Current Nanoscience (v.7, #4)

Graphical Abstracts by Bentham Science Publishers (i-vi).
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Preparation and Antitumor Effect of N-Trimethylchitosan/Fucoidan Ion-Complex Submicron Particles by Kazuya Hayashi, Masanaho Sasatsu, Yoshiharu Machida, Hiraku Onishi (497-502).
The aim of this study was to develop a delivery system to enable the promotion of the antitumor potential of fucoidan (FUC).FUC/N-trimethylchitosan (TMC) ion-complex submicron particles (FUC/TMC-SMP) were produced by ionic complexation, and theirparticle characteristics were investigated. Antitumor effect was examined in vivo using sarcoma 180-bearing mice by oral administration,and body weight loss was checked as an index of toxic side effects. FUC/TMC-SMP could be obtained by the complexation of negativelycharged fucoidan with positively charged N-trimethylchitosan under aqueous conditions. The mean particle size was 325 nm and meanFUC content was 47 % (w/w). Oral administration was conducted using two treatment schedules, that is, pre- and post-tumor inoculation.As to pre-treatment, oral administration was performed from 13 days before inoculation to 1 day before inoculation every other day. Forpost-treatment, preparation samples were administered orally from 1 day after inoculation to 13 days after inoculation every other day.FUC/TMC-SMP were more effective than FUC solution and suppressed tumor growth significantly in both treatment schedules.FUC/TMC-SMP are suggested to be a useful oral delivery system enhancing the antitumor potential of FUC.

PPSu-PEG Copolymers and their Application in the Preparation of Cisplatin-loaded Nanoparticles by Spiridoula Kyriakopoulou, George Mattheolabakis, Sofia Papadimitriou, Evangelos Karavas, Dimitrios Bikiarisb, Konstantinos Avgoustakis (503-509).
Nanoparticles based on poly(propylene succinate) copolymers with poly(ethyleneglycol) (PPSu-PEG) were prepared andevaluated in vitro for their potential for a more selective delivery of cisplatin to tumors using local hyperthermia. The copolymers weresynthesized through one-pot melt-polymerization under vacuum. Their thermal properties were investigated using DSC. PPSu-PEGnanoparticles loaded with cisplatin were prepared by a double emulsion method. Their colloidal stability, drug release properties, and invitro anticancer activity were assessed. The m.p. of the synthesized PPSu-PEG copolymers ranged between 40-45 °C. The PPSu-PEGnanoparticles were stable in aqueous media with high salt concentrations. The average size of the different compositions of the PPSu-PEG nanoparticles loaded with cisplatin ranged between 77 and 126 nm and all compositions exhibited low negative ζ-potential values.The PPSU-PEG/cisplatin nanoparticles released cisplatin much faster at 42 °C than at 37°C and exhibited comparable to free cisplatin cytotoxicityagainst HT 29 cells, which was increased when the incubation temperature was increased from 37 °C to 42 °C. The results justifyfurther investigation of the potential of PPSu-PEG copolymers for the development of temperature-sensitive, targetable cisplatinnanocarriers.

Nanomaterials are at the leading edge of the rapidly developing field of nanotechnology. Nanomaterials such as magnetic ironoxides and magnetic gold-coated iron oxides nanoparticles exhibit unusual optical, thermal, chemical, and physical properties, due to acombination of high-energy surface atoms compared to bulk solids. Their low toxicity, biocompatibility, and established protocols ofsynthesis have resulted in a tremendous upsurge of interest, and their applications as special biomolecule carriers via a stable immobilizationprocess show promise as sensitive detection tools. This review provides a comprehensive analysis of new synthetic routes, characterizationmethodologies, and functionalization protocols of magnetic and gold-coated magnetic iron oxides nanoparticles. Applicationsof these materials as scaffolds for biosensing and detection are also discussed.

Enhanced Topical Delivery of Cyclosporin-A Using PLGA Nanoparticles as Carrier by Sanyog Jain, Ankit Mittal, Amit K. Jain (524-530).
Cyclosporin-A is a drug of choice for the topical treatment of various dermatological diseases, however the drug failed topenetrate into intact skin barrier due to its high molecular weight, complex cyclic molecular structure and the barrier property of stratumcorneum (SC). Less than 1% of the drug reaches skin upon systemic administration and it further causes systemic toxicity. So the aim ofthe present work was to develop cyclosporine-A loaded PLGA nanoparticles for enhancing its topical delivery. Spherical shapednanoparticles with high entrapment efficiency (86%), low particle size (163 nm) and narrow polydispersity index (0.118) were preparedby emulsion diffusion evaporation technique. In vitro permeation studies were carried out using rat skin and 6.6 and 4.85 times higheramount of the drug was estimated in SC and dermis respectively as compared to free drug. No drug was detected in receptor compartmenthence the system might be devoid of risk of any systemic toxicity. Histological examination and TEWL measurement exhibited nomorphological changes upon application of nanoparticles on the skin. CLSM images suggested pilosebaceous route followed by nanoparticlesfor skin penetration. The system may be a promising carrier for topical delivery of cyclosporin.

