Current Nanoscience (v.7, #2)

Graphical Abstracts by Bentham Science Publishers (i-vi).
Full text available.

Perspectives in Nanomedicine-Based Research Towards Cancer Therapies by Yogesh M. Rane, Eliana B. Souto (142-152).
Nanomedicine is focused on the development of submicrometer carriers designed for improving the biodistribution of systemicallyadministered drugs. Nanoparticles have been exploited for immunoassays, immunohistochemistry, cancer diagnostics, bioseparationof specific cell populations, and cellular imaging. Public awareness on the use of these novel therapeutic approaches is increasingdue to the exponential boom of nanotechnologies in the latest years. With respect to cancer therapy, several tumour-targeted nanomedicineshave been evaluated over the years, and there is a clear evidence for substantial improvement of the therapeutic index of antineoplastics.The present review addresses the most relevant targeting strategies, discussing the major public awareness, therapeutic advancesand future directions in the development of tumour-targeted nanomedicines.

Nanotechnology as a New Tool for Fingermark Detection: A Review by Jessirie Dilag, Hilton J. Kobus, Amanda V. Ellis (153-159).
In recent years there has been a unique twist in fingermark research which has involved the implementation of nanotechnologyinto the structure, function and design of novel fingermark detection reagents. This is primarily because it is now well known that nanomaterialsafford novel physical and electronic behaviour. To this end it is possible to provide an entirely new approach for improved latentfingermark detection by using nanoscale dye- functionalized nanoparticles and intrinsically luminescent nanocrystals (quantum dots)which can provide not only improved contrast but a higher degree of functionality than conventional materials. This review highlights themost recent developments in the use of luminescent nanocrystals and non-luminescent nanoparticles for fingermark analysis.

Nanocarriers for Transmucosal Vaccine Delivery by Sanyog Jain, Kailas Khomane, Amit K. Jain, Prateek Dani (160-177).
Immunization has been realized as one of the most cost effective methods of controlling microbial infections. Currently, themost widely employed means of vaccine delivery includes intramuscular injection which is effective against pathogens invading via thesystemic route. The antibody titers do not extend to mucosal or serosal sites which are also the portals of entry for invading pathogens.Mucosal means of delivery comes as viable alternatives. The oral route for mucosal vaccination has not been successful in presenting antigensto the body. Acidic environment and inactivating enzymes of the GI tract degrade the antigen before it is presented to the M-cellsof Peyers patches. Nanocarrier based vaccines however, can help to overcome the problems associated with mucosal delivery. These carriershave shown to improve the bioavailability, act as adjuvant to provoke a stronger immune response while being targeted to associatedtissues, leading to improved success of vaccination which inculcates interest of nanotechnology in vaccination. This review encompassesa wide range of nanocarriers that have been of interest.

Surface Functionalization of Nanostructured Porous Silicon by APTS: Toward the Fabrication of Electrical Biosensors of Bacterium Escherichia coli by G. Recio-Sanchez, G. Dominguez-Canizares, M. Manso, I. Preda, V. Torres-Costa, A.Gutierrez, L. Soriano, R.J.Martin-Palma (178-182).
Nanostructured porous silicon (nanoPS) basically consists in a network of silicon nanocrystals with high specific surface. Itsintrinsic high surface reactivity makes nanoPS a very suitable material for the development of biosensors. In this work, the surface ofnanoPS was functionalized by the use of (3-aminopropyl)triethoxysilane solutions in toluene. Escherichia coli (E. coli) antibodies weresubsequently immobilized on the functionalized surfaces. Finally, fragments of this bacterium, which are specifically recognized by theantibodies, were immobilized. Moreover, devices with a metal/nanoPS/semiconductor/metal structure were fabricated aiming at the electricalbiosensing of E. Coli bacterium. The experimental results showed a strong variation of the current as a function of the presence/absence of bacterium E. Coli and surface concentration.

