Surface Of Oxide Nanoparticles Research Articles

Properties of Langmuir and immobilized layers of betulin diphosphate on aqueous solutions of zinc sulfate and on the surface of zinc oxide nanoparticles

This work examines the specific features of interaction of betulin diphosphate (BDP), exhibiting antitumor and wound-healing properties, with zinc cations during its immobilization on ZnO nanoparticles. The properties of Langmuir and transferred BDP monolayers from an aqueous subphase of zinc sulfate onto the surface of a solid substrate (CaF2, quartz) by the Langmuir—Schaefer method are investigated using IR and UV spectroscopy. It is shown that there is a twofold increase of the molecular area in the immobilized layers, while the compressibility modulus decreases by a factor of 1.5. Zinc oxide nanoparticles with immobilized BDP 10–20 nm in size (surface concentration of BDP is 100 mg g−1) retain the original hexagonal wurtzite structure. The efficiency of betulin diphosphate immobilized on the surface of zinc oxide nanoparticles is demonstrated in in vivo experiments for burn wounds in rats.

Atomic Scale Characterization of Fluxional Cation Behavior on Nanoparticle Surfaces: Probing Oxygen Vacancy Creation/Annihilation at Surface Sites.

Oxygen vacancy creation and annihilation are key processes in nonstoichiometric oxides such as CeO2. The oxygen vacancy creation and annihilation rates on an oxide's surface partly govern its ability to exchange oxygen with the ambient environment, which is critical for a number of applications including energy technologies, environmental pollutant remediation, and chemical synthesis. Experimental methods to probe and correlate local oxygen vacancy reaction rates with atomic-level structural heterogeneities would provide significant information for the rational design and control of surface functionality; however, such methods have been unavailable to date. Here, we characterize picoscale fluxional behavior in cations using time-resolved in situ aberration-corrected transmission electron microscopy to locate atomic-level variations in oxygen vacancy creation and annihilation rates on oxide nanoparticle surfaces. Low coordination number sites such as steps and edges, as well as locally strained sites, exhibited the greatest number of cation displacements, implying enhanced surface oxygen vacancy activity at these sites. The approach has potential applications to a much wider class of materials and catalysis problems involving surface and interfacial transport functionalities.

A Comparative Study of Iron Oxide Nanoparticles Surface Modified Using Carboxylic Acids

In the last decade nanotechnology has greatly developed in many research fields such as engineering, electronic, biological and many others. They can offer several possibilities to design tools, to create new techniques or improve the already existing ones, to discover innovative applications. Nano-science is one of the most important research and development frontiers in modern science. Nanotechnology is now widely used throughout the pharmaceutical industry, medicine, electronics, robotics, and tissue engineering. For biological and biomedical applications, magnetic iron oxide nanoparticles are the primary choice because of their biocompatibility, super-paramagnetic behavior and chemical stability.
 The purpose of this work is the design, development and surface modification of magnetic nanoparticles. Naked iron oxide nanoparticles have high chemical activity, toxicity and aggregate in the body fluid therefore providing surface coating for the stability of the magnetic nanoparticles. These protective shells not only stabilize the magnetic iron nanoparticles but also can be used for further functionalization. Here the iron oxide nanoparticles were prepared by co-precipitation method, then this nanoparticle is modified using acids- oleic acid and succinic acid and a comparative study is carried out. The TEM, FTIR and DSC characterization techniques were used to confirm the surface modification. After which, it was found the iron oxide nanoparticle with succinic acid gives a uniform coating of the three and can be used for further functionalization for various applications.

Unveiling the role of surface, size, shape and defects of iron oxide nanoparticles for theranostic applications.

