Current Nanoscience - Volume 14, Issue 4, 2018

Background: Vinorelbine bitartrate (VB), an important anticancer drug, is used to treat varieties of cancers in clinical, but its side effects when directly administered as an aqueous solution limit its application. Objective: To test anti-tumor activities of folate-decorated vinorelbine bitartrate-loaded recombinant human serum albumin nanoparticles (FA-rHSA-VBNPs). Method: A desolvation procedure was used to prepare vinorelbine bitartrate nanoparticles, then crosslinked with recombinant human serum albumin, and finally decorated with folic acid. The nanoparticles #39; surface morphology and particle size distribution were investigated in vitro. The in vitro antiproliferative activities were tested by the MTT assay, and the in vivo anti-tumor activities were investigated using S180 bearing mice. Result: We obtained spherical nanoparticles of 180 nm, and its size distribution was narrow. FArHSA- VBNPs and VB injection inhibited HO-8910, SK-OV-3, MCF-7, MX-1 and A-549 well, but showed little effect on Bel-7402, HepG-2 and PC-3. At 2 mg/kg, VB-FA-rHSANPs inhibited S180 by 83.20%, whereas VB injection inhibited 63.50%. Conclusion: In general, FA-rHSA-VBNPs exhibited much better cytotoxicity to all cancer cell lines than VB injection, and showed a dose-dependent effect in the survival towards the eight tumor cell lines. The cytotoxicity of FA-rHSA-VBNPs and VB injection on HO-8910 was significantly stronger than on the other seven human cancer cell lines. FA-rHSA-VBNPs showed much better anti-tumor activity against S180 than VB injection. FA-rHSA-VBNPs showed much better activities than VB injection both in vitro and in vivo anticancer tests.

Background: Titanium dioxide is the most suitable photocatalyst because of its biological and chemical inertness, cost effective and strong oxidizing power of its photo generated hold. Method: Both un-doped and Ag doped titanium dioxide were prepared by the sol-gel method. Tetraisopropyl orthotitanate was used as a precursor and calcined at 400°C for 3 h. The structural characteristics of the powders were studied by X-ray diffraction, Fourier transform infrared spectroscopy, and with a scanning electron microscope equipped with energy-dispersive X-ray spectrometry. The morphology was investigated by SEM imaging. The rutile phase was observed in XRD patterns in the case of 0.5% Ag doping. Result: The rutile phase was observed in XRD patterns in the case of 0.5% Ag doping. The results from photodegradation indicated that 0.1% and 0.5% Ag doped TiO2 exhibited higher activity than the un-doped TiO2 powder. Conclusion: The photocatalytic activity was enhanced to 72% by doping with Ag. The degradation kinetics were well described by a pseudo-second order kinetic model.

Background: In clinical applications, the treatment for the damaged tissue caused by disease, injury and trauma is done by autograft and allograft which replace the damaged organs. But, these treatments possess certain disadvantages like limited donor supply, being very expensive and infectious. Recently, the tissue engineering has emerged as a promising and alternate technique for repairing the damaged tissue without any replacement of the damaged organ. The tissue engineering technique comprises scaffolds made of biomaterials which could be able to adhere and proliferate the cells for new tissue growth. Objective: In this present study, polyurethane (PU) nanofiber incorporated with synthesized zinc oxide nanoparticles (ZnNPs) and virgin coconut oil (VCO) was successfully fabricated for tissue engineering applications using single stage electrospinning technique. Methodology: The ZnNPs nanoparticles were obtained through green synthesis by precipitation method using Coriandrum sativum (CS) aqueous leaf extracts. The prepared nanoparticles were examined by UV-VIS spectroscopy absorption, Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDS). The obtained ZnNPs from green synthesis was further incorporated into the PU matrix along with VCO using electrospinning technique. The fabricated nanocomposites were characterized through Scanning Electron Microscopy (SEM), Fourier- transform infrared spectroscopy (FTIR) and contact angle measurements. Results: The obtained nanoparticles using Coriandrum sativum (CS) aqueous leaf extracts exhibited absorption peak in the range of 285- 300 nm as revealed in the UV-VIS spectroscopy absorption. Further, the size of synthesized ZnNPs nanoparticles obtained from 40%, 80% and 100% CS extract was found to be 740 ± 53 nm, 542 ± 47 nm and 487 ± 61 nm using Image J. Moreover, Fourier- transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDS) confirmed the presence of zinc oxide. In the electrospun PU-VCO-ZnNPs membranes, the addition of ZnNPs and VCO into the polymer matrix reduced the fiber diameter in the range of 687 ± 208 nm and also pore diameter in the range of 1069 ± 259 nm compared to pure PU (Fiber diameter- 742 ± 185 nm and Pore diameter- 1382 ± 219 nm). FTIR revealed the existence of zinc oxide and VCO in PU by the formation of hydrogen bond. Further, energy-dispersive X-ray spectroscopy (EDS) also confirmed the presence of zinc oxide by showing 0.274% weight percentage in the PU matrix. Moreover, the contact angle measurements revealed the increasing hydrophobic nature of the prepared hybrid nanocomposites (91.6 ± 1.78°) compared to pure PU (80.9 ± 3.15°). Conclusion: The developed PU-VCO-ZnP nanocomposites with enhanced physiochemical characteristics might be suitable for the tissue engineering applications.

