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This work aimed to immobilize silver nanoparticles with catalytic and antibacterial activity (AgNPs) inside of the PEG-based hydrogel through a facile and green design. First, the hybrid hydrogels were prepared under solvent-free conditions based on dianhydride ethylenediamine tetraacetic acid, poly (ethylene glycol) of different molar mass, glycerol, and octa-aminopropyl polyhedral oligomeric silsesquioxane hydrochloride salt as organic and inorganic cross-linker agent. The well-dispersed AgNPs were fabricated in-situ in the polymeric matrix of the hybrid hydrogel through the reduction of Ag+ by NaBH4. The resulting hybrid nanocomposite hydrogels were characterized by various techniques, such as FT-IR spectroscopy, SEM, TEM, EDX, XRD, BET, and TGA. The swelling behavior, the antibacterial activity against the bacteria S. aureus (Gram-positive), and E. coli (Gram-negative), as well as the catalytic efficiency for the reduction reaction of 4-nitrophenol to 4-aminophenol of the nanocomposite hydrogels prepared, were examined. The facile and mass production synthetic method of the nanocomposite hydrogels, excellent dispersion of the AgNPs inside the hydrogel matrix, excellent catalytic recyclability, and antibacterial activity are some of the advantages of this system. The maximum inhibition zone was found to be 17.4 and 15.9 mm against the gram-positive species S. aureus and the gram-negative E. coli, respectively. Besides, the maximum catalytic activity was achieved in a short time period of 30 s.

A straightforward and facile method for the exfoliation of graphene sheets using poly(vinylpyrrolidone) nanoparticles of an average size of 42nm was developed and their dual role as pH-sensitive drug carrier and anti-cancer agent was evaluated. The cytotoxic impact of the exfoliated nanosheets (GRP-PVP-NP) was examined on various cells (HCT-116, HeLa, SCC-9, NIH-3T3 and HEK-293cells) by a series of assays. Their cytotoxic nature was attributed to affecting the mitochondrial enzyme activity, proliferation capability, and the formation of tight junctions in cancer cells. The endocytosis was found to be internalization mechanism for the cellular uptake of nanosheets. The generation of reactive oxygen species and elicitation of caspase-3 activity which was undoubtedly associated with triggering of oxidative stress speculated to be the dominant cause of the cytotoxic pattern of nanosheets against cancer cells. Additionally, the results also showed the role of the nanosheets as a pH-sensitive drug carrier through drug loading by supramolecular interaction. The efficient release of doxorubicin was seen at low pH and in an environment with a low oxygen concentration, thus under conditions mimicking the typical tumor microenvironment. Therefore, these findings provide the first evidence for a dual function of exfoliated graphene sheets and also elucidate the cytotoxic mechanism responsible for the cancer cell death.

Halloysite is a unique biocompatible aluminosilicate clay mineral with powder particles predominantly comprising of concentrically rolled nanotubular aggregates. Some recent studies have also contributed to its prospective case in oral drug delivery and dosage forms albeit with limited commercial viability. In this study, we have investigated the use of halloysite nanotubes (HNTs) as a directly compressible multifunctional tableting excipient using SeDeM diagram expert tool. SeDeM experimentations revealed that ~68% HNTs in the formulations were enough to be used as a directly compressible filler, binder, and disintegrant in diclofenac potassium formulations. In the next phase, a total of 8 formulations blends (IRF1–8) of diclofenac potassium (50 mg) with HNTs and Starch 1500® were prepared in different ratio using simple lattice mixture design and all were found satisfactory for direct compression. Compressed tablets (167 mg) had narrow weight variation (SD = ± 1.78 mg), good hardness (~9–9.5 kg), acceptable friability ( 92% against 75%). The dissolution profile was best fitted with Peppas-Sahlin model with Fickian diffusion as the only mechanism. f2 similarity test revealed that almost all the tablets were pharmaceutical equivalent to the marketed formulation of the drug. A shelf-life of ~34 months was found upon long-term stability testing of the optimized formulation. This study demonstrates that this novel and economically viable clay material has a strong potential for commercial use in tableting of drug by direct compression.

