Here, we report the construction of magnetic core-shell microparticles for oil removal with thermal driving regeneration property. Water-in-oil-in water (W/O/W) emulsions from microfluidics are used as templates to pr...Here, we report the construction of magnetic core-shell microparticles for oil removal with thermal driving regeneration property. Water-in-oil-in water (W/O/W) emulsions from microfluidics are used as templates to prepare core-shell microparticles with magnetic holed poly (ethoxylated trimethylolpropane triacrylate) (PETPTA) shells each containing a thermal-sensitive poly (N-Isopropylacrylamide) (PNIPAM) core. The microparticles could adsorb oil from water due to the special structure and be collected with a magnetic field. Then, the oil-filled microparticles would be regenerated by thermal stimulus, in which the inner PNIPAM microgels work as thermal-sensitive pistons to force out the adsorbed oil. At the same time, the adsorbed oil would be recycled by distillation. Furthermore, the adsorption capacity of the microparticles for oil keeps very stable after 1st cycle. The adsorption and regeneration performances of the microparticles are greatly affected by the size of the holes on the outer PETPTA shells, which could be precisely controlled by regulating the interfacial forces in W/O/W emulsion templates. The optimized core-shell microparticles show excellent oil adsorption and thermal driving regeneration performances nearly without secondary pollution, and would be a reliable green adsorption material for kinds of oil.展开更多
Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulveriz...Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulverization during the lithiation/delithiation process.The high stress induced by the Li concentration gradient and anisotropic deformation is the main reason for the fracture of Si particles.Here we present a new stress mitigation strategy by uniformly distributing small amounts of Sn and Sb in Si micron-sized particles,which reduces the Li concentration gradient and realizes an isotropic lithiation/delithiation process.The Si8.5Sn0.5Sb microparticles(mean particle size:8.22μm)show over 6000-fold and tenfold improvements in electronic conductivity and Li diffusivity than Si particles,respectively.The discharge capacities of the Si_(8.5)Sn_(0.5)Sb microparticle anode after 100 cycles at 1.0 and 3.0 A g^(-1)are 1.62 and 1.19 Ah g^(-1),respectively,corresponding to a retention rate of 94.2%and 99.6%,respectively,relative to the capacity of the first cycle after activation.Multicomponent microparticle anodes containing Si,Sn,Sb,Ge and Ag prepared using the same method yields an ultra-low capacity decay rate of 0.02%per cycle for 1000 cycles at 1 A g^(-1),corroborating the proposed mechanism.The stress regulation mechanism enabled by the industry-compatible fabrication methods opens up enormous opportunities for low-cost and high-energy-density Li-ion batteries.展开更多
Background: Due to worldwide increases in the prevalence of antibiotic-resistant bacteria, it is necessary to develop an active drug delivery system that can enable therapeutics to reach their molecular targets. Maint...Background: Due to worldwide increases in the prevalence of antibiotic-resistant bacteria, it is necessary to develop an active drug delivery system that can enable therapeutics to reach their molecular targets. Maintaining the concentration of any drug in the blood at a certain level for a long time is critical in the practice of drug therapy. With the increased frequency of drug use, the blood concentration of drugs exceeds the therapeutic level, leading to toxicity or ineffectiveness. To solve these problems, in recent years, much attention has been given to developing micro/nano preparations by encapsulating biologically active compounds on polymeric carriers. Therefore, we aimed to extract pectin from sea buckthorn peel, prepare microcapsules containing antibiotics, and determine their physical and chemical properties. Methods: Wastes were separated from sea buckthorn under “Medical raw materials Dry fruit of Hippophae rhamnoides MNS 5225:2002”. Pectin was isolated from sea buckthorn waste according to the “method for determination of pectins MNS3080:1981” standard. The degree of esterification was determined according to ISO 7623:2016. Antibiotic encapsulation with coacervates and water-based emulsions was performed. Antibiotic sensitivity was determined by microdilution according to the Clinical Laboratory Standard Institute (МТ100-S27) method. The results were determined between standard strains of Staphylococcus aureus ATCC 29213 and MRSA ATCC 2758 at different dilution concentrations. Result: Pectin is a brown powder with a sour taste and no odor. There was 71.4% esterification of pectin, 8.9% yield, 1.3% free carboxyl group, 3.2% methylated carboxyl group, 4.5% total carboxyl group, 3.5% ash, and 0.1% nitrogen. A study of the antibacterial activity of pectin containing doxycycline hyclate found that the inhibition of bacterial growth was 0.8 times less than that of pure pectin. It was 1 time less than that of doxycycline alone, and 33 times smaller than that of wontaxime when compared to pure pectin. Pectin containing doxycycline hyclate inhibited MRSA growth at a concentration 6 times lower than pure pectin. This was 2 times lower than doxycycline alone, and 8 times lower than wontaxime. Conclusion: Pectin yields 1.3 after 60 minutes of separation at a sediment concentration ratio of 1:1.15 and pH = 2. Pectin itself is antibacterial against MRSA.展开更多
Objective: Hemp seed oil is perfect for most skin types;it moisturizes skin and protects it from inflammation, oxidation, and other causes of aging. The problem is that the Hemp oil-based products do not penetrate the...Objective: Hemp seed oil is perfect for most skin types;it moisturizes skin and protects it from inflammation, oxidation, and other causes of aging. The problem is that the Hemp oil-based products do not penetrate the skin;they remain on the skin’s surface. Recently researchers have been trying to prepare nano emulsions of hemp oil to facilitate its permeation to deep skin layers. In all techniques used today, surfactants are added to the emulsification process. These surfactants may cause unwanted skin side effects. In the present study, we prepare micronized Hemp (m-Hemp) without using any surfactants in the micronization process, thus avoiding the side effects associated with surfactant addition. Methods & Results: Particles size of m-Hemp was evaluated using electron microscopy. Various sizes of m-Hemp were found, the smallest being 100 nm in diameter. The antioxidation properties of m-Hemp were measured using the Electron Spin Resonance (ESR) technique and were found to be enhanced. Skin topography and morphology following a cream containing m-Hemp treatment were visualized by Optical Profilometry and ESEM respectively. The results show a marked improvement in skin topography in all measured parameters. In addition, human keratinocytes (HaCaT) were exposed to inflammatory conditions and were then treated using Hemp. As a result, one of the key inflammatory factors (IL-2) was significantly reduced after treatment with m-Hemp (p ≤ 0.0001). The skin penetration of the cream containing m-Hemp was tested on human skin using the IMOPE (Iterative Multi-plane Optical Property Extraction) system. The results indicate that m-Hemp penetrates both the stratum corneum and the deep epidermal layers towards the dermis. Conclusion: The new cream prepared with micronized Hemp shows significant anti-inflammatory and antioxidative effects and demonstrates the entrance of m-Hemp to the skin epidermal layer.展开更多