Objective: The next generation wireless communication systems are a major research concern of THz systems. The THz band offers very large bandwidth which is required for applications involving ultra high data rates. The objective of this research paper is therefore, greatly focused on the design and analysis of an ultra wideband antenna providing bandwidth enhancement. The use of graphene patch as conducting material in the antenna possesses enormous potential to enhance gain, radiation efficiency, radiated power and bandwidth on account of extraordinary electromagnetic properties and functionalities of the graphene material. Method: The graphene based nano-antenna has been accurately designed using finite element method (FEM) based high frequency simulator (HFSS) software. This design introduces truncated corners/edges in square nano-patch antenna with semi-circular radius of 0.7 μm to the microstrip feeding line on SiO2 as substrate with thickness of 1.8 μm and permittivity of εr= 4 in THz region. Result: The proposed design achieves the impedance bandwidth of 1.39 THz at 13.0 THz, 1.36 THz at 15.0 THz and more than 5THz at 18.0 THz. The 3D plot depicts gain and directivity, having maximum value of 7.1011 dB and 7.2781 dB respectively at the resonant frequency. Truncations in the antenna introduce co polarization and cross polarization. Further the radiation efficiency for graphene based arc truncated square patch antenna on silicon dioxide substrate is determined as a function of frequency for operating frequency band and has been observed to be more than 90% at respective resonant frequencies. Conclusion: The performance of graphene based antenna has been evaluated considering equally truncated arcs on its opposite corners and their effect on antenna characteristics is analyzed by determining different parameters including bandwidth, return loss, VSWR, directivity, gain, radiation efficiency, 2D and 3D radiation patterns. The antenna provides improved impedance bandwidth of more than 5 THz in the band of operation from 10 to 20 THz. Moreover the gain, directivity and radiation efficiency achieved are much improved for the proposed graphene antenna.

Background: Polyphenolics such as curcumin suffer from low aqueous solubility and extensive first pass metabolism which resulted in reduced oral bioavailability. Nanoformulations are increasingly investigated to overcome these obstacles and enhance the bioavailability of these polyphenolic bioactives. Objective: The objective of the present work is to develop a novel ethylcellulose based curcumin nano-delivery system for controlled release and enhanced antioxidant activities. Method: Nanoparticles were prepared following a simple nanoprecipitation method. Preformulation study was conducted through DSC and FTIR spectroscopy which showed that both the drug and the polymer were compatible. The surface morphology, particle size distribution and zeta potential of the nanoparticles were also analyzed along with drug release mechanism and antioxidant activities. Result: The Z-average (d) of the nanoparticle was found to be 472 nm and the particles were found to possess a negative zeta-potential. The aqueous dispersibility of curcumin was significantly improved by the nanoparticulate formulation. Sustained release for over 12 hours was achieved and the release mechanism was found to be Fickian diffusion. Conclusions: Determination of DPPH and LPO inhibition activity indicates that the nanoparticulate formulation of curcumin resulted in significant enhancement of its antioxidant activities.