The effect of the particles size of ZnO nanoparticles, synthesized into the microstructure of honeycomb-porous block copolymer films (poly[(2-hydroxyethylmethacrylate)m-block-poly(N-phenylmaleimide)n]) with different lengths, on the thermal, morphological and optical properties of the porous-structured films were investigated. The functional nanoparticles (NPs) were synthesized by wet preparation methods involving the porous copolymer films. The presence of the copolymer allows the coordination of Zn2+ precursor with the hydrophilic part of the self-assembled block copolymers resulting in hierarchically-ordered NP arrays. With this approach, the microphase separation inside of the polymer domains was used for the organization of pre-formed NPs in their cavities. The results indicated that the sub-domains formed by hydrophilic moiety represent an additional advantage for the diffusion and formation of ZnO nanoparticles. Absorption spectra of the ZnO NPs showed an excitation band around 300 nm, indicating a blue-shift with respect to the ZnO bulk material (at 373 nm). The size and the spherical morphology of the prepared ZnO NPs were determined by transmission electron microscopy (TEM). The overall morphology of polymer nanocomposite (ZnO embedded in the block copolymer) was determined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Keywords: ZnO nanoparticles, Honeycomb patterned porous films, Amphiphilic block copolymer, Thermal and optical properties

Hydrogen adsorption in porous nanostructured polyaniline (PANI) has been investigated to determine its potential as a hydrogen storage media. Residual gas analysis and thermogravimetric analysis were used to investigate the cyclical hydrogen adsorption in PANI. A hydrogen storage capacity of up to 3 wt % was obtained by charging the polymers at up to 3.0 × 106 Pa hydrogen at elevated temperature. Multiple charge and discharge cycles have been shown, with good retention beyond 106 sec.

Block copolymers have been recognized as versatile materials to prepare nanoporous polymer films or mem- branes, but their potential has not been completely explored. This study focuses on the formation and characterization of nanoporous polymer films based on poly(styrene)-block-(methylmethacrylate/methacrylic acid); (PS-b-MMA/MAA) were obtained through atom transfer radical polymerization (ATRP), by using two different protocols: annealing and annealing- irradiation; for improving the formation of microporous surface. The composition, crystallinity and structural order of the films were studied by Raman spectroscopy. The film polymer thickness was obtained through very high resolution ellip- sometry (VHRE). Finally, atomic force microcopy (AFM) and scanning electron microscopy (SEM) techniques were used to detect changes in the porous-structure. These results show that the morphological properties of the block copolymer were affected via the modification of two variables, UV-radiation time and annealing. SEM and AFM micrographs showed that the morphology exhibit a porous ordered structure. Contact angle measurement suggests additional interactions between hydrophilic functional groups that influence the film wettability.

The biocompatibility and ease of functionalization of gold nanoparticles underlie significant potential in biotechnology and biomedicine. Eight different proteins were examined in the preparation of gold nanoparticles (AuNPs) in aqueous medium under microwave irradiation. Six of the proteins resulted in the formation of AuNPs. The intrinsic pH of the proteins played an important role in AuNPs with strong surface plasmon bands. The hydrodynamic size of the nanoparticles was larger than the values observed by TEM and ImageJ. The formation of a protein layer on the AuNPs accounts for this difference. The AuNPs exhibited sensitivity towards varying pH conditions, which was confirmed by determining the difference in the isoelectric points studied by using pH-dependent zeta potential titration. Cytotoxicity studies revealed anticancerous effects of the AuNPs at a certain micromolar concentration by constraining the growth of cancer cells with different efficacies due to the use of different proteins as capping agents. The positively charged AuNPs are internalized by the cells to a greater level than the negatively charged AuNPs. These AuNPs synthesized with protein coating holds promise as anticancer agents and would help in providing a new paradigm in area of nanoparticles.

Palladium nanoparticles are synthesized by an one-step, solvent-less, mechano-chemical reduction of potassium tetrachloropalladate(II) using an amphiphilic organic polymer, poly(vinylpyrrolidone). We demonstrate that poly(vinylpyrrolidone) can act both as reducing as well as capping agent in the solid state, without a solvent, for the synthesis of palladium nanoparticles at room temperature in conjunction with vibration milling. Besides, as an example, the application of the dendritic-like palladium nanoparticles as a catalyst is also investigated for the reduction reaction of 4-nitrophenol to 4-aminophenol at room temperature.

