Facile synthesis of monodispersed Fe2O3 nanoparticles and its cellular uptake and cytotoxicity studies.

Monodispersed Fe2O3 nanoparticles were fabricated with a facile hydrothermal synthetic route by using Fe(NO3)3 x 7H2O and glycin as reagents without using any templates or surfactants in this report. The prepared nanoparticles were pure hexagonal alpha-Fe2O3 particles from the characterization of XRD analysis. The Fe2O3 nanoparticles with a narrow size distribution and a mean diameter of - 50 nm can be well dispersed in water. Cellular uptake and cellular responses of the as-prepared Fe2O3 nanoparticles for human cancer cells have been studied. The Fe2O3 nanoparticles can be readily uptake by the cells, but no obvious oxidative damages in the cells can be detected after an incubation of 24 h. Also the treatment of Fe2O3 nanoparticles did not induce any changes in cell viability and cell proliferation. These results demonstrate that the Fe2O3 nanoparticles prepared with our method are remarkably biocompatible, which can be used as a substitute with high biosafety for the present iron oxides materials in different kinds of applications.

Composite hybrid membrane of chitosan-silica in pervaporation separation of MeOH/DMC mixtures.

Chitosan-silica hybrid membranes (CSHMs) were prepared by cross-linking chitosan (CS) with 3-aminopropyl-triethoxysilane (APTEOS). The dynamic behaviors of the CS membrane and the CSHM were investigated in pervaporation (PV) of methanol/dimethyl carbonate (MeOH/DMC) mixtures. The membranes were characterized by X-ray diffraction (XRD), contact angle meter, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The transition state of PV processes were studied. During the PV processes, the amorphous region of the membranes increases and the contact angle between MeOH and the membrane decreases within a range of operating time and then remains almost constant implying a reconstruction occurred on the membrane surface. The silica is well distributed in the CSHM matrix and the thermal stability of the CSHM is enhanced. The time for a PV process to reach a steady state decreases with increasing MeOH concentration or feed temperature, and it is longer for the CSHM than the CS membrane under the same operating condition. Swelling experiments show that the degree of swelling (DS) is greatly depressed by cross-linking CS with APTEOS. Sorption data indicate that the selectivity of solubility and diffusion of the CSHM are greatly improved over the CS membrane. The CSHM presents superior separation behaviors over other membranes with a flux of 1265 g/(hm(2)) and separation factor of 30.1 in PV separation of 70 wt% MeOH in feed at 50 degrees C.

In vivo study of doxorubicin-loaded cell-penetrating peptide-modified pH-sensitive liposomes: biocompatibility, bio-distribution, and pharmacodynamics in BALB/c nude mice bearing human breast tumors.

In vivo evaluation of drug delivery vectors is essential for clinical translation. In BALB/c nude mice bearing human breast cancer tumors, we investigated the biocompatibility, pharmacokinetics, and pharmacodynamics of doxorubicin (DOX)-loaded novel cell-penetrating peptide (CPP)-modified pH-sensitive liposomes (CPPL) (referred to as CPPL(DOX)) with an optimal CPP density of 4%. In CPPL, a polyethylene glycol (PEG) derivative formed by conjugating PEG with stearate via acid-degradable hydrazone bond (PEG2000-Hz-stearate) was inserted into the surface of liposomes, and CPP was directly attached to liposome surfaces via coupling with stearate to simultaneously achieve long circulation time in blood and improve the selectivity and efficacy of CPP for tumor targeting. Compared to PEGylated liposomes, CPPL enhanced DOX accumulation in tumors up to 1.9-fold (p<0.01) and resulted in more cell apoptosis as a result of DNA disruption as well as a relatively lower tumor growth ratio (T/C%). Histological examination did not show any signs of necrosis or inflammation in normal tissues, but large cell dissolving areas were found in tumors following the treatment of animals with CPPL(DOX). Our findings provide important and detailed information regarding the distribution of CPPL(DOX) in vivo and reveal their abilities of tumor penetration and potential for the treatment of breast cancer.

An efficient PEGylated liposomal nanocarrier containing cell-penetrating peptide and pH-sensitive hydrazone bond for enhancing tumor-targeted drug delivery.

