Multimodal nanomaterials are useful for providing enhanced diagnostic information simultaneously for a variety of in vivo imaging methods. According to our research findings, these multimodal nanomaterials offer promising applications for cancer therapy.
Results
Melanin nanoparticles can be used as a platform imaging material and they can be simply produced by complexation with various imaging active ions. They are capable of specifically targeting epidermal growth factor receptor (EGFR)-expressing cancer cells by being anchored with a specific antibody. Ion-doped melanin nanoparticles were found to have high bioavailability with long-term stability in solution, without any cytotoxicity in both in vitro and in vivo systems.
Conclusion
By combining different imaging modalities with melanin particles, we can use the complexes to obtain faster diagnoses by computed tomography deep-body imaging and greater detailed pathological diagnostic information by magnetic resonance imaging. The ion-doped melanin nanoparticles also have applications for radio-diagnostic treatment and radio imaging-guided surgery, warranting further proof of concept experimental.
Cancer stem cells (CSCs) are highly proliferative and tumorigenic, which contributes to chemotherapy resistance and tumor occurrence. CSCs specific therapy may achieve excellent therapeutic effects, especially to the drug-resistant tumors.
Results
In this study, we developed a kind of targeting nanoparticle system based on cationic albumin functionalized with hyaluronic acid (HA) to target the CD44 overexpressed CSCs. All-trans-retinoic acid (ATRA) was encapsulated in the nanoparticles with ultrahigh encapsulation efficiency (EE%) of 93% and loading content of 8.37%. TEM analysis showed the nanoparticles were spherical, uniform-sized and surrounded by a coating layer consists of HA. Four weeks of continuously measurements of size, PDI and EE% revealed the high stability of nanoparticles. Thanks to HA conjugation on the surface, the resultant nanoparticles (HA-eNPs) demonstrated high affinity and specific binding to CD44-enriched B16F10 cells. In vivo imaging revealed that HA-eNPs can targeted accumulate in tumor-bearing lung of mouse. The cytotoxicity tests illustrated that ATRA-laden HA-eNPs possessed better killing ability to B16F10 cells than free drug or normal nanoparticles in the same dose, indicating its good targeting property. Moreover, HA-eNPs/ATRA treatment decreased side population of B16F10 cells significantly in vitro. Finally, tumor growth was significantly inhibited by HA-eNPs/ATRA in lung metastasis tumor mice.
Conclusions
These results demonstrate that the HA functionalized albumin nanoparticles is an efficient system for targeted delivery of antitumor drugs to eliminate the CSCs.
Standard microorganism isolating technology applied for complex multiphase environmental samples such as soil or sediment needs pre-treatment steps to remove living cells from their mixed-phase microniche, by creating a liquid-phase sample. This process removes synergetic relationships, which help to maintain viability of yet-to-be-cultured and hard-to-culture bacteria. In this paper we demonstrate a high throughput Laser Micro-Sampling (LMS) technology for direct isolation of pure microbial cultures and microbial consortia from soil. This technology is based on laser printing of soil microparticles by focusing near-infrared laser pulses on specially prepared samples of a soil/gel mixture spread onto a gold-coated glass plate. Microsamples of soil are printed on glucose-peptone-yeast agar plates, to estimate the LMS process influence on functional and taxonomic microbial diversity, and on «Eco-log» sole carbon sources microplates, to investigate functional diversity by “metabolic fingerprinting”. The obtained results are compared with traditionally treated soil samples. It was shown that LMS treatment leads to increasing of cultured biodiversity and modifies the functional diversity. The strain of rare genus Nonomuraea was isolated by LMS from complex natural environment without using media selective for this genus.
In this article, we explore the capacity of formed Schiff base complexes to trap metal atoms or ions, using their aromatic ends. The intrinsic geometry of each complex defines the process of substitution. Two cases were studied; one involving a trans Schiff base complex and the other considering how a salen ligand, with nickel systems traps chromium. We also assessed the nature of the new bonds and the frontier molecular orbitals.
The low bending rigidity of graphene facilitates the formation of folds into the structure. This curvature change affects the reactivity and electron transport of the sheet. One novel extension of this is the intercalation of small molecules into these folds. We construct a model incorporating a single-walled carbon nanotube into a sheet of folded graphene. Variational calculus techniques are employed to determine the minimum energy structure and the resulting curves are shown to agree well with molecular dynamics study.
