemotherapies. In this framework, azide-terminated polyethylene oxide (PEO) chains coupled to a 22-carbon chain were synthesized (azide-PEO₉₀₀-docosanoate). The resulting amphiphile was further functionalized by introducing different sugar moieties to the PEO chains via the click chemistry approach. Sub-30 nm, negatively charged, and spherical nanoparticles were prepared in water by self-assembly of the synthesized molecules using the straightforward nanoprecipitation protocol. The produced entities do not induce hemolysis in red blood cells at c ≤ 200 μg mL^-1, and they are not cytotoxic to healthy cells [telomerase immortalized rhesus fibroblasts (Telo-RF)] at c ≤ 50 μg mL^-1. The sugar-decorated nanoparticles are less cytotoxic compared with their naked counterparts at the concentration range assessed. The kinetics of cellular uptake of both entities into normal (Telo-RF) and tumor (HeLa) cells were monitored via fluorescence microscopy and flow cytometry. The nanoparticles are internalized faster in cancer cells than in normal cells, regardless of functionalization. Moreover, the functionalized nanoparticles are internalized faster in HeLa cells, while the reverse was observed in healthy Telo-RF cells. The distinct surface characteristics of the assemblies create an opportunity to expedite the uptake of nanoparticles particularly by tumor cells, and this accordingly can lead to a more effective intracellular delivery of therapeutic molecules loaded into nanoparticle's reservoirs.

Sugared biomaterial binding lectins: achievements and perspectives

Lectins, a distinct group of glycan-binding proteins, play a prominent role in the immune system ranging from pathogen recognition and tuning of inflammation to cell adhesion or cellular signalling. The possibilities of their detailed study expanded along with the rapid development of biomaterials in the last decade. The immense knowledge of all aspects of glycan-lectin interactions both in vitro and in vivo may be efficiently used in bioimaging, targeted drug delivery, diagnostic and analytic biological methods. Practically applicable examples comprise photoluminescence and optical biosensors, ingenious three-dimensional carbohydrate microarrays for high-throughput screening, matrices for magnetic resonance imaging, targeted hyperthermal treatment of cancer tissues, selective inhibitors of bacterial toxins and pathogen-recognising lectin receptors, and many others. This review aims to present an up-to-date systematic overview of glycan-decorated biomaterials promising for interactions with lectins, especially those applicable in biology, biotechnology or medicine. The lectins of interest include galectin-1, -3 and -7 participating in tumour progression, bacterial lectins from Pseudomonas aeruginosa (PA-IL), E. coli (Fim-H) and Clostridium botulinum (HA33) or DC-SIGN, receptors of macrophages and dendritic cells. The spectrum of lectin-binding biomaterials covered herein ranges from glycosylated organic structures, calixarene and fullerene cores over glycopeptides and glycoproteins, functionalised carbohydrate scaffolds of cyclodextrin or chitin to self-assembling glycopolymer clusters, gels, micelles and liposomes. Glyconanoparticles, glycan arrays, and other biomaterials with a solid core are described in detail, including inorganic matrices like hydroxyapatite or stainless steel for bioimplants.

Recent Advances in the Chemistry of Glycoconjugate Amphiphiles

Glyconanoparticles essentially result from the (covalent or noncovalent) association of nanometer-scale objects with carbohydrates. Such glyconanoparticles can take many different forms and this mini review will focus only on soft materials (colloids, liposomes, gels etc.) with a special emphasis on glycolipid-derived nanomaterials and the chemistry involved for their synthesis. Also this contribution presents Low Molecular Weight Gels (LMWGs) stabilized by glycoconjugate amphiphiles. Such soft materials are likely to be of interest for different biomedical applications.

A shear-induced network of aligned wormlike micelles in a sugar-based molecular gel. From gelation to biocompatibility assays

A new low molecular weight hydrogelator with a saccharide (lactobionic) polar head linked by azide-alkyne click chemistry was prepared in three steps. It was obtained in high purity without chromatography, by phase separation and ultrafiltration of the aqueous gel. Gelation was not obtained reproducibly by conventional heating-cooling cycles and instead was obtained by shearing the aqueous solutions, from 2 wt% to 0.25 wt%. This method of preparation favored the formation of a quite unusual network of interconnected large but thin 2D-sheets (7nm-thick) formed by the association side-by-side of long and aligned 7nm diameter wormlike micelles. It was responsible for the reproducible gelation at the macroscopic scale. A second network made of helical fibres with a 10-13nm diameter, more or less intertwined was also formed but was scarcely able to sustain a macroscopic gel on its own. The gels were analysed by TEM (Transmission Electronic Microscopy), cryo-TEM and SAXS (Small Angle X-ray Scattering). Molecular modelling was also used to highlight the possible conformations the hydrogelator can take. The gels displayed a weak and reversible transition near 20°C, close to room temperature, ascribed to the wormlike micelles 2D-sheets network. Heating over 30°C led to the loss of the gel macroscopic integrity, but gel fragments were still observed in suspension. A second transition near 50°C, ascribed to the network of helical fibres, finally dissolved completely these fragments. The gels showed thixotropic behaviour, recovering slowly their initial elastic modulus, in few hours, after injection through a needle. Stable gels were tested as scaffold for neural cell line culture, showing a reduced biocompatibility. This new gelator is a clear illustration of how controlling the pathway was critical for gel formation and how a new kind of self-assembly was obtained by shearing.

Chirality inversion, supramolecular hydrogelation and lectin binding of two thiolactose amphiphiles constructed on a di-lauroyl-l-tartaric acid scaffold

The supramolecular self-assembly mode of two diacyl-glycoamphiphiles depends on the length of the flexible achiral ethoxylated linker.

New glycosylated conjugate copolymer N-acetyl-β-D-glucosaminyl-pluronic: Synthesis, self-assembly and biological assays

This work describes the synthesis of a new glycosylated conjugate copolymer, GlcNAc-PEO75-PPO30-PEO75-GlcNAc (GlcNAc-PluronicF68-GlcNAc), using click chemistry from Pluronic(®) F68 and propargyl-2-N-acetamido-2-deoxy-β-D-glucopyranoside. Micelles were prepared by the self-assembly of GlcNAc-PluronicF68-GlcNAc in phosphate-buffered solution. The critical micelle concentration was determined by fluorescence spectroscopy, and the value was found to be equal to 5.8mgmL(-1). The Gibbs free energy (ΔG) of micellization is negative, indicating that the organization of amphiphiles is governed by the hydrophobic effects in an entropy-driven process. The scattering characterization of GlcNAc-PluronicF68-GlcNAc micelles showed a hydrodynamic radius of 8.7nm and negative zeta potential (-21.0±0.9mV). The TEM image evidences the spherical shape of the objects self-assemble into highly regular micelles having a mean diameter of 10nm. The SAXS profile confirmed the spherical shape of the assemblies comprising a swollen PPO core (Rcore=2.25nm) stabilized by PEO chains following Gaussian statistics. The results of the comet assay showed that the GlcNAc-PluronicF68-GlcNAc micelles were not genotoxic, and the cell viability test was higher than 97% for all concentrations, demonstrating that GlcNAc-PluronicF68-GlcNAc is not toxic.