Quantum Light Generation Based on GaN Microring toward Fully On-Chip Source.

An integrated quantum light source is increasingly desirable in large-scale quantum information processing. Despite recent remarkable advances, a new material platform is constantly being explored for the fully on-chip integration of quantum light generation, active and passive manipulation, and detection. Here, for the first time, we demonstrate a gallium nitride (GaN) microring based quantum light generation in the telecom C-band, which has potential toward the monolithic integration of quantum light source. In our demonstration, the GaN microring has a free spectral range of 330 GHz and a near-zero anomalous dispersion region of over 100 nm. The generation of energy-time entangled photon pair is demonstrated with a typical raw two-photon interference visibility of 95.5±6.5%, which is further configured to generate a heralded single photon with a typical heralded second-order autocorrelation g_{H}^{(2)}(0) of 0.045±0.001. Our results pave the way for developing a chip-scale quantum photonic circuit.

Preparation and antitumor activity of bFGF-mediated active targeting doxorubicin microbubbles.

Characterization and antitumor activity of basic fibroblast growth factor-mediated active targeting doxorubicin microbubbles (bFGF-DOX-MB) were investigated. Pluronic F68 with chemical conjugation of doxorubicin (DOX-P) and peptide KRTGQYKLC-conjugated DSPE-PEG2000 were prepared. bFGF-DOX-MB had a normal distribution of particle size, with average particle size of 2.7 µm. Using A549 mouse model, bFGF-DOX-MB combined ultrasound showed the best inhibition effect on tumor volume growth among all the test groups. Similar conclusion was obtained from experimental measurements of tumor weight change and blood cell count. From the results, chemotherapeutic drug inhibition on tumor growth could be enhanced by local ultrasound combined with active targeting bFGF-DOX-MB, which might provide a potential application for ultrasound-mediated chemotherapy.

Experiment on the feasibility of using modified gelatin nanoparticles as insulin pulmonary administration system for diabetes therapy.

Polymeric nanoparticles are widely used as targeted carriers for biomacromolecules. In this paper, modified gelatin nanoparticles were prepared and their feasibility as insulin pulmonary administration system was investigated. D: ,L: -glyceraldehyde and poloxamer 188 were used for gelatin nanoparticle preparation. Novel water-in-water emulsion technique was used to prepare insulin-loaded nanoparticles. Morphological examination of insulin-loaded nanoparticles was carried out using scanning electron microscopy (SEM). Intratracheal instillation of insulin-loaded nanoparticles was performed to evaluate animal hypoglycemic effect. With fluorescence labeling of insulin, alveolar deposition and absorption of insulin-loaded nanoparticles were investigated. Histological changes in the lung were also observed to evaluate the safety. From the micromorphology observation, insulin-loaded nanoparticles under gelatin-poloxamer 188 ratio at 1:1 showed smooth and uniform surface, with average particle size 250 nm and Zeta potential -21.1 mV. From animal experiment, insulin-loaded nanoparticles under gelatin-poloxamer 188 ratio at 1:1 promoted insulin pulmonary absorption effectively and showed good relative pharmacological bioavailability. Proved by alveolar deposition result, FITC-insulin-loaded nanoparticle group was characterized by an acute and rapid hypoglycemic effect. In addition, nanoparticles could guarantee the safety of lung by reducing insulin deposition in lung. A transient weak inflammatory response was observed at 1 day after administration. With good physical characterization, high bioavailability, fast and stable hypoglycemic effect, insulin-loaded nanoparticles might be developed as a novel insulin pulmonary system for diabetes therapy.

Characterization and anti-tumor activity of chemical conjugation of doxorubicin in polymeric micelles (DOX-P) in vitro.

Characterization and anti-tumor activity of chemical conjugation of doxorubicin (DOX) in polymeric micelles were investigated. Polymeric micelles with chemical conjugation of doxorubicin (DOX-P) were prepared. Succinic anhydride activated pluronic F68 was first synthesized and the primary amine group in doxorubicin was conjugated to the terminal carboxyl of pluronic F68 via a amide. The resulting polymeric micelles in aqueous solution were characterized by measurement of size, ξ-potential, drug loading and critical micelle concentration. From characterization results, DOX-P micelles had superiorities over physically-loaded DOX micelles in loading efficiency, diameter and CMC value. From drug release experiment in vitro, DOX-P micelles reached a sustained release profile for DOX. The cytotoxic activity of the micelles against A549/DOX cells was greater than free DOX. Fluorescence microscope observation and flow cytometry analysis supported the enhanced cellular uptake of the micelles. From A549/DOX cells experiments, DOX-P micelles could enhance DOX anti-tumor activity and circumvent the multi-drug resistance (MDR) of A549/DOX cells. With low CMC value, high loading efficiency, nanometer diameter, good penetration ability and controlled release behaviour, DOX-P micelles might be developed as a new cancer targeted delivery system.

An in vivo experiment to improve pulmonary absorption of insulin using microbubbles.

BACKGROUND: Gas-filled phospholipid-based ultrasonic microbubbles (PUMs) are widely used in diagnostic imaging. The micro- or nanoparticle size and the physiochemical nature of shell provide the potential for a new way to improve pulmonary absorption for peptides and proteins. METHODS: Male Sprague-Dawley rats were fasted for 12 h. Then insulin solution and insulin-PUM mixture solution were administered by intratracheal instillation. The hypoglycemic effect was observed to evaluate insulin absorption after lung administration. Fluorescein isothiocyanate-dextran (molecular mass, 4 kDa) was used as the index of evaluating drug alveolar deposition and absorption by visualization techniques. RESULTS: Administration of insulin solution containing PUMs significantly reduced the blood glucose levels of Sprague-Dawley rats, compared with administration of insulin-only solution. The minimum reductions of the blood glucose concentration produced by insulin solution containing PUMs and by an insulin-only solution reached 60.81% and 34.60% of the initial glucose levels, respectively, and their bioavailabilities relative to subcutaneous injection were 48.58% and 29.09%, respectively. Histopathological study of the lung showed no changes in the morphology of the pulmonary alveoli after administration to these drugs. Only a slight inflammatory cell infiltration in the alveoli could be found in some rats. CONCLUSION: These results suggested that PUMs might be used as an effective way to improve pulmonary absorption for peptides and proteins.

