Orange-emissive carbon quantum dots for ligand-directed Golgi apparatus-targeting and in vivo imaging.

The Golgi apparatus is one of the most important organelles in cells. Targeting and monitoring the morphology and structure of the Golgi apparatus are crucial and challenging. Aimed at the cysteine (Cys) receptor on the surface of the Golgi apparatus, ligand-directed carbon quantum dots (CQDs) were synthesized for Golgi apparatus-targeting imaging. In order to reduce the interference of tissue self-fluorescence and enhance the tissue penetration depth, orange-emissive levorotatory CQDs (L-CQDs) with Golgi apparatus-targeting ability were synthesized using the strategy of inheriting Cys residues and the inherent conjugated electronic structure of neutral red. They exhibit excitation-dependent, fluorescence stability, rich surface Cys residues, excellent biocompatibility, and low toxicity. As a Golgi apparatus-targeting agent, L-CQDs can quickly enter cells for Golgi apparatus-targeting imaging, and can also penetrate through biological tissue for imaging in vivo. The surface Cys residues of CQDs actively target the Cys receptors on the surface of the Golgi apparatus to achieve Golgi apparatus-targeting imaging.

Environmental Monitoring of Parvovirus B19 in the Kidney Transplantation Ward of a Chinese Teaching Hospital.

Purpose: Parvovirus B19 (B19V) infection is a viral threat after kidney transplantation. It is mainly transmitted by close-contact inhalation of aerosolized viral particles. The risk of nosocomial spread of B19V in the transplantation ward is quite high. This study aimed to evaluate the quality of routine disinfection and the effectiveness of isolation measures in the wards of B19V-infected kidney transplant recipients. Patients and Methods: Throat swab samples of 19 kidney transplant recipients admitted to the isolation ward and three healthcare workers (HCWs) were collected for viral DNA detection. Routine disinfection procedures were performed twice a day in general and B19V isolation wards. Environmental surface and air samples were collected for viral DNA detection before and after disinfection. Results: A total of four patients were diagnosed with B19V infection and transferred to the B19V isolation ward, of which only two had positive throat swab samples. The other 15 patients and all HCWs tested negative for B19V. A total of 88 environmental surface and air samples were collected. Eight of the environmental samples collected in the B19V isolation ward before disinfection tested positive for B19V, while one sample tested positive after disinfection. In the general wards, all environmental samples collected before disinfection tested negative for B19V. All 24 samples collected from ambient air, whether in B19V isolation or general wards, before or after disinfection, tested negative for B19V. Conclusion: Existing methods of routine or terminal disinfection for air and object surfaces were effective in eliminating B19V from object surfaces and ambient air in the isolation and general wards. Material surfaces that are exposed to high frequency and easily contaminated by blood, body fluids, and indoor air were the focus of cleaning and disinfection. Nosocomial cross-infection of other immunocompromised patients and HCWs can be avoided if appropriate prevention and control measures are taken.

High pH tolerance of a chitosan-PAA nanosuspension for ophthalmic delivery of pilocarpine.

In this paper, nanoparticles composed of chitosan (CS) and poly(acrylic acid) (PAA) were prepared by template polymerization for use as ophthalmic drug carrier. Before the polymerization, hydrogen peroxide was used to cut down the molecular weight of chitosan to improve its solubility and tolerance of pH values in the physiological condition. We found that, as the hydrogen peroxide concentration increased up to 2 M, the reaction temperature was kept at 60 degrees C and depolymerization for 2 h, the molecular weight of chitosan was cut down to 4.1 x 10(4) and its pH tolerance was increased up to 7.1. The modified chitosan (MCS) is expected to tolerate in neutral condition without any precipitation. MCS-PAA nanoparticles for use as an ophthalmic drug carrier were successfully prepared using template polymerization of acrylic acid in the modified chitosan solution. The particle size of the nanoparticles was significantly affected by the pH value of the medium. Both in vitro and in vivo studies reveal that the prepared nanoparticles either modified or unmodified have the better ability in sustaining the release of pilocarpine than the simulated tear fluid and commercial eye drops.

Pilocarpine-loaded chitosan-PAA nanosuspension for ophthalmic delivery.

Chitosan-poly(acrylic acid) (CS-PAA) nanoparticles, to be used as ophthalmic drug carrier, were successfully prepared using template polymerization of acrylic acid (AA) in a chitosan solution. When the polymerization was done at 70 degrees C for 45 min with a CS/AA weight ratio of 1:1, the surface structure of the prepared nanoparticles was most stable with the smallest mean diameter (92.0 +/- 7.5 nm) and a stable zeta potential (25.5 +/- 2.6 mV) in a buffer solution (pH 4.5). The size of the nanoparticles dramatically increased with the pH value of the medium. Both in vitro and in vivo studies revealed that the prepared nanoparticle suspension was better at sustaining the release of pilocarpine than either simulated tear fluid or commercial eye drops.

Characterization of pilocarpine-loaded chitosan/Carbopol nanoparticles.

Patients using ophthalmic drops are faced with frequent dosing schedules and difficult drop instillation. Therefore, a long-lasting pilocarpine-loaded chitosan (CS)/Carbopol nanoparticle ophthalmic formulation was developed. The physicochemical properties of the prepared nanoparticles were investigated using dynamic light scattering, zeta-potential, transmission electron microscopy, Fourier transform infrared ray spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The sustained-release effects of pilocarpine-loaded nanoparticles were evaluated using in-vitro release and in-vivo miotic tests, and compared with pilocarpine in solution, gel and liposomes. We found that the prepared nanoparticles were about 294 nm in size. DSC and FT-IR studies suggested that an electrostatic interaction between CS and Carbopol contributes at least in part to the stabilization of pilocarpine/CS/Carbopol nanoparticles. When compared with pilocarpine in solution, gel or liposomes, the best slow-release profile of pilocarpine from the prepared nanoparticles occurred in a dissolution test. In the in-vivo miotic study, pilocarpine-loaded CS/Carbopol nanoparticles showed the most significant long-lasting decrease in the pupil diameter of rabbits. The advantages of CS and Carbopol are good biocompatibility, biodegradability and low toxicity. CS is also a mucoadhesive polymer. Thus, pilocarpine/CS/Carbopol nanoparticles may provide an excellent potential alternative ophthalmic sustained-release formulation of pilocarpine for clinical use. CS/Carbopol nanoparticles may also be useful for a variety of other therapeutic delivery systems.

[Intraoperative 125I brachytherapy combined with chemotherapy for pancreatic cancer].

OBJECTIVE: To evaluate the efficacy, toxicity and survival of intraoperative 125I brachytherapy combined with chemotherapy for advanced pancreatic cancer. METHODS: Thirty-six patients with advanced pancreatic cancer were randomized to two groups: brachy-chemotherapy group (n = 18) and control group (n = 18). For the combined group, intraoperative 125I implantation and gemcitabine, 5-Fu were given. For the control group, intratumoral injection of absolute alcohol was done. RESULTS: The CR + PR rate of brachy-chemotherapy group was 38.9% with pain relief in 77.8%, while that of control group was 0 with pain relief in 22.2% (P < 0.05). Although there were some toxicity in brachy-chemotherapy group, treatment was well tolerated. The 6-, 12-month survival rates of brachy-chemotherapy group were 71.4% and 21.4% and those of control group were 38.5% and 7.7%, respectively. The median survival time was 10.6 months and 5.2 months for the two groups, between which the difference was significant (P < 0.05). CONCLUSION: Interoperative 125I brachytherapy combined with chemotherapy for advanced pancreatic cancer can control tumor, relieve pain and improve quality of life. It is safe and effective.