Cell-penetrating peptides (CPPs) as small molecular transporters with abilities of cell penetrating, internalization, and endosomal escape have potential prospect in drug delivery systems. However, a bottleneck hampering their application is the poor specificity for cells. By utilizing the function of hydration shell of polyethylene glycol (PEG) and acid sensitivity of hydrazone bond, we constructed a kind of CPP-modified pH-sensitive PEGylated liposomes (CPPL) to improve the selectivity of these peptides for tumor targeting. In CPPL, CPP was directly attached to liposome surfaces via coupling with stearate (STR) to avoid the hindrance of PEG as a linker on the penetrating efficiency of CPP. A PEG derivative by conjugating PEG with STR via acid-degradable hydrazone bond (PEG2000-Hz-STR, PHS) was synthesized. High-performance liquid chromatography and flow cytometry demonstrated that PHS was stable at normal neutral conditions and PEG could be completely cleaved from liposome surface to expose CPP under acidic environments in tumor. An optimal CPP density on liposomes was screened to guaranty a maximum targeting efficiency on tumor cells as well as not being captured by normal cells that consequently lead to a long circulation in blood. In vitro and in vivo studies indicated, in 4 mol% CPP of lipid modified system, that CPP exerted higher efficiency on internalizing the liposomes into targeted subcellular compartments while remaining inactive and free from opsonins at a maximum extent in systemic circulation. The 4% CPPL as a drug delivery system will have great potential in the clinical application of anticancer drugs in future.

Atypical imaging observations of branchial cleft cysts.

The aim of the present study was to assess the atypical imaging manifestations of branchial cleft cysts (BCCs) confirmed by pathology. Computerized tomography (CT) or magnetic resonance imaging (MRI) of 17 BCC cases were reviewed. The imaging features, including laterality, location, border, attenuation and internal architecture, were evaluated. All 17 cases were second BCCs, including 5 cases of Bailey type I classification cysts and 12 cases of type II classification cysts. The atypical imaging features included signal and morphological abnormalities. The abnormal signal intensities were caused by intracapsular bleeding (n=2) or solidification of cystic fluid (n=2). Intracystic hemorrhaging revealed homogeneous hyperintensity on T1-weighted image (T1WI) and T2-weighted image (T2WI). Solidification of cystic fluid revealed slightly homogeneous hyperintensity compared with muscle on T1WI and homogeneous hypointensity on T2WI without enhancement. The aberrant morphology mainly presented as thickening of the cystic wall (n=13). Thickened walls of BCCs with ill- (n=5) or well- (n=8) defined borders were observed in 13 patients. In 3 patients, significant enhancement was identified following intravenous gadolinium administration (n=4). When with atypical CT or MRI features are presented, the typical location of BCCs can help in the diagnosis, as it is located at the lateral portion of the neck adjacent to the anterior border of the mandibular angle or sternocleidomastoid muscle. The atypical observations, including variable signals, imply that the cystic content has changed. Thickened walls indicate inflammation or cancerous tendency and patients with ill-defined margins, vascular involvement or lymphadenopathy atelectasis indicate malignant conversion.

[Epidemiological features and pathogenic characteristics of hand, foot and mouth disease in Gansu Province, China during 2008-2012].

