Why nanodiamond carriers manage to overcome drug resistance in cancer

Nanodiamonds represent an attractive potential carrier for anticancer drugs. The main advantages of nanodiamond particles with respect to medical applications are their high compatibility with non-cancerous cells, feasible surface decoration with therapeutic and cancer-cell targeting molecules, and their relatively low manufacturing cost. Additionally, nanodiamond carriers significantly increase treatment efficacy of the loaded drug, so anticancer drugs execute more effectively at a lower dose. Subsequently, lower drug dose results in less extensive side effects. The carriers decorated with a targeting molecule accumulate primarily in the tumor tissue, and those nanodiamond particles impair efflux of the drug from cancer cells. Therapeutic approaches considering nanodiamond carriers were already tested in vitro, as well as in vivo. Now, researchers focus particularly on the possible side effects of nanodiamond carriers applied systemically in vivo. The behavior of nanodiamond carriers depends heavily on their surface coatings, so each therapeutic complex must be evaluated separately. Generally, it seems that site-specific application of nanodiamond carriers is a rather safe therapeutic approach, but intravenous application needs further study. The benefits of nanodiamond carriers are remarkable and represent a potent approach to overcome the drug resistance of many cancers

An in vitro study on the antibacterial effects of chlorhexidine-loaded positively charged silver nanoparticles on Enterococcus faecalis

This study successfully developed a positively charged silver nanocomplex as a nanocarrier for chlorhexidine (CHX) using ionic liquids. This nanocomplex can interestingly deliver the antibacterial agent with a synergistic effect. In this study, we synthetized and characterized a positively charged silver nanocomplex (AgNPs+) and CHX-loaded positively charged silver nanoparticles (CHX@AgNPs+) using UV-visible spectroscopy, transmission electron microscopy, X-ray diffractometer, Fourier transform infrared spectroscopy, and Zetasizer. Then, the loading efficiency and release profile of XHX from nanocomplex were evaluated. The antibacterial activity was evaluated by employing two standard microdilution tests to obtain the minimum bactericidal and inhibitory concentrations. The average sizes of 27.43 nm and 29.66 nm were obtained for AgNPs+ and CHX@AgNPs+, respectively. The CHX@AgNPs+ showed a constant release of CHX, making them a more effective antibacterial agent against Enterococcus faecalis (E. faecalis) than CHX or AgNPs+ alone. Antibacterial assays showed that CHX@AgNPs+ significantly reduced the viability of the bacterial strain compared to CHX as the standard irrigant. AgNPs+ had an antibacterial effect similar to CHX only at intermediate concentrations (12 and 25 μg/mL), and their effects were significantly less than those of CHX at other concentrations (3, 6, 50, and 100 μg/mL). The effects of CHX@AgNPs+ were statistically greater than those of AgNPs+ at all concentrations tested. The MIC values of CHX@AgNPs+ and CHX were 50 and 100 μg/mL. However, AgNPs+ were not showed MIC value at tested concentrations. Therefore, the designed nanocomplex can be regarded as a potential root canal disinfectant with clinical applications for bacterial infections

Graphene oxide and its derivatives as promising In-vitro bio-imaging platforms

Intrinsic fluorescence and versatile optical properties of Graphene Oxide (GO) in visible and near-infrared range introduce this nanomaterial as a promising candidate for numerous clinical applications for early-diagnose of diseases. Despite recent progresses in the impact of major features of GO on the photoluminescence properties of GO, their modifications have not yet systematically understood. Here, to study the modification effects on the fluorescence behavior, poly ethylene glycol (PEG) polymer, metal nanoparticles (Au and Fe3O4) and folic acid (FA) molecules were used to functionalize the GO surface. The fluorescence performances in different environments (water, DMEM cell media and phosphate buffer with two different pH values) were assessed through fluorescence spectroscopy and fluorescent microscopy, while Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) and Scanning electron microscopy (SEM) were utilized to evaluate the modifications of chemical structures. The modification of GO with desired molecules improved the photoluminescence property. The synthesized platforms of GO-PEG, GO-PEG-Au, GO-PEG-Fe3O4 and GO-PEG-FA illustrated emissions in three main fluorescence regions (blue, green and red), suitable for tracing and bio-imaging purposes. Considering MTT results, these platforms potentially positioned themselves as non-invasive optical sensors for the diagnosis alternatives of traditional imaging agents. A correction for this article can be viewed at https://doi.org/10.1038/s41598-020-75090-

