Multi-stable fluorescent silica nanoparticles obtained from in situ doping with aggregation-induced emission molecules

2015 ◽  
Vol 3 (45) ◽  
pp. 8775-8781 ◽  
Author(s):  
Yi-Feng Wang ◽  
Jing Che ◽  
Yong-Chao Zheng ◽  
Yuan-Yuan Zhao ◽  
Fei Chen ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Gastric Fluid ◽  
Silica Matrix ◽  
Simulated Gastric Fluid ◽  
Aggregation Induced Emission ◽  
Fluorescent Silica Nanoparticles ◽  
Photo Stability

Rigid structures provided by silica matrix restrict the intramolecular rotations of AIE molecules, and fluorescence of CWQ-11@SiO2 nanoparticles maintains excellent pH-, viscosity- and photo-stability, especially stable in simulated gastric fluid.

scholarly journals Gelucire BasedIn SituGelling Emulsions: A Potential Carrier for Sustained Stomach Specific Delivery of Gastric Irritant Drugs

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ashwin Saxena ◽  
Arun K. Mishra ◽  
Navneet Verma ◽  
Shiv S. Bhattacharya ◽  
Amitava Ghosh ◽  
...  
Keyword(s):  
Crosslinking Agent ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Albino Rats ◽  
Low Viscosity ◽  
Release Studies ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

Non steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed medications to the geriatric patients for the treatment of arthritis and other painful disorders. The major side effects of NSAIDs are related to their effects on the stomach and bowels. The present study concerns assessment of the potential of liquidin situgelling emulsion formulations (emulgels) as patient compliant stomach specific sustained release carrier for the delivery of highly gastric irritant drug, Piroxicam. Emulgels were prepared, without using any emulgent, by mixing different concentrations of molten Gelucire 39/01 with low viscosity sodium alginate solution prepared in deionized water at 50°C. CaCO3was used as buoyancy imparting as well as crosslinking agent. Emulgels so prepared were homogenous, physically stable, and rapidly formed into buoyant gelled mass when exposed to simulated gastric fluid (SGF, pH 1.2). Drug release studies carried out in SGF revealed significant retardation (P<0.05) of Piroxicam release from emulgels compared to conventionalin situgelling formulations prepared without Gelucire 39/01. Pharmacodynamic studies carried out inalbino ratsrevealed significantly increased analgesic/anti-inflammatory response fromin situemulgels compared to conventionalin situgelling formulations. Further,in vivotoxicity studies carried out inalbino ratsrevealed no signs of gastric ulceration upon prolonged dosing.

Tetraphenylethene probe based fluorescent silica nanoparticles for the selective detection of nitroaromatic explosives

2021 ◽  
Author(s):  
Muhammad Azhar Hayat Nawaz ◽  
Lianjie Meng ◽  
Huipeng Zhou ◽  
Jia Ren ◽  
Sohail Anjum Shahzad ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Selective Detection ◽  
Fluorometric Method ◽  
Nitroaromatic Explosives ◽  
Aggregation Induced Emission ◽  
Fluorescent Silica Nanoparticles ◽  
Positively Charged

A simple and sensitive fluorometric method is developed utilizing aggregation-induced emission probe based silica nanoparticles for the detection of nitroaromatic explosives. A positively charged tetraphenylethene based probe (TPE-C2-2+) is doped...

scholarly journals STATISTICAL DESIGN AND DEVELOPMENT OF A LIQUID ORAL FLOATING IN SITU GEL OF METFORMIN HYDROCHLORIDE FOR SUSTAINED RELEASE: PHARMACODYNAMIC AND TOXICITY (HISTOPATHOLOGY) STUDIES

2019 ◽  
pp. 96-104
Author(s):  
RASHMI MATHEWS ◽  
B. PRAKASH RAO ◽  
ABBULU KONDE ◽  
SUDARSHAN S. ◽  
NAWRES A. TAHA ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Statistical Design ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Metformin Hydrochloride ◽  
In Situ Gel ◽  
Gastric Residence Time ◽  
Glucose Levels

Objective: To statistically design, optimize and evaluate a liquid oral, floating in situ gel of metformin hydrochloride (MH) to increase the gastric residence time (the absorption window being the upper part of the duodenum), sustain and modulate the release behavior of the drug. No liquid oral SR formulations of MH are yet available in the market. Methods: A simple mixing based ionic cross-linking method was used for the formulation. A Two-square Factorial Design was employed and the effect of sodium alginate and three categorical levels of HPMC (K4M, K100M, E50) on the response variables were studied. Results: The optimized formulation gelled instantaneously in simulated gastric fluid and showed>24 h floating. The drug release in 1h was 37.98 %, followed by a moderate sustained release for 12 h. Pharmacodynamic studies showed a significant reduction in blood glucose levels in Wistar rats. Short term preclinical safety studies revealed no toxicity to pancreatic tissues. On the contrary, faster regeneration of the β cells of the islets of Langerhans was observed with the group treated with the optimized formulation. Stability studies revealed a 2-year shelf life. Conclusion: An elegant, needle-free, in situ gelling, SR liquid oral of metformin hydrochloride could be developed with drug release modulated as per official specifications for SR formulations of MH. This would be an interesting alternative for geriatric patients who find it difficult to swallow bulky tablets.