Graphical Abstract Using calculus of variations, the elastic bending energy and van der Waals energy are minimised giving rise to Euler-Lagrange equation for which analytical solutions are derived to determine the optimal curved sturctures of graphene wrapped around carbon nanotubes . Overall agreement between the analytical solutions (with different values of bending rigidities) and results from molecular dynamics simulations (grey) is shown here for (6,6), (8,8) and (10,10) armchair nanotubes, respectively.
Bond critical points (BCPs) in the quantum theory of atoms in molecules (QTAIM) are shown to be a consequence of the molecular topology, symmetry, and the Poincaré-Hopf relationship, which defines the numbers of critical points of different types in a scalar field. BCPs can be induced by a polarizing field or by addition of a single non-bonded atom to a molecule. BCPs and their associated bond paths are therefore suggested not to be a suitable means of identifying chemical bonds, or even attractive intermolecular interactions.
Gold nanoparticles (AuNPs) are attracting interest as potential therapeutic agents to treat inflammatory diseases, but their anti-inflammatory mechanism of action is not clear yet. In addition, the effect of orally administered AuNPs on gut microbiota has been overlooked so far. Here, we evaluated the therapeutic and gut microbiota-modulating effects, as well as the anti-inflammatory paradigm, of AuNPs with three different coatings and five difference sizes in experimental mouse colitis and RAW264.7 macrophages.
Results
Citrate- and polyvinylpyrrolidone (PVP)-stabilized 5-nm AuNPs (Au-5 nm/Citrate and Au-5 nm/PVP) and tannic acid (TA)-stabilized 5-, 10-, 15-, 30- and 60-nm AuNPs were intragastrically administered to C57BL/6 mice daily for 8 days during and after 5-day dextran sodium sulfate exposure. Clinical signs and colon histopathology revealed more marked anti-colitis effects by oral administration of Au-5 nm/Citrate and Au-5 nm/PVP, when compared to TA-stabilized AuNPs. Based on colonic myeloperoxidase activity, colonic and peripheral levels of interleukin-6 and tumor necrosis factor-α, and peripheral counts of leukocyte and lymphocyte, Au-5 nm/Citrate and Au-5 nm/PVP attenuated colonic and systemic inflammation more effectively than TA-stabilized AuNPs. High-throughput sequencing of fecal 16S rRNA indicated that AuNPs could induce gut dysbiosis in mice by decreasing the α-diversity, the Firmicutes/Bacteroidetes ratio, certain short-chain fatty acid-producing bacteria and Lactobacillus. Based on in vitro studies using RAW264.7 cells and electron spin resonance oximetry, AuNPs inhibited lipopolysaccharide (LPS)-triggered inducible nitric oxide (NO) synthase expression and NO production via reduction of Toll-like receptor 4 (TLR4), and attenuated LPS-induced nuclear factor kappa beta activation and proinflammatory cytokine production via both TLR4 reduction and catalytic detoxification of peroxynitrite and hydrogen peroxide.
Conclusions
AuNPs have promising potential as anti-inflammatory agents; however, their therapeutic applications via the oral route may have a negative impact on the gut microbiota.
In this study, the doped defects in nitromethane crystals were investigated using first-principles calculations for the first time. We introduce dopant atoms in the interstitial sites of the nitromethane lattice, aiming to study the effects of element-doping on the structural properties, electronic properties, and sensitivity characteristics. The obtained results show that doped defects obviously affect the neighboring nitromethane molecules. The modification of electronic properties shows that the band gaps are significantly influenced by doped defects. Partial density of states and population analysis further reveal the mechanism for sensitivity control of nitromethane. It is shown that the new electronic states were introduced in the forbidden bands and the doped defects resulted in charge redistributions in the systems.
The structure and stability of various ternary complexes in which an extended aromatic system such as coronene interacts with ions/atoms/molecules on opposite faces of the π-electron cloud were investigated using ab initio calculations. By characterizing the nature of the intermolecular interactions using an energy decomposition analysis, it was shown that there is an interplay between various types of interactions and that there are co-operativity effects, particularly when different types of interactions coexist in the same system.