Natural vs. synthetic phosphate as efficient heterogeneous compounds for synthesis of quinoxalines

Natural phosphate (NP) and synthetic fluorapatite phosphate (SFAP) were proposed as stable, inexpensive, readily available and recyclable catalysts for the condensation of 1,2-diamines with 1,2-dicarbonyls in methanol to afford quinoxaline at room temperature. NP provided as high as 92–99% yield for quinoxalines in short reaction times (i.e., 1–45 min), while SFAP created quinoxalines with 87–97% yield in 60–120 min. From the chemical analyses, X-ray fluoresecency, X-ray diffraction, energy dispersive X-ray and Fourier-transform infrared spectroscopy methods, two main phases (CaO, P2O5) appeared in NP together with other low content phases (SiO2, Fe2O3). Compared to other phases, apatite (CaO and P2O5 as Ca10(PO4 )6) played a major role in the catalytic activity of NP. SFAP with similar Ca/P atomic ratio showed a relatively lower catalytic activity than NP for the condensation of 1,2-diamine with 1,2-dicarbonyl in methanol at ambient temperature. To investigate the recyclability of catalysts, the surface properties of NP and 6-recycled NP were investigated using scanning electron microscopy, energy dispersive X-ray and Brunauer–Emmett–Teller and Barrett– Joyner–Halenda methods. Some differences were observed in NP and 6-recycled NP’s particle size, surface area, the volume and size of pores, and the content of elements; nevertheless, the use–reuse process did not noticeably change the catalytic property of NP

Controlled growth of atomically thin transition metal dichalcogenides via chemical vapor deposition method

Two-dimensional (2D) transition metal dichalcogenides (TMDC) have attracted great research interest due to their potential application in electronics, optoelectronics, electrocatalysis, and so on. To satisfy expectations, high-quality materials with designed structures are highly desired through the controlled growth of TMDC. Chemical vapor deposition (CVD) offers facile control in synthesizing 2D TMDC as well as a high degree of freedom for tuning their structures and properties. In this review, we elaborate on recent advances in CVD techniques for synthesizing atomically thin TMDC. The novel techniques for achieving continuous uniform 2D films are provided along with insights into the growth mechanisms. Moreover, approaches toward high-quality materials by growing large single crystals and oriented domains are thoroughly summarized. The strategies for controlling the crystal thickness, phase, and doping condition are also discussed. Finally, we address the challenges in the field and prospective research directions

Association of vitamin D-binding protein and vitamin D3 with insulin and homeostatic model assessment (HOMA-IR) in overweight and obese females

Objective: Equivocal association the contribution of 25-hydroxyvitamin D (25(OH)D) and the well-accepted role of vitamin D-binding protein (VDBP) on bioavailability of 25(OH)D or its independent roles, has led to possible association of the VDBP in glucose metabolism. This study was conducted to evaluate the relationships among 25(OH)D, VDBP, glucose/insulin metabolism and homeostatic model assessment (HOMA-IR). Blood samples were collected from 236 obese and overweight women. VDBP and 25(OH)D levels, and biochemical parameters were measured using an enzyme-linked immunosorbent assay (ELISA). An impedance fat analyzer was utilized to acquire the body composition. Results: Using the multivariate linear regression, a reverse relationship was observed between VDBP and (HOMA-IR), such that women with higher VDBP displayed lower insulin resistance. The relationship was independent of age, body mass index, standardized energy intake and physical activity (p = 0.00). No significant relationship between 25(OH)D levels, FBS, body composition or insulin resistance were observed (p > 0.2). Current study observed that higher level of VDBP may be associated with lower levels of insulin and HOMA-IR, thus the evaluation of VDBP in diverse population groups seems to have significant clinical value in evaluating the prevalence of DM or early stage of glucose intolerance