Background: Considerable interest is observed in the usage of nanomaterials in medicine and medical diagnostics. Quantum dots powerful fluorescent probes, seem to be interesting agents for medical imaging that could be used to label cells for cellular tracing as well as for traceable drug/gene delivery. It is expected that their use can be crucial in pharmacokinetic and pharmacodynamic studies of drug candidates. However, their widespread and safe use must be preceded by examination of their toxicity. Method: A group of quantum dots (CdS, CdSe, CdTe), which contains cadmium ions in its core composition has been chosen for biological activity studies – examination the effect of surface chemistry for their toxicity (MTT test). Result: Quantum dots usually are hydrophobic due to inorganic core with chains of hydrophobic ligands (TOP/TOPO) remaining after synthesis. Exchange of the ligand for the hydrophilic one enables dispersion of QD in water, application to the living organisms and assessment of their influence using in vitro models. In this study, we report how modification of the surface of CdX quantum dots (with and without ZnS coating) affects their biological activity. Conclusion: Three different ligands (cysteine, dihydrolipoic acid-DHLA, and mercaptoundecanoic acid-MUA) and two cell lines MRC-5 and A549 (similar origin and function, different proliferation – one was normal, another was carcinoma) were used to test thoroughly biological activity of surface- modified CdX quantum dots.

Background: In recent years, admirable research is being conducted on phyto-organic moieties from diverse biological sources for use as green bimetallic catalysts in organic pollutant degradation has a modern green nanoscience and technology for the green bimetallic catalyst for organic pollutant degradation. Furthermore, due to the lack of abundance of monometallic source materials, the researcher dedicated their efforts, to produce ultra-small bimetallic nanomaterials owing to their high stability, synergetic effect on catalytic behavior. In this connection, our present investigation focuses on the utilization of biomolecules from mushrooms to fabricate green goldpalladium (Au/Pd) bimetallic quantum dots (QDs) for the degradation of an organic dye (methylene blue). Method: The approach can reduce the usage of harmful chemicals and environmentally harmless. Moreover, the ultra-small structures possess high catalytic behavior, which can be used for industrial and environmental processes such as pollutant oxidation in exhaust catalytic converters. The reduction and formation of bimetallic catalysts were investigated by UV-Vis spectroscopy. The surface morphology and size of the QDs were analyzed from TEM images. The crystalline nature of the Au/Pd QDs was characterized by SAED and X-ray diffraction patterns. Result: FT-IR investigation revealed the interaction between the QDs and the surface-adsorbed (physiochemical) biomolecules responsible for the possible pathway of the reduction and stabilization of the QDs. Conclusion: The Au/Pd QDs synthesized by using biomimetic approach showed excellent catalytic properties and could be used in the degradation of the organic dye in the presence of NaBH4.

Background: Lovastatin (LOV), a highly lipophilic drug associated with poor oral bioavailability, belongs to the class of cholesterol lowering drugs. With the objective to improve the solubility and to attain sustained release, solid lipid nanoparticles (SLNs) have been formulated. Method: Lovastatin loaded solid lipid nanoparticles (LOV-SLNs) were prepared by pre-emulsion and probe sonication method. LOV-SLNs were studied by Atomic Force Microscope (AFM), Differential Scanning Calorimetry (DSC) and Reverse Phase High Performance Liquid Chromatography (RP-HPLC). Result: The particle size and zeta potential of optimized formulation were found to be 169.4±14.1 nm and -24.1 mV, respectively. Conclusion: The in vitro drug release studies confirmed the sustained release nature of the formulation and revealed that the drug released from the prepared LOV-SLNs is the combination of dissolution, diffusion and erosion. The data obtained from in vitro dissolution study show that LOV-SLNs is a promising colloidal system which could significantly improve the oral bioavailability of LOV by improving the solubility.

Background: Ultrasound can destroy target tissue through various mechanisms, such as acoustic cavitation which can be fatal to cells. The existence of nanoparticles in a liquid provides nucleation sites for the cavitation bubbles and this leads to increase in the quantity of bubbles. Objective: In this study, we investigated the combination effect of gold nanoparticles and therapeutic ultrasound waves on 4T1 cells. Method: The 4T1 cells were incubated with gold nanoparticles for 24, 48 and 72 h and divided into 4 groups: (1) control, (2) gold nanoparticles, (3) ultrasound waves alone (4) ultrasound waves in the presence of gold nanoparticles. Cell viability assay was used for the detection of cytotoxicity effects. Results: The results showed a significant decrease in viability of cells which were irradiated with ultrasound waves in the presence of gold nanoparticles. Conclusion: Acoustic cavitation in the presence of nanoparticles has been presented as a way to increase therapeutic effects on cells.