Graphical abstract Weak OH-π, π-π and van der Waals-π ternary systems are stabilized through dispersion interactions. Cation-π ternary systems are stabilized by through-space electrostatic interactions.
Density functional theory calculations were carried out to investigate the formation mechanism of the thymine-thymine (6–4) dimer ((6–4)TT), which is one of the main DNA lesions induced by ultraviolet radiation and is closely related to skin cancers. The DNA backbone was found to have nonnegligible effects on the triplet reaction pathway, particularly the reaction steps involving substantial base rotations. The mechanism for the isomerization from (6–4)TT to its Dewar valence isomer (DewarTT) was also explored, confirming the necessity of absorbing a second photon. In addition, the solvation effects were examined and showed considerable influence on the potential energy surface.
Textile printing and dyeing wastewater is usually characterized by high pH, high turbidity, poor bio-degradability, complex composition, and high chrominance, and is discharged in large amounts. It has been regarded as one of the hardest to treat forms of industrial wastewater. Conventional physicochemical technologies can remove these contaminants from water bodies, but at the expense of high energy consumption and high cost. Alternatively, biological processes with limited energy consumption, low cost and high efficiency are considered as promising technologies. Among them, the anaerobic biological processes have been proven to be effective for the treatment of high-concentration textile printing and dyeing wastewater. In this mini-review, recent advances on high-rate anaerobic technologies for such purposes are reviewed. Current limitations of these technologies are summarized, and future research directions are indicated.
There is a constant need to improve antiretrovirals against HIV since therapy is limited by cost, side effects and the emergence of drug resistance. Kudzu is a climbing vine from which the root extract (Pueraria lobata), rich in isoflavones and saponins, has long been used in traditional Chinese medicine for a variety of purposes, from weight loss to alcoholism prevention. Here we show that Kudzu root extract significantly inhibits HIV-1 entry into cell lines, primary human CD4+T lymphocytes and macrophages, without cell-associated toxicity. Specifically, Kudzu inhibits the initial attachment of the viral particle to the cell surface, a mechanism that depends on the envelope glycoprotein gp120 but is independent from the HIV-1 cell receptor CD4 and co-receptors CXCR4/CCR5. This activity seems selective to lentiviruses since Kudzu inhibits HIV-2 and simian immunodeficiency virus, but does not interfere with Hepatitis C, Influenza, Zika Brazil and adenovirus infection. Importantly, depending on the dose, Kudzu can act synergistically or additively with the current antiretroviral cocktails against HIV-1 and can block viruses resistant to the fusion inhibitor Enfuvirtide. Together our results highlight Kudzu’s root extract value as a supplement to current antiretroviral therapy against HIV.
Present molecular dynamics simulations indicate that the methanol component in a methanol/water mixture is more likely to be trapped in a cyclic peptide nanotube (CPNT), while water molecules tend to be present at the channel mouths as transient guests. Channel water resides mainly between methanol and the CPNT wall, resulting in a distinct decrease in the H-bond number per channel methanol. Six designed CPNTs with different channel diameters and outer surface characteristics all possess distinct selectivity to methanol over water. Of these, the amphipathic 8?×?(AQ)4-CPNT exhibits the best performance. Results in this study provide basic information for the application of a CPNT to enrich methanol from a methanol/water mixture.
The present paper reports the analysis of surface decoration on the structural, electronic, and optical properties of (n,0) ZnO nanotubes, performed by means of a density function theory based ab-initio approach. Fe functionalization induced buckling in ZnO nanotubes affects its electronic and optical properties. Increase in Fe functionalization leads to better stability of ZnO nanotube and shows enhanced metallic character. The possibility of its use in optoelectronics has been analyzed in terms of dielectric constant, absorption coefficient, and refractive index. In another observation, the high sensitivity of the HCN molecule for the Fe-incorporated ZnO nanotube suggests it as a potential gas sensor.
Magnetic shielding constants for an isolated fullerene C60, cucurbituril CB[9], and the host-guest complex C60@CB[9] were calculated as a function of separation of the monomers. Our results in the gas phase and water indicate a significant variation of the magnetic properties for all atoms of the monomers in the complex and after liberation of fullerene C60 from the interior of the CB[9] cavity. The interaction between the two monomers results in a charge transfer that collaborates with a redistribution of electron density to deshield the monomers.
