Synthesis of iron nanoparticles, its characterization and anti-microbial activity assessment

We report the efficacy of the Iron nanoparticles (IONPs) and assessed two different approaches for the synthesis of IONPs i.e. Polyol and co-precipitation method and further, evaluate their antimicrobial properties. Ferrous sulphate heptahydrate salts were reduced with ethylene glycol to obtain IONP and Fe+2 and Fe+3 co-precipitation reaction was performed with KOH at optimum heating. Further, synthesized (IONPs) were characterized by hydrodynamic radii measurement done by DLS clearly indicating the size of IONPs is 79.75nm in polyol based and 135.1 nm in co-precipitation method. The biological efficacy in terms of antimicrobial activity was assessed by the Kirby Bauer method, applied for both Gram-positive and Gram-negative bacteria such as Staphylococcus aureus and Escherichia coli, respectively. The ZOI values i.e. Zone of inhibition diameter was found to be clearly visible in both S. aureus and E. coli, indicating bactericidal activity. Further growth kinetics studies and bacterial genotoxicity was also assessed. Hence, IONPs synthesized are proposed to have great potential as an antibacterial agent and can be used in drug delivery.

Preparation and in vitro evaluation of redox-responsive silica-loaded arsenic trioxide nano-drug delivery system / 中草药

Objective: The redox-responsive drug delivery system of MSN-SS-PEG@As2O3 was constructed based on mesoporous silica nanoparticle (MSN), which was modified by both redox-sensitive disulfide bonds and non-toxic, non-immunogenic polyglycols (PEG), and loaded the arsenic trioxide (As2O3) by electrostatic adsorption and evaluated in vitro. Methods: Silica was synthesized by coprecipitation method. The redox-responsive carrier (MSN-SS-PEG) was synthesized on the basis of silica, (3-mercaptopropyl) trimethoxysilane, 2-(2-pyridyldithio) ethylamine hydrochloride and methoxy terminated PEG. The particle size and Zeta potential of MSN-SS-PEG were measured by Malvern particle size analyzer; The structure of the carrier was verified by infrared spectroscopy; The morphology and physical and chemical properties of the carrier were investigated by transmission electron microscopy (TEM) and small angle powder diffraction; The drug loading efficiency of MSN-SS-NH2@As2O3 and MSN-SS-PEG@As2O3 were investigated by inductively coupled plasma emission spectrum (ICP). The drug loading was further verified by thermogravimetry (TGA). In vitro release characteristics of the drug delivery system under different pH conditions were investigated by dialysis bag method. MTT assay was used to investigate the toxicity of carrier and delivery system to human normal hepatocytes (L02) or human hepatocarcinoma (HepG2) cells. Results: The potential of MSN, MSN-SS-NH2, MSN-SS-PEG was (-13.40 ± 0.87), (31.63 ± 0.90), (27.70 ± 5.60) mV, respectively. The final potential of modified carrier was positive. The particle size of MSN-SS-PEG was (159.60 ± 3.10) nm. The results of TEM showed that MSN, MSN-SS-NH2 and MSN-SS-PEG were all round or quasi round; The drug loading of MSN-SS-PEG@As2O3 was 4.38%, which measured by ICP; The release in vitro showed that MSN-SS-PEG@As2O3 was redox sensitive response. Compared with L02 cells, HepG2 cells were more sensitive to the toxicity of the carrier, and with the increase of the carrier concentration, the cell survival rate of MSN-SS-PEG was higher than that of MSN-SS-NH2, suggesting that PEG modification can further reduce the cytotoxicity of the carrier and improve the biocompatibility of the carrier. In addition, MTT results showed that the inhibitory effect of MSN-SS-PEG@As2O3 on HepG2 cell was significantly higher than that of other groups. Conclusion: The carrier prepared in this paper had a round and uniform particle size. The modified silica can release under the special microenvironment of the tumor and increase the accumulation of the drug in the tumor site. The delivery system has a good application in tumor therapy as a tumor micro-environment responsive carrier.