Iron oxide nanoparticles (IONPs) are well-known contrast agents for MRI for a wide range of sizes and shapes. Their use as theranostic agents requires a better understanding of their magnetic hyperthermia properties and also the design of a biocompatible coating ensuring their stealth and a good biodistribution to allow targeting of specific diseases. Here, biocompatible IONPs of two different shapes (spherical and octopod) were designed and tested in vitro and in vivo to evaluate their abilities as high-end theranostic agents. IONPs featured a dendron coating that was shown to provide anti-fouling properties and a small hydrodynamic size favoring an in vivo circulation of the dendronized IONPs. While dendronized nanospheres of about 22 nm size revealed good combined theranostic properties (r2 = 303 mM s-1, SAR = 395 W gFe-1), octopods with a mean size of 18 nm displayed unprecedented characteristics to simultaneously act as MRI contrast agents and magnetic hyperthermia agents (r2 = 405 mM s-1, SAR = 950 W gFe-1). The extensive structural and magnetic characterization of the two dendronized IONPs reveals clear shape, surface and defect effects explaining their high performance. The octopods seem to induce unusual surface effects evidenced by different characterization techniques while the nanospheres show high internal defects favoring Néel relaxation for magnetic hyperthermia. The study of octopods with different sizes showed that Néel relaxation dominates at sizes below 20 nm while the Brownian one occurs at higher sizes. In vitro experiments demonstrated that the magnetic heating capability of octopods occurs especially at low frequencies. The coupling of a small amount of glucose on dendronized octopods succeeded in internalizing them and showing an effect of MH on tumor growth. All measurements evidenced a particular signature of octopods, which is attributed to higher anisotropy, surface effects and/or magnetic field inhomogeneity induced by tips. This approach aiming at an analysis of the structure-property relationships is important to design efficient theranostic nanoparticles.

1,2-Dimyristoyl-sn-glycero-3-phosphocholine promotes the adhesion of nanoparticles to bio-membranes and transport in rat brain.

1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) coated on the surface of superparamagnetic iron oxide nanoparticles (SPIONs) has advantages in neurotherapy and drug delivery. In this study, the surface of polyvinylpyrrolidone (PVP)-SPIONs was modified with DMPC, then PVP-SPIONs and DMPC/PVP-SPIONs were co-incubated with rat adrenal pheochromocytoma (PC-12) cells to observe the effect of DMPC on the distribution of SPIONs in cells, and further PVP-SPIONs and DMPC/PVP-SPIONs were implanted into the substantia nigra of Sprague-Dawley (SD) rats by stereotaxic injection, and the brain tissues were removed at both twenty-four hours and seven days after injection. The distribution and transport of nanoparticles in the substantia nigra in vivo were explored in these different time periods. The results show that DMPC/PVP-SPIONs were effectively distributed on the membranes of axons, as well as dendritic and myelin sheaths. The attachment of nanoparticles to bio-membranes in the brain could result from similar phospholipid structures of DMPC and the membranes. In addition, DMPC/PVP-SPIONs were transported in the brain faster than those without DMPC. In vitro experiments found that DMPC/PVP-SPIONs enter cells more easily. These characteristics of iron oxide nanoparticles that are modified by phospholipids lead to potential applications in drug delivery or activating neuron membrane channels.

The detection of chymotrypsin using peptides covalent bound to the surface of graphene oxide and gold nanoparticles

In this study, pyrene was used as a fluorescent dye for peptides.

Peptide modified manganese-doped iron oxide nanoparticles as a sensitive fluorescence nanosensor for non-invasive detection of trypsin activity in vitro and in vivo.

Herein, a fluorescence turn-on nanosensor (MnIO@pep-FITC) has been proposed for detecting trypsin activity in vitro and in vivo through covalently immobilizing an FITC modified peptide substrate of trypsin (pep-FITC) on manganese-doped iron oxide nanoparticle (MnIO NP) surfaces via a polyethylene glycol (PEG) crosslinker. The conjugation of pep-FITC with MnIO NPs results in the quenching of FITC fluorescence. After trypsin cleavage, the FITC moiety is released from the MnIO NP surface, leading to a remarkable recovery of FITC fluorescence signal. Under the optimum experimental conditions, the recovery ratio of FITC fluorescence intensity is linearly dependent on the trypsin concentration in the range of 2 to 100 ng mL−1 in buffer and intracellular trypsin in the lysate of 5 × 102 to 1 × 104 HCT116 cells per mL, respectively. The detection limit of trypsin is 0.6 ng mL−1 in buffer or 359 cells per mL HCT116 cell lysate. The MnIO@pep-FITC is successfully employed to noninvasively monitor trypsin activity in the ultrasmall (ca. 4.9 mm3 in volume) BALB/c nude mouse-bearing HCT116 tumor by in vivo fluorescence imaging with external magnetic field assistance, demonstrating that it has excellent practicability.