DETERMINATION OF A SUITABLE CONDITION OF GRAFT COPOLYMERIZATION OF VINYLTRIETHOXYSILANE ONTO NR TO FORM NANOMATRIX STRUCTURE

2018 ◽  
Vol 91 (4) ◽  
pp. 767-775 ◽  
Author(s):  
Yuanbing Zhou ◽  
Yoshimasa Yamamoto ◽  
Seiichi Kawahara
Keyword(s):  
Silica Nanoparticles ◽  
Graft Copolymerization ◽  
Monomer Concentration ◽  
Minor Component ◽  
Suitable Condition ◽  
Average Diameter ◽  
Silica Matrix ◽  
Rubber Particles ◽  
Hydrolysis And Condensation ◽  
Nanomatrix Structure

ABSTRACT Graft copolymerization of vinyltriethoxysilane (VTES) onto NR particles in the latex stage is a unique reaction, since it occurs together with hydrolysis and condensation of the triethoxysilane group of VTES to form a colloidal silica linking to the rubber particles. These reactions may contribute to the formation of a silica nanomatrix structure that consists of a dispersoid of rubber particles as the major component and a silica matrix as the minor component. Here, the graft copolymerization of VTES followed by hydrolysis and condensation is investigated to determine a suitable condition to prepare NR with a silica nanomatrix structure. The mechanical properties of the resulting graft copolymer are discussed in relation to the morphology, silica content, and gel content of the rubber. Based on morphological observations, NR particles with an average diameter of approximately 1 μm are well dispersed in a nanomatrix consisting of silica nanoparticles. The thickness of the silica nanomatrix increases as the monomer concentration increases, and a long incubation time generates large silica nanoparticles. The tensile strength and viscoelastic properties are significantly improved by forming the silica nanomatrix structure, with its continuous structure that prevents the NR particles from merging.

scholarly journals Formulation of Quaternized Aminated Chitosan Nanoparticles for Efficient Encapsulation and Slow Release of Curcumin

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 449
Author(s):  
Ahmed M. Omer ◽  
Zyta M. Ziora ◽  
Tamer M. Tamer ◽  
Randa E. Khalifa ◽  
Mohamed A. Hassan ◽  
...  
Keyword(s):  
Slow Release ◽  
Sodium Tripolyphosphate ◽  
Chitosan Nanoparticles ◽  
Gastric Fluid ◽  
Release Profile ◽  
Simulated Gastric Fluid ◽  
Maximum Value ◽  
Structure Surface ◽  
Drug Encapsulation Efficiency

An effective drug nanocarrier was developed on the basis of a quaternized aminated chitosan (Q-AmCs) derivative for the efficient encapsulation and slow release of the curcumin (Cur)-drug. A simple ionic gelation method was conducted to formulate Q-AmCs nanoparticles (NPs), using different ratios of sodium tripolyphosphate (TPP) as an ionic crosslinker. Various characterization tools were employed to investigate the structure, surface morphology, and thermal properties of the formulated nanoparticles. The formulated Q-AmCs NPs displayed a smaller particle size of 162 ± 9.10 nm, and higher surface positive charges, with a maximum potential of +48.3 mV, compared to native aminated chitosan (AmCs) NPs (231 ± 7.14 nm, +32.8 mV). The Cur-drug encapsulation efficiency was greatly improved and reached a maximum value of 94.4 ± 0.91%, compared to 75.0 ± 1.13% for AmCs NPs. Moreover, the in vitro Cur-release profile was investigated under the conditions of simulated gastric fluid [SGF; pH 1.2] and simulated colon fluid [SCF; pH 7.4]. For Q-AmCs NPs, the Cur-release rate was meaningfully decreased, and recorded a cumulative release value of 54.0% at pH 7.4, compared to 73.0% for AmCs NPs. The formulated nanoparticles exhibited acceptable biocompatibility and biodegradability. These findings emphasize that Q-AmCs NPs have an outstanding potential for the delivery and slow release of anticancer drugs.

Modelling inactivation of wild‐type and clinical Escherichia coli O26 strains using UV‐C and thermal treatment and subsequent persistence in simulated gastric fluid

2019 ◽  
Vol 127 (5) ◽  
pp. 1564-1575 ◽  
Author(s):  
V.S. Castro ◽  
D.K.A. Rosario ◽  
Y.S. Mutz ◽  
A.C.C. Paletta ◽  
E.E.S. Figueiredo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Treatment ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Wild Type ◽  
Uv C
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