Gold nanoclusters (AuNCs) have gained interest during the recent years because of their low toxicity and finer size for the bioimaging and biolabeling applications in comparison to the semiconductor quantum dot analogues. Diverse materials such as sulfur compounds, peptides, dendrimers, proteins, etc., are exploited for the preparation of AuNCs. Henceforth, highly fluorescent, water-soluble, and few atom-containing gold nanoclusters are created using a rapid, straightforward, and green method. In this regard for the first time chicken egg white (CEW), one of the most unique materials, is utilized in an aqueous solution under basic conditions at physiological temperature for the preparation of AuNCs. Tyrosine and tryptophan amino acid residues are responsible for the conversion of Au ions to Au(0) under alkaline condtions. CEW contains four major proteins of which the main constituent protein, ovalbumin also leads to the formation of the AuNCs with a higher fluorescence emission compared to the CEW. The ratios between the different reaction partners are very crucial, along with temperature and time for the preparation of AuNCs with high photoluminescence emission. The limited vibrational motion of the proteins under alkaline condition and the bulkiness of the proteins help in the formation of AuNCs.

Graphene nanosheets were prepared by the direct exfoliation of graphite in an aqueous lysozyme solution using ultrasonication. Atomic force microscopy studies indicated that the nanosheets possessed small lateral dimensions of less than three layers. Raman spectroscopy suggested that defects were introduced by the sonication process. These defects were primarily edge defects, not basal-plane defects. Cytotoxicity studies revealed that the lysozyme-supported nanosheets possessed anticancer activity at certain micromolar concentrations. Three other proteins and gold nanoparticles prepared with those proteins were examined as aids in graphene exfoliation. The overall protein or nanoparticle charge played an important role in the graphite exfoliation to graphene. All of the graphene dispersions were sensitive to pH. Changing the pH reversibly converted the graphene from a highly dispersed state to an aggregated state and vice versa. Although no lateral dimension differences were observed in the nanosheets prepared using the nanoparticles, their cell viability percentages varied depending on the particular protein used.

A new layout of predictable and controllable complementary logic circuits based on hybrid nanodevices comprising p-channel single-walled carbon nanotube (SWNT) and n-channel zinc oxide (ZnO) nanowire transistors providing a hybrid approach to combine advantageous characteristic functions for the modulation of the current and operating voltage in transistors through proton radiation generated charge, was studied. A suspension of SWNTs obtained through an arc discharge process in 1,2, dichlorobenzene (o-DCB) was prepared by a combination of sonication and centrifugation. 1 mg of SWNTs in 10 mL of o-DCB was sonicated for 5 mm and the SWNT suspension was then centrifuged for 200 mm at 16000 g followed by ultra centrifugation for 2 h at 325 000 g. The current-VTCs of transistors and logic circuits were measured using a semiconductor parameter analyzer. It was possible to achieve high performance logic circuits by selectively controlling the threshold voltages of transistors through the population of proton radiation generated charges in the dielectric layer.

The commercial, water-soluble poly(sodium anetole sulfonate) (PAnS), poly(sodium vinylsulfonate) (PVS), and poly(sodium 4-styrene sulfonate) (PStyS) were investigated as metal ion binding reagents using the liquid-phase-polymer-based retention (LPR) technique. The retention profiles of the following metal ions: Co(II), Ni(II), Ca(II), Mg(II), Pb(II), Cd(II), Zn(II), Cr(III), and Cu(II) were obtained by the LPR technique at pH 3, 5, and 7, and by changing the filtration factor Z from 0 to 10. As the pH increased, the affinity towards the metal ions increased slightly. By increasing the filtration factor Z, the affinity for the metal ions did not decrease significantly. This means that the ligand–metal interaction was strong, and it is not possible to break it by washing with water at the same pH of the filtration cell. Copyright © 2006 John Wiley & Sons, Ltd.