In Ukrainian

The prevalence of tin compounds, economic affordability and non-toxicity determine its wide range of applications. Modern scientific literature on the properties, methods of preparation and application of tin nanooxide is analyzes in review. Its main characteristics and structural features are described. The ability of tin cations to be in two oxidation states, the ease of reduction of Sn+4 to Sn+2 and reverse oxidation, determines the redox properties of the SnO2 surface. In addition to stable oxides Sn4+ and Sn2,+ the existence of a homologous series of Snn+1O2n metastable compounds is assumed. It is proved that four-coordinated Sn+2 cations on the SnO2 surface can coexist only with oxygen vacancies in the immediate environment. Such cationic sites have the properties of strong Lewis acids and are highly reactive. Computer simulation of the SnO2 crystal surface allows us to propose a number of catalytic activity of SnO2 surfaces: (110) < (001) < (100) < (101). Preparation methods and synthesis parameters (nature and type of precursor, stabilizing agent and solvent, duration and temperature of the reaction, pH of the reaction mixture, etc.) determine the physicochemical properties of nanoparticles (shape, size, morphology and degree of crystallinity). The main (sol-gel, precipitation and coprecipitation, CVD, spray pyrolysis, hydrothermal, “green”) and less common (detonation, electric discharge) methods of nano-SnO2 obtaining are analyzed in the work. A variety of methods of synthesis and conditions makes it possible to obtain SnO2 nanoparticles with desired properties, which determine the activity of tin oxide in redox reactions, namely: nanosize and morphology of particles with prevalence of the most reactive faces - (100) і (101). Among the methods that do not require complex hardware design, one can dwell on the methods of sol-gel, "green" and coprecipitation. Tin oxide is traditionally used as an abrasive for polishing metal, glass and ceramic products. The transition to nanosized particles allows this material to reversibly absorb and release oxygen, which has determined its use in the design of gas-sensitive and biosensors, the creation of solar cells, fuel cells, lithium-ion batteries, oxidation catalysts, transparent and photoconductors. The multivalence and the presence of oxygen vacancies on the surface of tin oxide nanoparticles, the ease and speed of penetration into the cell membrane give nano-SnO2 properties of medicinal preparations, which makes it possible to use it in biomedical technologies for the treatment of diseases associated with oxidative stress lesions. The size, concentration of nanoparticles and modification of their surface are the key factors of influence, which usually intensify the antimicrobial, antibacterial, antitumor and antioxidant activity of the material.

Nucleotide Adsorption on Iron(III) Oxide Nanoparticle Surfaces: Insights into Nano-Geo-Bio Interactions Through Vibrational Spectroscopy.

Molecular processes at geochemical interfaces impact many environmental processes that are critical to the fate and transport of contaminants in water systems. Often these interfaces are coated with natural organic matter, oxyanions, or biological components, yet little is understood about these coatings. Herein, we are interested in better understanding the interaction of biological components with nanoscale iron oxide minerals. In particular, we use attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to investigate the adsorption behavior of deoxyadenosine monophosphate (dAMP) on hematite nanoparticle surfaces as a function of pH and in the presence and absence of adsorbed phosphate. These results show that fewer nucleotides adsorb at higher pH. Additionally, when phosphate anions are preadsorbed, nucleotide adsorption is significantly limited due to site-blocking by adsorbed inorganic phosphate. The pH dependence provides insights into the adsorption process and the importance of electrostatic interactions. Preadsorbed phosphate affects the binding mode of dAMP, suggesting synergistic interactions between the coadsorbates. Two-dimensional correlation spectroscopy was used to further analyze the infrared spectra. Based on this analysis, a dAMP adsorption pathway onto a preadsorbed phosphate-hematite surface was proposed, suggesting the displacement of adsorbed phosphate by dAMP. Overall, this study provides some insights into geochemical-biological interactions on nanoscale iron oxide surfaces using vibrational spectroscopy.