Amphoteric Polymer-Clay Nanocomposites with Drug-Controlled Release Property by Xiaoying Wang, Bo Liu, Xiaohui Wang, Runcang Sun (183-190).
Quaternized carboxymethyl chitosan (QCMC) is a novel derivative of chitosan with great potential in clinical medicine application.In this study, in order to widen its application, QCMC was used to intercalate into organic rectorite (OREC) to prepare polymer/layered silicate nanocomposite. XRD and TEM results showed that QCMC had been inserted into the interlayer of layered silicate;the largest interlayer distance was 4.7nm when the mass ratio of QCMC to OREC was 2:1. FTIR, XRD, 27Al-NMR, 29Si-NMR and Zetapotential analyses indicated that there was strong interaction between QCMC and OREC. Thermal study demonstrated that the introductionof OREC improved the thermal stability of QCMC. QCMC and nanocomposite nanoparticles with size aound 400nm were preparedvia crosslinking with calcium alginate, and their drug-controlled release properties were investigated. It was found that the incorporationof OREC had important effect on the drug-delivery property of QCMC. In comparison with the nanoparticles made of pure QCMC, thenanoparticles obtained from the nanocomposites could encapsulate BSA more effectively and release the drug more slowly. Therefore, itcan be confirmed that QCMC/OREC nanocomposites are more suitable to be used in the biomedicine field than single QCMC.

The clinical application of apomorphine, a dopamine receptor agonist for treating Parkinsons disease, is limited by its instabilityand the need for frequent injections. In the present work, apomorphine was encapsulated within liposomes to protect it from degradationand enhance the permeability across the blood-brain barrier (BBB). Stearylamine was used to produce a positive surface charge forthe liposomes. The liposomal systems with different compositions were characterized by the mean size, zeta potential, drug encapsulationpercentage, stability, and in vitro release characteristics. PEGylated liposomes and liposomes incorporating Brij 78 showed a size of130~160 nm. When Tween 80 was added to the liposomes, the vesicle size increased to > 260 nm. Apomorphine was successfully entrappedby liposomes with an encapsulation percentage of > 70%, with the systems containing Brij 78 showing the highest level of 99%.The loading of apomorphine into liposomes resulted in slower release behavior compared to the drug in an aqueous solution. In comparisonto free drug, apomorphine in PEGylated liposomes exhibited greater stability in plasma. The in vivo brain uptake of PEGylatedliposomes after an intravenous bolus injection into rats was monitored by in vivo real-time bioluminescence imaging for 1 h. The resultsshowed that the uptake of PEGylated liposomes into the brain was rapid and prolonged. PEGylated liposomes may offer a promisingstrategy for targeting apomorphine to the brain. This opens up new opportunities for treating Parkinsons disease.

The aim of the present work was to evaluate the effects of lipid colloid systems on skin permeation of two antipsoriatic drugs,calcipotriol and methotrexate. Colloidal systems made of Precirol (solid lipid nanoparticles, SLN), Precirol+squalene (nanostructuredlipid carriers, NLC), and squalene (lipid emulsions, LE) as the lipid core material were prepared. Calcipotriol was encapsulated in the innerphase of these carriers due to its high lipophilicity. The hydrophilic methotrexate resided in the aqueous phase of the systems. Particlesizes of SLN, NLC, and LE were 303, 192, and 212 nm, respectively. LE showed a lower negative zeta potential (-20 mV) compared toSLN and NLC (-30 mV). In vitro skin permeation was measured with a Franz assembly. The results showed that lipid colloids increasedcalcipotriol permeation via nude mouse skin by 2.6~3.2-fold over the aqueous control. Application of lipid colloids enhancedmethotrexate penetration by 4.5~10.8-fold. Drug permeation was affected by the composition of the inner phases. The permeation of bothdrugs generally showed a trend of NLC > LE > SLN. The mechanisms of the permeation enhancement by nanoparticles were elucidatedusing various barriers against drug permeation, including delipidized skin, hairy mouse skin, and cellulose membranes. We determinedthat the release rate, partitioning ability to the skin, and enhancer effect were major factors enhancing drug permeation. Occlusivenessand follicular pathways were less important for calcipotriol and methotrexate delivery. The in vivo confocal laser scanning microscopicprofiles confirmed the importance of the partitioning process for lipophilic drugs. The in vivo examination of transepidermal water lossdemonstrated the maintenance of skin integrity after a 24-h application of lipid colloid systems.