Background: Due to the high theoretical specific capacity and energy density, lithium– sulfur batteries are regarded as promising next-generation energy storage devices. However, they suffer from rapid capacity fading and poor cyclic stability, which is far from the practical application. Developing an effective sulfur impregnation method is of great importance, especially meeting the demand for large-scale commercial application. In this work, we have prepared reduced graphene oxide (rGO) via microwave method as the host for high-performance sulfur cathode and three methods (melt-diffusion method, chemical precipitation method and chemical precipitation-melt diffusion method) have been explored to synthesize rGO@S composites for high-performance lithium-sulfur batteries. Method: Graphene oxides (GO) were prepared from natural graphite by modified Hummer's method. Then reduced graphene oxide (rGO) was synthesized by microwave method. rGO@S composites were prepared by melt-diffusion method, chemical precipitation method and chemical precipitation- melt diffusion method. The galvanostatic charge/discharge measurements and electrochemical impedance spectroscopy were analyzed to obtained the overall performance of lithiumsulfur batteries. Result: The chemical precipitation-melt diffusion method is an effective strategy to achieve appropriate sulfur encapsulation, where smaller sulfur is impregnated uniformly into abundant pores of rGO matrix. As a result, the CM-rGO@S composite delivers a high initial discharge capacity of 1108.8 mAh g-1 at a current density of 0.2 C, and maintains a stable capacity of 751.3 mAh g-1 after 80 cycles. Furthermore, the CM-rGO@S composite exhibits enhanced cyclic stability and excellent rate capability, delivering a capacity of 598.4 mAh g-1 after 200 cycles at a high current density of 0.5 C with a capacity retention of 65.8%. Conclusion: In summary, the rGO@S composite prepared by chemical precipitation-melt diffusion method shows outstanding electrochemical performance, such as superior cycle stability and excellent rate capability. It demonstrated that the chemical precipitation-melt diffusion method is an effective strategy to achieve appropriate sulfur encapsulation, where smaller sulfur is impregnated uniformly into abundant pores of rGO matrix. We believe that this attempt can give insights on the other cathode preparation for achieving high performance lithium-sulfur batteries.

Background: Co3O4 in nano-size has been found efficient in electronic and optoelectronic devices. P-type semiconductor behavior, typical spinel crystal structure, and dual optical band gap extend the practical application of Co3O4 nanoparticles. Objective: The main objective of the presented work is to exploit the Co3O4 nanoparticles as chemisensor and dielectric material. Method: Nanoparticles of Co3O4 was prepared by hydrothermal method. The structural and optical properties of as-grown nanoparticles were investigated by powder XRD, FE-SEM, EDS, FTIR, UVVIS- NIR spectrophotometer, and Raman spectrometer. Sensing, and dielectric properties were explored by measuring the response of current versus voltage (I-V), and capacitance versus frequency (C-f), respectively. Result: As-grown nanoparticles exhibited the distinguished properties, such as: well crystalline cubic structure of lattice parameter (a = 8.083 ũ, comparable crystallite (~ 60 nm) and particle sizes (~ 65nm), dual optical energy band gaps (1.75 eV, 3.1 eV), the high value of sensitivity (31.48 μA mM- 1cm-2) and dielectric constant, low value of dielectric loss, and a good ac conductivity. Low value of dielectric loss indicates the purity and a good optical behavior of the material. A possible sensing mechanism has been explained, and a factual method of data evaluation has been authenticated. Conclusion: As-gown nanoparticles were found suitable for chemi-sensor and capacitor. Low particle size, p-type conductivity, dual energy band gap, well crystalline nature, the high value of dielectric constant, low value of dielectric loss, and good ac conductivity demonstrate the potential candidature of Co3O4 nanoparticles as efficient charge carriers in chemical sensors and capacitors.