Drug Release Characteristics of P(AA-co-DMAA)/SA Interpenetrating Polymer Network Hydrogels

2011 ◽  
Vol 399-401 ◽  
pp. 1165-1168
Author(s):  
Na Na Wang ◽  
Song Bai Lin ◽  
Ke Ping Wang ◽  
Ai Ru Ke
Keyword(s):  
Reaction Time ◽  
Release Rate ◽  
Ph Value ◽  
Polymer Network ◽  
Phosphate Buffer Solution ◽  
Interpenetrating Polymer Network ◽  
Buffer Solution ◽  
Berberine Hydrochloride ◽  
Effects Of Ph ◽  
The One

P(AA-co-DMAA) superporous drug-loaded hydrogels containing berberine hydrochloride were prepared by dispersion polymerization in foam system with acrylic acid (AA) and N,N-dimethyl acrylamide (DMAA) as monomers. Then sodium alginate (SA) as the second network was added to the system, and P(AA-co-DMAA)/SA interpenetrating polymer network (IPN) hydrogels were formed. The effects of pH value, reaction time between SA and glutaric dialdehyde (GA), the concentration of SA and GA on release behavior of berberine hydrochloride were discussed. The FT-IR spectra showed that P(AA-co-DMAA)/SA IPN hydrogels were synthesized successfully. The inverted fluorescence micrograph of P(AA-co-DMAA)/SA showed that some part of the superporous structures were still retained.The cumulative release profiles showed that the release rates were slightly higher in pH=6.8 phosphate buffer solution (PBS) than the one in pH=1 HCl solution. The release rate was the slowest in distilled water, only 7.3% within 24h. When the reaction time between SA and GA was shortened, the release speed of berberine hydrochloride became faster. The pore size of P(AA-co-DMAA) hydrogels was reduced with the concentration of SA and GA increased, and the release rate decreased due to the more dense network structures.

A pH/Temperature-Sensitive Semi-IPN Bead for Drug Release Carrier

2010 ◽  
Vol 148-149 ◽  
pp. 1449-1452 ◽  
Author(s):  
Kui Lin Deng ◽  
Yu Bo Gou ◽  
Jian Zuo ◽  
Li Rong Dong ◽  
Qian Li ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Polymer Network ◽  
Phosphate Buffer Solution ◽  
Interpenetrating Polymer Network ◽  
Temperature Sensitive ◽  
Buffer Solution ◽  
Hydrogel Beads ◽  
Drug Delivery Carrier ◽  
Temperature Sensitive Hydrogel ◽  
Stimuli Sensitive

A series of pH/temperature sensitive hydrogel beads with semi-interpenetrating polymer network (semi-IPN), composed of sodium alginate and poly(N-acryloylglycinate) were prepared as drug delivery carrier. In pH=2.3 phosphate buffer solution (PBS), the release amount of indomethacin incorporated into the beads was about 9% within 610 min, while this value approached to 68% in pH=7.4 PBS. The release rate of indomethacin was higher at 37 than that at 20 . In addition, the release amount of indomethacin was increased with increasing poly(N-acryloylglycinate) content. These results suggest that the stimuli-sensitive beads have the potential to be used as an effective pH/temperature delivery system in bio-medical fields.

Temperature- and pH-tunable plasmonic properties and SERS efficiency of the silver nanoparticles within the dual stimuli-responsive microgels

2014 ◽  
Vol 2 (35) ◽  
pp. 7326-7335 ◽  
Author(s):  
Xiaoyun Liu ◽  
Xiuqin Wang ◽  
Liusheng Zha ◽  
Danli Lin ◽  
Jianmao Yang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Network Structure ◽  
Ph Value ◽  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Stimuli Responsive ◽  
Plasmonic Property

Plasmonic property and SERS efficiency of the silver nanoparticles embedded within the microgels with an interpenetrating polymer network structure can be reversibly tuned by temperature and pH value.