The commercial polymers poly(ethylene imine) (PEI), poly(ethylene imine epichlorohydrin), and poly(dimethylamine-co-epichlorohydrin) were purified and fractionated by ultrafiltration. Their metal-ion-binding properties with respect to different ligand groups and the effect of the concentration on the retention properties were investigated. The amine ligands of the polymers formed the most stable complexes with the metal ions. In general, there was an effect of the pH and polymer fraction size on the retention properties. As the pH and polymer fraction size increased, the affinity to bind metal ions also increased. PEI had the highest metal-retention values, particularly at higher pHs, at which the amine groups were nonprotonated and could coordinate easily with the metal ions. Only Pb(II) was poorly retained. The affinity for all the metal ions, except Pb(II), increased significantly at pH 5. The metal-ion retention decreased quickly as the filtration factor increased, except for Cu(II), Co(II), Ni(II), Cd(II), and Zn(II) ions, which were retained by over 40% at a filtration factor of 4. For other metal ions such as Pb(II), Ca(II), and Mg(II), only 10% remained bound to the polymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 222–231, 2005

The water-soluble polymers poly(styrene sulfonic acid-co-maleic acid) and poly(acrylic acid-co-maleic acid) were investigated with respect to their metal-ion-binding ability with ultrafiltration. The studied metal ions included Ag(I), Cu(II), Ni(II), Co(II), Ca(II), Mg(II), Pb(II), Cd(II), Zn(II), Al(III), and Cr(III) ions. The retention properties of the polyelectrolytes for the metal ions depended strongly on the ligand type. As for the carboxylate ligands, with increasing concentration and pH, the metal-binding affinity increased. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1091–1099, 2005

The concept of chemoremediation in the liquid homogeneous phase using polymer reagents as a green technology is presented and outlined. It is based on the retention of polymer­metal complexes in aqueous solution according to their molecular size by using membrane filtration. The fundamentals of the metal ion interaction with respect to enrichment and separation procedures are discussed, and the role of polymer­metal complexes is assessed. The formation conditions of these polymer­metal complexes as well as major factors influencing the process are investigated. In addition, recent developments using this method are evaluated, and several application examples are highlighted.

Copolymers from 2-acrylamido-2-methyl-propane sulfonic acid (APSA) and N-acryloyl-N-methyl piperazine (AP) were synthesized by radical polymerization with ammonium peroxydisulfate as the initiator. The copolymerization yield ranged between 93 and 95%. The copolymers were completely water soluble, and were characterized by FTIR and NMR spectroscopy. The copolymer composition was determined from elemental analysis through the S/C ratio. The binding capacity for metal ion was studied by the LPR technique at different pH and filtration factors. The retention depended strongly on the pH and on the copolymer composition. With increasing pH and increasing content of APSA units in the copolymer, the metal ion retention increased. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 22–30, 2001

Poly(acrylamide-co-4-vinylpyridine) synthesized by radical bulk polymerization behaves in water as a typical polyelectrolyte. According to the viscosimetric studies, the addition of strong electrolytes, like KNO 3 (0.1 M), completely suppressed the polyelectrolyte effect. The interactions between this copolymer and a number of metal ions were also studied by viscosimetry in aqueous solution. The reduced viscosity decreased with an increase of the copper(II) concentration due to an intrapolymeric complex formation. It was shown that the reduced viscosity of the polymer-metal complexes depends on the pH. It decreased for a constant ratio between the copolymer and the metal ions Fe 3+ , Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ . Among these cations, Cu 2+ showed the strongest effect. These results were compared with the corresponding data of both homopolymers.

A self-assembled diblock copolymer containing styrene (S), methyl methacrylate and a certain percentage of hydrophilic segment of poly(methacrylic acid) (i.e., poly(styrene)-block-poly(methyl methacrylate/methacrylic acid) was synthesized via the ATRP method in two steps. This was followed by a partial hydrolysis of the methyl ester linkages of the methyl methacrylate block under acidic conditions. The resultant block copolymer had a narrow molecular weight dispersity (Ð According to the results, the block copolymer shows good transparency in the visible region (when containing 20, 30 and 50 wt.% nanoparticles) and was able to absorb UV irradiation below 350 nm, indicating good UV-screening effects. The thermo gravimetric analysis data showed that the block copolymer composite is more thermally stable compared to the pure block copolymer. The self-assembled nanoscale morphology of the diblock copolymer results in the formation of uniformly distributed spherical nano particles within the polymer matrix.