A Critical Review on Biogenic Silver Nanoparticles and their Antimicrobial Activity by T.N.V.K.V. Prasad, Venkata Subba Rao Kambala, Ravi Naidu (531-544).
The new bio-branch of nanotechnology is considered to be one of the fastest emerging fields often called as Nanobiotechnology.Recent studies on exploitation of the nature's secrets for the synthesis of inorganic materials are relatively new and exciting area ofresearch with considerable potential for development. Among the inorganic materials, noble metals research is been always interesting,silver in particular. Nanoscale silver has been proved to be one of the potential antibacterial, antifungal and anti-inflammatory agents.Biologically synthesized silver nanoparticles can be more effective in the medicinal applications due to their diversified surface coatings(biomaterial). The present review gives an idea about the importance of biogenic metallic silver nanoparticles, their characterization andpotential antimicrobial properties.

Combination of Microneedles with PLGA Nanoparticles as a Potential Strategy for Topical Drug Delivery by Wei Zhang, Baoyue Ding, Renjie Tang, Xueying Ding, Xuemei Hou, Xiaoyu Wang, Shengying Gu, Lei Lu, Yi Zhang, Shen Gao, Jing Gao (545-551).
Penetration of PLGA nanoparticles in the hairless mouse skin petreated by microneedles was studied in vitro using nanoparticlescontaining coumarin 6 and R-phycoerythrin (R-PE) as fluorescent probe. Confocal laser scanning microscopy (CLSM) was used tovisualize the distribution of nanoparticles and the high performance liquid chromatography (HPLC) was utilized to quantify the amountof the nanoparticles. The CLSM images revealed that nanoparticles (diameter 160.1±1.97nm) could penetrate into the skin through themicroconduits created with microneedles and reach the depth of more than 42.19im. The quantitative results showed that the amount ofnanoparticles deposited in the skin increased by microneedles was about twice that in the control group in a period of 48h. However, thenanoparticle was not able to reach the receptor compartment. In additional, the penetration and the distribution of nanoparticles was significantlyinfluenced by the particle size (diameter ranged from 160.1±1.97nm to 288.2±6.62nm). These results suggested that the combinationof PLGA nanoparticles with microneedles could be a useful method to increase topical drug delivery and improving therapy bysupplying drug reservoirs to the skin.

A Facile Approach to Polymer/clay Nanocomposite by In Situ Redox Polymerization by Jun Chen, Jun Qiao, Hai-Long Liu, Wan-Yun Yin, Guo-Chao Fu, Qian-Feng Zhang (552-555).
A simple and environmental friendly synthetic method for the preparation of polymer/clay nanocomposite was introduced.Poly(methyl methacrylate)/ montmorillonite nanocomposites with a high filling of clay were obtained by one step in situ redox polymerizationin aqueous dispersion. Triethanolamine hydrochloride was used as intercalative modifier for montmorillonite via ion exchange reactionto introduce hydroxyl groups on the surface of montmorillonite layers which generated free radicals to initiate polymerization reactionwith ceric ions. Exfoliation or intercalation structures are related to the clay content of nanocomposites and are evidenced by bothX-ray diffraction spectroscopy (XRD) and transmission electron microscopy (TEM). Characterization results of extracted nanocompositeindicate the existence of polymer chain on the surface of montmorillonite layers. Effect of concentration of triethanolamine hydrochlorideon the structure of poly(methyl methacrylate) nanocomposites was also investigated.

Polydiacetylene (PDA) vesicles with various cross-linking degree were prepared by adding different quantity of ethylenediamine.Ag nanoparticles were added into above systems to form the cross-linked PDA/Ag composite vesicles. UV-vis spectra and transmissionelectron microscopy (TEM) were used to confirm the formation of the cross-linked PDA/Ag composite vesicles. Their thirdordernonlinear optical (NLO) properties were investigated in detail. A pronounced enhancement of the third-order nonlinear optical susceptibility..(3) was observed with increasing of the cross-linking degree, which should be ascribed to the coupling effect of strong localfield near the adjacent PDA/Ag composite vesicles.