Objective:To evaluate the effect of preoperative dietary intervention on the gastrointestinal reaction of microparticle transcatheter arterial chemoembolization(TACE).Methods:A total of 60 patients with primary liver ...Objective:To evaluate the effect of preoperative dietary intervention on the gastrointestinal reaction of microparticle transcatheter arterial chemoembolization(TACE).Methods:A total of 60 patients with primary liver cancer who were treated in our hospital from January 2018 to October 2018 were selected for this study.The random sampling method was used to divide the patients into an intervention group(30 cases)and a control group(30 cases).The control group received routine intervention,whereas the intervention group received optimized nursing intervention.The incidence of gastrointestinal reactions,the vomiting frequency,the average vomiting volume,the incidence of stomach discomfort,the quality of life,and the anxiety and depression indicators of both groups were compared.Results:The results of all indicators of the intervention group were better than those of the control group.The incidence of gastrointestinal reactions in the intervention group was 13.9%,which was lower than 43.3%of the control group.The scores of QLQ-C30 of the intervention group were higher than those of the control group;the SAS and SDS scores in the intervention group were lower than those of the control group.Conclusion:Preoperative dietary intervention can reduce the incidence of gastrointestinal reactions of microparticle TACE and improve the symptoms of gastric discomfort among patients.展开更多
Article continues and complements our previous articles on the HM16 ether (ETH) model. Here, we describe the mechanism of occurrence of the submicroparticle (SMP). A general hypothesis, HFVI, is introduced for the mod...Article continues and complements our previous articles on the HM16 ether (ETH) model. Here, we describe the mechanism of occurrence of the submicroparticle (SMP). A general hypothesis, HFVI, is introduced for the modalities of interaction between two SMPs, based on periodic mechanical percussion forces, produced by fundamental vibrations FVs. A mechanism for describing the interaction between a SMPs and the ETH is presented. Positive and negative particles are defined by their membrane types of movement, such as +, <span style="white-space:nowrap;">−</span><em>u</em>/+, <span style="white-space:nowrap;">−</span><em>v</em> vibrations, and rotations at speeds +<span style="white-space:nowrap;">Ω</span>/<span style="white-space:nowrap;">−</span><span style="white-space:nowrap;">Ω</span>. The process of creating a pair of SMPs is discussed. Applying HFVI to the interaction between pairs of SMPs immobile in ETH, and considering longitudinal FVL, was obtained the forces of attraction/repulsion +<em>F</em><sub><em>L</em>21</sub>/–<em>F<sub>L</sub></em><sub>21</sub>, which correspond to the completed Coulomb force<em> F<sub>CC</sub></em> including gravitation. The resultant <em>F</em><sub>RL21</sub> will form an oriented field of forces, which is a quasielectric field <em>QE</em>, equivalent to actual <em>E</em> electric field. Considering transversal FVT, was obtained the vibratory forces +, <span style="white-space:nowrap;">−</span><em>F<sub>T</sub></em><sub>21</sub>, whose resultant forms an vibrating field of forces, <em>QHs</em>, a quasimagnetic special field, which may explain some of the quantum properties of SMPs. Considering a mobile SMP, two new<em> <span style="white-space:nowrap;">γ</span></em> strains in ETH appear. Strains <em><span style="white-space:nowrap;">γ</span><sub>L</sub></em> are created by the displacement of SMP with velocity<em> V</em>, whose force +, <span style="white-space:nowrap;">−</span><em>F<sub>T</sub></em><sub>12</sub> is the support of a component of the magnetic field <em>H</em> (quasimagnetic field <em>QH</em>), giving the <em>QH<sub>L</sub></em> component. Strains <em>γ</em><sub>R</sub> are created by the rotation of SMP with speed <span style="white-space:nowrap;">Ω</span>, whose force +, <span style="white-space:nowrap;">−</span><em>F</em><sub>R12</sub> constitutes physical support of the component <em>QH<sub>R</sub></em> of magnetic field <em>H </em>(<em>i.e. QH)</em><em></em>. The creation of a photon PH is modelled as a special ESMP containing two zones of opposed rotations, and a mechanism is presented for its movement in the ETH with speed <em>c</em> based on the HS hypothesis of screwing in ETH, with frequency <em>ν</em>.展开更多
Microparticles are small cell vesicles that can be released by almost all eukaryotic cells during cellular stress and cell activation. Within the last 1-2 decades it has been shown that microparticles are useful blood...Microparticles are small cell vesicles that can be released by almost all eukaryotic cells during cellular stress and cell activation. Within the last 1-2 decades it has been shown that microparticles are useful blood surrogate markers for different pathological conditions, such as vascular inflammation, coagulation and tumour diseases. Several studies have investigated the abundance of microparticles of different cellular origins in multiple cardiovascular diseases. It thereby has been shown that microparticles released by platelets, leukocytes and endothelial cells can be found in conditions of endothelial dysfunction, acute and chronic vascular inflammation and hypercoagulation. In addition to their function as surrogate markers, several studies indicate that circulating microparticles can fuse with distinct target cells, such as endothelial cells or leukocyte, and thereby deliver cellular components of their parental cells to the target cells. Hence, microparticles are a novel entity of circulating, paracrine, biological vectors which can influence the phenotype, the function and presumably even the transcriptome of their target cells.This review article aims to give a brief overview about the microparticle biology with a focus on endothelial activation and arterial hypertension. More detailed information about the role of microparticles in pathophysiology and disease can be found in already published work.展开更多
A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELI...A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELISA).A systematic comparison between the MmPs-CLEIA and colorimetric ELISA concluded that the MPs-CLEIA exhibited fewer dosages of immunoreagents,less total assay time,and better linearity,recovery,precision,sensitivity and validity.AFP was detected in forty human serum samples by the proposed MPs-CLEIA and ELISA,and the results were compared with commercial electrochemiluminescence immunoassay (ECLIA) kit.The correlation coefficient between MPs-CLEIA and ELISA was obtained with R 2 0.6703;however,the correlation between MPs-CLEIA and ECLIA (R 2 0.9582) was obviously better than that between colorimetric ELISA and ECLIA (R 2 0.6866).展开更多
A type of triangular pyramid-shaped microparticles of puerarin was synthesized by using oil-in-oil microemulsion approach which is simple and economical under the action of copper substrate.The pyramid-shaped micropar...A type of triangular pyramid-shaped microparticles of puerarin was synthesized by using oil-in-oil microemulsion approach which is simple and economical under the action of copper substrate.The pyramid-shaped microparticles would be made up of deposit of nanospheres or nanorods and have two significant characters.One is its complex surface morphology like coral reef.The other is a lot of nanopores in existence in the microparticle body.Two possible formation routes were speculated.展开更多