Electrochemistry and Electrocatalysis of Hemoglobin Based on Graphene Quantum Dots Modified Electrode

2020 ◽  
Vol 16 (3) ◽  
pp. 308-315
Author(s):  
Xiaoyan Li ◽  
Hui Xie ◽  
Guiling Luo ◽  
Yanyan Niu ◽  
Xiaobao Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Modified Electrode ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Catalytic Reduction ◽  
Graphene Quantum Dots ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Detection Range ◽  
Electrochemical Behaviors

Background: Graphene quantum dots (GQD) is a new member of carbon nanomaterial that has attracted increasing attention owing to its better chemical inertness, low cytotoxicity, large specific surface area, cheap cost, suitable conductivity and excellent biocompatibility. Methods: Electrochemical behaviors of this modified electrode were studied by cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical investigations of Nafion/Hb/GQD/ CILE were carried out with electrochemical parameters calculated. Results: In the phosphate buffer solution with a pH value of 5.0, good linear relationships between the catalytic reduction current and the concentration of substrate were got for TCA (6.0~100.0 mmol·L-1), NaNO2 (2.0~12.0 mmol·L-1) and H2O2 (6.0~30.0 mmol·L-1). The proposed method was applied to NaNO2 concentration detection in soak water from picked vegetables with satisfactory results. Conclusion: This Nafion/Hb/GQD/CILE had a good bioelectrocatalytic activity to different substrates such as trichloroacetic acid, NaNO2 and H2O2 reduction with the advantages including wide detection range, low detection limit and good stability. Therefore, the application of GQD in electrochemical sensor was extended in this paper.

Encapsulation of Urease in Molybdenum Trioxide Sol-Gel

2004 ◽  
Vol 828 ◽  
Author(s):  
Prashant K. Jha ◽  
P. I. Gouma
Keyword(s):  
Gas Sensing ◽  
Molybdenum Trioxide ◽  
Ph Value ◽  
Sol Gel ◽  
Microstructural Analysis ◽  
Phosphate Buffer Solution ◽  
Gaseous Ammonia ◽  
Buffer Solution ◽  
Transmission Electron ◽  
The Matrix

ABSTRACTMolybdenum trioxide sol-gel matrices were tested for their ability to host biomaterials in their structures without adversely affecting the activity of the encapsulated biomolecules. The sol-gel composites were prepared at room temperature; the urease was added during the hydrolysis step to ensure proper encapsulation in the pore structure of the sol. Phosphate buffer solution was added during this stage to maintain the pH value of the sol in the bio-compatible range. The activity of incorporated urease was tested by exposing composite sol-gel material to standard urea test solutions and measuring the amount of gaseous ammonia (released by the reaction of urea with water in the presence of urease) using an ammonia electrode. The concentration of urea solutions ranged from 1mM to 10mM. An electronic olfactory system (EOS 835) was also employed to detect the presence of gaseous ammonia. Gas sensing tests were done to verify the sensitivity of the matrix to ammonia. Microstructural analysis was carried out by means of scanning and transmission electron microscopy. It was found that urease retained its activity inside molybdenum trioxide sol-gels that are sensitive to ammonia. These hybrid nanoporous composites are useful in the field of biosensors and fuel cells.

Preparation and Drug Release Behavior from a Temperature-Sensitive Poly(aspartic Acid) Derivatives Hydrogel

2013 ◽  
Vol 711 ◽  
pp. 18-21
Author(s):  
Kui Lin Deng ◽  
Chun Xiu Li ◽  
Ting Gao ◽  
Xiao Dan Fu ◽  
Wen Hui Jin ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Aspartic Acid ◽  
Ph Value ◽  
Phosphate Buffer Solution ◽  
Temperature Sensitive ◽  
Release Behavior ◽  
Buffer Solution ◽  
Drug Release Behavior ◽  
Drug Delivery Carrier ◽  
Increasing Temperature

In this paper, a new pH/temperature-sensitive beads with semi-interpenetrating polymeric network based on sodium alginate(SA) and poly(aspartic acid) derivatives(M-E-PSI) were prepared using as drug delivery carrier. With indomethacin as a drug model，we investigated the release behaviors of indomethacin in different pH value, temperature and ratio of SA/ M-E-PSI. It turned out that the release amount of indomethacin in pH=2.1 phosphate buffer solution(PBS) was evidently higher than that in pH=7.4 PBS. And also, the release amount of indomethacin was also increased with increasing temperature and poly(aspartic acid) derivatives content in the beads.