Cu(II) Schiff base complex on magnetic support: An efficient nano-catalyst for oxidation of olefins using H2O2 as an eco-friendly oxidant

A heterogeneous magnetic supported copper(II) nanocatalyst has been obtained through the reaction of 2-hydroxy-1-naphthaldehyde with the functionalized silica coated iron oxide nanoparticle (Fe3O4@SiO2@NH2) to synthesize immobilized Schiff base ligand (Fe3O4@SiO2/Schiff base). This procedure was followed by the addition of Cu(CH3COO)2·H2O to the prepared particles in order to form the copper(II) Schiff base complex on the surface of iron oxide nanoparticles. Versatile techniques such as FT-IR, SEM, XRD, ICP-OES, EDS and VSM were employed to characterize the synthesized Cu nanocatalyst. Furthermore, its catalytic functionality has been investigated for the oxidation of various olefins with the help of hydrogen peroxide (H2O2) as an eco-friendly oxidant. In the next step, the final samples of reactions were isolated quite simply by using magnets and analyzed by GC and GC–MS instruments. The obtained copper(II) nanocatalyst grants some superiorities such as simple magnetic separation from the mixture, short reaction time (2 h) and high conversion through green processes exclusively for styrene (conversion: 100%) and norbornene (conversion: 79%).

Release of a liver anticancer drug, sorafenib from its PVA/LDH- and PEG/LDH-coated iron oxide nanoparticles for drug delivery applications

The use of nanocarriers composed of polyethylene glycol- and polyvinyl alcohol-coated vesicles encapsulating active molecules in place of conventional chemotherapy drugs can reduce many of the chemotherapy-associated challenges because of the increased drug concentration at the diseased area in the body. The present study investigated the structure and magnetic properties of iron oxide nanoparticles in the presence of polyvinyl alcohol and polyethylene glycol as the basic surface coating agents. We used superparamagnetic iron oxide nanoparticles (FNPs) as the core and studied their effectiveness when two polymers, namely polyvinyl alcohol (PVA) and polyethylene glycol (PEG), were used as the coating agents together with magnesium–aluminum-layered double hydroxide (MLDH) as the nanocarrier. In addition, the anticancer drug sorafenib (SO), was loaded on MLDH and coated onto the surface of the nanoparticles, to best exploit this nano-drug delivery system for biomedical applications. Samples were prepared by the co-precipitation method, and the resulting formation of the nanoparticles was confirmed by X-ray, FTIR, TEM, SEM, DLS, HPLC, UV–Vis, TGA and VSM. The X-ray diffraction results indicated that all the as-synthesized samples contained highly crystalline and pure Fe3O4. Transmission electron microscopy analysis showed that the shape of FPEGSO-MLDH nanoparticles was generally spherical, with a mean diameter of 17 nm, compared to 19 nm for FPVASO-MLDH. Fourier transform infrared spectroscopy confirmed the presence of nanocarriers with polymer-coating on the surface of iron oxide nanoparticles and the existence of loaded active drug consisting of sorafenib. Thermogravimetric analyses demonstrated the thermal stability of the nanoparticles, which displayed enhanced anticancer effect after coating. Vibrating sample magnetometer (VSM) curves of both produced samples showed superparamagnetic behavior with the high saturation magnetization of 57 emu/g for FPEGSO-MLDH and 49 emu/g for FPVASO-MLDH. The scanning electron microscopy (SEM) images showed a narrow size distribution of both final samples. The SO drug loading and the release behavior from FPEGSO-MLDH and FPVASO-MLDH were assessed by ultraviolet–visible spectroscopy. This evaluation showed around 85% drug release within 72 h, while 74% of sorafenib was released in phosphate buffer solution at pH 4.8. The release profiles of sorafenib from the two designed samples were found to be sustained according to pseudo-second-order kinetics. The cytotoxicity studies confirmed the anti-cancer activity of the coated nanoparticles loaded with SO against liver cancer cells, HepG2. Conversely, the drug delivery system was less toxic than the pure drug towards fibroblast-type 3T3 cells.