AIM To evaluate platelet activation markers in psoriasis patients, compared to controls, and investigate their association with the inflammatory burden of psoriasis.METHODS Forty psoriatic patients without cardiovascu...AIM To evaluate platelet activation markers in psoriasis patients, compared to controls, and investigate their association with the inflammatory burden of psoriasis.METHODS Forty psoriatic patients without cardiovascular disease,and 12 healthy controls were subjected to measurement of baseline platelet CD62 P, CD63 and CD42 b expression, platelet-leukocyte complexes, i.e., platelet-monocyte complexes(PMC), platelet-neutrophil complexes(PNC) and platelet-lymphocyte complexes, and concentrations of platelet-derived microparticles(PMPs) using flow cytometry. Both larger-size(0.5-0.9 μm) and smallersize(< 0.5 μm) PMPs were determined. Serum interleukin(IL)-12 and IL-17 levels were also measured by enzyme-linked immunosorbent assay. The severity of psoriasis was evaluated by the Psoriasis Area Severity Index(PASI).RESULTS PMP concentrations were significantly higher in psoriasis patients than controls [mean±standard error of mean(SEM): 22±5/μL vs 11±6/μL; P=0.018), for both smaller-size(10±2/μL vs 4±2/μL; P=0.033) and larger-size(12±3/μL vs 6±4/μL; P=0.014) PMPs. Platelet CD62 P, CD63 and CD42 b expression and circulating PMC and PNC were similar between the two groups. Lower circulating PLC were observed in psoriasis patients compared to controls(mean±SEM: 16%±3% vs 23%±6%; P=0.047). Larger-size PMPs were related with IL-12 levels(P<0.001) and smaller-size PMPs with both IL-12 and IL-17 levels(P<0.001). Total PMPs also correlated with IL-12(P<0.001). CD63 expression was positively correlated with both IL-12 and IL-17(P<0.05). Increased PASI score was associated with increased levels of larger-size PMPs(r=0.45; P=0.011) and increased CD63 expression(r=0.47; P<0.01).CONCLUSION PMPs, known to be predictive of cardiovascular outcomes, are increased in psoriasis patients, and associated with high inflammatory disease burden. Enhanced platelet activation may be the missing link leading to cardiovascular events in psoriatic patients.展开更多
The deterioration of endothelial structure plays a very important role in the development of vascular diseases. It is believed that endothelial dysfunction starts in the early stage of kidney disease and is a risk fac...The deterioration of endothelial structure plays a very important role in the development of vascular diseases. It is believed that endothelial dysfunction starts in the early stage of kidney disease and is a risk factor of an unfavorable cardiovascular prognosis. Because a direct assessment of biological states in endothelial cells is not applicable, the measurement of endothelial microparticles(EMPs) detached from endothelium during activation or apoptosis is thought to be a marker of early vascular disease and endothelial dysfunction in children with chronic kidney disease(CKD). Few studies have shown increased circulating EMPs and its relationship with cardiovascular risk factors in patients with CKD.MPs contain membrane proteins and cytosolic material derived from the cell from which they originate. EMPs having CD144, CD 146, CD31+/CD41-, CD51 and CD105 may be used to evaluate the vascular endothelial cell damage and determine asymptomatic patients who might be at higher risk of developing cardiovascular disease in CKD and renal transplant.展开更多
Purpose: A series of clinical studies have established the safety and efficacy of transcatheter arterial chemoembolization(TACE) with gelatin sponge microparticles(GSMs) in treating hepatocellular carcinoma(HCC). HCC ...Purpose: A series of clinical studies have established the safety and efficacy of transcatheter arterial chemoembolization(TACE) with gelatin sponge microparticles(GSMs) in treating hepatocellular carcinoma(HCC). HCC can lead to obvious necrosis inside tumors, especially larger ones, although it is unclear whether such necrotic tumor tissue can induce favorable immune reactions against the tumor. Myeloid-derived suppressor cells(MDSCs)have immunosuppressive functions and are currently considered a very important cell type affecting tumor immunity. This study observed changes in MDSC frequency in peripheral blood before and after GSM–TACE to evaluate the effect on the immune function of HCC patients.Methods: Eight patients diagnosed with HCC underwent GSM–TACE treatment in the Hepatobiliary Interventional Department of Beijing Tsinghua Chang Gung Hospital, Beijing, China;we followed up with the patients over a period of 30 days post-surgery. We used flow cytometry(FCM) to quantify the frequency of MDSCs in peripheral blood before TACE, 10 days after surgery and 30 days after surgery.Results: MDSC frequency after GSM–TACE had a significant downward trend. Pre-TACE, it was 30.73% ? 11.93%,decreasing to 18.60% ? 11.37% at 10 days after operation. This decrease was not statistically significant(P > 0.05). MDSC frequency was even lower 30 days after TACE(7.63% ? 7.32%) than at 10 days after TACE(P < 0.05), and there was a significant difference compared with pre-TACE(P < 0.001). We evaluated tumor response at 30 days after GSM–TACE according to the Modified Response Evaluation Criteria in Solid Tumors(mRECIST), and all eight patients showed partial response(PR).Conclusion: Our results confirmed that GSM–TACE was beneficial for improving anti-tumor immunity in the treatment of HCC.展开更多
This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other...This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH)3 microparticles in direct contact with zinc powder.Electrochemical properties of zinc electrodes containing Y(OH)3 microparticles were discussed through the measurements of potentiodynamic polarization and cyclic voltammetry.Simultaneously,the test cells making use of such modified zinc powder were assembled to further evaluate the availability of Y(OH)3 microparticles in improving the cycle properties of zinc electrodes.It was found that good alkaline environment generated by ultrasonic irradiation of high power led to the formation of Y(OH)3 microparticles on the surface of modified zinc powder due to high-energy jets of immersion solution.In particular,the Y(OH)3 microparticles formed with the ultrasonic power of 440 W made the greatest contributions to hinder the corrosion of zinc electrode and the dissolution of zinc oxidation products in alkaline electrolyte as compared with other power parameters.Besides,the detections of assembled cells at a high discharge current density of 250 mA/cm2 revealed that the Y(OH)3 microparticles obtained with ultrasonic power of 440 W provided the alkaline zinc electrode with low capacity loss and persistent cycle behavior.The great improvement over the corrosion behavior and cycle properties of zinc electrode is possibly ascribed to the uniform distribution of Y(OH)3 microparticles on the surface of modified zinc powder.展开更多
Ultra-thin flexible films have attracted wide attention because of their excellent ductility and potential versatility.In particular,the energy-harvesting films(EHFs)have become a research hotspot because of the indis...Ultra-thin flexible films have attracted wide attention because of their excellent ductility and potential versatility.In particular,the energy-harvesting films(EHFs)have become a research hotspot because of the indispensability of power source in various devices.However,the design and fabrication of such films that can capture or transform di erent types of energy from environments for multiple usages remains a challenge.Herein,the multifunctional flexible EHFs with e ective electro-/photo-thermal abilities are proposed by successive spraying Ag microparticles and MXene suspension between on waterborne polyurethane films,supplemented by a hot-pressing.The optimal coherent film exhibits a high electrical conductivity(1.17×10^(4)S m^(-1)),excellent Joule heating performance(121.3℃)at 2 V,and outstanding photo-thermal performance(66.2℃ within 70 s under 100 mW cm^(-1)).In addition,the EHFs-based single-electrode triboelectric nanogenerators(TENG)give short-circuit transferred charge of 38.9 nC,open circuit voltage of 114.7 V,and short circuit current of 0.82μA.More interestingly,the output voltage of TENG can be further increased via constructing the double triboelectrification layers.The comprehensive ability for harvesting various energies of the EHFs promises their potential to satisfy the corresponding requirements.展开更多