Results of pilot comparisons of national standards for the activity of hydrogen ions in aqueous solutions

2021 ◽  
pp. 66-72
Author(s):  
Sergey V. Prokunin ◽  
Andrey N. Shchipunov ◽  
Daria A. Vengina ◽  
Frank Bastkowskiy ◽  
Emrah Uysal ◽  
...  
Keyword(s):  
Ph Value ◽  
Aqueous Media ◽  
Phosphate Buffer Solution ◽  
Hydrogen Index ◽  
National Standards ◽  
Measuring Instruments ◽  
Buffer Solution ◽  
Working Standard ◽  
Average Value ◽  
State Register

The enormous needs in ensuring the measurement of the hydrogen index in various industries and the national economy of Russia make the measurement of the hydrogen index one of the most important methods for monitoring aqueous media. In 2013, work was carried out to enter into the State Register of Measuring Instruments of the Russian Federation a buffer solution and a standard titer with a pH value of 7.00 – a working pH standard of the 2nd category, which is one of the most demanded of non-standard solutions for verification and calibration pH measuring instruments. To confirm the metrological characteristics, pilot comparisons were organized within COOMET. This article presents the results of a pilot comparison to determine the pH of a phosphate buffer solution – a working standard of рН=7.00. 8 metrological institutes and 10 metrological organizations took part in the comparisons. The results obtained showed that the overwhelming majority of the participants in the comparisons presented the results of pH measurements, which have an uncertainty not exceeding ±0.03 of the average value, which is an acceptable criterion for measuring the pH.

Selective Detection of Dopamine in the Presence of Uric Acid Using Polymerized Phthalo Blue Film Modified Carbon Paste Electrode

2014 ◽  
Vol 895 ◽  
pp. 447-451 ◽  
Author(s):  
Jamballi G. Manjunathaa ◽  
Mohamad Deraman ◽  
Nur Hamizah Basri ◽  
I.A. Talib
Keyword(s):  
Uric Acid ◽  
Carbon Paste Electrode ◽  
Phosphate Buffer Solution ◽  
Electrode Reaction ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
Buffer Solution ◽  
Peak Current ◽  
Effects Of Ph ◽  
Paste Electrode

A convenient and useful method for the voltammetric determination of dopamine (DA) and uric acid (UA) based on poly (Phthalo blue) modified carbon paste electrode (PTBMCPE) is reported in this paper. The PTBMCPE exhibits excellent electro-catalytic activities for the oxidationreduction of DA and UA, as well as eliminating the interference. Factors influencing the detection processes are optimized and the kinetic parameters are calculated. The effects of pH, scan rate and concentration of dopamine on the peak current were investigated, and the results indicated that the peak current of dopamine is the highest in 0.2 M pH 7.0 Phosphate buffer solution (PBS) and the electrode reaction corresponds to a rate-controlled process. The proposed method possesses the distinct advantages of simple, appropriate for operation, good reproducibility and highly selective and sensitive.

scholarly journals The Degradation Properties of MgO Whiskers/PLLA Composite In Vitro

2018 ◽  
Vol 19 (9) ◽  
pp. 2740 ◽  
Author(s):  
Yun Zhao ◽  
Bei Liu ◽  
Hongwei Bi ◽  
Jinjun Yang ◽  
Wei Li ◽  
...  
Keyword(s):  
Ph Value ◽  
Composite Films ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
In Vitro Degradation ◽  
Final Weight ◽  
Cell Affinity ◽  
Degradation Properties ◽  
Composite Samples

In this study, composite films of stearic acid–modified magnesium oxide whiskers (Sa–w-MgO)/poly-l-lactic acid (PLLA) were prepared through solution casting, and the in vitro degradation properties and cytocompatibility of the composites with different whisker contents were investigated. The results showed that the degradation behavior of the composite samples depended significantly on the whisker content, and the degradation rate increased with the addition of MgO content. Furthermore, the degradation of the composites with higher contents of whiskers was influenced more severely by the hydrophilicity and pH value, leading to more final weight loss, but the decomposition rate decreased gradually. Furthermore, the pH value of the phosphate buffer solution (PBS) was obviously regulated by the dissolution of MgO whiskers through neutralization of the acidic product of PLLA degradation. The cytocompatibility of the composites also increased remarkably, as determined from the cell viability results, and was higher than that of PLLA at the chosen whisker content. This was beneficial for the cell affinity of the material, as it notably led to an enhanced biocompatibility of the PLLA, in favor of promoting cell proliferation, which significantly improved its bioactivity, as well.

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