Ruthenium Oxide Nanotubes Via Template Electrosynthesis by Rosalinda Inguanta, Germano Ferrara, Patrizia Livreri, Salvatore Piazza, Carmelo Sunseri (210-218).
Ruthenium oxide nanotubes were fabricated by a single-step galvanostatic deposition using porous anodic alumina membraneas template. For the electrodeposition process, we used a electrochemical cell specifically designed in order to employ only 0.5 ml of 0.02M RuCl3-xH2O solution. The deposition from a very small volume was specifically addressed owing to the high cost of ruthenium compounds,which could be of some relevance from an applicative point of view. Several techniques were used to characterize the samplesprior to and after thermal treatment, which was carried out at different temperatures in order to study the crystallization process of the deposit.Raman spectroscopy of as-deposited nanotubes revealed the presence of RuO2 vibrating modes, while XRD patterns did not showRuO2 peaks, consequently the formation of a subnano-crystalline structure was proposed. After thermal treatment at different temperatureabove 600°C, they crystallized in the tetragonal form of RuO2. Both XRD analysis and Raman spectroscopy revealed that crystal size ofthe deposit grew with temperature up to 1000°C. SEM investigations showed the formation of nanotubes having an uniform average externaldiameter, while wall thickness changed throughout the height.

Icosahedral Ni Nanowires Formed from Nanocontacts Breaking: Identification and Characterization by Molecular Dynamics by Samuel Pelaez, Pedro A. Serena, Carlo Guerrero, Ricardo Paredes, Pedro Garcia-Mochales (219-226).
We present and discuss an algorithm to identify and characterize the long icosahedral structures (staggered pentagonalnanowires with 1-5-1-5 atomic structure) that appear in Molecular Dynamics simulations of metallic nanowires of different species subjectedto stretching. The use of this algorithm allows the identification of pentagonal rings forming the icosahedral structure as well as thedetermination of its number np , and the maximum length of the pentagonal nanowire Lp m. The algorithm is tested with some ideal structures to show its ability to discriminate between pentagonal rings and other ring structures. We applied the algorithm to Ni nanowireswith temperatures ranging between 4K and 865K, stretched along the [111], [100] and [110] directions. We studied statistically the formationof pentagonal nanowires obtaining the distributions of length Lp m and number of rings np as function of the temperature. TheLp m distribution presents a peaked shape, with peaks located at fixed distances whose separation corresponds to the distance between twoconsecutive pentagonal rings.

Fabrication, Microstructure and Properties of Zinc Oxide Nanowhisker Reinforced Lead Zirconate Titanate Nanocomposites by Da-Wei Wang, Mao-Sheng Cao, Jie Yuan, Hai-Bo Lin, Quan-Liang Zhao, De-Qing Zhang (227-234).
Zinc oxide nanowhisker (ZnOw) reinforced lead zirconate titanate (PZT) nanocomposites were prepared by a conventionalsolid state processing. The incorporation of ZnOw has effects on microstructures, electrical and mechanical properties of PZT/ZnOwnanocomposites. Microstructure studies show that ZnOw dispersed in the PZT matrix leads to the decline of grain size and change of fracturemode for the PZT/ZnOw nanocomposites. Mechanical properties of the nanocomposites are dependent upon the content of ZnOwnonlinearly and could be improved significantly with small addition of ZnOw. In particular, the compression and fracture strengths of thePZT/2wt.% ZnOw nanocomposites sintered at 1200°C are approximately 180% and 150% of the monolithic PZT, respectively. Electricalproperties of the nanocomposites could be evidently adjustable with different additions of ZnOw. The new piezoelectric nanocompositeswith good electrical and excellent mechanical properties are promising candidates for further applications.

Low-Dimensional Carrier Statistics in Nanostructures by Rabia Qindeel, Munawar A. Riyadi, Mohammad Taghi Ahmadi, Vijay K. Arora (235-239).
The carrier statistics in a low-dimensional nanostructure with length in one or more of the three dimensions plummeting belowcarriers De Broglie wavelength is investigated. The probability distribution, the Fermi level, intrinsic velocity, and energy of the carriersare sternly affected on reducing dimensionality from 3-dimensional (3-D) bulk configuration. The carrier statistics for degenerate andnon-degenerate regimes for nanostructures is worked out with an emphasis to predict the ultimate carrier velocity in a high electric field.The general results presented are applicable to all materials once the carrier concentration and ambient temperature are identified.

