Biography:

In the past Xiuhua Zhao has collaborated on articles with Jie Zhang and Yuangang Zu. One of their most recent publications is High catalytic active palladium nanoparticles gradually discharged from multilayer films to promote Suzuki, Heck and Sonogashira cross coupling reactions. Which was published in journal Journal of Colloid and Interface Science.

More information about Xiuhua Zhao research including statistics on their citations can be found on their Copernicus Academic profile page.

Xiuhua Zhao's Articles: (11)

High catalytic active palladium nanoparticles gradually discharged from multilayer films to promote Suzuki, Heck and Sonogashira cross coupling reactions

Highlights•The release amount of catalysts could be easily controlled by removing the film.•High catalytic efficiency with extremely low Pd-loading down to 10−6 mol%.•High stability in the air and free phosphorus ligands.

Preparation and characterization of vitexin powder micronized by a supercritical antisolvent (SAS) process

AbstractVitexin is a flavonoid drug with poor water solubility commonly used to prevent heart diseases. The poor water solubility of vitexin limits its dissolution, which strongly impairs drug bioavailability. The aim of this work was to improve its bioavailability by reducing particle size in a supercritical antisolvent process (SAS) using supercritical carbon dioxide as an antisolvent agent and dimethyl sulfoxide (DMSO) as a solvent. In order to optimize the parameters of SAS process, the whole experiment was designed and conducted in an orthogonal array design (OAD), OA 16(45). The obtained optimum micronization conditions were as follows: precipitation pressure 25 MPa, precipitation temperature 50 °C, concentration of vitexin solution 2 mg/mL and vitexin solution flow rate at 6.7 mL/min. Under this condition, the mean particle size (MPS) of vitexin was reduced to 126 ± 18.5 nm.In addition, both the processed vitexin particles and the unprocessed one were characterized by Scanning Electron Microscopy (SEM), Dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), Liquid chromatography tandem mass spectrometry (LC-MS/MS), X-ray diffraction (XRD) and Differential scanning calorimeters (DSC). The results showed that SAS micronization process did not induce degradation of vitexin and the processed vitexin particles had lower crystallinity. Finally, the dissolution rates of the processed and unprocessed vitexin were evaluated, the results showed that there was a significant increase of the dissolution rate of the processed vitexin comparing with the unprocessed vitexin. Moreover, vitexin nanosuspension of high concentration can be prepared by dissolving processed vitexin in physiological saline. These results suggest that micronized vitexin may have a great potential in cardiovascular and cerebrovascular diseases therapy.

Validation and in situ application of a modified thermal dissipation probe for evaluating standing water use of a clumped bamboo: Bambusa chungii

Highlights•We improved the accuracy of the shorted TDP method for its application on Bamboo.•TDP underestimated JS by 27.5% compared with the actual water loss from the pot experiment.•The hydrological impacts of Bamboo will be enhanced by the prolonged drought in South China.

Process optimization studies of 10-Hydroxycamptothecin (HCPT)-loaded folate-conjugated chitosan nanoparticles by SAS-ionic crosslink combination using response surface methodology (RSM)

Abstract10-Hydroxycamptothecin (HCPT) is a well-established topoisomerase I inhibitor of a broad spectrum of cancers. However, poor aqueous solubility, low instability, and toxicity to normal tissues have limited its clinical development. A novel HCPT-containing drug carrier system was developed to overcome these disadvantages. The response surface methodology was used to optimize the process of preparing HCPT–chitosan nanoparticles (HCPT–CSNPs) by the SAS-ionic crosslink (supercritical antisolvent SAS) combination method; the resulting HCPT–CSNPs were then conjugated with folate for specific targeting. A central composite design, composed of four independent variables, namely, chitosan concentration, TPP concentration, HCPT nanoparticle concentration, and crosslink time, was applied in the modeling process. The mean particle size and drug entrapment efficiency (DEE) of HCPT–CSNPs were chosen as response variables. The interactive effects of the four independent variables on the response variables were also studied. Nanoparticle characteristics such as morphology, DEE, and mean particle size were investigated. The optimum conditions for preparing HCPT–CSNPs were determined as follows: folate-coupled chitosan concentration 2.46 mg/ml, TPP concentration 7.73 mg/ml, HCPT nanoparticle concentration 0.48 mg/ml, and crosslinking time 47.4 min. Optimum conditions for preparing desired HCPT–CSNPs with a mean particle size of 173.5 nm and entrapment efficiency of 77.3% were obtained. The resulting folate-conjugated HCPT–CSNPs (FA–HCPT–CSNPs) reveal that the amount of folate conjugation was 197.64 mg/g CS. FA–HCPT–CSNPs used in drug carrier systems could have potential value in HCPT-sensitive tumors.