Hypromellose acetate succinate(HPMCAS) microparticles containing the poorly-water soluble drug celecoxib(CEL) were prepared by electrospraying intended for oral drug delivery. Various solvent mixtures with different s...Hypromellose acetate succinate(HPMCAS) microparticles containing the poorly-water soluble drug celecoxib(CEL) were prepared by electrospraying intended for oral drug delivery. Various solvent mixtures with different solubility for CEL and HPMCAS were used to induce changes in the polymer structural conformation of the microparticles. The performance of the prepared microparticles was evaluated by studying the solid state from, particle size and morphology, radial drug distribution and drug release. CEL was amorphous in all electrosprayed HPMCAS microparticles. The particle size and morphology was dependent on the solubility of HPMCAS in the solvent mixture used with poorer solvents resulting in smaller microparticles with rougher appearance. The CEL distribution on the particles surface was relatively homogeneous and similar for all microparticles. Drug release from the microparticles was observed at a higher rate depending on the solubility of HPMCAS in the solvent used for electrospraying, and in all cases an at least 4-fold higher rate was observed compared with the crystalline drug. Drug precipitation from the supersaturated solution was inhibited by HPMCAS for all microparticles based on its parachute effect while crystalline CEL did not reach supersaturation. This study demonstrated that electrospraying can be used to produce microparticles with tailored properties for pharmaceutical application by adjusting solvent selection.展开更多
Recently there has been a wide concern on inorganic nanoparticles as drug delivery carriers. CaCO3 particles have shown promising potential for the development of carriers for drugs, but little research had been perfo...Recently there has been a wide concern on inorganic nanoparticles as drug delivery carriers. CaCO3 particles have shown promising potential for the development of carriers for drugs, but little research had been performed regarding their safe dosage for maximizing the therapeutic activity without harming biosystems. In this study, we assessed the biological safety of porous spherical CaCO3 microparticles on Hela cells. The reactive oxygen species (ROS), glutathione (GSH), carbonyl content in proteins (CCP), DNA-protein crosslinks (DPC) and cell viability were measured. Results showed that with the exposure concentration increase, ROS and CCP in Hela cells presented a significant increase but GSH contents in Hela cells and cell viability showed a significant decrease respectively compared with the control. DPC coefficient ascended, but no statistically significant changes were observed. The results indicated that porous spherical CaCO3 microparticles may induce oxidative damage to Hela cells. But compared with other nanomaterials, porous spherical CaCO3 appeared to have good biocompatibility. The results implied that porous spherical calcium carbonate microparticles could be applied as relatively safe drug vehicles, but with the caveat that the effect of high dosages should not be ignored when attempting to maximize therapeutic activity by increasing the concentration.展开更多
Chitosan (CS) microparticles with and without cross-linking were prepared by a water-in-oil emulsion solvent diffusion method without any surfactants. Aqueous CS solution and ethyl ace- tate were used as water and oil...Chitosan (CS) microparticles with and without cross-linking were prepared by a water-in-oil emulsion solvent diffusion method without any surfactants. Aqueous CS solution and ethyl ace- tate were used as water and oil phases, respectively. Genipin was used as a cross-linker. Influ- ences of genipin ratios and cross-linking times on CS microparticle characteristics were investigated. Non-cross-linked and cross-linked CS microparticles were spherical in shape and rough in surface. Microparticle matrices showed porous structures. Surface roughness, mean par- ticle sizes and bulk density of CS microparticles increased and their dissolutions in acetic acid solution decreased when genipin ratio and cross- linking time increased.展开更多
With hydrophilic surface and high surface area, porous silica has been applied to load insoluble drugs. Compared to solvent equilibrium method, resveratrol(RES)–mesoporous silica microparticles(MSM) solid dispersion ...With hydrophilic surface and high surface area, porous silica has been applied to load insoluble drugs. Compared to solvent equilibrium method, resveratrol(RES)–mesoporous silica microparticles(MSM) solid dispersion prepared by fluid bed demonstrated higher drug loading and more complete dissolution. Pore volume and diameter have more remarkable effects than surface area to the drug loading and in vitro dissolution profiles. RES–polyethylene glycol solid dispersion with high drug loading showed fast but incomplete dissolution due to the recrystallization. The combination of fluid bed and MSM was an effective strategy to improve drug loading as well as dissolution for poorly water-soluble drugs.展开更多
【正】Objective:To preliminarily investigate three different lipid matrices consisting of two natural homolipids from Capra hircus(goat fat) and Bovine Spp.(tallow fat) and one semi-synthetic lipid(Softisan~? 142) sep...【正】Objective:To preliminarily investigate three different lipid matrices consisting of two natural homolipids from Capra hircus(goat fat) and Bovine Spp.(tallow fat) and one semi-synthetic lipid(Softisan~? 142) separately structured with Phospholipon~? 90G(P90G) as potential delivery systems for poorly water soluble drugs.Methods:The structured lipid matrices were characterized by differential scanning calorimetry(DSC) and employed to prepare solid lipid microparticles(SLMs) by the melt homogenization method using gradient concentrations of polysorbate 80 and at different emulsification times of 2,5 and 10 min using a Silverson mixer. The SLMs were analyzed for morphology and particle size,thermal properties,stability studies and determination of injectability.Results:The results showed that SLM production was optimum at 5%of lipid matrices,1.5%of polysorbate 80 and emulsification time of 5 min.Increase in polysorbate 80 concentrations decreased the particle size of the SLMs.The SLMs were well formed, spherical,smooth and non-porous with particle sizes in the ranges of(13.90±2.10)μm -(0.09±0.01)μm for SLMs produced from the structured - tallow fat;(13.40±1.30)μm-(0.10±0.01)μm for the structured - goat fat and(13.40±2.00)μm-(2.10±1.00)μm for the structured Softisan~? 142 lipid matrices.DSC traces showed that Softisan~? 142 was the most crystalline of all three bulk matrices due to its high enthalpy(-7.962 mW/mg) while tallow fat was the least(-5.067 mW/mg) but addition of P90G to the matrices lowered their enthalpies mostly in the structured goat fat matrices.The SLMs when stored at 4-6°C were most stable and syringeable with 27 G needle.Conclusions:This suggests that structured goat fat matrices with the enthalpy of -2.813 mW/mg will mosdy favour drug loading of some poorly soluble drugs more than tallow fat(-4.892 mW/mg) and Softisan? 142(-5.501 mW/mg).展开更多
