scholarly journals Docetaxel-loaded Poly(3HB-co-4HB) Biodegradable Nanoparticles: Impact of Co-polymer Composition

2020 ◽  
Author(s):  
Faisalina Ahmad Fisol ◽  
Fabio Sonvico ◽  
Paolo Colombo ◽  
Amirul Al-Ashraf Abdullah ◽  
Habibah A. Wahab ◽  
...  
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Water Soluble ◽  
Polymer Composition ◽  
Narrow Particle Size Distribution ◽  
Wide Range ◽  
Polymer Ratio

Polyhydroxyalkanoate (PHA) co-polymers show relatively higher in vivo degradation rate compared to other PHAs thus they received a great deal of attention for a wide range of medical applications. Nanoparticles (NPs) loaded with poorly water soluble anticancer drug docetaxel (DCX) were produced using poly 3-hydroxybutyrate-co-4-hydroxybutyrate, P(3HB-co-4HB), co-polymers biosynthesised from Cupriavidus sp. USMAA1020 isolated from Malaysian environment. Three co-polymers with different molar proportions of 4-hydroxybutirate (4HB) were used: 16% (PHB16), 30% (PHB30) and 70% (PHB70) 4HB-containing P(3HB-co-4HB). Blank and DCX loaded nanoparticles were then characterized for their size and size distribution, surface charge, encapsulation efficiency and drug release. Pre-formulation studies showed that an optimised formulation could be achieved through the emulsification/solvent evaporation method using PHB70 with the addition of 1.0% PVA, as stabilizer and 0.03% VitE-TPGS, as surfactant. DCX-loaded PHB70 nanoparticles (DCX-PHB70) gave the desired particle size distribution in term of average particles sizes around 150 nm and narrow particle size distribution (PDI below 0.100). The encapsulation efficiencies result showed that at 30% w/w drug-to-polymer ratio: DCX- PHB16 NPs were able to encapsulate up to 42% of DCX; DCX-PHB30 NPs encapsulated up to 46% of DCX and DCX-PHB70 NPs encapsulated up to 50% of DCX within the nanoparticles system. Approximately 60% of DCX was released from the DCX-PHB70 NPs within 7 days for 5%, 10% and 20% of drug to polymer ratio while for the 30% and 40% drug to polymer ratios, an almost complete drug release (98%) after 7 days of incubation was observed.

scholarly journals Docetaxel-Loaded Poly(3HB-co-4HB) Biodegradable Nanoparticles: Impact of Copolymer Composition

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2123 ◽  
Author(s):  
A.F. Faisalina ◽  
Fabio Sonvico ◽  
Paolo Colombo ◽  
A.A. Amirul ◽  
H.A. Wahab ◽  
...  
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Encapsulation Efficiency ◽  
Water Soluble ◽  
Narrow Particle Size Distribution ◽  
Average Particle ◽  
Wide Range ◽  
Polymer Ratio

Polyhydroxyalkanoate (PHA) copolymers show a relatively higher in vivo degradation rate compared to other PHAs, thus, they receive a great deal of attention for a wide range of medical applications. Nanoparticles (NPs) loaded with poorly water-soluble anticancer drug docetaxel (DCX) were produced using poly(3-hydroxybutyrate-co-4-hydroxybutyrate), P(3HB-co-4HB), copolymers biosynthesised from Cupriavidus malaysiensis USMAA1020 isolated from the Malaysian environment. Three copolymers with different molar proportions of 4-hydroxybutirate (4HB) were used: 16% (PHB16), 30% (PHB30) and 70% (PHB70) 4HB-containing P(3HB-co-4HB). Blank and DCX-loaded nanoparticles were then characterized for their size and size distribution, surface charge, encapsulation efficiency and drug release. Preformulation studies showed that an optimised formulation could be achieved through the emulsification/solvent evaporation method using PHB70 with the addition of 1.0% PVA, as stabilizer and 0.03% VitE-TPGS, as surfactant. DCX-loaded PHB70 nanoparticles (DCX-PHB70) gave the desired particle size distribution in terms of average particle size around 150 nm and narrow particle size distribution (polydispersity index (PDI) below 0.100). The encapsulation efficiency result showed that at 30% w/w drug-to-polymer ratio: DCX- PHB16 NPs were able to encapsulate up to 42% of DCX; DCX-PHB30 NPs encapsulated up to 46% of DCX and DCX-PHB70 NPs encapsulated up to 50% of DCX within the nanoparticle system. Approximately 60% of DCX was released from the DCX-PHB70 NPs within 7 days for 5%, 10% and 20% of drug-to-polymer ratio while for the 30% and 40% drug-to-polymer ratios, an almost complete drug release (98%) after 7 days of incubation was observed.

scholarly journals Characteristics of Aerosol during a Severe Haze-Fog Episode in the Yangtze River Delta: Particle Size Distribution, Chemical Composition, and Optical Properties