Original Contribution2-D and 3-D Ultrasound for Tumor Volume Analysis: A Prospective Study

AbstractUltrasound (US) allows real-time tumor assessment. We evaluated the volumetric limits of 2-D and 3-D US, compared with magnetic resonance imaging (MRI), with a prospective institutional review board–approved clinical evaluation of US-to-MRI volumetric correlation. US images of pre- and post-neoadjuvant breast cancers were obtained. Volume discrepancy was evaluated with the non-parametric Wilcoxon signed-rank test. Expected inter-observer variability <14% was evaluated as relative paired difference (RPD); clinical relevance was gauged with the volumetric standard error of the mean (SEM). For 42 patients, 133 of 170 US examinations were evaluable. For tumors ≤20 cm3, both highly correlated to MRI with RPD within inter-observer variability and Pearson's correlation up to 0.86 (0.80 before and 0.86 after neoadjuvant chemotherapy, respectively). Lesions 20–40 cm3 had US-to-MRI discrepancy within inter-observer variability for 2-D (RPD: 13%), but not 3-D (RPD: 27%) US (SEM: 1.47 cm3 for 2-D, SEM: 2.28 cm3 for 3-D), suggesting clinical utility. Tumors >40 cm3 correlated poorly. Tumor volumes ≤20 cm3 exhibited a good correlation to MRI. Studies of clinical applications are warranted.

Preparation, formula optimization and antitumor actions of mannitol coupling camptothecin nanoparticles

AbstractThe purpose of this work is to prepare a formulation using mannitol coupling Camptothecin (CPT) nanoparticles (CPT-NPs) to circumvent the difficult solubilization practice based on central composite experimental statistical design. CPT-NPs were prepared with a high-pressure homogenization technique method. The independent variables considered for the optimization of CPT-NPs were percentage of CPT in raw material (CPT and mannitol), concentration of CPT in working liquid, cycles numbers and homogenizer pressure for drug loading efficiency, particle size and polydispersity index. Analysis of variance (ANOVA) statistical test was used to assess the optimization. The optimized CPT-NPs showed an appropriate drug loading efficiency (18.09 ± 2.13%), a homogeneous particle size (165.33 ± 37.23 nm) and a low polydispersity index (0.29 ± 0.01). The CPT-NPs group show higher inhibition ratio (79.95%) of H22 tumor growth in vivo compared with TPT and CPT at the same dose. Changes in mice body weight demonstrate CPT-NPs have the lower toxicity. The results of biodistribution studies indicated the obviously superiority of CPT-NPs in increasing the accumulation of CPT within tumor. Overall, CPT-NPs under optimum conditions are considered to be potentially feasible to overcome formulation challenges for drug delivery.

Pharmaceutical nanotechnologyEnhancement of solubility, antioxidant ability and bioavailability of taxifolin nanoparticles by liquid antisolvent precipitation technique

AbstractTaxifolin is a kind of flavanonol, whose antioxidant ability is superior to that of ordinary flavonoids compounds owing to its special structure. However, its low bioavailability is a major obstacle for biomedical applications, so the experiment is designed to prepare taxifolin nanoparticles by liquid antisolvent precipitation (LAP) to improve its bioavailability. We selected ethanol as solvent, deionized water as antisolvent, and investigated primarily the type of surfactant and adding amount, drug concentration, volume ratio of antisolvent to solvent, precipitation temperature, dropping speed, stirring speed, stirring time factors affecting drug particles size. Results showed that the poloxamer 188 was selected as the surfactant and the particle size of taxifolin obviously reduced with the increase of the poloxamer 188 concentration, the drug concentration and the dropping speed from 0.08% to 0.45%, from 0.04 g/ml to 0.12 g/ml, from 1 ml/min to 5 ml/min, respectively, when the volume ratio of antisolvent to solvent increased from 2.5 to 20, the particle size of taxifolin first increased and then decreased, the influence of precipitation temperature, stirring speed, stirring time on particle size were not obvious, but along with the increase of mixing time, the drug solution would separate out crystallization. The optimum conditions were: the poloxamer 188 concentration was 0.25%, the drug concentration was 0.08 g/ml, the volume ratio of antisolvent to solvent was 10, the precipitation temperature was 25 °C, the dropping speed was 4 ml/min, the stirring speed was 800 r/min, the stirring time was 5 min. Taxifolin nanosuspension with a MPS of 24.6 nm was obtained under the optimum conditions. For getting taxifolin nanoparticles, the lyophilization method was chosen and correspondingly γ-cyclodextrin was selected as cryoprotectant from γ-cyclodextrin, mannitol, lactose, glucose. Then the properties of raw taxifolin and taxifolin nanoparticles were characterized by scanning electron microscopy (SEM), fourier-transform infrared spectroscopy (FTIR), high performance liquid chromatography–mass spectrometry (LC–MS), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermo gravimetric (TG), and the conclusion was drawn that taxifolin nanoparticles can be converted into an amorphous form but its chemical construction cannot been changed. Furthermore, dissolving capability test, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity and reducing power assay, solvent residue test were also carried out. The experimental data showed that the solubility and the dissolution rate of taxifolin nanoparticles were about 1.72 times and 3 times of raw taxifolin, the bioavailability of taxifolin nanoparticles increased 7 times compared with raw taxifolin, and the antioxidant capacity of taxifolin nanoparticles was also superior to raw taxifolin. Furthermore, the residual ethanol of the taxifolin nanoparticles was less than the ICH limit for class 3 solvents of 5000 ppm or 0.5% for solvents and could be used for pharmaceutical. These results suggested that taxifolin nanoparticles might have potential value to become a new oral taxifolin formulation with high bioavailability.

