Volume Ratio Of Water Phase Research Articles

Bisphosphonate-functionalized coordination polymer nanoparticles for the treatment of bone metastatic breast cancer

Bone is the most common organ affected by metastatic breast cancer. Targeting cancers within the bone remains a great challenge due to the inefficient delivery of therapeutic to bone. In this study, a polyethylene glycol (PEG) coated nanoparticles (NPs) made of a Zn2+ coordination polymer was linked with a bone seeking moiety, alendronate (ALN), to deliver cisplatin prodrug (DSP) to the bone. The particle sizes of this novel system, DSP-Zn@PEG-ALN NPs, were regulated by adjusting the volume ratio of water phase to oil phase in microemulsion. It was small enough (about 55nm) to extravasate through the clefts (80nm) of the bone's sinusoidal capillaries and localize into metastatic bones. DSP-Zn@PEG-ALN NPs showed much higher affinity for hydroxyapatite in vitro and bone in vivo than non-targeted DSP-Zn@PEG NPs and cisplatin. In addition, the in vivo biodistribution studies demonstrated that about 4-fold of platinum was delivered to the bone metastatic lesions than that in healthy bones by DSP-Zn@PEG-ALN NPs intravenously. Finally, DSP-Zn@PEG-ALN NPs not only inhibited the tumor growth efficiently but also reduced the osteocalastic bone destruction. Besides, DSP-Zn@PEG-ALN NPs showed significantly reduced toxicity of cisplatin. These results indicate that the DSP-Zn@PEG-ALN NPs have a great potential in enhancing chemotherapeutic efficacy for the treatment of bone metastatic breast cancer.

The high water solubility of inclusion complex of taxifolin-γ-CD prepared and characterized by the emulsion solvent evaporation and the freeze drying combination method

This study selected γ-cyclodextrin (γ-CD) as the inclusion material and prepared inclusion complex of taxifolin-γ-CD by the emulsion solvent evaporation and the freeze drying combination method to achieve the improvement of the solubility and oral bioavailability of taxifolin. We selected ethyl acetate as the oil phase, deionized water as the water phase. The taxifolin emulsion was prepared using adjustable speed homogenate machine in the process of this experiment, whose particle size was related to the concentration of taxifolin solution, the volume ratio of water phase to oil phase, the speed and time of homogenate. We knew through the single-factor test that, the optimum conditions were: the concentration of taxifolin solution was 40mg/ml, the volume ratio of water phase to oil phase was 1.5, the speed of homogenate was 5000rpm, the homogenate time was 11min. Taxifolin emulsion with a MPS of 142.5nm was obtained under the optimum conditions, then the high-concentration taxifolin solution (3mg/ml) was obtained by the rotary evaporation process. Finally, the inclusion complex of taxifolin-γ-CD was prepared by vacuum freeze-dry. The characteristics of the inclusion complex of taxifolin-γ-CD were analyzed using SEM, FTIR, XRD, DSC, and TG. The FTIR results analyzed the interaction of taxifolin and γ-CD and determined the molecular structure of the inclusion complex of taxifolin-γ-CD. The analysis results of XRD, DSC and TG indicated that the inclusion complex of taxifolin-γ-CD was obtained and showed significantly different characteristics with taxifolin. In addition, dissolving capability test, antioxidant capacity test, solvent residue test were also carried out. The experimental datas showed that the solubility of inclusion complex of taxifolin-γ-CD at 25°C and 37°C were about 18.5 times and 19.8 times of raw taxifolin, the dissolution rate of inclusion complex of taxifolin-γ-CD were about 2.84 times of raw taxifolin, the bioavailability of inclusion complex of taxifolin-γ-CD increased 3.72 times compared with raw taxifolin, and the antioxidant capacity of inclusion complex of taxifolin-γ-CD was also superior to raw taxifolin. Furthermore, the amounts of residual solvent of the inclusion complex of taxifolin-γ-CD were suitable for pharmaceutical use. These results suggested that inclusion complex of taxifolin-γ-CD may have potential value to become a new oral taxifolin formulation with high solubility.

Hydrolysis of Glucose to 5-Hydroxymethylfurfural

We used solid acid and solid base we made ourselves prepared 5-hydroxymethylfurfural (5-HMF) from glucose. Researched on the effects of quality ratio of solid acid and solid base, substrate concentration, volume ratio of two phases, reaction temperature and reaction time on 5-HMF yield. Results were shown that the conditions quality ratio of solid acid and solid base was 3: 4, substrate concentration was 50%, volume ratio of water phase and organic phase was 1: 2, reaction temperature was 120 °C, time for 12 h were the best that 5-HMF yield reached 48.39%.

Preparation of Poly (L-lactic Acid) Microsphere

Poly (L-lactic acid) (PLLA) microspheres were prepared by a solvent evaporation method based on an oil/water emulsion. The effect of the mass ratio of PLLA and poly(vinyl alcohol) (PVA) on the formation of the microspheres was discussed, and the influence of extraction speed of dichloromethane on the microsphere morphology was also studied. Moreover, the influences of the PLLA concentration and the volume ratio of water phase to dichloromethane phase were investigated. The results showed that stable microspheres can be obtained under the conditions that the mass ratio of PLLA to PVA is 20:1. Porous microspheres were obtained under faster evaporating speed of dichloromethane. The microsphere size increased with increasing PLLA concentration. The microsphere size also increased with the increase of the volume ratio of water phase to dichloromethane phase.

Efficient synthesis of optically active organosilyl alcohol via asymmetric reduction of acyl silane with immobilized yeast

Synthesis of optically active organosilyl alcohol via asymmetric reduction of prochiral acyl silane with immobilized Saccharomyces cerevisiae type II (a mutant from S. cerevisiae by UV irradiation treatment, named UV SC II) cells compared to free UV SC II cells was studied. It has been found that higher yield and enantiomeric excess (e.e.) of the product could be achieved with immobilized UV SC II cells. To further enhance the product yield and the product e.e., an aqueous/organic biphasic system was used as the reaction medium. The influence of various factors, such as shake speed, organic solvent, volume ratio of water phase to organic phase, buffer pH of water phase, reaction temperature and substrate concentration, was systematically studied and the reaction conditions were optimized with respect to the initial reaction rate, the product yield and the product e.e. All the above-mentioned factors had effect on the reaction to some extent. n-Hexane was found to be the best organic solvent. The optimum shake speed, volume ratio of water phase to organic phase, buffer pH, reaction temperature and substrate concentration were 150 rpm, 1/2, 8.0, 30 °C and 42 mM, respectively, under which the product yield and the product e.e. were as high as 97.4 and 95.4%.