The modification of glass-type surfaces by several hydrophilic polymers of different molecular masses and functional properties [chitosan, dextran, poly(oxyethylene), poly(ethyleneimine) and poly(acrylamide)] with respect to the application for direct immunoprobes was investigated. Activation of the surface was carried out by silanisation and the polymers were coupled to the surface via amide bonds. The carboxyl derivative of a hapten was attached to the functional groups of the polymers by carbodiimide-activated coupling. As a reference system, the ligand was directly coupled to the silanised surface. Non-specific protein adsorption, specific binding of antibodies and regeneration were monitored by evaluation of reflectance spectra obtained by white light interference at a thin silica layer ( RifS ). All polymer modified layers showed improved properties compared to those with direct attachment of the hapten. The non-specific adsorption was reduced to 5–50%. Binding of a specific antibody was significantly increased by the polymer modification: Mass transport limited binding of the specific antibody in low concentrations (30 nM) up to a surface coverage value of 2 ng/mm 2 and a maximum surface coverage in the range of a monolayer of IgG (5–6 ng/mm 2 ) was observed for most of the polymers. The surface coverage found for IgG bound specifically to the dextran-modified surface exceeded a protein monolayer.

Poly(N-acetyl)iminoethylene. poly(N-propionyl)iminoethylene and poly(N-acetyl)-2,2-dimethyliminoethylene were prepared by cationic polymerization in solution of 2-methyl- 2-oxazoline, 2-ethyl-2-oxazoline, and 2,4,4-trimethyl-2-oxazoline respectively. The 13C NMR spectra of the polymers obtained showed different sets of shifts for the carbon atoms of the backbone as well as for the N-acylimino side chain due to the restricted rotation of the Nacylimino group. The temperature dependence of the N-acylimino side chain signals showed a different coalescence behaviour depending on the substituents at both the main and the side chain.

We report a facile, one-pot, shape-selective synthesis of gold nanoparticles in high yield by the reaction of an aqueous potassium tetrachloroaurate(III) solution with a commercially available detergent. We prove that a commercial detergent can act as a reducing as well as stabilizing agent for the synthesis of differently shaped gold nanoparticles in an aqueous solution at an ambient condition. It is noteworthy that the gold nanoparticles with different shapes can be prepared by simply changing the reaction conditions. It is considered that a slow reduction of the gold ions along with shape-directed effects of the components of the detergent plays a vital function in the formation of the gold nanostructures. Further, the as-prepared gold nanoparticles showed the catalytic activity for the reduction reaction of 4-nitrophenol in the presence of sodium borohydride at room temperature.

Carbon nanotubes (CNTs) constitute a novel class of nanomaterials with remarkable applications in diverse domains. However, the main intrincsic problem of CNTs is their insolubility or very poor solubility in most of the common solvents. The basic key question here is: are carbon nanotubes dissolved or dispersed in liquids, specifically in water? When analyzing the scientific research articles published in various leading journals, we found that many researchers confused between "dispersion" and "solubilization" and use the terms interchangeably, particularly when stating the interaction of CNTs with liquids. In this article, we address this fundamental issue to give basic insight specifically to the researchers who are working with CNTs as well asgenerally to scientists who deal with nano-related research domains.

Copolymers of 4-vinylpyridine and N-allylthiourea with different mole fractions were synthesized by radical copolymerization in bulk. The AIBN-initiated copolymerization was found to strongly favor the 4-vinylpyridine monomer in the copolymer composition. This was confirmed by viscosity measurements with a linear relationship between the reduced viscosity and the comonomer content. Interactions and complexation of the water-soluble copolymers with nine metal ions were investigated in aqueous solution by means of a membrane filtration technique. This technique is designed to remove and separate metal ions from diluted solutions by binding them to soluble polymers. The effects of several parameters, such as copolymer composition, filtration factor, and pH were studied as a function of the interaction of the copolymers with metal ions. A strong selectivity for copper(II) was found which was pronounced at a monomer ratio of 1:2 (4-vinylpyridine: N-allylthiourea). Also a partial interaction of iron(III) and the copolymer (2:1) was observed at pH 3 which was strongly pH-dependent.