Phase management in single-crystalline vanadium dioxide beams

A systematic study of various metal-insulator transition (MIT) associated phases of VO2, including metallic R phase and insulating phases (T, M1, M2), is required to uncover the physics of MIT and trigger their promising applications. Here, through an oxide inhibitor-assisted stoichiometry engineering, we show that all the insulating phases can be selectively stabilized in single-crystalline VO2 beams at room temperature. The stoichiometry engineering strategy also provides precise spatial control of the phase configurations in as-grown VO2 beams at the submicron-scale, introducing a fresh concept of phase transition route devices. For instance, the combination of different phase transition routes at the two sides of VO2 beams gives birth to a family of single-crystalline VO2 actuators with highly improved performance and functional diversity. This work provides a substantial understanding of the stoichiometry-temperature phase diagram and a stoichiometry engineering strategy for the effective phase management of VO2

A new operational method to solve Abel's and generalized Abel's integral equations

Based on Jacobi polynomials, an operational method is proposed to solve the generalized Abel's integral equations (a class of singular integral equations). These equations appear in various fields of science such as physics, astrophysics, solid mechanics, scattering theory, spectroscopy, stereology, elasticity theory, and plasma physics. To solve the Abel's singular integral equations, a fast algorithm is used for simplifying the problem under study. The Laplace transform and Jacobi collocation methods are merged, and thus, a novel approach is presented. Some theorems are given and established to theoretically support the computational simplifications which reduce costs. Also, a new procedure for estimating the absolute error of the proposed method is introduced. In order to show the efficiency and accuracy of the proposed method some numerical results are provided. It is found that the proposed method has lesser computational size compared to other common methods, such as Adomian decomposition, Homotopy perturbation, Block-Pulse function, mid-point, trapezoidal quadrature, and product-integration. It is further found that the absolute errors are almost constant in the studied interval

Loading rate dependency of maximum nanoindentation depth in nano-grained NiTi shape memory alloy

We examined the effect of loading rate on maximum nanoindentation depth for nano-grained superelastic NiTi shape memory alloy during stress-induced phase transformation. The depth decreases significantly with increasing loading rate. It is argued that the observed rate dependency is attributed to the release and transfer of latent heat during indentation and the temperature dependence of the material's transition stress. Dimensional analysis further shows that the depth is mainly governed by the normalized average stress in the phase transition zone and the ratio of heat conduction time over loading time. Experimental results support the rationale

Surfactant effect on forage yield and water use efficiency for berseem clover and basil in intercropping and limited irrigation treatments

Quantifying crop response to irrigation is important for establishing effective irrigation management strategies. The present study was conducted to evaluate the response of berseem clover and basil to limited irrigation in an additive intercropping system using a surfactant. The experimental treatments were carried out in split–split plots based on a completely randomized block design with three replications. The limited irrigation treatments comprised of replenishment of I100full irrigation, I75= 25% limited and I50= 50% limited weekly evaporation and plant water requirements which were assigned to the main plots. The planting systems of sole berseem clover and sole basil culture along with additive inter cropping of berseem clover + 50% basil were assigned to the subplots. Water treatments of control (wateralone) and water + surfactant were assigned to the sub-subplots. Results show that severely limited irrigation (I50) dramatically reduced the forage yield of berseem clover and basil by 19.5% compared with the control (I100). The severity of the adverse effects of limited irrigation stress decreased by the surfactant application in irrigation by water + surfactant (9.5% decrement compared to full irrigation). The highest irrigation water use efficiency (2.7 kg m−3) was achieved in I50 treatment with an added surfactant. The highest total dry matter yield (berseem clover + basil dry matter) (9257.9 kg ha−1) was obtained from additive intercropping of berseem clover 100% + basil 50% while irrigated by water + surfactant