Based on the electrostatic interaction between carboxymethylated chitosan (CMCH) and negatively charged CdTe quantumdots, and the selective crosslinking of CMCH using glutaraldehyde(GA), we demonstrated the formation of Fe3O4/SiO2/CMCH/CdTemicrospheres. The dense silicate shells of Fe3O4 nano-particles (NPs) protect the luminescence quenching from Fe3O4 NPs, so the compositemicrospheres have great fluorescence and emulative magnetism. These multifunctional fluorescence/magnetic microspheres leadto robust and water dispersible nanoparticle colloidosomes, and should be of great importance for diagnostics application and specificbiological applications.

Bonding Strength, Hardness and Bioactivity of Nano Bioglass-Titania Nano Composite Coating Deposited on NiTi Nails by Mojtaba Nasr-Esfahani, Reza Ebrahimi-Kahrizsangi, Mohammad Saleh Dadash, Saeed Karbasi (568-575).
In the present investigation a titania network encapsulating nano bioactive glass 58s (NBG) particulate phase is proposed as abioceramic composite coating. The grain size of NBG particles was uniform and its nano scale (50 - 60 nm) confirmed with transmissionelectron microscopy (TEM). XRD pattern of NBG particles, calcinated at 600°C in air confirmed that the calcinated glass generally existedin amorphous state. Thermogravimetry (TG) curves for the bulk of NBG-Titania gel indicated that the organic and inorganic precursorshave been decomposed completely before 600°C. Nickel-titanium alloy (Nitinol®) Nails was dip-coated with NBG-Titania compositevia the sol-gel route. The morphology, structure and component of the composites films were evaluated using environmental scanningelectron microscope (SEM) and field emission scanning electron microscope (FESEM). Also, FTIR confirmed the presence of Si-OSibands on the calcinated NBG-Titania films. The hardness of the prepared films was investigated using micro hardness test method.The results verified that the presence of NBG particles in titania matrix enhanced gradually the mechanical data of the prepared films(450 VHN). Direct pull-off test recorded a mean coating-substrate bonding strength larger than 16 MPa. The in vitro bioactivity of preparedfilms indicates that hydroxyapatite nuclei can form and grow on the surface of NBG-Titania films coated on Nitinol alloy. The presentstudy shows that due to their excellent bioactivity, hardness and bonding strength to substrate, NBG-Titania coatings are practicalbiocomposite films in biomedical applications.

Research Progress of Nanostructured Materials for Heterogeneous Catalysis by Xuehua Yu, Yucai Hu, Li Zhou, Fengjing Cao, Yingxia Yang, Tao Liang, Junhui He (576-586).
When the nanostructured materials were used as heterogeneous catalysts by comparing with traditional powder catalysts, thenanostructured materials exhibited special properties of nanoparticles and new effects caused by nanostructured combination, with manyunmatchable improvements in the aspects of size, shape, surface structure, numbers of reaction active sites, catalytic selectivity and soon. Because of those advantages, the nanostructured materials have great potential application in the field of heterogeneous catalysis andhave become the hotspot of materials science in the area of heterogeneous catalysis gradually. In this paper, the advantages of nanostructuredmaterials for heterogeneous catalysis were concisely summarized; the nanostructured materials, which included supported nanostructuredcatalysts and non-supported nanostructured catalysts, were discussed as an emphasis in application of heterogeneous catalysis.Finally, the development trends of nanostructured catalysts were indicated.

Liposome-linear polyethyleneimine-DNA Nanocomplexes for Gene Delivery: Preparation, Characterization and In Vitro Transfection Activity by Javad Motaharinia, Mohammad Ramezani, Mohammad Malaekeh-Nikouei, Bizhan Malaekeh-Nikouei (587-593).
The aim of the present study was to improve transfection efficiency using different combinations of cationic liposomes, linearpolyethylenimine and DNA. A novel gene delivery system (lipopolyplex) was developed by premixing cationic liposomes containingcholesterol or oligoamine modified cholesterol (derivative I-III) and linear polyethyleneimines (PEIs) following addition of plasmid atthree different C/P ratios. The resultant complexes were characterized for their size, zeta potential and ability of DNA condensation. Luciferasereporter gene was used for determination of transfection efficiency in Neuro2A cells. Mean particle size of prepared complexeswas less than 200 nm and they showed positive surface charge. The transfection efficiency of vectors was reduced by increasing in carrierconcentration/plasmid DNA ratio (C/P ratio) while gene expression of cationic liposome or PEI was increased at higher C/P ratios. Complexescomposed of PEI 2.5 or 250 kDa and liposome containing derivative I had the highest transfection activity. Furthermore, non-viralvectors described in this study showed low cytotoxicity. The results show that small and large molecular weight linear PEI in combinationwith liposome have little toxicity and may enhance transfection efficiency.