In this study, nanostructured microparticles was developed with polycaprolactone (PCL), poly(vinyl alcohol) (PVAL) and nanoparticles of the commercial sodium clay NT-25®by using the spray drying technique. The...In this study, nanostructured microparticles was developed with polycaprolactone (PCL), poly(vinyl alcohol) (PVAL) and nanoparticles of the commercial sodium clay NT-25®by using the spray drying technique. The systems obtained were characterized by Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic Laser Light Scattering (DLS) and Differential Scanning Calorimetry (DSC). The NMR <sup>13</sup>C and FTIR techniques showed that both polymers were present in the microparticles and the DSC analysis revealed a small variation in the glass transition temperature of the PCL. The XRD and SEM analyses showed that the microparticles produced were amorphous and had a concave morphology. The NT-25 nanoload reduced the microparticles’ size due to the multiple interactions formed in the hybrid nanocomposite material. Therefore, it was possible to develop microparticles by using biodegradable and biocompatible polymers, with different polarities, allowing the incorporation of hydrophilic and hydrophobic materials and enabling the inclusion of otherwise incompatible materials in the same system.展开更多
基金This work was supported by the National Natural Science Foundation of China[grant numbers 21706219]。
文摘Here, we report the construction of magnetic core-shell microparticles for oil removal with thermal driving regeneration property. Water-in-oil-in water (W/O/W) emulsions from microfluidics are used as templates to prepare core-shell microparticles with magnetic holed poly (ethoxylated trimethylolpropane triacrylate) (PETPTA) shells each containing a thermal-sensitive poly (N-Isopropylacrylamide) (PNIPAM) core. The microparticles could adsorb oil from water due to the special structure and be collected with a magnetic field. Then, the oil-filled microparticles would be regenerated by thermal stimulus, in which the inner PNIPAM microgels work as thermal-sensitive pistons to force out the adsorbed oil. At the same time, the adsorbed oil would be recycled by distillation. Furthermore, the adsorption capacity of the microparticles for oil keeps very stable after 1st cycle. The adsorption and regeneration performances of the microparticles are greatly affected by the size of the holes on the outer PETPTA shells, which could be precisely controlled by regulating the interfacial forces in W/O/W emulsion templates. The optimized core-shell microparticles show excellent oil adsorption and thermal driving regeneration performances nearly without secondary pollution, and would be a reliable green adsorption material for kinds of oil.
基金This work was supported by the General Research Fund scheme of the Hong Kong Research Grants Council(Project No.15227121)the Hong Kong Polytechnic University(ZVGH).
文摘Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulverization during the lithiation/delithiation process.The high stress induced by the Li concentration gradient and anisotropic deformation is the main reason for the fracture of Si particles.Here we present a new stress mitigation strategy by uniformly distributing small amounts of Sn and Sb in Si micron-sized particles,which reduces the Li concentration gradient and realizes an isotropic lithiation/delithiation process.The Si8.5Sn0.5Sb microparticles(mean particle size:8.22μm)show over 6000-fold and tenfold improvements in electronic conductivity and Li diffusivity than Si particles,respectively.The discharge capacities of the Si_(8.5)Sn_(0.5)Sb microparticle anode after 100 cycles at 1.0 and 3.0 A g^(-1)are 1.62 and 1.19 Ah g^(-1),respectively,corresponding to a retention rate of 94.2%and 99.6%,respectively,relative to the capacity of the first cycle after activation.Multicomponent microparticle anodes containing Si,Sn,Sb,Ge and Ag prepared using the same method yields an ultra-low capacity decay rate of 0.02%per cycle for 1000 cycles at 1 A g^(-1),corroborating the proposed mechanism.The stress regulation mechanism enabled by the industry-compatible fabrication methods opens up enormous opportunities for low-cost and high-energy-density Li-ion batteries.
文摘Background: Due to worldwide increases in the prevalence of antibiotic-resistant bacteria, it is necessary to develop an active drug delivery system that can enable therapeutics to reach their molecular targets. Maintaining the concentration of any drug in the blood at a certain level for a long time is critical in the practice of drug therapy. With the increased frequency of drug use, the blood concentration of drugs exceeds the therapeutic level, leading to toxicity or ineffectiveness. To solve these problems, in recent years, much attention has been given to developing micro/nano preparations by encapsulating biologically active compounds on polymeric carriers. Therefore, we aimed to extract pectin from sea buckthorn peel, prepare microcapsules containing antibiotics, and determine their physical and chemical properties. Methods: Wastes were separated from sea buckthorn under “Medical raw materials Dry fruit of Hippophae rhamnoides MNS 5225:2002”. Pectin was isolated from sea buckthorn waste according to the “method for determination of pectins MNS3080:1981” standard. The degree of esterification was determined according to ISO 7623:2016. Antibiotic encapsulation with coacervates and water-based emulsions was performed. Antibiotic sensitivity was determined by microdilution according to the Clinical Laboratory Standard Institute (МТ100-S27) method. The results were determined between standard strains of Staphylococcus aureus ATCC 29213 and MRSA ATCC 2758 at different dilution concentrations. Result: Pectin is a brown powder with a sour taste and no odor. There was 71.4% esterification of pectin, 8.9% yield, 1.3% free carboxyl group, 3.2% methylated carboxyl group, 4.5% total carboxyl group, 3.5% ash, and 0.1% nitrogen. A study of the antibacterial activity of pectin containing doxycycline hyclate found that the inhibition of bacterial growth was 0.8 times less than that of pure pectin. It was 1 time less than that of doxycycline alone, and 33 times smaller than that of wontaxime when compared to pure pectin. Pectin containing doxycycline hyclate inhibited MRSA growth at a concentration 6 times lower than pure pectin. This was 2 times lower than doxycycline alone, and 8 times lower than wontaxime. Conclusion: Pectin yields 1.3 after 60 minutes of separation at a sediment concentration ratio of 1:1.15 and pH = 2. Pectin itself is antibacterial against MRSA.
文摘Objective: Hemp seed oil is perfect for most skin types;it moisturizes skin and protects it from inflammation, oxidation, and other causes of aging. The problem is that the Hemp oil-based products do not penetrate the skin;they remain on the skin’s surface. Recently researchers have been trying to prepare nano emulsions of hemp oil to facilitate its permeation to deep skin layers. In all techniques used today, surfactants are added to the emulsification process. These surfactants may cause unwanted skin side effects. In the present study, we prepare micronized Hemp (m-Hemp) without using any surfactants in the micronization process, thus avoiding the side effects associated with surfactant addition. Methods & Results: Particles size of m-Hemp was evaluated using electron microscopy. Various sizes of m-Hemp were found, the smallest being 100 nm in diameter. The antioxidation properties of m-Hemp were measured using the Electron Spin Resonance (ESR) technique and were found to be enhanced. Skin topography and morphology following a cream containing m-Hemp treatment were visualized by Optical Profilometry and ESEM respectively. The results show a marked improvement in skin topography in all measured parameters. In addition, human keratinocytes (HaCaT) were exposed to inflammatory conditions and were then treated using Hemp. As a result, one of the key inflammatory factors (IL-2) was significantly reduced after treatment with m-Hemp (p ≤ 0.0001). The skin penetration of the cream containing m-Hemp was tested on human skin using the IMOPE (Iterative Multi-plane Optical Property Extraction) system. The results indicate that m-Hemp penetrates both the stratum corneum and the deep epidermal layers towards the dermis. Conclusion: The new cream prepared with micronized Hemp shows significant anti-inflammatory and antioxidative effects and demonstrates the entrance of m-Hemp to the skin epidermal layer.
