Nanocore-Shell Bone Filler Contained Mesoporous Silica Modified with Hydroxyapatite Precursors; Wrapped in a Natural Metal-Phenolic Network.

Various therapeutic strategies have been developed to address bone diseases caused by aging society and skeletal defects caused by trauma or accidental events. One such approach is using bone fillers, such as hydroxyapatite (HA) and bioactive glasses. Although they have provided effective osteogenesis, infection and inflammation due to the surgical procedure and uncontrolled ion release can hinder the efficiency of bone regeneration. In response to these challenges, immobilizing a neutral metal-phenolic network on the surface of osteoconductive nanoparticles would be the master key to achieving a gradual, controlled release during the mineralization period and reducing infection and inflammation through biological pathways. In this regard, a mesoporous silica nanocomposite modified by an HA precursor was synthesized to enhance bone regeneration. In addition, to improve the therapeutic effects, its surface was wrapped with a magnesium-phenolic network made from pomegranate extract, which can simultaneously produce anti-inflammatory and antibacterial effects. The obtained core-shell nanocomposite was characterized by its physicochemical properties, biocompatibility, and bioactivity. The in vitro studies revealed that the synthesized nanocomposite exhibits higher osteogenic activity than the control groups, as confirmed by alizarin red staining. Moreover, the nanocomposite maintained low toxicity as measured by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and increased antibacterial activity against Staphylococcus aureus and Escherichia coli compared with the control groups. Therefore, this research presents a promising strategy for bone regeneration, combining the advantages of mesoporous silica nanocomposite modified by an HA precursor with the beneficial effects of a magnesium-phenolic network.

A curcumin-nicotinoyl derivative and its transition metal complexes: synthesis, characterization, and in silico and in vitro biological behaviors.

Curcumin-nicotinoyl (Cur-Nic) was synthesized by the chemical modification of the curcumin structure, characterized, and used as a ligand for the synthesis of copper(II) and zinc(II) complexes. The biological activities of Cur-Nic and its metal complexes were predicted using the PASS and Swiss Target Prediction online software, respectively, and docking studies with tyrosine-protein kinase SRC were performed using the PyRx software to predict their anticancer activities. The toxicity effects of the complexes on a human breast cancer cell line (MCF-7) compared to a healthy breast cell line (MCF-10A) were investigated by the MTS assay. Although the metal complexes maintained the least toxicity against normal cells, the results indicated that compared to curcumin and Cur-Nic, the cytotoxicity toward cancer cells increased due to the complexation process. Moreover, the antibacterial evaluation of the compounds against a Gram-positive bacterium (MRSA) and a Gram-negative bacterium (E. coli) indicated that the Cu(II) complex and Cur-Nic were the best, respectively. Also, the Zn(II) complex was the most stable compound, and the Cu(II) complex was the best ROS scavenger based on the in vitro evaluation.

A label-free SPR biosensor for specific detection of TLR4 expression; introducing of 10-HDA as an antagonist.

Toll-like receptor 4 (TLR4) is actively involved in many health-related problems, including transplantation rejection and autoimmune diseases. Therefore, it is important to identify an antagonist to inhibit the TLR4-induced immune cell activation. In our previous study, 10-hydroxy-2-decanoic acid (10-HDA) was introduced as a potential antagonist for TLR4; however, possible interaction between 10-HDA and TLR4 needed to be detected. Due to the ability of surface plasmon resonance (SPR) biosensor to confirm the specific interactions between receptors and ligands, a new configuration of SPR biosensor proposed to detect the possible interaction between 10-HDA and TLR4. Hence, 10-HDA was immobilized using the (3-aminopropyl) triethoxysilane (APTES) polymer as a crosslinking agent on the Ag-MgF2 surface. Besides, genetically modified HEK293T cells with high TLR4 expression were used to study the possible interaction between 10-HDA and TLR4. Surprisingly, the SPR angle was significantly reduced in the presence of HEK cells expressing TLR4, while HEK cells without TLR4 did not affect the SPR angle. So, the proposed SPR biosensor successfully detected the interaction betweenTLR4 and 10-HDA. The sensitivity and detection limit of the biosensor were achieved at 0.05 and 0.5 million cells expressing TLR4, respectively, with a two-fold dynamic range.

