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.

Vitamin D3 improves spatial memory and modulates cytokine levels in aged rats.

Vitamin D3 deficiency is associated with an increased risk of dementia. An association between vitamin D3 deficiency and subjective cognitive complaints in geriatric patients has been previously reported. This study aimed to evaluate the effects of two doses of vitamin D3 on spatial memory (using the Radial Maze) and cytokine levels [tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and interleukin-10 (IL-10)] on 2-, 6-, 13-, 22-, and 31-month-old male Wistar rats. Animals were supplemented with vitamin D3 at doses of 42 IU/kg and 420 IU/kg for 21 days. A radial maze test was performed to evaluate spatial memory. After the behavioral test, the frontal cortex and hippocampus were dissected for enzyme immunoassay analyses to measure the cytokine levels (TNFα, IL-1ß, IL-6, and IL-10). Our results showed that vitamin D3 supplementation reversed spatial memory impairment at the supplemented doses (42 and 420 IU/kg) in 6-, 13-, and 22-month-old animals and at a dose of 420 IU/kg in 31-month-old animals. The lower dose (42 IU/kg) regulates both pro- and anti-inflammatory cytokines mainly in the frontal cortex. Our results suggest that vitamin D3 has a modulatory action on pro- and anti-inflammatory cytokines, since older animals showed increased cytokine levels compared to 2-month-old animals, and that vitamin D3 may exert an immunomodulatory effect on aging.

Co-encapsulation of sodium diethyldithiocarbamate (DETC) and zinc phthalocyanine (ZnPc) in liposomes promotes increases phototoxic activity against (MDA-MB 231) human breast cancer cells.

There has been considerable interest in the development of novel photosensitisers for photodynamic therapy (PDT). The use of liposomes as drug delivery systems containing simultaneously two or more drugs is an attractive idea to create a new platform for PDT application. Therefore, the aim of this study was to evaluate the synergistic effect of diethyldithiocarbamate (DETC) and zinc phthalocyanine (PDT) co-encapsulated in liposomes. The reverse-phase evaporation method resulted in the successful encapsulation of DETC and ZnPc in liposomes, with encapsulation efficiencies above 85 %, mean size of 308 nm, and zeta potential of - 36 mV. The co-encapsulation decreased the cytotoxic effects in mouse embryo fibroblast (NIH3T3) cells and inhibited damage to human erythrocytes compared to free DETC + ZnPc. In addition, both the free drugs and co-encapsulated ones promoted more pronounced phototoxic effects on human breast cancer cells (MDA-MB231) compared to treatment with ZnPc alone. This synergistic effect was determined by DETC-induced decreases in the antioxidant enzyme activity of superoxide dismutase (SOD) and glutathione (GSH).

Elucidating Bauhinia variegata lectin/phosphatidylcholine interactions in lectin-containing liposomes.

Investigations focused on the interactions of nanoparticles with lectins are relevant since it is well accepted that such proteins can be recognized by carbohydrates as parts of cell membranes. This can ultimately enhance the cellular uptake of the produced assemblies. In this framework, the physical interactions of phosphatidylcholine (PC) liposomes and the Bauhinia variegate lectin (BVL) are reported here. BVL-liposome interactions were characterized by a variety of techniques to understand the influence of BVL in the structural features, thermodynamic and spectroscopic properties of the hybrid material. The produced system is composed of 56% w/w lectin, and the scattering techniques show the presence of stable vesicular structures with a mean diameter DH ∼ 100 nm. The FTIR and NMR results showed a strong lectin effect on the PC choline region, restricting the rotational motion of the lipid group. The BVL-liposome interaction promoted hardening of the protein as evidenced by circular dichroism spectroscopy. The photophysics results suggest higher rigidity of the system in the presence of BVL. The BVL may be present in the inner or outer polar surface of the liposomes. The system was shown to be relatively stable and therefore potentially useful for carbohydrate recognition of nanoparticles.

Self-assembled carbohydrate-based vesicles for lectin targeting.

This study examined the physicochemical interactions between vesicles formed by phosphatidylcholine (PC) and glycosylated polymeric amphiphile N-acetyl-ß-d-glucosaminyl-PEG900-docosanate (C22PEG900GlcNAc) conjugated with Bauhinia variegata lectin (BVL). Lectins are proteins or glycoproteins capable of binding glycosylated membrane components. Accordingly, the surface functionalization by such entities is considered a potential strategy for targeted drug delivery. We observed increased hydrodynamic radii (RH) of PC+C22PEG900GlcNAc vesicles in the presence of lectins, suggesting that this aggregation was due to the interaction between lectins and the vesicular glycosylated surfaces. Furthermore, changes in the zeta potential of the vesicles with increasing lectin concentrations implied that the vesicular glycosylated surfaces were recognized by the investigated lectin. The presence of carbohydrate residues on vesicle surfaces and the ability of the vesicles to establish specific interactions with BVL were further explored using atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS) analysis. The results indicated that the thickness of the hydrophilic layer was to some extent influenced by the presence of lectins. The presence of lectins required a higher degree of polydispersity as indicated by the width parameter of the log-normal distribution of size, which also suggested more irregular structures. Reflectance Fourier transform infrared (HATR-FTIR), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis.) analyses revealed that the studied lectin preferentially interacted with the choline and carbonyl groups of the lipid, thereby changing the choline orientation and intermolecular interactions. The protein also discretely reduced the intermolecular communication of the hydrophobic acyl chains, resulting in a disordered state.

New glycosylated conjugate copolymer N-acetyl-ß-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-ß-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.