文摘Objective:To evaluate the effect of preoperative dietary intervention on the gastrointestinal reaction of microparticle transcatheter arterial chemoembolization(TACE).Methods:A total of 60 patients with primary liver cancer who were treated in our hospital from January 2018 to October 2018 were selected for this study.The random sampling method was used to divide the patients into an intervention group(30 cases)and a control group(30 cases).The control group received routine intervention,whereas the intervention group received optimized nursing intervention.The incidence of gastrointestinal reactions,the vomiting frequency,the average vomiting volume,the incidence of stomach discomfort,the quality of life,and the anxiety and depression indicators of both groups were compared.Results:The results of all indicators of the intervention group were better than those of the control group.The incidence of gastrointestinal reactions in the intervention group was 13.9%,which was lower than 43.3%of the control group.The scores of QLQ-C30 of the intervention group were higher than those of the control group;the SAS and SDS scores in the intervention group were lower than those of the control group.Conclusion:Preoperative dietary intervention can reduce the incidence of gastrointestinal reactions of microparticle TACE and improve the symptoms of gastric discomfort among patients.
文摘Article continues and complements our previous articles on the HM16 ether (ETH) model. Here, we describe the mechanism of occurrence of the submicroparticle (SMP). A general hypothesis, HFVI, is introduced for the modalities of interaction between two SMPs, based on periodic mechanical percussion forces, produced by fundamental vibrations FVs. A mechanism for describing the interaction between a SMPs and the ETH is presented. Positive and negative particles are defined by their membrane types of movement, such as +, <span style="white-space:nowrap;">−</span><em>u</em>/+, <span style="white-space:nowrap;">−</span><em>v</em> vibrations, and rotations at speeds +<span style="white-space:nowrap;">Ω</span>/<span style="white-space:nowrap;">−</span><span style="white-space:nowrap;">Ω</span>. The process of creating a pair of SMPs is discussed. Applying HFVI to the interaction between pairs of SMPs immobile in ETH, and considering longitudinal FVL, was obtained the forces of attraction/repulsion +<em>F</em><sub><em>L</em>21</sub>/–<em>F<sub>L</sub></em><sub>21</sub>, which correspond to the completed Coulomb force<em> F<sub>CC</sub></em> including gravitation. The resultant <em>F</em><sub>RL21</sub> will form an oriented field of forces, which is a quasielectric field <em>QE</em>, equivalent to actual <em>E</em> electric field. Considering transversal FVT, was obtained the vibratory forces +, <span style="white-space:nowrap;">−</span><em>F<sub>T</sub></em><sub>21</sub>, whose resultant forms an vibrating field of forces, <em>QHs</em>, a quasimagnetic special field, which may explain some of the quantum properties of SMPs. Considering a mobile SMP, two new<em> <span style="white-space:nowrap;">γ</span></em> strains in ETH appear. Strains <em><span style="white-space:nowrap;">γ</span><sub>L</sub></em> are created by the displacement of SMP with velocity<em> V</em>, whose force +, <span style="white-space:nowrap;">−</span><em>F<sub>T</sub></em><sub>12</sub> is the support of a component of the magnetic field <em>H</em> (quasimagnetic field <em>QH</em>), giving the <em>QH<sub>L</sub></em> component. Strains <em>γ</em><sub>R</sub> are created by the rotation of SMP with speed <span style="white-space:nowrap;">Ω</span>, whose force +, <span style="white-space:nowrap;">−</span><em>F</em><sub>R12</sub> constitutes physical support of the component <em>QH<sub>R</sub></em> of magnetic field <em>H </em>(<em>i.e. QH)</em><em></em>. The creation of a photon PH is modelled as a special ESMP containing two zones of opposed rotations, and a mechanism is presented for its movement in the ETH with speed <em>c</em> based on the HS hypothesis of screwing in ETH, with frequency <em>ν</em>.
文摘Microparticles are small cell vesicles that can be released by almost all eukaryotic cells during cellular stress and cell activation. Within the last 1-2 decades it has been shown that microparticles are useful blood surrogate markers for different pathological conditions, such as vascular inflammation, coagulation and tumour diseases. Several studies have investigated the abundance of microparticles of different cellular origins in multiple cardiovascular diseases. It thereby has been shown that microparticles released by platelets, leukocytes and endothelial cells can be found in conditions of endothelial dysfunction, acute and chronic vascular inflammation and hypercoagulation. In addition to their function as surrogate markers, several studies indicate that circulating microparticles can fuse with distinct target cells, such as endothelial cells or leukocyte, and thereby deliver cellular components of their parental cells to the target cells. Hence, microparticles are a novel entity of circulating, paracrine, biological vectors which can influence the phenotype, the function and presumably even the transcriptome of their target cells.This review article aims to give a brief overview about the microparticle biology with a focus on endothelial activation and arterial hypertension. More detailed information about the role of microparticles in pathophysiology and disease can be found in already published work.
基金supported by the National Basic Research Program of China (973 Program,no. 2007CB714507)National Nature Science Foundation of China (no. 90813015)
文摘A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELISA).A systematic comparison between the MmPs-CLEIA and colorimetric ELISA concluded that the MPs-CLEIA exhibited fewer dosages of immunoreagents,less total assay time,and better linearity,recovery,precision,sensitivity and validity.AFP was detected in forty human serum samples by the proposed MPs-CLEIA and ELISA,and the results were compared with commercial electrochemiluminescence immunoassay (ECLIA) kit.The correlation coefficient between MPs-CLEIA and ELISA was obtained with R 2 0.6703;however,the correlation between MPs-CLEIA and ECLIA (R 2 0.9582) was obviously better than that between colorimetric ELISA and ECLIA (R 2 0.6866).
基金Anhui Provincial Natural Science Foundation(No.08020303080) for financial support of this work
文摘A type of triangular pyramid-shaped microparticles of puerarin was synthesized by using oil-in-oil microemulsion approach which is simple and economical under the action of copper substrate.The pyramid-shaped microparticles would be made up of deposit of nanospheres or nanorods and have two significant characters.One is its complex surface morphology like coral reef.The other is a lot of nanopores in existence in the microparticle body.Two possible formation routes were speculated.