Smart co-delivery of miR-34a and cytotoxic peptides (LTX-315 and melittin) by chitosan based polyelectrolyte nanocarriers for specific cancer cell death induction.

A novel polyelectrolyte nanocarrier was synthesized via layer-by-layer self-assembly of polycationic and polyanionic chains. The nanocarrier is composed of polyglutamate grafted chitosan core, dextran sulfate as a complexing agent, and polyethyleneimine shell decorated with folic acid. This polyelectrolyte complex has unique physicochemical properties so that the core is considered as an efficient carrier for LTX-315 and melittin peptides, and the shell is suitable for delivery of miR-34a. The spherical nanocarriers with an average size of 123 ± 5 nm and a zeta potential of -36 ± 1 mV demonstrated controlled-release of gene and peptides ensured a synergistic effect in establishing multiple cell death pathways on chemoresistance human breast adenocarcinoma cell line, MDA-MB-231. In vitro cell viability assays also revealed no cytotoxicity for the nanocarriers, and an IC50 of 15 µg/mL and 150 µg/mL for melittin and LTX-315, respectively, after 48 h, whereas co-delivery of melittin with miR-34a increased smart death induction by 54%.

Chemical stabilization of γ-polyglutamate by chitosan and the effect of co-solvents on the stability.

In protein-based formulations, conformational distortions and attractive interactions may cause insoluble and undesired aggregates. In the case of ionic peptides, including cationic or anionic, commonly electrostatic interactions are the main factors that control structure assembling. In this study, it was proposed that grafting of chitosan (CS) to γ-polyglutamic acid (γ-PGA) might exhibit much strong inhibiting effect on the formation of protein aggregates due to multiple amino groups and hydrophilic properties. To guarantee stable and safe biopharmaceutical formulation, the potency of a variety of stabilizers including sugars (glucose, sucrose), polyols (sorbitol, glycerol), surfactant (Tween 20), salting-out salt (PBS), and also different pH values have been evaluated on stabilizing or destabilizing the native state of CS-g-PGA copolymer using FTIR, CD, DLS, and SDS-PAGE. The comparable analysis revealed that the stability of CS-g-PGA was strongly dependent on pH owing to the polyelectrolyte characteristics of the polymers. Altogether these results implied that CS at optimized conditions might be an important precursor for the pharmaceutical industry and function as a new polymer for aggregation suppression and protein stabilization.

10-hydroxy-2-decenoic acid a bio-immunomodulator in tissue engineering; generates tolerogenic dendritic cells by blocking the toll-like receptor4.

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.

Hierarchical multifunctional graphene oxide cancer nanotheranostics agent for synchronous switchable fluorescence imaging and chemical therapy.

A nanotheranostics platform was synthesized based on PEGylated graphene oxide-gold nanoparticles and specified with aptamer toward the MUC-1-positive tumor cells. Subsequently, it was loaded with doxorubicin, used for non-invasive fluorescence imaging and therapy of breast and colon tumors. The success of the nano-coating at each synthesis step was characterized through FTIR, XRD, TGA, FE-SEM, EDAX, Zeta-potential, and fluorescence spectroscopy. Besides, the ability of the designed platform in targeted imaging, drug delivery, and in vitro therapy were evaluated using fluorescence microscopy and flow cytometry. The selected aptamer acts as a quencher, resulting in an "on/off" fluorescence biosensor. When the aptamer specifically binds to the MUC-1 receptor, its double strands separate, leading to the drug release and the recovery of the fluorescence of ("On" state) at the excitation wavelength of 300 nm. Based on cell toxicity results, this platform has more toxicity toward the MUC-1-positive tumor cells (HT-29 and MCF-7) compared  to MUC-1-negative cells (Hep-G2), representing its selective performance. Thus, this nano-platform can be introduced as a multifunctional cancer nanotheranostics system for tracing particular biomarkers, non-invasive imaging, and targeted chemotherapy. Graphical abstract.

Aptamer/magnetic nanoparticles decorated with fluorescent gold nanoclusters for selective detection and collection of human promyelocytic leukemia (HL-60) cells from a mixture.

In the present work, a fluorescent gold nanoclusters (GNCs)/superparamagnetic (Fe3O4/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 Fe3O4@SiO2 nanoparticles followed by poly(ethylene glycol) dimethacrylate (PGD) addition at room temperature to form Fe3O4/GNCs nanoprobe. Surface functionalization of the Fe3O4/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 Fe3O4/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 Fe3O4/GNCs nanoprobe (Fe3O4/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.