This study aims to analyze the epidemiological features and pathogenic characteristics of hand, foot and mouth disease (HFMD) in Gansu Province, China and to provide a basis for the development of effective prevention and control measures. The descriptive epidemiological analysis was used to analyse the data of HFMD cases in Gansu. The specimens collected from hospitals were subjected to RT-PCR or real-time PCR to detect human enterovirus (HEV) nucleic acid, and HEV strains were isolated using human rhabdomyosarcoma cells and human laryngeal carcinoma cells. The complete VP1-encoding region of several identified enterovirus A71 (EV71) and coxsackievirus A16 (CVA16) was subjected to full-length amplification by RT-PCR and then to sequencing and analysis. A total of 52 550 HFMD cases were reported in Gansu from 2008 to 2012, including 205 severe cases and 27 deaths. The incidence rates in the whole province from 2008 to 2012 were 22.42/10(5), 49.29/10(5), 47.20/10(5), 27.27/10(5), and 55.84/10(5), respectively. There were cases in all the 14 cities or prefectures in Gansu, and Lanzhou had the largest number of cases (16 001 cases), accounting for 30.45% of all cases in the province. HFMD cases were mostly reported during May to July, accounting for 51.69% of all cases throughout the year. The male-to-female ratio was 1.69:1. Of all the cases, 87.59% were under the age of five. Of the 5 416 cases for laboratory tests, 3 322 (61.34%) were positive for HEV nucleic acid, including EV71 (46.96%), CVA16 (41.57%), and other HEVs (11.47%). Among the 186 severe cases, 114 (61.29%) were positive for HEV nucleic acid, and 82.46% of the positive cases for EV71. All the 25 dead cases were infected with EV71. A total of 402 strains were isolated from 3 111 specimens collected from hospitals (2 123 throat swab specimens, 705 stool specimens, and 705 herpes specimens), including EV71 (70.15%), CVA16 (27.11), other coxsackievirus A (3.98%), coxsackievirus B (2.49%), echovirus (1.74%), and adenovirus (1.99%). The genotyping of VP1- encoding region showed that all the 194 EV71 strains isolated during 2008-2012 belonged to the C4a evolutionary branch of C4 subtype; among the 45 CVA16 strains, 12 belonged to the Bla evolutionary branch of B1 subtype and 33 to the B1b evolutionary branch, and B1b became the predominant subtype in 2012. In conclusion, in Gansu Province, HFMD occurs mostly in children under the age of five; EV71 and CVA16 are the main pathogens of this disease, and the two are predominant alternately from 2008 to 2012; the severe and dead cases of HFMD are closely related to infection with EV71; the types of pathogens varied across different regions in the same year during 2008-2012.

Preparation, characterization and adsorption properties of a novel 3-aminopropyltriethoxysilane functionalized sodium alginate porous membrane adsorbent for Cr(III) ions.

In this study, we prepared 3-aminopropyl-triethoxysilane (APTEOS) functionalized sodium alginate (SA) porous membrane adsorbent (APTEOS/SA) and tested its adsorption performance for removing of Cr(III) ions. The physico-chemical properties of the pristine and Cr(III) ions loaded APTEOS/SA were investigated by FT-IR, SEM-EDX, TG, AFM, and contact angle goniometer methods. To investigate the adsorption kinetics of Cr(III) ions onto this newly developed APTEOS/SA, we performed a batch of experiments under different adsorption conditions: solution pH, adsorbent dose, initial Cr(III) ion concentration, adsorption temperature, and contact time. The APTEOS/SA exhibited an encouraging uptake capacity of 90.0mg/g under suitable adsorption conditions. To study the mechanism of adsorption process, we examined the Lagergren pseudo-first-order and pseudo-second-order kinetic model, the intra-particular diffusion model, and the Crank model. Kinetics experiments indicated that the pseudo-first-order model displayed the best correlation with adsorption kinetics data. The Crank model showed that the intra-particle solute diffusion was the main rate-controlling step. Furthermore, our adsorption equilibrium data could be better described by the Freundlich equation. We also carried out consecutive adsorption-desorption experiments eight times to show that the APTEOS/SA has encouraging adsorption-desorption efficiencies. The results indicates that the prepared adsorbent is promising for using as an effective and economical adsorbent for Cr(III) ions removal.

[Fouling reasons and cleaning methods of nanofiltration membrane filtrated with the effluent of membrane bioreactor].

In order to investigate the fouling reasons and cleaning methods of nanofiltration membrane fouled with the effluent of membrane bioreactor (MBR), FEG-SEM-EDS, FTIR, AFM and contact angle system, were applied to analyze the membrane fouling layer. The results showed that, the foulants included both organic and inorganic substances, which contained phosphorous (P) and magnesium (Mg). After investigations of membrane surfaces through different cleaning steps, it was showed that critic acid cleaning could remove Mg and most of P, which were inorganic; and subsequent sodium hydroxide cleaning could remove the residual P, which probably came from organic acid, organic phosphorous or protein. The roughness increased from 79.5 nm to 111.2 nm with fouling, but the hydrophilicity didn't change obviously according to the contact angle from 55.6 degrees to 62.1 degrees. But after acid cleaning, the roughness decreased to 51.9 nm and the contact angle changed to be 96.0 degrees, which showed the organic foulants were exposed and the surface changed to be hydrophobic. And after subsequent alkali cleaning, the roughness and the hydrophilicity were both close to those of the new membrane. These results concluded that acid cleaning followed by alkali cleaning could remove most of the foulants. It was also suggested that organic matters fouled the membrane in the initial stage, and inorganic matters aggravated the membrane fouling subsequently.