Liquid phase coprecipitation of gemcitabine magnetic-targeting nanoparticles / 国际药学研究杂志

Objective: To use the liquid phase coprecipitation method for preparing gemcitabine magnetic nanoparticles to the pouch, and explore the preparation process in a number of conditions. Methods: The effect of different stirring speeds, Fe3+/ Fe2+ ratio, pH, temperature of Fe3O4 powder and emulsification condition, ultrasonic time, curing temperature on the preparation of targeted magnetic nanoparticles were observed. Results: The preparation of Fe3O4 nanoparticles was as follows: 800 r / min of stirring speed, 1.7: 1 Fe3+/Fe2+ ratio, pH=9, the reaction temperature of 60 °C, and the 5: 40 water / oil compared, ultrasonic time of 10 min, 100 °C curing temperature. Conclusion: Fe3O4 powder with small particle size, high purity, and no agglomeration are prepared, the stability of the gemcitabine magnetic nanoparticles capsule is good.

Liquid phase coprecipitation of gemcitabine magnetic-targeting nanoparticles / 国际药学研究杂志

Objective To use the liquid phase coprecipitation method for preparing gemcitabine magnetic nanoparticles to the pouch,and explore the preparation process in a number of conditions. Methods The effect of different stirring speeds,Fe3+/Fe2+ratio,pH,temperature of Fe3O4 powder and emulsification condition,ultrasonic time,curing temperature on the preparation of target?ed magnetic nanoparticles were observed. Results The preparation of Fe3O4 nanoparticles was as follows:800 r/ min of stirring speed,1.7∶1 Fe3+/Fe2+ratio,pH=9,the reaction temperature of 60℃,and the 5∶40 water/oil compared,ultrasonic time of 10 min, 100℃curing temperature. Conclusion Fe3O4 powder with small particle size,high purity,and no agglomeration are prepared,the stability of the gemcitabine magnetic nanoparticles capsule is good.

Investigation of Structural, Morphological, Magnetic Properties and Biomedical applications of Cu2+ Substituted Uncoated Cobalt Ferrite Nanoparticles

ABSTRACT In the present work, Cu2+ substituted cobalt ferrite (Co1-xCuxFe2O4, x = 0, 0.3, 0.5, 0.7 and 1) magnetic nanopowders were synthesized via chemical co-precipitation method. The prepared powders were investigated by various characterization methods such as X-ray diffraction analysis (XRD), scanning electron microscope analysis (SEM), vibrating sample magnetometer analysis (VSM) and fourier transform infrared spectroscopy analysis (FTIR). The XRD analysis reveals that the synthesized nanopowders possess single phase centred cubic spinel structure. The average crystallite size of the particles ranging from 27-49 nm was calculated by using Debye-scherrer formula. Magnetic properties of the synthesized magnetic nanoparticles are studied by using VSM. The VSM results shows the magnetic properties such as coercivity, magnetic retentivity decreases with increase in copper substitution whereas the saturation magnetization shows increment and decrement in accordance with Cu2+ substitution in cobalt ferrite nanoparticles. SEM analysis reveals the morphology of synthesized magnetic nanoparticles. FTIR spectra of Cu2+ substituted cobalt ferrite magnetic nanoparticles were recorded in the frequency range 4000-400cm-1. The spectrum shows the presence of water adsorption and metal oxygen bonds. The adhesion nature of Cu2+ substituted cobalt ferrite magnetic nanoparticles with bacteria in reviewed results indicates that the synthesized nanoparticles could be used in biotechnology and biomedical applications.

