A VANET privacy protection scheme based on fair blind signature and secret sharing algorithm

Vehicular ad hoc network (VANET) is a traffic application of wireless sensor network, which is also a new mobile ad hoc networks composed of vehicle nodes, roadside units, service providers and other components. In VANET, data is transmitted by the wireless channel, which is subject to potential threat like information leak and data attack due to the openness and sensitivity of the auto organization network itself. How to ensure the identity privacy and trusted communication in VANETs is the key issue to be solved urgently. The existing work usually uses authentication mechanism, but the user’s privacy disclosure is inevitable during the authentication process. Some anonymous authentication schemes have been proposed to solve the problem of privacy disclosure regardless of considering anonymity abuse. However, anonymity abuse is also severe in VANET. In view of the above problems, this paper proposes a scheme based on fair blind signature and secret sharing algorithm. By security analysis and experiment, the scheme has been proved to be higher anonymity and higher efficiency

Synthesis of dumbbell-like ZnO microcrystals via a simple solution route

National Natural Science Foundation of China [81000660]; National Nature Science Foundation of China [90923042]; Xiamen Science and Technology project [3502Z20123001]Uniform dumbbell-like ZnO microcrystals had been successfully fabricated on a large scale via a facile solution technique under mild conditions. Obtained ZnO, with length of 1.2 to 1.6 mu m and diameters of 350 to 600 nm, exhibited well-defined dumbbell-like morphology and hexagonal wurtzite structure and grew along the [001] direction. Effects of the reactant concentration on the sizes and morphologies of the ZnO products had been investigated, indicating that the reactant concentration played a crucial role in determining final sizes and shapes of the samples. In addition, the growth process of the dumbbell-like ZnO microcrystals was studied, and a possible formation mechanism was proposed. Furthermore, the optical properties of ZnO samples obtained at various reaction times were also investigated by photoluminescence (PL) spectroscopy. The PL spectra of the as-prepared dumbbell-like ZnO microcrystals showed a strong UV emission peak

Phytosomes Loaded with Mitomycin C-Soybean Phosphatidylcholine Complex Developed for Drug Delivery

A novel formulation system of phytosomes loaded with mitomycin C soybean phosphatidylcholine (MMC-SPC) complex (MMC-loaded phytosomes) was prepared by a solvent evaporation method combined with a nanoprecipitation technique for the purpose of development of an MMC drug delivery system. The MMC-loaded phytosomes were evaluated by average particle size, zeta-potential, and residual drug-loading content as well as an in vitro drug release profile. Furthermore, in vitro stability tests and in vitro/vivo biological evaluations of the MMC-loaded phytosomes were performed. DSC, FTIR, and XRD demonstrated that MMC interacted physically with SPC within the phytosomes. DLS and ELS described a dispersion with an average particle size of 210.87 nm, a narrow size distribution (PDI 0.251), and a zeta-potential of -33.38 mV. SEM, TEM, and AFM images showed that the MMC-loaded phytosomes were spherical and intact vesicles. In vitro stability tests demonstrated that the average particle size and residual drug-loading content of the MMC-loaded phytosomes had no evident change at different storage conditions. In vitro drug release profiles indicated biphasic behavior with an initial burst release, followed by a subsequent prolonged sustained release. In vitro cytotoxicity assays with H-22 cells showed that the MMC-loaded phytosomes had remarkable cytotoxicity. In vivo antitumor effect of the MMC-loaded phytosomes also revealed a dose-dependent and superior curative inhibitory effect on tumor growth without loss of body weight compared to free MMC. Histopathological analysis of specimens taken from tumor tissues indicated that MMC-loaded phytosomes had lethal effect to hepatoma cell. These findings suggested that the MMC-loaded phytosomes can serve as a promising and effective formulation for drug delivery and cancer therapy

Development of multifunctional folate-poly(ethylene glycol)-chitosan-coated Fe3O4 nanoparticles for biomedical applications

The efficacy of magnetic nanoparticles (MNPs) for biomedical applications depends on the specic targeting capacity, blood circulation time and magnetic susceptibility. Functionalized chitosan-coated Fe3O4 nanoparticles (CS-coated Fe3O4 NPs) were synthesized by a non-solvent-aided coacervation procedure followed by a chemical crosslinking procedure. The surfaces of CS-coated Fe3O4 NPs were successfully functionalized with folate-poly(ethylene glycol)-COOH (FA-PEG) to obtain novel FA-PEG-CS-coated Fe3O4 NPs endowed with long blood circulation and specic targeting capacity. The as-synthesized NPs were characterized by dynamic light scattering, transmission electron microscope, X-ray diffraction, thermal gravimetric analysis, vibration sample magnetometer, Fourier transform infrared spectroscopy, and confocal laser scanning microscopy. As a result, the novel FA-PEG-CS-coated Fe3O4 NPs showed excellent biocompatibility, magnetic properties, good dispersibility, and proper hydrodynamic sizes in an aqueous medium. The specific targeting capacity of the as-synthesized NPs to cancer cells was also investigated. It was observed that the uptake of the FA-PEG-CS-coated Fe3O4 NPs by HeLa cells was significantly enhanced compared to the CS-coated Fe3O 4 NPs and mPEG-CS-coated Fe3O4 NPs. These results clearly indicate that our novel FA-PEG-CS-coated Fe3O 4 NPs with remarkable specific targeting capacity, long blood circulation, and superparamagnetism hold great promise for biomedical applications, including targeted drug delivery and hyperthermia therapy. [Figure not available: see fulltext.] ? 2014 The Polymer Society of Korea and Springer Sciene+Business Media Dordrecht

A comparative in vitro evaluation of self-assembled PTX-PLA and PTX-MPEG-PLA nanoparticles

National Natural Science Foundation of China [81000660, 31271071]; Xiamen Science and Technology Project [3502Z20123001, 3502Z20114007]We present a dialysis technique to direct the self-assembly of paclitaxel (PTX)-loaded nanoparticles (NPs) using methoxypolyethylene glycol-poly(d,l-lactide) (MPEG-PLA) and PLA, respectively. The composition, morphology, particle size and zeta potential, drug loading content, and drug encapsulation efficiency of both PTX-PLA NPs and PTX-MPEG-PLA NPs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, dynamic light scattering, electrophoretic light scattering, and high-performance liquid chromatography. The passive targeting effect and in vitro cell viability of the PTX-MPEG-PLA NPs on HeLa cells were demonstrated by comparative cellular uptake and MTT assay of the PTX-PLA NPs. The results showed that the PTX-MPEG-PLA NPs and PTX-PLA NPs presented a hydrodynamic particle size of 179.5 and 441.9 nm, with a polydispersity index of 0.172 and 0.189, a zeta potential of -24.3 and -42.0 mV, drug encapsulation efficiency of 18.3% and 20.0%, and drug-loaded content of 1.83% and 2.00%, respectively. The PTX-MPEG-PLA NPs presented faster release rate with minor initial burst compared to the PTX-PLA NPs. The PTX-MPEG-PLA NPs presented superior cell cytotoxicity and excellent cellular uptake compared to the PTX-PLA NPs. These results suggested that the PTX-MPEG-PLA NPs presented more desirable characteristics for sustained drug delivery compared to PTX-PLA NPs