Catalytic and antimicrobial properties of \u03b1-amylase immobilised on the surface of metal oxide nanoparticles

New methods of obtaining products containing enzymes reduce the costs associated with obtaining them, increase the efficiency of processes and stabilize the created biocatalytic systems. In the study a catalytic system containing the enzyme α-amylase immobilized on ZnO nanoparticle and Fe3O4 nanoparticles was created. The efficiency of the processes was obtained with variables: concentrations of enzymes, temperatures and times, to define the best conditions for running the process, for which were determined equilibrium and kinetics of adsorption. The most effective parameters of α-amylase immobilization on metal oxides were determined, obtaining 100.8 mg/g sorption capacity for ZnO and 102.9 mg/g for Fe3O4 nanoparticles. Base on the best parameters, ZnO-α-amylase was investigated as an antimicrobial agent and Fe3O4-α-amylase was tested as a catalyst in the process of starch hydrolysis. As a result of the conducted experiments, it was found that α-amylase immobilized on Fe3O4 nanoparticles maintained high catalytic activity (the reaction rate constant KM = 0.7799 [g/dm3] and the maximum reaction rate Vmax = 8.660 [g/(dm3min)]).

Enhanced antimicrobial and full-thickness wound healing efficiency of hydrogels loaded with heparinized ZnO nanoparticles: In vitro and in vivo evaluation

Nanotechnology-based fabricated wound dressings are known as appropriate substrates to enhance healing in both acute and chronic wounds. These types of materials have the ability to deliver therapeutic agents. In this study, a wound dressing including heparinized zinc oxide nanoparticles in combination with chitosan and poly(vinyl alcohol) was developed to investigate its antibacterial and regenerative properties in a rat model of full thickness skin wounds. By adding nanoparticles, the mechanical strength increased up to twice as compared to the sample without nanoparticles. In addition, heparin release profile follows the Hixson-Crowell release kinetic. Protein adsorption enhanced by adding nanoparticles in hydrogels and the prepared wound dressings were completely biocompatible. In terms of antibacterial activity, the minimum inhibitory concentration decreased by conjugation of heparin on the surface of zinc oxide nanoparticles compared to the non-functionalized nanoparticles, and, this shows the increased antibacterial synergistic effect by adding heparin to nanoparticles. Furthermore, it was found that the heparinized zinc oxide nanoparticles effectively accelerate wound closure, re-epithelialization and decrease collagen deposition compared to other groups after implantation. Hence, the prepared wound dressings have the capacity to significantly enhance healing of acute wounds.

Genetic Tuning of Iron Oxide Nanoparticle Size, Shape, and Surface Properties in Magnetospirillum magneticum

AbstractDifferent applications require iron oxide nanoparticles (IONPs) of varying size, shape, crystallinity, and surfaces that can be controlled through the synthesis reaction conditions. Under ambient conditions, Magnetospirillum magneticum AMB‐1 builds uniform Fe3O4 IONPs with shapes and crystal forms difficult to achieve with chemical synthesis. Genetic engineering can be used to change their properties, but there are few tools to fine‐tune expression over a wide range. To this end, ribosome binding sites, minimal constitutive promoters, and inducible systems (IPTG, aTc, and OC6) with large dynamic range are designed. These are used to control M. magneticum genes that affect IONP properties, including size (mamC), morphology (mms6), chain length (mamK), and surface coating (mamC fusions). These systems increase the fraction of IONPs that are less than 30 nm, produce rounded particles, and lead to the production of intracellular chains with 24 or more IONPs. In addition, the R5 peptide from diatoms is found to silica coat the surface of metal oxide nanoparticles (Fe, Ti, Ta, Hf) and can be genetically directed to the IONP surface. This work demonstrates the genetic control of IONP properties, but also highlights the robustness of the system, which complicates genetic engineering to produce radically different particles and structures.

