Outbreak of febrile illness caused by coxsackievirus A4 in a nursery school in Beijing, China.

BACKGROUND: Coxsackievirus A4 (CV-A4) is classified as human enterovirus A according to its serotype. CV-A4, an etiological agent of hand, foot, and mouth disease, affects children worldwide and can circulate in closed environments such as schools and hospitals for long periods. FINDINGS: An outbreak of febrile illness at a nursery school in Beijing, China, was confirmed to be caused by CV-A4. Phylogenetic analysis of the complete genome of the isolated strain showed that the virus belongs to the same cluster as the predominant CV-A4 strain in China. This outbreak was controlled by effective measures. CONCLUSIONS: The early identification of the pathogen and timely intervention may be the most critical factors in controlling an outbreak caused by CV-A4 in a preschool.

Preparation of polyglycerol mediated superparamagnetic graphene oxide nanocomposite and evaluation of its adsorption properties on tetracycline.

In this paper, we synthesized a polyglycerol(PG)-mediated superparamagnetic graphene oxide nanocomposite called MGON, consisting of PG-modified superparamagnetic iron oxide nanoparticles (SPION) covalently bonded to PG-functionalized graphene oxide (GO). MGON exhibits better dispersibility and colloidal stability in aqueous solution than the magnetic graphene oxide reported in the literature. The physicochemical properties of MGON were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and UV-vis spectroscopy. Applied to the adsorption of tetracycline (TC) in aqueous solution as an adsorbent, the MGON showed excellent adsorption performance with the maximum adsorption capacity of 684.93 mg/g at 298 K. Adsorption kinetics and isotherm results indicate that the adsorption process conforms to the pseudo-second-order kinetics and Langmuir isotherm models. Adsorption thermodynamics has confirmed that the adsorption process of TC on MGON is spontaneous and endothermic. With the increase of temperature, the adsorption capacity of MGON increases continuously, and the adsorption capacity of MGON is the largest when the pH value is 7. Furthermore, the π-π and cation-π interaction, amidation reaction, and hydrogen bonding can be used to explain the adsorption mechanism of TC on MGON. Desorption and regeneration experiments showed that MGON still had 67.65% regenerative performance after five cycles. Hence, MGON is a promising adsorbent in the removal of tetracycline from wastewater.

Red fluorescent ZnO nanoparticle grafted with polyglycerol and conjugated RGD peptide as drug delivery vehicles for efficient target cancer therapy.

In the field of modern nanomedicine, ZnO nanoparticles were considered as an emerging candidate for drug delivery because of their inherent biocompatibility and stability. However, the poor dispersibility in a physiological medium obstructed their clinic applications. In this paper, the red fluorescence ZnO nanoparticles were synthesized, using a facile chemical method of polyol in boiling trimethylene glycol (TREG) with zinc acetate. The as-synthesized ZnO nanoparticles were first time grafted with PG layer through ring-opening polymerization of glycidol (ZnO-PG). As calculated from the TGA data, the weight ratio of the grafted PG was about 68 wt%. Then, the ZnO-PG engineered to conjugate with arginine-glycine-aspartate (RGD) peptide by stepwise organic reactions. Finally, anticancer drugs Doxorubicin hydrochloride (DOX) was immobilized on ZnO-PG-RGD (approximately 21.8 ±â€¯0.9 nm) to form ZnO-PG-RGD/DOX. The drug release percentage reaches 70.6% within 48 h under pH 5.2, which was more than 3-fold higher than that pH 7.4. The properties of ZnO nanoparticles and its derivatives were detected by power XRD, TEM, EDS, FTIR, TGA, DLS, Zeta potential and UV. The grafted PG layer not only largely enhanced the dispersibility, but also inhibited ZnO nanoparticles from the uptake by U87MG and Hela cells. In contrast, ZnO-PG-RGD was selectively taken up by U87MG, not Hela cells, demonstrating an obvious targeting property. When ZnO-PG-RGD/DOX was used, U87MG cells showed specificity damaged compared with Hela cells. Thus, functionalized ZnO nanoparticle was a promising nanomaterial in cancer theranostics.

Polyglycerol grafting and RGD peptide conjugation on MnO nanoclusters for enhanced colloidal stability, selective cellular uptake and cytotoxicity.

An efficient surface engineering strategy for MnO nanoparticles was developed to attain enhanced colloidal stability, selective uptake by and toxicity to specific cancer cells. Specifically, MnO nanoclusters prepared by polyol method were grafted with polyglycerol (MnO-PG), and then conjugated with arginine-glycine-aspartate peptide (MnO-PG-RGD) through stepwise organic reactions. The physicochemical properties of the surface engineered MnO nanoclusters were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, dynamic light scattering, zeta potential, transmission electron microscopy and high-resolution transmission electron microscopy. The grafted PG layer not only largely enhanced the dispersibility and colloidal stability of MnO nanoclusters in physiological media, but also effectively inhibited non-specific cellular uptake of MnO-PG. MnO-PG-RGD was selectively taken up by human glioblastoma U87MG cells overexpressing αvß3 integrins through receptor-mediated endocytosis. The internalized MnO-PG-RGD was mainly located in the lysosomes of U87MG cells. The acidity of lysosomes accelerated Mn2+ ions releasing, which promoted intracellular oxidative stress and further led to cell damage and apoptosis. The results indicate that appropriate surface functionalization can enable MnO nanoparticles to act as a potential anticancer agent in addition to their MRI functionality.

Polyglycerol mediated covalent construction of magnetic mesoporous silica nanohybrid with aqueous dispersibility for drug delivery.

Construction of nanohybrids with chemical and colloidal stability is of great importance for the exploration of their potential applications in biomedical field. In this work, a versatile strategy based on polyglycerol (PG) mediated covalent linkage is developed to fabricate a core-satellite nanohybrid, termed MMSN, consisting of a mesoporous silica nanoparticle (MSN) as a core and many superparamagnetic iron oxide nanoparticles (SPION) on the outer surface. In this synthetic strategy, the PG grafted SPION is derivatized to convert partial periphery hydroxyl groups to carboxyl moieties, followed by attachment to aminated MSN through amide bonds. The PG layer accounting for ~17wt% of MMSN not only serves as a tether to connect the two nanoparticles but also greatly enhances the colloidal stability of the nanohybrid, resulting in no significant change in hydrodynamic diameter and zeta potential during four months. Taking advantage of the combined porosity and magnetic property of the nanohybrid, a photosensitizer chlorin e6 (Ce6) is loaded on MMSN and efficiently delivered into target cells under magnetic guidance, leading to an enhanced efficacy of photodynamic therapy (PDT). The versatile strategy presented here opens up a new route to rational design and fabrication of multifunctional nanohybrids for various biomedical purposes.