Enhancing chemotherapeutic drug inhibition on tumor growth by ultrasound: an in vivo experiment.

An in vivo study on enhancing epirubicin hydrochloride (EPI) inhibition on tumor growth by ultrasound (US) was reported. Five-week-old male nude mice were used and HL-60 cells were s.c. (subcutaneous injection) inoculated in axilla of these mice. Six groups were designed and five consecutive treatments were applied to investigate the inhibition on tumor growth and body weight growth. US applied locally to the tumor resulted in a substantially increased drug uptake in tumor cells. The inhibition on tumor growth depended on the position of drug injection and phospholipid-based microbubble (PMB) application. Tumor growth rate under group 1 (PMB+US) was similar to that of blank control. The order of the inhibition on tumor volume growth was: group 4 (s.c. EPI+PMB+US) > group 5 intraperitoneal (i.p. EPI+PMB+US) > group 2 (i.p. EPI) > group 3 (s.c. EPI+US) > group 1 (PMB+US). Similar conclusion was obtained from experimental measurements of tumor weight change. The order of animal survival status for EPI administration groups was: group 4 > group 5 > group 2 > group 3. Chemotherapeutic drug inhibition on tumor growth could be enhanced by local US combined with PMB, which might provide a potential application for US-mediated chemotherapy.

Experiment on enhancing antitumor effect of intravenous epirubicin hydrochloride by acoustic cavitation in situ combined with phospholipid-based microbubbles.

OBJECTIVE: An in vivo study on enhancing antitumor effect of intravenous epirubicin hydrochloride (EPI) by acoustic cavitation in situ combined with phospholipid-based microbubbles (PMB) was reported. METHODS: Five-week-old male nude mice were used, and HCT-116 cells were s.c. (subcutaneous injection) inoculated in axilla of these mice. Five groups were designed and five consecutive treatments were applied to investigate the tumor growth, body weight growth, and normal organ growth. RESULTS: Inhibition effects on tumor growth were observed in all groups treated by EPI. However, the potency of tumor growth retardation caused by EPI depended on the application of PMB and US in situ. An effective retardation on tumor growth and improved mice survival status were observed when intravenous EPI combined with sonicated PMB in situ. Short-term lingering sensitive period for chemotherapeutic drugs after acoustic cavitation was also observed in experiment under asynchronous administration of EPI and sonicated PMB. CONCLUSION: Intravenous EPI combined with PMB-mediated cavitation in situ might provide a potential application for US-mediated chemotherapy.

Synthesis and characterization of Poloxamer 188-grafted heparin copolymer.

BACKGROUND: Poloxamer 188 is a safe biocompatible polymer that can be used in protein drug delivery system. AIM: In this study, a new heparin-poloxamer 188 conjugate (HP) was synthesized and its physicochemical properties were investigated. HP structure was confirmed by Fourier transform infrared spectroscopy (FTIR) and Hydrogen-1 nuclear magnetic resonance spectroscopy ((1)H-NMR). Content of the conjugated heparin was analyzed using Toluidine Blue. The critical micelle concentration (CMC) of the copolymer was determined by a fluorescence probe technique. The effect of HP on the gelation of poloxamer 188 was characterized by the rheological properties of the HP-poloxamer hydrogels. Solubility and viscosity of HP were also evaluated compared with poloxamer 188. RESULTS: From the results, the solubility of the conjugated heparin was increased compared with free heparin. The content of heparin in HP copolymer was 62.9%. The CMC of HP and poloxamer 188 were 0.483 and 0.743 mg/mL, respectively. The gelation temperature of 0.4 g/mL HP was 43.5 degrees C, whereas that of the same concentration of poloxamer 188 was 37.3 degrees C. With HP content in poloxamer 188 solution increasing, a V-shape change of gelation temperature was observed. CONCLUSION: Considering the importance of poloxamer 188 in functional material, HP may prove to be a facile temperature-sensitive material for protein drug-targeted therapy.

[Comparison of the clinical effects between gold-alloy post-core-crowns and nickel-chromium-alloy post-core-crowns].

PURPOSE: To evaluate the clinical effects between gold-alloy post-core-crowns and nickel-chromium-alloy post-core-crowns. METHODS: Four hundred incisors, canines and premolars from 289 patients were selected. The crown had been destroyed seriously and root canal therapy was carried out. The root canal and the surface of the root were prepared well, then silicone impression material was injected into the root canal and the prepared plastic pin was inserted. Precise impression was taken and divided into two groups randomly. Group A was restored by gold-alloy post-core-crowns, while Group B was restored by nickel-chromium-alloy post-core-crowns. The patients were followed up for 3 years, the clinical effects were evaluated and compared using SPSS10.0 software package for Chi-square test. RESULTS: There was no significant difference(P>0.05) of maintenance rate between the two groups, but there was significant difference (P<0.05) in the occurence of inflammation and staining of gingiva. CONCLUSION: Gold-alloy post-core-crown is more suitable for restoration of teeth defects than nickel-chromium-alloy post-core-crown. Supported by Research Fund of Medical Science and Technology of Guangdong Province (Grant No. WSTJJ20070101310103196603041632).