Atmosphere ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 56 ◽  
Author(s):  
Ankang Liu ◽  
Honglei Wang ◽  
Yi Cui ◽  
Lijuan Shen ◽  
Yan Yin ◽  
...  
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Chemical Composition ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Water Soluble ◽  
Air Masses ◽  
Soluble Ions ◽  
Wide Range ◽  
Water Soluble Ions

Particle size distribution, water soluble ions, and black carbon (BC) concentration in a long-term haze-fog episode were measured using a wide-range particle spectrometer (WPS), a monitor for aerosols and gases (MARGA), and an aethalometer (AE33) in Nanjing from 16 to 27 November, 2018. The observation included five processes of clean, mist, mix, haze, and fog. Combined with meteorological elements, the HYSPLIT model, and the IMPROVE model, we analyzed the particle size distribution, chemical composition, and optical properties of aerosols in different processes. The particle number size distribution (PNSD) in five processes differed: It was bimodal in mist and fog and unimodal in clean, mix, and haze. The particle surface area size distribution (PSSD) in different processes showed a bimodal distribution, and the second peak of the mix and fog processes shifted to a larger particle size at 480 nm. The dominant air masses in five processes differed and primarily originated in the northeast direction in the clean process and the southeast direction in the haze process. In the mist, mix, and fog processes local air masses dominated. NO3− was the primary component of water soluble ions, with the lowest proportion of 45.6% in the clean process and the highest proportion of 53.0% in the mix process. The ratio of NH4+ in the different processes was stable at approximately 23%. The ratio of SO42− in the clean process was 26.2%, and the ratio of other processes was approximately 20%. The average concentration of BC in the fog processes was 10,119 ng·m−3, which was 3.55, 1.80, 1.60, and 1.46 times that in the processes of clean, mist, mix, and haze, respectively. In the different processes, BC was primarily based on liquid fuel combustion. NO3−, SO42−, and BC were the main contributors to the atmospheric extinction coefficient and contributed more than 90% in different processes. NO3− contributed 398.43 Mm−1 in the mix process, and SO42− and BC contributed 167.90 Mm−1 and 101.19 Mm−1, respectively, during the fog process.

The effect of fineness of grinding of a sample on the loss of material from nylon bags incubated in the rumen of sheep

1987 ◽  
Vol 1987 ◽  
pp. 123-123
Author(s):  
D.J. Kyle ◽  
F.D.DeB. Hovell ◽  
J. Bajracharya
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Filter Paper ◽  
Water Soluble ◽  
Barley Straw ◽  
Hammer Mill ◽  
Wide Range ◽  
Soluble Material ◽  
Zero Time

The measurement of the degradability of a roughage by means of the nylon bag technique usually requires the preparation of the sample by grinding with a laboratory hammer mill. There is a wide range of screen sizes available which produce samples which range from a fine flour to coarser materials containing particles several millimeters in length. The objective of this experiment was to examine the effect of fineness of grinding on the degradation of roughages as measured by the nylon bag technique.Samples of hay and barley straw were ground through a 1 mm screen (fine) or through a bar screen with 3-5 by 33 mm slots (coarse). Two grammes contained in nylon bags were incubated in the rumen of each of four sheep fed on a good quality roughage, giving four observations per sample. All bags were introduced into the rumen at the same time relative to feeding. Zero-time losses were determined by washing bags without incubation. Water soluble material by filtration through a Whatman No. 1 filter paper. The particle size distribution of the hay used in Expt 1 is shown by Fig 1.

Effects of Multiple Impacts and Size Distribution of Particles on Erosion Predictions Using CFD

2007 ◽  
Author(s):  
Yongli Zhang ◽  
Brenton S. McLaury ◽  
Siamack A. Shirzai
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Target Material ◽  
Average Particle ◽  
Multiple Impacts ◽  
Cfd Simulations ◽  
Erosion Damage ◽  
Wide Range

Erosion equations are usually obtained from experiments by impacting solid particles entrained in a gas or liquid on a target material. The erosion equations are utilized in CFD (Computational Fluid Dynamics) models to predict erosion damage caused by solid particle impingements. Many erosion equations are provided in terms of an erosion ratio. By definition, the erosion ratio is the mass loss of target material divided by the mass of impacting particles. The mass of impacting particles is the summation of (particle mass × number of impacts) of each particle. In erosion experiments conducted to determine erosion equations, some particles may impact the target wall many times and some other particles may not impact the target at all. Therefore, the experimental data may not reflect the actual erosion ratio because the mass of the sand that is used to run the experiments is assumed to be the mass of the impacting particles. CFD and particle trajectory simulations are applied in the present work to study effects of multiple impacts on developing erosion ratio equations. The erosion equation as well as the CFD-based erosion modeling procedure is validated against a variety of experimental data. The results show that the effect of multiple impacts is negligible in air cases. In water cases, however, this effect needs to be accounted for especially for small particles. This makes it impractical to develop erosion ratio equations from experimental data obtained for tests with sand in water or dense gases. Many factors affecting erosion damage are accounted for in various erosion equations. In addition to some well-studied parameters such as particle impacting speed and impacting angle, particle size also plays a significant role in the erosion process. An average particle size is usually used in analyzing experimental data or estimating erosion damage cases of practical interest. In petroleum production applications, however, the size of sand particles that are entrained in produced fluids can vary over a fairly broad range. CFD simulations are also performed to study the effect of particle size distribution. In CFD simulations, particle sizes are normally distributed with the mean equaling the average size of interest and the standard deviation varying over a wide range. Based on CFD simulations, an equation is developed and can be applied to account for the effect of the particle size distribution on erosion prediction for gases and liquids.