Carbon nanotubes constitute a novel class of nanomaterials with potential applications in many areas. The attachment of metal nanoparticles to carbon nanotubes is new way to obtain novel hybrid materials with interesting properties for various applications such as catalysts and gas sensors as well as electronic and magnetic devices. Their unique properties such as excellent electronic properties, a good chemical stability, and a large surface area make carbon nanotubes very useful as a support for gold nanoparticles in many potential applications, ranging from advanced catalytic systems through very sensitive electrochemical sensors and biosensors to highly efficient fuel cells. Here we give an overview on the recent progress in this area by exploring the various synthesis approaches and types of assemblies, in which nanotubes can be decorated with gold nanoparticles and explore the diverse applications of the resulting composites.

Poly (hydroxybutyrate) membranes were used as substrates for cold plasma treatment with perfluorohexane. By varying a gas mixture of perfluorohexane and hydrogen, surface coatings of different hydrophobicity were obtained. In addition, inorganic glass slides were treated correspondingly. The plasma-treated samples were analyzed by ESCA with respect to the surface composition and by contact angle measurements with respect to the surface free energy. Atomic structures and surface energies of the deposited layers on the polymer substrates were compared to those on inorganic substrates. In both cases a strong correlation was found between the fluorine/carbon ratio as well as the oxygen/carbon ratio and the surface free energy. Furthermore, the plasma-treated membranes were investigated and characterized by their changed permeation properties in order to identify the influence of the surface coatings on the bulk properties. Up to a coating density of 50–100 γ/cm2 the filtration properties of the treated membranes remained unaffected.

The complexing behavior of poly(ethyleneimine) 5-sulfonyl-8-hydroxyquinoline (POX) with palladium(II) ions in aqueous solution was studied by means of spectrophotometry in the visible region. It was shown that poly(ethyleneimine) 5-sulfonyl-8-hydroxyquinoline forms a stable, water-soluble, orange-colored complex which has a maximum absorption at a wavelength of 424 nm. The effect of pH, concentration of poly(ethyleneimine) 5-sulfonyl-8-hydroxyquinoline, concentration of palladium(II) ions, and time were investigated. The results show that in a pH range between 2 and 5, the absorbance is constant for 40 minutes. The linear concentration range for palladium(II) ions was determined to be 0-2.5 μg · ml-1 and the molar extinction coefficients 1.06 · 104 (1 · mol-1 · cm-1) for the polymeric derivative and 7.15 · 103 for the monomeric 8-hydroxyquinoline. The effect of tartaric acid as a masking agent was examined in order to eliminate the influence from other ions. The simultaneous presence of K(I), Cs(I), Li(I), Ba(II), Ca(II), Cd(II), Hg(II), Mn(II), Ni(II), Al(III), As(III), Au(III), Cr(III), Fe(III), Pt(IV), As(V) did not interfere with the complexation of poly(ethyleneimine) 5-sulfonyl-8-hydroxyquinoline and palladium(II). However, it was found that NH4 + interferes strongly. The polymer 8-hydroxyquinoline derivative exhibited a 45% higher sensitivity to Pd(II) ions in comparison to the low-molecular-weight 8-hydroxyquinoline.

A functional water-soluble polymer was prepared by cationic polymerization of 1-(2-hydroxyethyl) aziridine in solution (acetonitrile, dimethylformamide, dichloromethane and toluene) using boron trifluoride etherate (1–5 mol%) as initiator. The polymerization in acetonitrile was studied as a function of time and temperature. It occurred without an induction period. The yield and the viscosity of the polymers increased on increasing the polarity of the solvent, the temperature, and the time. The polymers were characterized by elemental analysis, FT-i.r., 1 H-NMR and 13 C-NMR spectroscopy.