Poly(acrylic acid) capped iron oxide nanoparticles via ligand exchange with antibacterial properties for biofilm applications

Biofilm infections pose a rising threat to public health due to its existing protective shield, which preventing biocide penetration. Here, the oleate-capped iron oxide nanoparticles (OIONPs) were synthesized by the high-temperature method first; after then, the poly(acrylic acid)-capped iron oxide nanoparticles (PIONPs) were obtained via a ligand exchange reaction between OIONPs and sodium poly(acrylic acid). The physicochemical properties of PIONPs were evaluated by Fourier-transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Transmission Electron Microscopy (STEM), Dynamic Light Scattering (DLS), and zeta potential. The FT-IR analysis confirmed the successful ligand exchange on the surface of iron oxide nanoparticles. STEM images displayed that the prepared PIONPs were monodisperse spherical nanoparticles. The PIONPs were stable in ultrapure water and could be kept for 5 weeks without aggregation. Next, Cell Counting Kit-8 (CCK-8) assay and fluorescent images confirmed the excellent cytocompatibility of PIONPs, while the iron concentration of PIONPs was in the range of 5∼120 mg/L. Finally, PIONPs exhibited efficient antibacterial activity against E. coli and S. aureus, and Staphylococcus aureus subsp. aureus Rosenbach (SASAR) biofilm could be destroyed by treating PIONPs under alternating current (AC) applied field conditions.

Electrochemical sensing of cytochrome c using Graphene Oxide nanoparticles as platform

An improved cytochrome c (Cyt c) biosensor based on immobilization of cytochrome c oxidase (COx) on the surface of graphene oxide nanoparticles (GONPs) electrodeposited onto pencil graphite (PG) electrode. Characterization of graphene oxide nanoparticle was done by Transmission electron microscopy (TEM), Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction study (XRD). The working electrode (COx/GONPs/PG) was characterized at its different stages of fabrication by scanning electron microscopy (SEM) and FTIR. Fabrication of Cyt c biosensor was done by connecting COx/GONPs/PG as working electrode, Ag/AgCl as reference electrode and Pt as auxiliary electrode to potentiostat. The mechanism of detection of present biosensor was based on oxidation of Cyt c (reduced) to Cyt c (oxidized) by COx resulting in flow of electrons through GONPs to the PG electrode, hence current generated is proportional to the concentration of Cyt c. Present biosensor exhibited optimum potential at 0.49 V with optimum pH 7.5 and optimum temperature 35°C. Biosensor showed linearity within 40–180 ng/ml having 40 ng/ml limit of detection. The precision i.e. within and between-batch coefficients of variation (CVs) were found <0.04% and <0.21% respectively. The enzyme electrode lost 50% of its initial activity when operated for more than 6 months on weekly basis. It was applied for detection of Cyt c level in in apparently healthy and diseased human sera. The present biosensing method was co-related with standard colorimetric method and co-relation coefficient was found 0.99.

Biosynthesis of Zinc oxide nanoparticles and their application for antimicrobial treatment of burn wound infections

The current study demonstrated the green fabrication of Zinc oxide nanoparticles (ZnO NPs) using the leaf extract of Coleus amboinicus (C. amboinicus) by an environment-friendly method. The leaf extract of C. amboinicus acts as capping and reducing agent during the fabrication of ZnO NPs. The prepared ZnO NPs were characterized by utilizing analytical techniques such as photoluminescence spectroscopy (PL), Transmission Electron microscopy (TEM), Energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–vis) and x-ray diffraction spectroscopy (XRD). The XRD pattern confirmed the formation of polydisperse ZnO NPs having crystalline nature. The FTIR spectrum demonstrated the biomolecular capping on the surface of zinc oxide nanoparticles. The prepared ZnO NPs displayed excellent antimicrobial activities over several gram positive and gram-negative microbial pathogens. Further, wound healing studies in rats revealed that wound closure rate was greater in the ZnO NPs treated rats at all doses when related with the untreated group (negative control group), therefore, this indicates the effective wound healing ability of prepared ZnO NPs.