Ophthalmic solution of thiolated chitosan-pirenoxine sodium-layered double hydroxides hybrid nanocomposites / 中国药科大学学报

@#Ophthalmic solution of organic-inorganic layered double hydroxides hybrid nanocomposites based on layered double hydroxides(LDH)intercalated with pirenoxine sodium(PRN)and chitosan-glutathione(CG)was prepared, characterized and evaluated using rabbit precorneal retention. Mg-Al-PRN-LDH, Zn-Al-PRN-LDH and CG-PRN-LDH were synthesized by co-precipitation. The nanocomposites were characterized by laser particle sizer, powder X-ray diffraction(X-RD), fourier transform infrared spectra(FTIR)and transmission electron micrographs(TEM). The release of PRN from Mg-Al-PRN-LDH, Zn-Al-PRN-LDH, and CG-PRN-LDH nanocomposites and API in artificial tear was compared. Based on in vivo precorneal retention studies, PRN-LDH and CG-PRN-LDH nanocomposite dispersions showed significantly higher AUC(3. 72-, 7. 59-folds)and MRT(2. 18-, 2. 60-folds)than that of the commercial eye drops group. Organic-inorganic layered double hydroxides hybrid nanocomposites CG-PRN-LDH dispersions could remarkably improve precorneal retention of PRN.

Oxidación catalítica de tolueno y 2-propanol sobre óxidos mixtos de Mn y Co obtenidos por coprecipitación / Catalytic oxidation of toluene and 2-propanol over Mn and Co mixed oxides obtained by coprecipitation method / A oxidação catalítica de tolueno e 2-propanol em óxidos mistos de Mn e de Co, obtidos por coprecipitação

Óxidos mixtos de manganeso y cobalto, con relaciones molares M²++Mg2+ /M3+=3 y M2+/ Mg2+=1, fueron preparados por el método de coprecipitación. Los sólidos fueron caracterizados mediante las técnicas de difracción de rayos X (XRD), temperatura programada de reducción (TPR-H2) y adsorción de N2 en área superficial; éstos fueron empleados para la oxidación catalítica de una mezcla de dos compuestos orgánicos representativos de COVs: el tolueno y el 2-propanol. El óxido mixto de manganeso logró el 100% de oxidación de la mezcla de COVs, mientras que el óxido mixto de cobalto no alcanzó una oxidación total. El catalizador Mn-Mg-Al presentó las menores temperaturas de oxidación de tolueno y 2-propanol en la mezcla, haciéndolo el catalizador más eficiente. El desempeño catalítico superior de dicho óxido se asocia principalmente con su mejor comportamiento redox, comparado con el del óxido de cobalto. Con el fin de evaluar el efecto de la composición del reactivo, se estudió la oxidación catalítica individual de tolueno y 2-propanol sobre el óxido mixto de manganeso. El catalizador fue activo en la oxidación de los dos COVs individuales, pero el tolueno fue el compuesto más difícil de oxidar. Dicho catalizador mostró 100% de conversión del tolueno hacia CO2, mientras que el 2-propanol produjo primero acetona, la cual posteriormente fue oxidada hasta CO2. Las temperaturas de oxidación de los componentes en la mezcla de COVs fueron superiores que en la conversión individual de tolueno y 2-propanol. Este resultado sugiere un posible efecto inhibitorio en la oxidación de 2-propanol cuando se tienen mezclas de los COVs.

Manganese and cobalt mixed oxides with M2++Mg2+/M3+=3 y M2+/Mg2+=1 ratios were obtained by the coprecipitation method. The solids were characterized using X-ray diffraction (XRD), temperature-programmed reduction (H2-TPR), N2 adsorption and in the catalytic oxidation of two VOCs: toluene and 2-propanol. Manganese mixed oxide reached 100% conversion of the mixture of VOCs while cobalt mixed oxide did not achieve a complete oxidation. The catalyst Mn-Mg-Al showed the lowest temperature oxidation of toluene and 2-propanol in the mixture. The highest performance of the oxide catalyst Mn-Mg-Al is associated with the better redox potential in the manganese catalyst. Manganese mixed oxide was active in the oxidation of the single VOCs, where the scale of difficulty to oxidize the different organic compounds evaluated was: 2-propanol < toluene. The mixed oxide showed 100% conversion to CO2 in the oxidation of toluene, while the 2-propanol was first oxidized to acetone. It suggests that there is an inhibitory effect on the oxidation of 2-propanol in the mixture of VOCs.

