In recent years, the green synthesis of silver nanoparticles using various plant extracts has attracted great attention. This is because, these methods are simple, inexpensive and, eco-friendly. In this study, it was observed that silver ions were reduced by phlomis leaf extract after 5 min, leading to the formation of crystalline silver nanoparticles. Phlomis species is known as a rich source of flavonoids, phenylpropanoids and other phenolic compounds. The silver nanoparticles produced by the phlomis extract were characterized by different techniques including UV-vis spectrophotometry, X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and FT-IR. The SEM and TEM results indicated that AgNPs were predominantly spherical in shape with an average particle size of 25 nm. In addition, the antibacterial activity of biologically synthesized nanopartilcles against Gram-positive (Staphyloccocus aureus and Bacillus cereus) and Gram-negative (Salmonella typhimurium and Escherichia coli) bacteria was proved. This study, therefore, showed that the phlomis leaf extract could be used for the green synthesis of silver nanoparticles with the appropriate antibacterial activity.

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The authors introduce a new kind of surface artificial biomimetic receptor, referred to as aptameric imprinted polymer (AIP), for separation of biological macromolecules. Highly dispersed magnetic nanoparticles (MNPs) were coated with silica and then functionalized with methacrylate groups via silane chemistry. The aptamer was covalently immobilized on the surface of nanoparticles via a "thiol-ene" click reaction. Once the target analyte (bovine serum albumin; BSA) has bound to the aptamer, a polymer is created by 2-dimensional copolymerization of short-length poly(ethylene glycol) and (3-aminopropyl)triethoxysilane. Following removal of BSA from the polymer, the AIP-MNPs presented here can selectively capture BSA with a specific absorbance (κ) as high as 65. When using this AIP, the recovery of BSA from spiked real biological samples is >97%, and the adsorption capacity is as high as 146 mg g. In our perception, this method has a wide scope in that it may be applied to the specific extraction of numerous other biomolecules. Graphical abstract Schematic presentation of the AIP (aptamer-imprinted polymer) introduced here. The surface of silica coated magnetic nanoparticles is modified with a polymer that is covalently modified with an aptamer against bovine serum albumin (BSA).

In the present work, a fluorescent gold nanoclusters (GNCs)/superparamagnetic (Fe 3 O 4 /GNCs) nanoprobe was prepared via a facile approach for the selective detection and imaging of human leukemica cancer cells (HL-60). (γ-Mercaptopropyl)trimethoxysilane (MPS) was used as a stabilizer to prepare functionalized GNCs. The prepared GNCs@MPS was then self-assembly decorated on the surface of Fe 3 O 4 @SiO 2 nanoparticles followed by poly(ethylene glycol) dimethacrylate (PGD) addition at room temperature to form Fe 3 O 4 /GNCs nanoprobe. Surface functionalization of the Fe 3 O 4 /GNCs with the thiol-modified KH1C12 aptamer was done through thiol-en click reaction between PGD and the thiol group of the aptamer. An extensive characterization of the Fe 3 O 4 /GNCs revealed strong red fluorescence (λ em =627 nm), T 2 -based contrast agent for MRI and excellent colloidal and photo stability in buffer medium. So, the aptamer-functionalized Fe 3 O 4 /GNCs nanoprobe (Fe 3 O 4 /GNCs/Aptamer) is capable to uptake and dual-image HL-60 cancer cells from a mixture. Furthermore, the MRI signal intensity of the pictures decreased linearly with an increase in the concentrations of the nanoprobe. It is also enable to detect cancer cells from a range of concentrations 10 up to 200 cells μL −1 . The fluorescent/magnetic characteristics of the nanoprobe are of great significance for MRI-based and fluorescence imaging and collection of HL-60 cancer cells which implies potential help for the development of early diagnosis of highly malignant human leukemia.

The combination of diagnosis and targeted therapy within a single nanoplatform is one of the remarkable advances in molecular medicine.

Gold nanoparticle–piroxicam anion conjugates (Au NP–Pir) were synthesized in a green method using laser ablation of a gold foil in an aqueous solution of anionic piroxicam (NaPir). The produced Au NP–Pir conjugates were characterized by different spectroscopic techniques and transmission electron microscopy. The fluorescence and absorption spectra of Au NP–Pir colloidal solution were recorded at different concentrations of the Au NPs to investigate the effect of conjugation on the spectral properties of both the free Pir anion and Au NPs. Comparing the FT-IR spectrum of the colloidal solution of Au NP–Pir with that of the solution of the free Pir anion indicates that this anion binds to the surface of Au NPs through its different binding sites, viz., the pyridyl nitrogen atom, the SO2 group, and the amide oxygen atom. To support the experimental observations, theoretical calculations were also performed to evaluate the interaction of different binding sites of Pir with one Au atom and the effect of this interaction on the IR spectrum of Pir. In a more realistic theoretical study, the optimized geometry of Pir on the Au(111) surface was calculated, and its orientation toward the surface of Au was obtained. The calculations show that the pyridyl ring of Pir prefers to orient perpendicular to the surface of Au, and the O atoms of the SO2 and amide groups are responsible for the interaction with the surface. The cytotoxic effect of the free Pir anion and Au NP–Pir conjugates against the Jurkat T-cells was studied using an MTT assay. The results show that only the Au NP–Pir conjugates have significant anticancer activity against the Jurkat T-cells with an IC50 value of 33.8 ± 2 μg/mL. In comparison with the pure Au NPs and free Pir, the Au NP–Pir conjugates show a significant antimicrobial activity against two pathogens including Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus).

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Dendritic cells (DCs), in response to the biomaterials, utilize toll‐like receptors (TLRs) to become mature or tolerogenic through TLRs‐dependent signaling pathways, especially TLR4. Regarding the physicochemical properties of biomaterials, some of such signaling pathways are activated. Unsaturated fatty acids have been explored as an antagonist for TLRs and lead to the tolerogenic phenotype of DCs. Here we showed that, although cultured DCs on both chitosan and Alginate‐polyethyleneimine (Alg‐PEI) films became fully mature, 10‐hydroxy‐2‐decanoic acid (10‐HDA), an unsaturated fatty acid found in royal jelly, led to the tolerogenic immunophenotype of DCs on both films. The cultured cells on the films possessed iDCs‐like morphology in the presence of 10‐HDA. Moreover, 10‐HDA expressed lower levels of CD80, CD83, CD86, and HLA‐DR, a higher level of IL‐10, and lower level of IL‐12 in the cultured DCs on both films. Furthermore, HEK293T cells expressing only TLR4 (HEK‐TLR4 cells) were co‐cultured with LPS, a specific agonist for TLR4, and 10‐HDA. The 10‐HDA significantly reduced the expression of tumor necrosis factor‐a (TNF‐α) in the HEK‐TLR4 cells compared to treated only with LPS. These findings indicate that the 10‐HDA acts as an antagonist of TLR4; therefore, potentially can be used in autoimmune diseases and preventing the rejection of biomaterials implantation and allograft transplantation.