Eliminated UV Light Emitted from Nanostructured Silica Thin Film using H2 Plasma by ICP-CVD by Ding-Liang Chiang, Min-Hsiung Hon, Lay Gaik Teoh, Jiann Shieh, Bing-Ming Cheng, Hsiao-Chi Lu, Hsu-Chun Cheng (240-244).
Nanostructured mesoporous silica thin film has been deposited on silicon substrate by the spin-coating technique using CTABas a template under acidic conditions. TGA, SEM, HRTEM, N2 adsorption-desorption isotherm, FTIR and synchrotron high flux beamlinewere used to characterize the microstructure and photoluminescence properties of the resulting film. After being calcined at 400 oCfor 12 h, the thin film exhibited a very smooth surface and interconnected pores, with a pore size of about 1-2 nm. The synchrotron photoluminescencespectra show that the samples after calcination have three obvious luminescence peaks around 322, 387 and 410 nm arisingfrom nonbridging oxygen hole centers (NBOHCs) and Si-OH surface complexes. The UV emission (322 nm) due to NBOHCs is inhibitedby H2 plasma treatment, indicating that the nonbridging oxygen was saturated by the hydrogen atoms.

We present a compact, semi-empirical model of Carbon Nanotube Field Effect Transistors (CNTFETs) directly and easily implementablein simulation software. A new procedure, based on a best-fitting between the measured and simulated values of output device characteristics, is proposed in orderto extract the optimal values of the CNTFET equivalent circuit elements.To verify the versatility of the proposed model, we use it in circuit simulators to design some electronic circuits. In particular we investigateabout the effects of the CNT quantum resistances and inductances, then demonstrating their role for both analog and digital applicationsat frequencies over about ten THz.

Microwave-Assisted Synthesis of Shuttle-shaped Single-Crystalline Te Nanotubes Decorated with Spherical Particles by Guangbin Ji, Lei Guo, Xiaofeng Chang, Yousong Liu, Lijia Pan, Yi Shi, YouLiao Zheng (254-259).
Shuttle-shaped single-crystalline Te nanotubes decorated with spherical particles on outer surface have been successfully synthesizedin reaction media of polyol solvent through a simple and rapid microwave-assisted approach. The length, outer diameter andwall thickness of as-synthesized Te nanotubes were roughly measured at 5-15 im, 300-500 nm and 100-150 nm, respectively. The crystalgrowth process of Te nanotubes was investigated and discussed as the key issue of this present study, and it was found that the scrollinggrowth-based mechanism would best account for the formation process of the shuttle-shaped Te nanotubes. Photoluminance (PL) measurementsdisplayed that the as-synthesized Te nanotubes can not only give strong violet blue emission but also strong red emission, andsuch unique optical property could be beneficial for nano-optical applications.

The Production of Nickel(hydr)Oxide Nanostructures Via the Thermolysis of Metalorganic Frameworks by Fatemeh Mohandes, Fatemeh Davar, Masoud Salavati-Niasari, Kamal Saberyan (260-266).
For the first time, we report the novel synthesis of flocculus-like spheres of nickel hydroxy hydrate with grain size of ~7nm viathe thermolysis of nickel phthalate polymer. Nickel phthalate polymer formulated as [Ni(Pht)(H2O)]n was simply prepared via a precipitationprocedure by mixing of 1,2-benzenedicarboxylic acid (phthalic acid) to nickel acetate salt under basic condition. Nickel hydroxy hydratenanostructures were obtained by thermolysis of [Ni(Pht)(H2O)]n polymer in the presence of oleic acid (OA) at 190 oC and NiOnanoparticles were formed via the thermolysis of nickel phthalate polymer in the presence of oleic acid and triphenylphosphine (TPP) athigher temperature. Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electronmicroscopy (SEM) and transmission electron microscopy (TEM) were applied for the characterization of products. The magnetic propertyof NiO nanoparticles were studied with vibrating sample magnetometer (VSM) at 300 K.