Growth Mechanism and Field Emission Characteristics of GaO/GaN Nanotips Using Iodine-assisted Enhanced Focused Ion Beam Etching by Zhan-Shuo Hu, Fei-Yi Hung, Shoou-Jinn Chang, Bohr-Ran Huang, Bo-Cheng Lin, Kuan-Jen Chen, Tse-Pu Chen, Wen-I Hsu (594-597).
GaN nanorods are fabricated with an AgO mask by a process of iodine-assisted focused ion beam etching (IFIBE). The transformationfrom GaN nanorod to GaN nanotip structure, the thermal treatment uses a high temperature of 800oC in air to increase the partialoxygen pressure resulting in the formation of a double mask, GaO and AgO. In addition, the Ag clusters react with the iodine gas toaffect the etching rate and retain a GaO zone on the GaN nanotip arrays. Oxide-capped GaN nanotips can be applied as field emitter. Theturn-on electric field was 2.2V/um when the current density was 0.1mA/cm2.

Synthesis and Characterization of Silicon Oxide Nanoflowers by C.W. Zhou, K.F. Cai, J.L. Yin (598-602).
Flower-like amorphous silicon oxide nanostructures were synthesized by a metal-catalyzed chemical vapor deposition methodon Si (111) wafers, using SiCl4 as the source of Si and Au as catalyst in a flowing H2-5% Ar atmosphere. The nanostructures were characterizedusing field-emission scanning electron microscopy, transmission electron microscopy equipped with electron energy dispersiveX-ray spectroscopy. Each flower-like nanostructure consists of many silicon oxide nanorods with smooth surface and uniform diameter.At early stage, the growth of the flower-like silicon oxide nanostructures was controlled by solid-liquid-solid and solid-vapor-liquid-solidmechanisms, and solid-vapor-liquid-solid and vapor-liquid-solid mechanisms at later stage. The silicon oxide nanoflowers show a photoluminescenceemission band at 339 nm, revealing that the nanoflowers might have potential applications in the future optoelectronic device.

Nanocrystalline zinc titanate powders were produced at the short sintering time by a sol-gel route. The effect of heat treatmentwas studied on the crystallization behavior of zinc titanates. The prepared sols showed a narrow particle size the average grain size of 68nm. The resulting nanopowders were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDAX), transmissionelectron microscopy (TEM), scanning electron microscope (SEM), ultra-violet diffuse reflectance (UV-DRS) and thermogravimetrythermal analysis (TG-DTA). Results of thermal analysis by DTA and TG suggest that decomposition of the precursor proceededvia dehydration reaction, decomposition, combustion reaction and Ecandrewsite phase formation. X-ray diffraction (XRD) and Fouriertransform infrared spectroscopy (FT-IR) revealed that the optimum temperature for Ecandrewsite nanopowders calcination is 900 °C.With the increase of annealing temperature a new crystallite Ecandrewsite was formed and the ultraviolet light absorption efficiency wasenhanced according to the UV-vis diffuse reflectance spectroscopy. The scanning electron microscope (SEM) observation shows that thenanopowders existed in the mode of polycrystalline structure and the average grain size 68 nm. A new absorption edge at higher wavelength(438 nm) for Ecandrewsite zinc titanate annealed at 900 °C is an indication that the nanopowder can absorb lights in the higherwavelength, and therefore they can more efficiently utilize lights for the photocatalytic purpose.

The aim of this study was design and development of colon-specific delivery system of satranidazole based on pectin microbeadsformed by cross-linking with calcium chloride. Satranidazole loaded calcium-pectinate microbeads were prepared by ionotropicgelation method. Application of response surface methodology was used to study the effect of pectin concentration, calcium chlorideconcentration and stirring speed on drug release and encapsulation efficiency. Particle size of the calcium-pectinate microbeads was determinedby particle size analyzer. The SEM was used to characterize the surface of these microbeads. In vitro drug-release studies wereperformed in conditions simulating stomach-to-colon transit in the presence and absence of rat cecal contents. The in vitro drug releasestudies exhibited low drug release at gastric pH, however continuous release of drug was observed from the formulation at colonic pH.Further, the release of drug from formulation was found to be higher in the presence of rat cecal contents, indicating the effect of colonicenzymes on the calcium pectinate microbeads. The significance of differences was evaluated by analysis of variance (ANOVA). Differenceswere considered statistically significant at P < 0.05. Thus, by experiment design important parameters affecting formulation characteristicsof satranidazole loaded calcium-pectinate microbeads can be identified for colon specific delivery.