Optical biosensing of Streptococcus agalactiae based on core/shell magnetic nanoparticle-quantum dot.

An immunomagnetic optical probe based on a core/shell magnetic nanoparticle-quantum dot was fabricated for detection of Streptococcus agalactiae, the causative agent of pneumonia and meningitis in newborns. The silica-coated magnetic nanoparticles conjugated with anti-S. agalactiae monoclonal antibody provided high specificity for pre-enrichment of bacteria from biological samples with a complex matrix such as milk. Compared with conventional methods such as culture and molecular techniques, the combination of fluorescent quantum dot and magnetic nanoparticle enhanced the sensitivity and speed of bacterial identification. The bio-functionalized fluorescent-magnetic nanoparticles were characterized by TEM, SEM, VSM, XRD, DLS, and FTIR and applied to the detection of S. agalactiae with a limit of 10 and 102 CFU/mL in PBS and milk, respectively. This immunomagnetic optical probe can be used for rapid isolation, sensitive, and specific detection of targeted bacteria without any treatment in clinical and animal samples in the presence of other infectious agents.

Nanosized aptameric cavities imprinted on the surface of magnetic nanoparticles for high-throughput protein recognition.

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-1. 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).

Layer by layer coating of NH2-silicate/polycarboxylic acid polymer saturated by Ni2+ onto the super magnetic NiFe2O4 nanoparticles for sensitive and bio-valuable separation of His-tagged proteins.

Magnetic nanoparticles NiFe2O4 was synthesized and covered in the silicate lattice of (3-Aminopropyl) triethoxysilane (APS) by the sol-gel process. Subsequently, the EDTA-dianhydride was attached to the amino surface of magnetic nanoparticles (MNPs) during the nucleophilic attack. This polycarboxylic layer trapped the high level of nickel ions for selective bonding to the His-tagged recombinant protein. The surface of MNPs was investigated by TEM, XRD, SEM (EDSA), VSM, BET, FT-IR and zeta potential analysis which characterized the size, chemical lattice, morphology, magnetic strength, specific surface area, functional groups and charge of the surface of nanoparticles. The performance and validity of the nanoparticles were studied by the purification of His-tagged green fluorescence protein (His-GFP). Also, the safety of proposed Ni-MNPs in the purification procedure of His-tagged proteins for pharmaceutical applications was proved by the determination of the nickel leakage level in the purified final protein using atomic absorption spectroscopy. In vitro cytotoxicity of Ni-MNPs and trace metal ions was investigated by the MTS assay technique. In addition, the comparison of biological activity in purified protein (GM-CSF) and commercial sample did not show any toxic effect.

Super magnetic nanoparticles NiFe2O4, coated with aluminum-nickel oxide sol-gel lattices to safe, sensitive and selective purification of his-tagged proteins.

Super magnetic nanoparticle NiFe2O4 with high magnetization, physical and chemical stability was introduced as a core particle which exhibits high thermal stability (>97%) during the harsh coating process. Instead of multi-stage process for coating, the magnetic nanoparticles was mineralized via one step coating by a cheap, safe, stable and recyclable alumina sol-gel lattice (from bohemite source) saturated by nickel ions. The TEM, SEM, VSM and XRD imaging and BET analysis confirmed the structural potential of NiFe2O4@NiAl2O4 core-shell magnetic nanoparticles for selective and sensitive purification of His-tagged protein, in one step. The functionality and validity of the nickel magnetic nanoparticles were attested by purification of three different bioactive His-tagged recombinant fusion proteins including hIGF-1, GM-CSF and bFGF. The bonding capacity of the nickel magnetics nanoparticles was studied by Bradford assay and was equal to 250 ± 84 µg Protein/mg MNP base on protein size. Since the metal ion leakage is the most toxicity source for purification by nickel magnetic nanoparticles, therefor the nickel leakage in purified final protein was determined by atomic absorption spectroscopy and biological activity of final purified protein was confirmed in comparison with reference. Also, in vitro cytotoxicity of nickel magnetic nanoparticles and trace metal ions were investigated by MTS assay analysis. The results confirmed that the synthesized nickel magnetic nanoparticles did not show metal ion toxicity and not affected on protein folding.