The aldol reaction in the presence of L-proline acting as an organocatalyst is a well-known example of asymmetric synthesis. Many theoretical and experimental studies have been carried out to probe the mechanism of this reaction. In this work, two levels of density functional theory in the gas phase and DMSO were used to elucidate the best pathways for this reaction, with the enamine and enol considered intermediates and L-proline considered either a reactant or a facilitator. The calculations indicated that both intermediates are formed simultaneously in the reaction medium. Interestingly, the formation of the enamine intermediate predominates in DMSO at room temperature, whereas the enol becomes the predominant intermediate upon the addition of water.
The solubility advantage (SA) of meloxicam cocrystalized with mono- and dicarboxylic acids was expressed in terms of equilibrium constants involving active pharmaceutical ingredient and coformer in aqueous solutions. It is argued that SA can be quantified by concentration of pairs formed in water. The pH and concentration of dissolved components is included explicitly in the model. The alternative behavior of mono- and dicarboxylic acids was emphasized and addressed to different structural motifs. The structural and energetic properties of meloxicam and its complexes with carboxylic acids were characterized, including tautmerism and dissociation in aqueous media. In particular, performed in silico modeling confirmed experimental observation that meloxicam dissolved in water or modest acidic solutions is expected to be a mixture of anionic form in equilibrium with at least five neutral isomers. Tautomer-related diversity of pairs formation and the possibility of salt formation is also discussed.
Selenium (Se) is an indispensable trace element required for animals and humans, and extra Se-supplement is necessary, especially for those having Se deficiency. Recently, selenium nanoparticles (SeNPs), as a special form of Se supplement, have attracted worldwide attention due to their distinguished properties and excellent bioactivities. In this present study, an eco-friendly and economic way to prepare stable SeNPs was introduced. SeNPs were synthesized in the presence of chitosan (CTS) and then embedded into chitosan/citrate gel, generating selenium nanoparticles-loaded chitosan/citrate complex (SeNPs-C/C). Additionally, the clinical potential of SeNPs-C/C was evaluated by using d-galactose (d-gal)-induced aging mice model.
Results
SeNPs in high uniform with an average diameter of around 50 nm were synthesized in the presence of chitosan, and reversible ionic gelation between chitosan and citrate was utilized to load SeNPs. Subsphaeroidal SeNPs-C/C microspheres of 1–30 μm were obtained by spay-drying. Single SeNPs were physically separated and embedded inside SeNPs-C/C microparticles, with excellent stability and acceptable release. Acute fetal test showed SeNPs-C/C was safer than selenite, with a median lethal dose (LD50) of approximately 4-fold to 11-fold of that of selenite. Oral administration of SeNPs-C/C remarkably retarded the oxidative stress of d-gal in Kunming mice by enhancing the activity of antioxidase, as evidenced by its significant protection of the growth, liver, Se retention and antioxidant bio-markers of mice against d-gal.
Conclusions
The design of SeNPs-C/C opens a new path for oral delivery of SeNPs with excellent stability, energy-conservation and environment-friendliness. SeNPs-C/C, as a novel supplement of Se, could be further developed to defend the aging process induced by d-gal.
Vegetable ‘mandi’ (road-side vegetable market) waste was converted to a suitable fermentation medium for cultivation of oleaginous yeast Rhodosporidium toruloides by steaming under pressure. This cultivation medium derived from waste was found to be a comparatively better source of nutrients than standard culture media because it provided more than one type of usable carbon source(s) to yeast.
Results
HPLC results showed that the extract contained glucose, xylose and glycerol along with other carbon sources, allowing triauxic growth pattern with preferably usage of glucose, xylose and glycerol resulting in enhanced growth, lipid and carotenoid production. Presence of saturated and unsaturated fatty acid methyl esters (FAMEs) (C14-20) in the lipid profile showed that the lipid may be transesterified for biodiesel production.
Conclusion
Upscaling these experiments to fermenter scale for the production of lipids and biodiesel and other industrially useful products would lead to waste management along with the production of value added commodities. The technique is thus environment friendly and gives good return upon investment.
