Drug carrier wonders: Synthetic strategies of zeolitic imidazolates frameworks (ZIFs) and their applications in drug delivery and anti-cancer activity.

With the rapid advancement of nanotechnology, stimuli-responsive nanomaterials have emerged as a feasible choice for the designing of controlled drug delivery systems. Zeolitic imidazolates frameworks are a subclass of Metal-organic frameworks (MOFs) that are recognized by their excellent porosity, structural tunability and chemical modifications make them promising materials for loading targeted molecules and therapeutics agents. The biomedical industry uses these porous materials extensively as nano-carriers in drug delivery systems. These MOFs not only possess excellent targeted imaging ability but also cause the death of tumor cells drawing considerable attention in the current framework of anticancer drug delivery systems. In this review, the outline of stability, porosity, mechanism of encapsulation and release of anticancer drug have been reported extensively. In the end, we also discuss a brief outline of current challenges and future perspectives of ZIFs in the biomedical world.

Yolk-shell Co3 O4 @Fe3 O4 /C Nanocomposites as a Heterogeneous Fenton-like Catalyst for Organic Dye Removal.

The yolk-shell Co3 O4 @Fe3 O4 /C nanocomposites with Co3 O4 as the core, Fe3 O4 /C as the shell, and a cavity structure were synthesized by the hard template method. The physical and chemical properties of the composites were characterized by SEM, TEM, XRD, TGA, XPS, BET, and VSM. The specific surface area of yolk-shell Co3 O4 @Fe3 O4 /C nanocomposites is 175.9 m2  g-1 , showing superparamagnetic properties. The yolk-shell Co3 O4 @Fe3 O4 /C nanocomposites were used as heterogeneous Fenton catalysts to activate peroxymonosulfate (PMS) to degrade MB, which showed high catalytic degradation performance. The degradation rate of MB reached 100 % within 30 min under the circumstances of the yolk-shell Co3 O4 @Fe3 O4 /C nanocomposites dosage of 0.1 g L-1 , the PMS dosage of 1.0 g L-1 , the initial MB concentration of 100 mg L-1 , an initial pH of 5.5, and a temperature of 30±2 °C. The enhanced catalytic performance of the yolk-shell Co3 O4 @Fe3 O4 /C nanocomposites can be attributed to the synergistic effect of the two catalytically active materials and the middle cavity. The effects of different operating parameters and co-existing anion species on MB degradation were also investigated. Electron paramagnetic resonance (EPR) analysis and quenching experiments confirmed that the formation of SO4 ⋅- in the yolk-shell Co3 O4 @Fe3 O4 /C/PMS system contributes to MB degradation. In addition, yolk-shell Co3 O4 @Fe3 O4 /C nanocomposites can be easily separated from the pollutant solution under the action of an external magnetic field, and the degradation rate of MB can still reach 98 % after five cycles, indicating that it has good stability and reusability and has broad application prospects in the field of water purification.

Structural and Magnetic Properties of Rare Earth Doped Multilayer Nanocable Arrays.

The structure and anisotropic magnetization of One-dimensional (1D) Nd/Co/PA66 coaxial nanocables prepared by a low cost physical infiltration and electrodeposition methods are investigated. The preparation of Co nanotubes, Co/PA66 two-layer nanotubes and Nd/Co/PA66 three-layer nanocales is described, respectively. The structure, chemical composition and magnetic properties of various nanomaterials were investigated. The results show that the magnetic properties were affected by the rare earth metal Nd and the structural properties. The residual magnetization ratio of Nd/Co/PA66 nanocables is the biggest due to the synergistic effect of Nd and Co. In addition, the magnetization processes of the nanostructure were discussed in detail. We believe that these methods may provide an idea for ferromagnetic alloys and permanent magnet material and suitable for future applications in perpendicular recording media.

Efficient photocatalytic degradation of toxic Alizarin yellow R dye from industrial wastewater using biosynthesized Fe nanoparticle and study of factors affecting the degradation rate.