文摘AIM To evaluate platelet activation markers in psoriasis patients, compared to controls, and investigate their association with the inflammatory burden of psoriasis.METHODS Forty psoriatic patients without cardiovascular disease,and 12 healthy controls were subjected to measurement of baseline platelet CD62 P, CD63 and CD42 b expression, platelet-leukocyte complexes, i.e., platelet-monocyte complexes(PMC), platelet-neutrophil complexes(PNC) and platelet-lymphocyte complexes, and concentrations of platelet-derived microparticles(PMPs) using flow cytometry. Both larger-size(0.5-0.9 μm) and smallersize(< 0.5 μm) PMPs were determined. Serum interleukin(IL)-12 and IL-17 levels were also measured by enzyme-linked immunosorbent assay. The severity of psoriasis was evaluated by the Psoriasis Area Severity Index(PASI).RESULTS PMP concentrations were significantly higher in psoriasis patients than controls [mean±standard error of mean(SEM): 22±5/μL vs 11±6/μL; P=0.018), for both smaller-size(10±2/μL vs 4±2/μL; P=0.033) and larger-size(12±3/μL vs 6±4/μL; P=0.014) PMPs. Platelet CD62 P, CD63 and CD42 b expression and circulating PMC and PNC were similar between the two groups. Lower circulating PLC were observed in psoriasis patients compared to controls(mean±SEM: 16%±3% vs 23%±6%; P=0.047). Larger-size PMPs were related with IL-12 levels(P<0.001) and smaller-size PMPs with both IL-12 and IL-17 levels(P<0.001). Total PMPs also correlated with IL-12(P<0.001). CD63 expression was positively correlated with both IL-12 and IL-17(P<0.05). Increased PASI score was associated with increased levels of larger-size PMPs(r=0.45; P=0.011) and increased CD63 expression(r=0.47; P<0.01).CONCLUSION PMPs, known to be predictive of cardiovascular outcomes, are increased in psoriasis patients, and associated with high inflammatory disease burden. Enhanced platelet activation may be the missing link leading to cardiovascular events in psoriatic patients.
文摘The deterioration of endothelial structure plays a very important role in the development of vascular diseases. It is believed that endothelial dysfunction starts in the early stage of kidney disease and is a risk factor of an unfavorable cardiovascular prognosis. Because a direct assessment of biological states in endothelial cells is not applicable, the measurement of endothelial microparticles(EMPs) detached from endothelium during activation or apoptosis is thought to be a marker of early vascular disease and endothelial dysfunction in children with chronic kidney disease(CKD). Few studies have shown increased circulating EMPs and its relationship with cardiovascular risk factors in patients with CKD.MPs contain membrane proteins and cytosolic material derived from the cell from which they originate. EMPs having CD144, CD 146, CD31+/CD41-, CD51 and CD105 may be used to evaluate the vascular endothelial cell damage and determine asymptomatic patients who might be at higher risk of developing cardiovascular disease in CKD and renal transplant.
基金Supported by a grant from National Natural Science Foundation of China(grant number 81571783)National Major Project for Infectious Diseases of China(2017ZX100203205005)
文摘Purpose: A series of clinical studies have established the safety and efficacy of transcatheter arterial chemoembolization(TACE) with gelatin sponge microparticles(GSMs) in treating hepatocellular carcinoma(HCC). HCC can lead to obvious necrosis inside tumors, especially larger ones, although it is unclear whether such necrotic tumor tissue can induce favorable immune reactions against the tumor. Myeloid-derived suppressor cells(MDSCs)have immunosuppressive functions and are currently considered a very important cell type affecting tumor immunity. This study observed changes in MDSC frequency in peripheral blood before and after GSM–TACE to evaluate the effect on the immune function of HCC patients.Methods: Eight patients diagnosed with HCC underwent GSM–TACE treatment in the Hepatobiliary Interventional Department of Beijing Tsinghua Chang Gung Hospital, Beijing, China;we followed up with the patients over a period of 30 days post-surgery. We used flow cytometry(FCM) to quantify the frequency of MDSCs in peripheral blood before TACE, 10 days after surgery and 30 days after surgery.Results: MDSC frequency after GSM–TACE had a significant downward trend. Pre-TACE, it was 30.73% ? 11.93%,decreasing to 18.60% ? 11.37% at 10 days after operation. This decrease was not statistically significant(P > 0.05). MDSC frequency was even lower 30 days after TACE(7.63% ? 7.32%) than at 10 days after TACE(P < 0.05), and there was a significant difference compared with pre-TACE(P < 0.001). We evaluated tumor response at 30 days after GSM–TACE according to the Modified Response Evaluation Criteria in Solid Tumors(mRECIST), and all eight patients showed partial response(PR).Conclusion: Our results confirmed that GSM–TACE was beneficial for improving anti-tumor immunity in the treatment of HCC.
基金supported by the Innovation Foundation of BUAA for Ph. D Graduates Provided by Beihang University in China
文摘This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH)3 microparticles in direct contact with zinc powder.Electrochemical properties of zinc electrodes containing Y(OH)3 microparticles were discussed through the measurements of potentiodynamic polarization and cyclic voltammetry.Simultaneously,the test cells making use of such modified zinc powder were assembled to further evaluate the availability of Y(OH)3 microparticles in improving the cycle properties of zinc electrodes.It was found that good alkaline environment generated by ultrasonic irradiation of high power led to the formation of Y(OH)3 microparticles on the surface of modified zinc powder due to high-energy jets of immersion solution.In particular,the Y(OH)3 microparticles formed with the ultrasonic power of 440 W made the greatest contributions to hinder the corrosion of zinc electrode and the dissolution of zinc oxidation products in alkaline electrolyte as compared with other power parameters.Besides,the detections of assembled cells at a high discharge current density of 250 mA/cm2 revealed that the Y(OH)3 microparticles obtained with ultrasonic power of 440 W provided the alkaline zinc electrode with low capacity loss and persistent cycle behavior.The great improvement over the corrosion behavior and cycle properties of zinc electrode is possibly ascribed to the uniform distribution of Y(OH)3 microparticles on the surface of modified zinc powder.
基金National Natural Science Foundation of China(51803190)National Key R&D Program of China(2019YFA0706802)for financial support。
文摘Ultra-thin flexible films have attracted wide attention because of their excellent ductility and potential versatility.In particular,the energy-harvesting films(EHFs)have become a research hotspot because of the indispensability of power source in various devices.However,the design and fabrication of such films that can capture or transform di erent types of energy from environments for multiple usages remains a challenge.Herein,the multifunctional flexible EHFs with e ective electro-/photo-thermal abilities are proposed by successive spraying Ag microparticles and MXene suspension between on waterborne polyurethane films,supplemented by a hot-pressing.The optimal coherent film exhibits a high electrical conductivity(1.17×10^(4)S m^(-1)),excellent Joule heating performance(121.3℃)at 2 V,and outstanding photo-thermal performance(66.2℃ within 70 s under 100 mW cm^(-1)).In addition,the EHFs-based single-electrode triboelectric nanogenerators(TENG)give short-circuit transferred charge of 38.9 nC,open circuit voltage of 114.7 V,and short circuit current of 0.82μA.More interestingly,the output voltage of TENG can be further increased via constructing the double triboelectrification layers.The comprehensive ability for harvesting various energies of the EHFs promises their potential to satisfy the corresponding requirements.