Brief ReportPhysicians’ Human Papillomavirus Vaccine Recommendations, 2009 and 2011

BackgroundPhysician recommendation is a key predictor of human papillomavirus (HPV) vaccine uptake. Understanding factors associated with recommendation is important for efforts to increase current suboptimal vaccine uptake.PurposeThis study aimed to examine physician recommendations to vaccinate female patients aged 11–26 years, in 2009 and 2011, at 3 and 5 years postvaccine licensure, respectively. A second aim was to identify trends in factors associated with vaccine recommendation for ages 11 and 12 years.MethodsNationally representative samples of physicians practicing family medicine, pediatrics, and obstetrics and gynecology were randomly selected from the American Medical Association Physician Masterfile (n=1538 in 2009, n=1541 in 2011). A mailed survey asked physicians about patient and clinical practice characteristics; immunization support; and frequency of HPV vaccine recommendation (“always” ≥75% of the time vs other). Analyses were conducted in 2012.ResultsCompleted surveys were received from 1013 eligible physicians (68% response rate) in 2009 and 928 (63%) in 2011. The proportion of physicians who reported always recommending HPV vaccine increased significantly from 2009 to 2011 for patients aged 11 or 12 years (35% vs 40%, respectively; p=0.03), but not for patients aged 13–17 years (53% vs 55%; p=0.28) or 18–26 years (50% vs 52%; p=0.52). Physician specialty, age, and perceived issues/barriers to vaccination were associated with vaccine recommendation for patients aged 11 or 12 in both years.ConclusionsResults suggest a modest increase in recommendations for HPV vaccination of girls aged 11 or 12 years over a 2-year period; however, recommendations remain suboptimal for all age groups despite national recommendations for universal immunization.

A flexible and highly pressure-sensitive PDMS sponge based on silver nanoparticles decorated reduced graphene oxide composite

Highlights•The Ag/rGO-PDMS sponge was synthesized by dip-drying method.•The pressure sensitivity of Ag/rGO-PDMS sponge enhances twenty-two times compared with that of rGO-PDMS sponge.•Ag NPs could reduce contact resistance between graphene nanosheets and improve conductivity of Ag/rGO-PDMS sponge.•The Ag/rGO-PDMS sponge can be used for detecting various mechanical forces and radial artery blood pulses in real-time.

Research paperMelatonin-loaded silica coated with hydroxypropyl methylcellulose phthalate for enhanced oral bioavailability: Preparation, and in vitro-in vivo evaluation

Highlights•The silica loaded with melatonin, and then coated with HP55.•The release of melatonin was markedly increased in vitro study.•The bioavailability of MLT-SiO2-HP55 was 3.5 times as raw melatonin.

Phase II multicenter trial of Caphosol for the reduction of mucositis in patients receiving radiation therapy for head and neck cancer

SummaryPurposeWe conducted a phase II multicenter study evaluating Caphosol in patients receiving head and neck radiation (H/N RT) +/− chemotherapy or biologic sensitizer.Materials/MethodsThe primary endpoint of the study tested the rate of functional mucositis (WHO grade > or equal to 2) with the hypothesis that <75% of patients would develop > or equal to 2 mucositis with Caphosol compared with a historical rate of >90%. New methods were applied with higher than historic rigor. 5 Institutions were included in this study: Moffitt Cancer Center (MCC), MD Anderson Cancer Center (MDACC), Duke University Cancer Center (DUCC), University of Florida (UF) and Temple University Cancer Center (TUCC). Caphosol was taken by patients at least 4 times a day and up to 10 times per day commencing with day 1 of RT and for a total duration of 8 weeks after completion of RT. Detailed questionnaires were completed weekly by patients and a unique algorithm was used to generate the WHO grade of mucositis.Results98 Patients were enrolled in the study. 59/98 (60%) patients were evaluable for the primary endpoint giving us 80% power. All evaluable patients experienced WHO grade > or equal to 2 mucositis and the trial failed to reject the null hypothesis. > or equal to 2 mucositis rates at weeks 2, 4, 6, 11 and 15 were as follows: 45%, 90%, 98%, 71%, 50%.ConclusionWe were unable to demonstrate that Caphosol significantly reduced WHO grade 2 or higher mucositis below a 90% historic rate. We are not surprised with this finding given our rigorous methodology in grading.

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