Óxidos mistos de cobalto e manganês com relações M2++Mg2+/M3+=3 y M2+/ Mg2+=1 foram preparados pelo método de coprecipitação. Os sólidos foram caracterizados pelas técnicas de difração de raios-X (XRD), temperatura programada de redução (TPR-H2), área superficial adsorção do N2 e na oxidação catalítica de dois compostos orgânicos representativos (COVs): tolueno e 2-propanol. O catalisador Mn-Mg- Al apresentou as menores temperaturas de oxidação da mistura, fazendo-lo o catalisador mais eficiente. O desempenho catalítico superior do óxido Mn-Mg-Al está associado principalmente a seu melhor desempenho redox em comparação com o óxido de cobalto. Mn-Mg-Al catalisador foi ativo na oxidação dos dois individuais COVs, sendo o tolueno o composto mais difícil de oxidar seguido do 2-propanol. Óxidos mistos de manganês mostro 100% de conversão até CO2 para tolueno, enquanto que o 2-propanol produz em primeiro lugar acetona, que posteriormente é oxidada a CO2. Temperaturas de oxidação dos componentes da mistura de compostos orgânicos voláteis é maior do que a única conversão de tolueno e 2-propanol. Este resultado sugeriu um possível efeito inibitório sobre a oxidação de 2-propanol ao ter misturas de COV.

Study of Binary and Ternary Solid Dispersion of Spironolactone Prepared By Co-Precipitation Method for the Enhancement of Oral Bioavailability.

The study was designed to formulate novel spironolactone, a BCS class II drug loaded solid dispersion system (SDs) with improved dissolution rate. For this purpose binary and ternary solid dispersion were prepared by co-precipitation method using Poloxamer-407 only and mixture of poloxamer-407 with a second polymer such as HPMC 6cps, HPC, Kollicoat IR, Kollidon VA 64 respectively. To prepare binary SDs poloxamer 407 was used in three concentrations: 33%, 50% and 66.67% wt/wt of total SDs, whereas in case of ternary SDs, poloxamer 407 was used at 15%, 25% 35% wt/wt of the total SDs content and the concentration of the second polymer is maintained at fixed amount (1gm). In vitro dissolution study was carried out in a USP type II dissolution apparatus in 0.1 N hydrochloric acid solution for 1 hour. Release property of spironolactone from two different SDs was examined. Both the systems showed improved release profile compared with pure spironolactone powder. Enhanced release of spironolactone from the optimized SDs was characterized in light of cumulative percent release, % release after 5 min of dissolution and release rate of the drug from different SDs. When the amount of carriers increased with a decrease in drug content, the release of spironolactone was elevated. And it was found that almost two fold increase in the release of spironolactone while 66.67% poloxamer was used.

Study of binary and ternary solid dispersion of ibuprofen for the enhancement of oral bioavailability.

To develop a novel ibuprofen loaded solid dispersion system (SDs) with enhanced dissolution rate, binary and ternary solid dispersion were prepared by co-precipitation method using poloxamer-407 only and mixture of poloxamer-407 with a second polymer such as HPMC 6cps, HPC, Kollicoat IR, Kollidon VA 64 respectively. In case of binary SDs, poloxamer 407 was used in three concentrations: 33%, 50% and 66.67% wt/wt of total SDs. In case of ternary SDs, poloxamer 407 was used at 15%, 25% 35% wt/wt of the total SDs content while maintaining the concentration of the second polymer at fixed amount (1gm). In vitro dissolution study was conducted in phosphate buffer of pH 6.8 for 1h. Release property of ibuprofen from two different SDs was investigated. And in case of both the systems, enhanced release property was found where the release was compared with pure ibuprofen powder. Enhanced release of ibuprofen from the optimized SDs was characterized in light of cumulative percent release, % release after 5 min of dissolution and release rate of the drug from different SDs. When the amount of carriers increased with a decrease in drug content, the release of ibuprofen was elevated. And it was found that almost two fold increase in the release of ibuprofen while 66.67% poloxamer was used.