Ezetimibe is a poorly water-soluble drug with varying bioavailability. The main objective of present work was to develop selfnanoemulsifying drug delivery system (SNEDDS) for enhancing solubility and bioavailability of ezetimibe, which is widely used intreatment of homozygous familial hypercholesterolemia and homozygous sitosterolemia. The formulation of ezetimibe SNEDDS was optimizedby simplex lattice design, multiple regression analysis and ternary contour plot. The optimal formulation of SNEDDS comprisedof 7.058% oil (Oleic acid), 82.94% surfactant (Tween-80) and 10.0% co-surfactant (PEG-400). Pseudo-ternary phase diagrams were constructedto identify the efficient self-emulsification region. The average globule size of SNEDDS containing ezetimibe was about 90.63nm when diluted with water. No significant variations in globule size and ezetimibe content in SNEDDS were observed over a period of3 months at 40 ± 2°C/75 ± 5% RH and 25 ± 3°C (room temperature). In vitro diffusion studies showed remarkable increase in diffusionof drug. In vivo studies (in rats) showed significant increase in absorption of drug as compared to plain drug and marketed formulation.The data suggested use of SNEDDS to provide great potential as alternative to traditional oral formulations of ezetimibe.

Comparison of Al and Cu Ions Emissions by Nd:YAG Laser Matter Interaction by Rabia Qindeel, Yaccob Mat Daud, Nur-Shahidah, Noriah Bidin (628-632).
The infrared radiation from Nd:YAG laser (1604 nm, 8ns, 125mJ, 15.6MW) is focused by IR lens (20cm) to irradiate Cu andAl (99.99%) target in air. The angular distribution and arrival of ions are collected by Faraday Cups (FC). For anisotropic investigation,the cups are arranged at different positions (5cm and 10cm) from the targets at different angles (5°, 30°, 45°, 60° and 90°) with respect tothe normal on targets surface. Faraday Cups are biased at -100V and the ion current signals are obtained on Tektronix TDS 3054B DigitalStorage oscilloscope (500 MHz) through integrated circuit. The average kinetic energy of ions is also calculated. Maximum arrival rate ofions is observed at angle 5° and minimum ions flux is at angle 90° to normal on the target surface. The results show that the plume ispeaked strongly in forward direction. The laser matter interaction is good for the laser based ion sources generation, which can produce acollimated beam of ions because of forward peaking.

Recycling of Direct Dyes Wastewater by Nylon-6 Nanofibrous Membrane by Fereshteh Basiri, Seyed Abdolkarim Hosseini Ravandi, Mahmoud Feiz, Ahmad Moheb (633-639).
Textile processing industry generally requires significant amounts of process water for cleaning, rinsing, and dyeing purposesand therefore releases significant amounts of dye polluted waste streams into the environment. In recent years considerable attempts havebeen made to remove pollutants from these waste streams. One of the promising methods in this regard is membrane filtration. Utilizingthis separation method would necessitate the manufacture of effective membranes, such as nanofibrous membranes. Electrospinning is arelatively simple method to produce nanofibers from solutions of different polymers and polymer blends. This paper presents the resultsof a research on manufacturing a membrane filter by electrospinning Nylon-6 nanofibers on a carbon coated polyurethane substrate andimplementing this membrane for dye removal in a filtration system. The membrane sample contained nanofibers with an average diameterof 211 nm. Experiments were run with C.I. Direct yellow 12 as a typical dye pollutant. The effect of coating time, transmembranepressure, and two different pretreatment methods were investigated and it was observed that by the application of 150ppm coagulant materialat 0.75 bar pressure, a filtration efficiency of 98% was achieved.

Nanotechnology for Water Treatment by Amit K. Goyal, E.S. Johal, G. Rath (640-654).
Currently, 1.1 billion people are at risk due to lack of clean water and about 35 percent of people in the developing world diefrom water-related problem. To alleviate these problems water purification technology requires new approaches for effective managementand conservation of water resources. Nanotechnology has the potential to contribute a long-term water quality, availability and viabilityof water resources, through the use of advanced filtration materials that enable greater water reuse, recycling and desalinization.Recent advances strongly suggest that many of the current problems involving water quality can be addressed and potentially resolvedusing nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes, and nanoparticle enhanced filtration.This review highlights the uses of nanotechnology in areas relevant to water treatment including purification, separation, bioremediationand disinfection. Creating better disinfection and purification technologies could significantly reduce water borne diseases and further ensurecontinued economic prosperity of developed nations and create new economic opportunities for the developing world.