Synthesis of ZnO Nanoparticles Doped with Cobalt Using Bimetallic ZIFs as Sacrificial Agents.

We report here a simple two-stage synthesis of zinc–cobalt oxide nanoparticles. We used Zn/Co-zeolite imidazolate framework (ZIF)-8 materials as precursors for annealing and optional impregnation with a silicon source for the formation of a protective layer on the surface of oxide nanoparticles. Using bimetallic ZIFs allowed us to trace the phase transition of the obtained oxide nanoparticles from wurtzite ZnO to spinel Co3O4 structures. Using (X-ray diffraction) XRD and (X-ray Absorption Near Edge Structure) XANES techniques, we confirmed the incorporation of cobalt ions into the ZnO structure up to 5 mol.% of Co. Simple annealing of Zn/Co-ZIF-8 materials in the air led to the formation of oxide nanoparticles of about 20–30 nm, while additional treatment of ZIFs with silicon source resulted in nanoparticles of about 5–10 nm covered with protective silica layer. We revealed the incorporation of oxygen vacancies in the obtained ZnO nanoparticles using FTIR analysis. All obtained samples were comprehensively characterized, including analysis with a synchrotron radiation source.

Taurine-Conjugated Mussel-Inspired Iron Oxide Nanoparticles with an Elongated Shape for Effective Delivery of Doxorubicin into the Tumor Cells.

Multifunctional iron oxide magnetic nanoparticles, among them nanorods, were prepared with a mussel-inspired polydopamine (pDA) surface coating agent for cancer therapeutics. Taurine, a free sulfur-containing ß amino acid, was grafted on the pDA at the iron oxide nanoparticle surface to enhance its biocompatibility and targeted delivery action. Doxorubicin (DOX), an anticancer drug, was loaded on the prepared nanovehicles with an entrapment efficiency of 70.1%. Drug release kinetics were then analyzed using UV–vis and fluorescence spectroscopies, suggesting the pH-responsive behavior of the developed nanovehicle. The developed system was then tested on PC-3 cell lines to check its cellular response. Confocal microscopy observations and (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) and Annexin V-FITC assays used to evaluate cell toxicity and apoptosis reveal a dose-dependent nature of nanorods and can overcome the side effects of using free DOX with a targeted action.

Magnetic Iron Oxide Nanoparticles Immobilized with Sugar-Containing Poly(ionic liquid) Brushes for Efficient Trapping and Killing of Bacteria.

Poly(ionic liquid)s (PILs) such as polymeric quaternary ammonium compounds (PQACs) are among the most widely used disinfectant agents due to their broad-spectrum antimicrobial activity. However, the high cytotoxicity and difficult reclamation of PQACs remain as challenges for practical water treatment. Herein, we present the synthesis of sugar-incorporated PQACs, which could efficiently decrease the cytotoxicity toward mammalian cells (mouse fibroblast cells, L929). On the basis of the mussel-inspired surface chemistry, the functional glycopolymers could then be immobilized onto the surface of magnetic iron oxide nanoparticles, which are successfully used for the trapping and killing of bacteria. The sugar-containing PILs have combined the lectin-recognition behavior of glycopolymers and the antibacterial activity of PQACs. Antibacterial experiments demonstrate the high-performance of cationic hybrid nanocomposites in killing pathogenic Escherichia coli (E. coli), up to 100% sterilization efficiency. The nanocomposites could be facilely recovered under external magnetic field, and a high sterilization efficiency of 94% could be retained during a five-circulation use. Such hybrid nanocomposites are highly efficient, expediently recyclable, and low-cytotoxicity disinfectant agents and may have potential application for water disinfection treatment.