Determination of Urinary Manganese by Flame Atomic Absorption Spectrometry with Coprecipitation / 环境与健康杂志

0.05). Conclusion The present method has many advantages such as simplicity of operation,rapidity,better accuracy for the accurate quantitative analysis of urinary manganese.

Bcl-2-associated athanogene 1 regulates the glucocorticoid receptor activity in rat alveolar macrophages / 医学研究生学报

Objective: To investigate the expression changes of Bcl-2-associated athanogene 1(BAG-1) and its regulatory effect on the glucocorticoid receptor(GR) activity in rat alveolar macrophages in conditions of cell inflammation and glucocorticoid therapy.Methods: The expression changes of BAG-1 were detected by Western blot after lipopolysaccharide(LPS) and Dexamethasone(Dex) treatment of rat alveolar macrophages(AMs),the interaction between BAG-1 and GR determined by immune coprecipitation experiment,and the transcriptional activation of GR measured by relative luciferase activity assay.Results:After LPS and Dex treatment,the expression of BAG-1L in total protein increased but that of BAG-1S remained changed,BAG-1L rather than BAG-1S was detected in nuclear protein and its expression increased gradually within 24 hours,the interaction between BAG-1L and GR was observed in nucleoli,and the transcriptional activation of GR decreased,with a negative correlation between BAG-1L expression and GR activity.Conclusion:LPS and Dex acting on rat alveolar macrophages,the expression of BAG-1L increases,which,coupled with GR,translocates into nucleoli and inhibits GR activity.This might be the important mechanism that underlies glucocorticoid resistance in inflammation.

Study of characteristics of zirconia toughened glass infiltrated nanometer-ceramic composite powder(Al_2O_3/nZrO_2) / 实用口腔医学杂志

Objective: To investigate the properties of zirconia toughened glass infiltrated nanometer-ceramic composite (Al 2O 3/nZrO 2) . Methods: Zirconia toughened glass infiltrated nanometer-ceramic composite(Al 2O 3/nZrO 2)powder was prepared with combination of chemical co-precipitation method and ball milling. The shape, size, partical distribution, crystal phase and chemical composition were measured and analyzed. Results: (1) The crystal phase composition of the studied nanometer ceramic composite powder was made up with ?-Al 2O 3, t-ZrO 2 and m-ZrO 2 examined by XRD?(2) The density of the powder was 4.12 g/cm 3?(3) The particle distribution of the powder ranged 0.02～3.0 ?m?(4)Observed with SEM, the particle profile of the powder was regular, the ratio of length and width of the particles was about 1.2. Conclusion: The studied nanometer ceramic composite powder owns good homogeneity, stable chemical composition, reasonable powder-size gradation and may be favourable in the improvement of the packing density of ceramics.

Study on Dissolution Rate of Silymarin(Yiganling) Tablets Ⅰ.Dissolution Investigation of Silymarin and Its Solid Dispersion Tablets / 中成药

The dissolution rates of Yiganling Tablets produced by 6 pharmaceutical factories of China and Liganlong Tablets by MAOAUS Factory in German were investigated. As a result, after 30min, the dissolution of all Yiganling is below 30％ and that of Liganlong is 50%. After 120min, the largest dissolution of the former isn't over 43%, and that of the later is about 55％, which indicates that silymarin tablets dissolve more slowly and their bioavailability is lower. The dissolubility can be raised 37, 60 and 27 times, respectively if the silymarin was made into PEG fusion) PVP coprecipitation or ?-CD inclusion compound. The disolution rate (T_(50)) of correspording tablets are 14, 11 and 20min. The largest dissolution after 120min reaches about 80%-103％. There isn't any change observed in the structure of silymarin in solid dispersion when it was identified with UV, IR and TLC. The micropolariscope photograph shows the crystal degree decreased and the dispersity increased.