This paper proposes selective deposition of electrospun alginate-based nanofibers through a charged shadow mask to form anarray of nonwoven microspots on cell-repelling hydrogel surfaces; subsequently, the target cells are seeded onto these nanofiber-basedextracellular matrix (ECM) scaffolds to create cell-based microarrays. The needle tip contains a drop of a blended solution of alginate andpolyethylene oxide (PEO); an Al-coated glass shadow mask with micron-sized holes was used for selective deposition to form the patternedmicrospots of nonwoven mats. The shadow mask was applied with a suitable voltage to repel the nanofibers from its surface,while simultaneously forcing them into the micron-sized holes and onto the cell-repelling hydrogel surface. The electric-field distributionof the electrostatic focusing through the charged shadow masks was numerically simulated and characterized. The experimental resultsshow that when the shadow mask is applied with a higher voltage, a larger dense central spot will be produced within the hole; in addition,the diameter is significantly reduced but the degree of diameter uniformity among the electrospun nanofibers improves. An arrayof 3..3 nonwoven microspots was successfully demonstrated to selectively deposit alginate-based nanofibers for cell patterning. BHK-21fibroblast cells were shown to selectively adhere onto the nonwoven microspot surfaces due to the existence of the cell-repelling hydrogelaround the microspots. The presented technique is simple and does not require complex surface modifications to selectively seedthe target cells onto these micron-sized nanofiber-based ECM scaffolds for potential applications in cell biology and tissue engineering.

Effect of Bimodal Size Distribution on Optical Properties of CdSe Nanocrystals by S.N. Sarangi, A.M.P. Hussain, S.N. Sahu (275-281).
Effect of bimodal size distribution (BSD) on optical properties of electrodeposited CdSe nanocrystalline thin films is reported.Grazing angle X-ray diffraction identifies two different nanocrystalline size regimes with both compressive and tensile strains coexistingin the same sample. The two size regimes change their size with the change of electrodeposition current density or temperature. Opticalabsorption studies reveal two absorption edges corresponding to the two different sizes. Presence of two well separated photoluminescence(PL) bands due to excitonic recombination supports the presence of BSD in the sample which is also confirmed from temperaturedependent PL measurements. The origin of the two PL bands are attributed to the transfer of thermally activated carriers between twosize regimes accompanied by excitonic recombination. Micro Raman scattering of nanocrystalline CdSe at 300K showed softening ofRaman phonon modes due to small size nanocrystallites but do not reflect the BSD effect.

Er-Doped ZnO Nanorod Arrays with Enhanced IR Emission by Using Au Island Films by Jian-Wei Lo, Chin-An Lin, Jr-Hau He (282-287).
Self-assembled nanorod array (NRA) heterostructures consisting of single-crystalline Er-doped ZnO NRAs on Au island filmshave been synthesized by a chemical method and proposed as one of the promising optoelectronic materials since the Er intra-4f shelltransition leads to 1540 nm emission for optical communication. The microstructural analysis, electronic structure analysis, and photoluminescencecharacterizations have been performed. The enhanced 1540 nm emission of Er-doped ZnO NRAs is due to the enhancementof deep level emission of ZnO host, which results from local field enhancement effects of Au island films, and subsequent energy transferto Er3+

The aim of this article is to provide a systematic method to perform experimental test and theoretical evaluation on adhesionproperties of the Cr/Al interface structure. A specified Cr/Al interface film assembly was deposited on the quartz glass by using RF magnetronsputtering. The elastic modulus and the hardness of the sample are tested by the nanoindentation tester. The test results show thatthe elastic modulus and the hardness of the sample have a nonlinear characteristic with different depth h of the interface structure. In themeantime, a finite element model is built to simulate the interface characteristics of the sample. The analysis shows that the stress mainlycentralizes close to the top of the nanoindentation tester and the maximum stress occurs in the second layer Al film, not the first layer Crfilm. The comparison between the test and the simulation shows the validity of the experimental test and the modeling method of eachother. It builds a basis for future work such as fabrication of Cr/Al interface structure for micro/nano manufacturing.