Development of highly robust and solar-light-responsive photocatalysts for the disposal of organic dyes from wastewater is a matter of great significance in order to solve the problems of water pollution. Solar-driven photocatalytic degradation of dyes is considered as a quite efficient, sustainable and cost-effective approach as it involved the inexhaustible and renewable source of energy. In photocatalytic processes, the generation of electron-hole pairs at the surface of the photocatalyst is accomplished by harvesting solar energy. The electron-hole pairs are converted into •OH radicals that are responsible for the degradation of dyes. Herein, we reported the synthesis of nanosized iron (FeNPs) using the aqueous fruit extract of Actinidia chinensis as a reducing as well as the stabilizing agent. The structure and morphology of synthesized nanoparticles were characterized using various advanced techniques. The TEM micrographs showed that the synthesized FeNPs was predominantly cubic and rod-shaped having the size in the range of 91.78-107 nm. The as-prepared FeNPs were acted as effective photocatalysts and their photocatalytic activity evaluated against alizarin yellow R (AYR) dye. The effect of different reaction conditions such as temperature, pH, time and catalyst loading on photocatalytic degradation of AYR dye was investigated under sunlight irradiation. The FeNPs showed promising photocatalytic activity and up to 93.7% of the dye was degraded in 42 h. The kinetics parameter of the reaction was also evaluated which showed that the photocatalytic degradation of AYR dye followed the pseudo-first-order reaction. In terms of better degradation, the role of FeNPs might be extended for the treatment of different organic dyes from wastewater.

Preparation of monodisperse porous polymeric ionic liquid microspheres and their application as stationary phases for HPLC.

In recent decades, ionic liquid-modified packing materials as stationary phases of high performance liquid chromatography (HPLC) have attracted widespread attention due to their comprehensive properties. In this work, monodisperse porous polymeric ionic liquid microspheres were directly prepared using a seeded emulsion polymerization method and applied as stationary phase of HPLC. The effects of porogen, monomer and crosslinker on the properties of porous P(IL-DVB) microspheres were investigated in detail. Porous P(IL-DVB) microspheres with good stability, monodispersity and relatively high specific surface area were selected as stationary phase to successfully separate benzene and its homologues, and nucleosides and alkaloids under reversed phase chromatography (RPLC) mode and hydrophilic interaction chromatography (HILIC) mode, respectively.

Preparation of photosensitive diazotized poly (vinyl alcohol-b-styrene) covalent capillary coatings for capillary electrophoresis separation of proteins.

In this paper, we have developed a novel method for the preparation of covalently connected capillary coatings in which diazotized poly (vinyl alcohol-b-styrene) (diazo-P(VA-b-St)) was used as a photosensitive coating agent. Firstly, the diazo-P(VA-b-St) coating was self-assembled on the inner surface of the capillary, and then irradiated by ultraviolet (UV) light to convert the ionic bonding into covalent bonding through the unique photochemical reaction of diazo groups. The covalently connected coatings inhibited the protein adsorption on the inner surface of the capillary, as a result, the baseline protein separation of ribonuclease A (RNase A), lysozyme (Lyz) and bovine serum albumin (BSA) were attained by utilizing the capillary electrophoresis (CE). The covalently connected diazo-P(VA-b-St) capillary coatings have greater CE separation performance with magnificent repeatability and enhanced stability, when compared with non-covalently coated or bare capillaries. This strategy to synthesize photosensitive diazo-P(VA-b-St) capillary coatings for their use in capillary electrophoresis separation of proteins is highly environment-friendly as it does not involve the use of extremely noxious and moisture penetrating coatings of silane.

Current status and future developments in preparation and application of nonspherical polymer particles.

Nonspherical polymer particles (NPPs) are nano/micro-particulates of macromolecules that are anisotropic in shape, and can be designed anisotropic in chemistry. Due to shape and surface anisotropies, NPPs bear many unique structures and fascinating properties which are distinctly different from those of spherical polymer particles (SPPs). In recent years, the research on NPPs has surprisingly blossomed in recent years, and many practical materials based on NPPs with potential applications in photonic device, material science and biomedical engineering have been generated. In this review, we give a systematic, balanced and comprehensive summary of the main aspects of NPPs related to their preparation and application, and propose perspectives for the future developments of NPPs.

Preparation of polymeric Janus microparticles with hierarchically porous structure and enhanced anisotropy.

Anisotropic Janus particles are of great interest for many applications. It is well known that behavior and utility of Janus particles are highly dependent on their chemistry and geometry. Herein, we report the synthesis of monodisperse polymeric Janus microparticles that were anisotropic not only in chemistry and shape but also in surface morphology and porosity, via a modified seeded polymerization technique. Chemical composition, shape, morphology and porosity of the polymeric Janus microparticles were flexibly controlled by utilizing different quantities and species of monomer and porogen. The polymeric Janus microparticles exhibited hierarchically porous structure, including micro- and meso-pores as evidenced by isothermal nitrogen adsorption and desorption. Due to the high specific surface area, anisotropy of the polymeric Janus microparticles was enhanced according to the greater fluorescence contrast on distinct sides of the polymeric Janus microparticles. Moreover, swelling and phase-separation processes of cross-linked seeds were in situ observed on an optical microscope to demonstrate the formation mechanism of the polymeric Janus microparticles.