基金the Danish Council for Inde-pendent Research(Grant No.DFF-12-131927)for financial sup-port of this project
文摘Hypromellose acetate succinate(HPMCAS) microparticles containing the poorly-water soluble drug celecoxib(CEL) were prepared by electrospraying intended for oral drug delivery. Various solvent mixtures with different solubility for CEL and HPMCAS were used to induce changes in the polymer structural conformation of the microparticles. The performance of the prepared microparticles was evaluated by studying the solid state from, particle size and morphology, radial drug distribution and drug release. CEL was amorphous in all electrosprayed HPMCAS microparticles. The particle size and morphology was dependent on the solubility of HPMCAS in the solvent mixture used with poorer solvents resulting in smaller microparticles with rougher appearance. The CEL distribution on the particles surface was relatively homogeneous and similar for all microparticles. Drug release from the microparticles was observed at a higher rate depending on the solubility of HPMCAS in the solvent used for electrospraying, and in all cases an at least 4-fold higher rate was observed compared with the crystalline drug. Drug precipitation from the supersaturated solution was inhibited by HPMCAS for all microparticles based on its parachute effect while crystalline CEL did not reach supersaturation. This study demonstrated that electrospraying can be used to produce microparticles with tailored properties for pharmaceutical application by adjusting solvent selection.
文摘Recently there has been a wide concern on inorganic nanoparticles as drug delivery carriers. CaCO3 particles have shown promising potential for the development of carriers for drugs, but little research had been performed regarding their safe dosage for maximizing the therapeutic activity without harming biosystems. In this study, we assessed the biological safety of porous spherical CaCO3 microparticles on Hela cells. The reactive oxygen species (ROS), glutathione (GSH), carbonyl content in proteins (CCP), DNA-protein crosslinks (DPC) and cell viability were measured. Results showed that with the exposure concentration increase, ROS and CCP in Hela cells presented a significant increase but GSH contents in Hela cells and cell viability showed a significant decrease respectively compared with the control. DPC coefficient ascended, but no statistically significant changes were observed. The results indicated that porous spherical CaCO3 microparticles may induce oxidative damage to Hela cells. But compared with other nanomaterials, porous spherical CaCO3 appeared to have good biocompatibility. The results implied that porous spherical calcium carbonate microparticles could be applied as relatively safe drug vehicles, but with the caveat that the effect of high dosages should not be ignored when attempting to maximize therapeutic activity by increasing the concentration.
文摘Chitosan (CS) microparticles with and without cross-linking were prepared by a water-in-oil emulsion solvent diffusion method without any surfactants. Aqueous CS solution and ethyl ace- tate were used as water and oil phases, respectively. Genipin was used as a cross-linker. Influ- ences of genipin ratios and cross-linking times on CS microparticle characteristics were investigated. Non-cross-linked and cross-linked CS microparticles were spherical in shape and rough in surface. Microparticle matrices showed porous structures. Surface roughness, mean par- ticle sizes and bulk density of CS microparticles increased and their dissolutions in acetic acid solution decreased when genipin ratio and cross- linking time increased.
文摘With hydrophilic surface and high surface area, porous silica has been applied to load insoluble drugs. Compared to solvent equilibrium method, resveratrol(RES)–mesoporous silica microparticles(MSM) solid dispersion prepared by fluid bed demonstrated higher drug loading and more complete dissolution. Pore volume and diameter have more remarkable effects than surface area to the drug loading and in vitro dissolution profiles. RES–polyethylene glycol solid dispersion with high drug loading showed fast but incomplete dissolution due to the recrystallization. The combination of fluid bed and MSM was an effective strategy to improve drug loading as well as dissolution for poorly water-soluble drugs.
文摘【正】Objective:To preliminarily investigate three different lipid matrices consisting of two natural homolipids from Capra hircus(goat fat) and Bovine Spp.(tallow fat) and one semi-synthetic lipid(Softisan~? 142) separately structured with Phospholipon~? 90G(P90G) as potential delivery systems for poorly water soluble drugs.Methods:The structured lipid matrices were characterized by differential scanning calorimetry(DSC) and employed to prepare solid lipid microparticles(SLMs) by the melt homogenization method using gradient concentrations of polysorbate 80 and at different emulsification times of 2,5 and 10 min using a Silverson mixer. The SLMs were analyzed for morphology and particle size,thermal properties,stability studies and determination of injectability.Results:The results showed that SLM production was optimum at 5%of lipid matrices,1.5%of polysorbate 80 and emulsification time of 5 min.Increase in polysorbate 80 concentrations decreased the particle size of the SLMs.The SLMs were well formed, spherical,smooth and non-porous with particle sizes in the ranges of(13.90±2.10)μm -(0.09±0.01)μm for SLMs produced from the structured - tallow fat;(13.40±1.30)μm-(0.10±0.01)μm for the structured - goat fat and(13.40±2.00)μm-(2.10±1.00)μm for the structured Softisan~? 142 lipid matrices.DSC traces showed that Softisan~? 142 was the most crystalline of all three bulk matrices due to its high enthalpy(-7.962 mW/mg) while tallow fat was the least(-5.067 mW/mg) but addition of P90G to the matrices lowered their enthalpies mostly in the structured goat fat matrices.The SLMs when stored at 4-6°C were most stable and syringeable with 27 G needle.Conclusions:This suggests that structured goat fat matrices with the enthalpy of -2.813 mW/mg will mosdy favour drug loading of some poorly soluble drugs more than tallow fat(-4.892 mW/mg) and Softisan? 142(-5.501 mW/mg).
文摘In this study, nanostructured microparticles was developed with polycaprolactone (PCL), poly(vinyl alcohol) (PVAL) and nanoparticles of the commercial sodium clay NT-25®by using the spray drying technique. The systems obtained were characterized by Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic Laser Light Scattering (DLS) and Differential Scanning Calorimetry (DSC). The NMR <sup>13</sup>C and FTIR techniques showed that both polymers were present in the microparticles and the DSC analysis revealed a small variation in the glass transition temperature of the PCL. The XRD and SEM analyses showed that the microparticles produced were amorphous and had a concave morphology. The NT-25 nanoload reduced the microparticles’ size due to the multiple interactions formed in the hybrid nanocomposite material. Therefore, it was possible to develop microparticles by using biodegradable and biocompatible polymers, with different polarities, allowing the incorporation of hydrophilic and hydrophobic materials and enabling the inclusion of otherwise incompatible materials in the same system.