Plasma polymerization of gases present in a low temperature plasma is a “clean” technique that is particularly well suited for biomedical material processing. This paper presents the first results of a project which studies the possibilities offered by this technique to prepare commercial lowcost membranes with the required bio- and hemocompatibility to be implanted in an organism. The deposition on polysulfone of films from a plasma containing a mixture of ethylene oxide and perfluorohexane in order to obtain very hydrophobic, less hydrophobic and intermediate coatings was studied. Results obtained by adding hydrogen to perfluorohexane are also discussed. The deposition of a thin coating from a perfluorohexane and hydrogen plasma was studied in order to optimize the surface properties of the treated membranes without affecting their filtering properties. The treated substrates have been characterized by measuring mass variations, by surface profilometry and contact angle techniques as well as by scanning electron microscopy and electron spectroscopy for chemical analysis.

Poly(4-acryloylmorpholine), poly(4-acryloylmorpholine-co-2-acrylamido-2-methyl-1-propane sulfonic acid), and poly(2-acrylamido-2-methyl-1-propane sulfonic acid) were synthesized by radical polymerization. The water-soluble polymers obtained, containing tertiary amino, amide, and sulfonic acid groups, were investigated, in view of their metal binding properties, as polychelatogens by using the liquid-phase polymer-based retention technique, under different experimental conditions. The metal ions investigated were Ag(I), Cu(II), Co(II), Ni(II), Cd(II), Pb(II), Zn(II), Cr(III), and Al(III). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 180–185, 2006

Implants for surgical needs are produced from different materials including metals, alloys, ceramics or polymers. Metal implants are preferred in those disciplines where sufficient mechanical strength is needed, including traumatology, orthopedic or dental surgery. Further, modern tissue engineering techniques require scaffold materials to generate shape and stability for in vitro generated transplants. However, the biocompatibility and surface contact of most implants or scaffold materials to vital bone or other tissues are not optimal. Therefore we investigated the biocompatibility of different polymer surfaces to an osteoblastic cell line as a function of wettability or hydrophobicity to describe some of the surface parameters influencing the cell to implant or cell to scaffold contact.Glass slides were coated with different polymers and in some cases physically or chemically modified. SAOS-2 osteosarcoma cells were used for the biocompatibility tests on 16 different polymers and modifications thereof. The viability of the adherent cells was investigated by MTT assay. Commercially available tissue culture vessels served as controls.We report that excellent biocompatibility to SAOS-2 osteoblastic cells can be obtained with hydrophobic surfaces generated for instance by epoxy resins. Chemical modification of epoxy resin surfaces yielded even a further increased viability index surpassing the viability index obtained with cell culture vessels.We conclude that modified hydrophobic surfaces represent an interesting group of compounds for coating endoprosthetic implants or scaffolds for the purposes of tissue engineering.

The feasibility of fouling mitigation of anion exchange membranes (AEMs) in the presence of humate was studied by adding three different types of water-soluble polymers, i.e., poly(acrylic acid) (PAA), poly(vinyl alcohol) (PVA), and poly(ethylene imine) (PEI), during electrodialysis (ED) desalination. Measurement of zeta potential of the humate used in this study showed highly negative potential (about −30 mV), implying that the humate had a strong fouling potential on the AEMs in ED. Of the three water-soluble polymers, PEI showed a positive zeta potential (about +14 mV) and is able to form an interpolymer complex with the humate. PAA and PVA hardly formed interpolymer complexes with humate due to electrostatic repulsion. The PEI–humate mixture with a volume ratio of 1:20 (PEI:humate) showed zero zeta potential, and a complexed humate with zero surface charge was formed, resulting in no fouling effects on the AEMs. Accordingly, the desalting ED experiments with PEI showed improved ED performance. Further, black colloids formed in the mixture did not cause the cell resistance to increase.

Water-soluble polymers containing carboxylic acid, phosphonic acid, and sulfonic acid groups were investigated as polychelatogens under different experimental conditions. The maximum retention capacity (MRC) of these polymers was determined at different pH and polymer–metal ion ratios. The metal ions investigated were: Ag(I), Cu(II), Co(II), Ni(II), and Cr(III). The MRC values of the divalent metal ions were found to be very similar and higher than those of the trivalent cations, and there was an important effect of the pH on the MRC. This indicates that the polymer–metal ion interactions were dominated by electrostatic forces. Copyright © 2003 John Wiley & Sons, Ltd.