Preparation of Porous Poly(Styrene-Divinylbenzene) Microspheres and Their Modification with Diazoresin for Mix-Mode HPLC Separations.

By using the two-step activated swelling method, monodisperse porous poly(styrene-divinylbenzene) (P(S-DVB)) microparticles were successfully synthesized. The influence of porogens, swelling temperatures and crosslinking agents on the porosity of porous microparticles was carefully investigated. Porous P(S-DVB) microparticles were used as a packing material for high performance liquid chromatography (HPLC). Several benzene analogues were effectively separated in a stainless-steel column as short as 75 mm due to the high specific surface area of the porous microparticles. Porous P(S-DVB) microparticles were further sulfonated and subsequently modified with diazoresin (DR) via electrostatic self-assembly and UV (ultraviolet) radiation. After treatment with UV light, the ionic bonding between sulfonated P(S-DVB) and DR was converted into covalent bonding through a unique photochemistry reaction of DR. Depending on the chemical structure of DR and mobile phase composition, the DR-modified P(S-DVB) stationary phase performed different separation mechanisms, including reversed phase (RP) and hydrophilic interactions. Therefore, baseline separations of benzene analogues and organic acids were achieved by using the DR-modified P(S-DVB) particles as packing materials in HPLC. According to the π-π interactional difference between carbon rings of fullerenes and benzene rings of DR, C60 and C70 were also well separated in the HPLC column packed with DR-modified P(S-DVB) particles.

Photosensitive diazotized poly(ethylene glycol) covalent capillary coatings for analysis of proteins by capillary electrophoresis.

A new method for the fabrication of covalently cross-linked capillary coatings of poly(ethylene glycol) (PEG) is described using diazotized PEG (diazo-PEG) as a new photosensitive coating agent. The film of diazo-PEG depends on ionic bonding and was first prepared on the inner surface of capillary by self-assembly, and ionic bonding was converted into covalent bonding after reaction of ultraviolet light with diazo groups through unique photochemical reaction. The covalently bonded coating impedance adsorption of protein on the central surface of capillary and hence the four proteins ribonuclease A, cytochrome c, bovine serum albumin, and lysosome can be baseline separated by using capillary electrophoresis (CE). The covalently cross-linked diazo-PEG capillary column coatings not only improved the CE separation performance for proteins compared to non-covalently cross-linked coatings or bare capillary but also showed a remarkable chemical solidity and repeatability. Because photosensitive diazo-PEG took the place of the highly noxious and silane moisture-sensitive coating reagents in the fabrication of covalent coating, this technique shows the advantage of being environment-friendly and having a high efficiency for CE to make the covalently bonded capillaries.

Self-assembled and covalently linked capillary coating of diazoresin and cyclodextrin-derived dendrimer for analysis of proteins by capillary electrophoresis.

Self-assembled and covalently linked capillary coatings of cyclodextrin-derived (CD) dendrimer were prepared using photosensitive diazoresin (DR) as a coupling agent. Layer by layer (LBL) self-assembled DR/CD-dendrimer coatings based on ionic bonding was fabricated first on the inner surface of capillary, and subsequently converted into covalent bonding after treatment with UV light through a unique photochemistry reaction of DR. Protein adsorption on the inner surface of capillary was suppressed by the DR/CD-dendrimer coating, and thus a baseline separation of lysozyme (Lys), myoglobin (Mb), bovine serum albumin (BSA) and ribonuclease A (RNase A) was achieved using capillary electrophoresis (CE). Compared with the bare capillary, the DR/CD-dendrimer covalently linked capillary coatings showed excellent protein separation performance with good stability and repeatability. Because of the replacement of highly toxic and moisture sensitive silane coupling agent by DR in the covalent coating preparation, this method may provide an environmentally friendly and simple way to prepare the covalently coated capillaries for CE.

Preparation of highly permeable BPPO microfiltration membrane with binary porous structures on a colloidal crystal substrate by the breath figure method.

A highly permeable brominated poly(phenylene oxide) (BPPO) microfiltration membrane with binary porous structures was fabricated by combination of the breath figure and colloidal crystal template methods. The pore size in the bottom layer of the membrane was adjusted by the diameter of SiO2 microspheres in the colloidal crystal template, while the pore size in the top layer of the membrane was adjusted by varying the BPPO concentration in the casting solution. The permeability of the membrane cast on the colloidal crystal substrate was much higher than that of the membrane cast on a bare silicon wafer. The binary porous BPPO membrane with high permeability and antifouling property was used for microfiltration applications.