Green synthesis of submicron copper powder with narrow particle size distribution via a simple methanol thermal reduction

2021 ◽  
Author(s):  
Xiaoping Chen ◽  
Jiaqi Fu ◽  
Jiangang Li ◽  
Bohong Chen ◽  
Lei Yang ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Green Synthesis ◽  
Size Distribution ◽  
Copper Powder ◽  
Reduction Method ◽  
Particle Distribution ◽  
Thermal Reduction ◽  
Narrow Particle Size Distribution

In this work, submicron copper powder with narrow particle distribution was synthesized via a simple methanol thermal reduction method without using any surfactants. Smaller copper powder with narrower particle size...

Organosilicon Comb-Shaped Surfactants for the Synthesis of Polymer Suspensions with a Narrow Particle Size Distribution

2021 ◽  
Vol 63 (3) ◽  
pp. 209-217
Author(s):  
A. A. Ezhova ◽  
I. A. Gritskova ◽  
S. A. Gusev ◽  
S. A. Milenin ◽  
V. V. Gorodov ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Narrow Particle Size Distribution

scholarly journals Encapsulation of Menthol in Beeswax by a Supercritical Fluid Technique

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Linjing Zhu ◽  
Hongqiao Lan ◽  
Bingjing He ◽  
Wei Hong ◽  
Jun Li
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Flow Rate ◽  
Saturated Solution ◽  
Narrow Particle Size Distribution ◽  
Solution Flow Rate ◽  
Process Conditions ◽  
Solution Flow ◽  
Expansion Temperature

Encapsulation of menthol in beeswax was prepared by a modified particles from gas-saturated solutions (PGSS) process with controlling the gas-saturated solution flow rate. Menthol/beeswax particles with size in the range of 2–50 μm were produced. The effects of the process conditions, namely, the pre-expansion pressure, pre-expansion temperature, gas-saturated solution flow rate, and menthol composition, on the particle size, particle size distribution, and menthol encapsulation rate were investigated. Results indicated that in the range of studied conditions, increase of the pressure, decrease of the gas-saturated solution flow rate, and decrease of the menthol mass fraction can decrease the particle size and narrow particle size distribution of the produced menthol/beeswax microparticles. An N2-blowing method was proposed to measure the menthol release from the menthol/beeswax microparticles. Results showed that the microparticles have obvious protection of menthol from its volatilization loss.

Hydrodynamic Properties of Fe 3 O 4 Kerosene-Based Ferrofluids with Narrow Particle Size Distribution

2005 ◽  
Vol 22 (11) ◽  
pp. 2944-2946 ◽  
Author(s):  
Zhang Jian-Hui ◽  
Xu Xue-Fei ◽  
Si Ming-Su ◽  
Zhou You-He ◽  
Xue De-Sheng
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Narrow Particle Size Distribution ◽  
Hydrodynamic Properties

Soil Cohesion Development under Different Pore and Size Characteristics

2020 ◽  
Author(s):  
Cagla Temiz ◽  
Fikret Ari ◽  
Selen Deviren Saygin ◽  
Sefika Arslan ◽  
Mehmet Altay Unal ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Soil Properties ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Soil Mass ◽  
General Terms ◽  
Soil Cohesion ◽  
Wide Range ◽  
Fluid Bed

<p>Soil cohesion (Co) is one of the most important physical soil characteristics and it is closely related to the basic soil properties and physical distribution forces (e.g. particle size distribution, pore sizes, shear strength) and so it is mostly determined by experimentally approaches with the help of other soil properties in general terms. Instead of using these assumptions, the fluidized bed approach provides an opportunity for direct measurement of intrinsic soil cohesion. In this study, soil cohesion development for different soil types was investigated with the fluid-bed method by which pressure drop in soil mass measures under increasing water pressures until the cohesion between particles disappears. For this purpose, 20 different soils varying with a wide range of relevant soil physical properties were sampled; such that clay, silt and sand contents varied between 2% and 56%, 1% and 50%, and 1% and 97%, respectively while porosity values were between 0.38 and 0.92. By those textural diversities of the soils, obtained cohesion values changed between 5203 N m<sup>-3</sup> and 212276 N m<sup>-3</sup>. Given results from regression analysis, a significant relationship was found between cohesion values of the soils and their porosity and silt fractions (R<sup>2</sup>: 86.6).These findings confirm that the method has a high potential to reflect differential conditions and show that soil cohesion could be modeled by such basic and easily obtainable parameters as particle size distribution and porosity, as well.<strong> </strong></p><p><strong>Key words</strong>; <strong>Mechanical soil cohesion, particle size distribution, fluidized bed approach, porosity</strong></p>

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