Polymer metal complexes of poly(styrene sulfonic acid-co-maleic acid) and Cu(II), Ni(II), Co(II), and Zn(II) were synthesized. The magnetic, spectral, and thermal properties, as well as the electrical conductivities, of the chelates were investigated, and possible structures were assigned to the polychelates. Semiempirical calculations at the AM1 level were carried out on the geometrical arrangement of the polychelates. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2546–2551, 2002

Multi-drug resistance against chemotherapeutic agents is a major problem in the treatment of cancer. It is primarily mediated by over-expression of P-glycoprotein (P-gp) encoded by the MDR-1 gene by the tumor cells. Most of the promising anticancer drugs such as doxorubicin, docetaxel, paclitaxel, and mitoxantrone are P-gp substrates. Thus, various ways for overcoming the multi-drug resistance, e.g. combination of an anticancer drug and a P-gp inhibitor or the formulation of nanoparticles in conjunction with anticancer drugs as well as the P-gp inhibitor, have been studied. Anticancer drug-loaded nanoparticles, such as paclitaxel-loaded polymer nanoparticles, are excellent candidates to overcome multi-drug resistance due to their enhanced therapeutic efficacy induced by increased cellular accumulation and sustained intracellular drug delivery. In this work, we developed an ampholytic copolymer that can encapsulate paclitaxel, and the resulting nanoparticles were found to have good water-solubility. In addition, in contrast to native paclitaxel, the paclitaxel-loaded nanoparticles were able to reverse multi-drug resistance in MCF7/ADR and MT-3/ADR cell lines, resulting in drug sensitivities comparable to the parental MCF7 and MT3 cell lines. P-gp expression was confirmed in both ADR cell lines by Western blotting, and its functionality was verified using a rhodamine accumulation and efflux assay. The nanoparticles were taken up by endocytosis in both cell lines and their enhanced therapeutic efficacy is probably due to the different mode of entry into the cell that may avoid the P-gp efflux pump. As a consequence higher concentrations of paclitaxel reach the nucleus and induce cell killing. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1726. doi:10.1158/1538-7445.AM2011-1726

The International Conference on Nanomaterials and Nanotechnology (NANO-2010) was organized by the Center for Nanoscience and Technology (CNST), K.S. Rangasamy College of Technology, in association with the Department of Nanobio Materials and Electronics (DNE), World Class University (WCU), Gwangju Institute of Science and Technology (GIST), South Korea, and the Technische Unversität Kaiserslautern, Germany, from 13 to 16 December 2010. The interdisciplinary conference was held at the KSRCT, Tiruchengode, Tamil Nadu, India, and included a series of scientific lectures, an exhibition, and a panel discussion with funding agencies such as the DST, Defense Research and Development Organization (DRDO), DAE, and the Council for Scientific and Industrial Research (CSIR).In addition, a special session for DRDO was arranged, including a benefit for the delegates to explore potential areas of collaboration with the DRDO laboratories. This special session on the “Application of Nanotechnology for National Security” was held 14 December 2010. Also, 13 companies exhibited their products in the exhibition hall. Distinguished persons from various funding agencies participated in the panel discussion to identify the road map for nanotechnology in India. The conference was enlightened by three plenary lectures, which included one given by Prof. Dr. Richard Ernst, Nobel laureate. In addition, 39 invited lectures and more than 560 contributed papers from over 24 countries were presented.We would like to thank IUPAC for coming forward to publish the invited papers in Pure and Applied Chemistry. Out of 39 invited lectures, 12 papers were accepted after peer review for publication. We also thank IUPAC for sponsoring this event.Our special thanks are due to the reviewers for their help with critical reviews and detailed comments on the manuscripts and also to the speakers for considering the reviewers’ comments.V. Rajendran, Burkard Hillbrands, and Kurt E. GeckelerConference Editors