pH-Responsive Model Drug Release from Silica-Poly(methacrylic acid) Interpenetrating Gel Hybrids

2001 ◽  
Vol 16 (5) ◽  
pp. 409-418 ◽  
Author(s):  
Kazuya Suzuki ◽  
Takeshi Yumura ◽  
Yuko Tanaka ◽  
Mitsuru Akashi
Keyword(s):  
Methacrylic Acid ◽  
Porous Silica ◽  
Silica Particles ◽  
Release Behavior ◽  
Stimuli Responsive ◽  
Ph Responsive ◽  
The Core ◽  
Ph Values ◽  
Brilliant Blue Fcf ◽  
Model Drug

Stimuli-responsive gel was hybridized with porous silica particles, by radical polymerization of methacrylic acid (MA) in the presence of a crosslinker. Brilliant Blue FCF (BBFCF) was encapsulated in the core of the particle and its release behavior from the particle under specific stimuli was studied. PMA gel hybridized silica particles showed specific release behavior at different pH values while normal silica particles released BBFCF at the same rate at all pHs.

scholarly journals A Comparison Study of Antiultraviolet and Sustained Release Properties of Polydopamine/Avermectin Microcapsule and Microsphere

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Zhichuan Shen ◽  
Xinhua Zhou ◽  
Huina Qiu ◽  
Hua Xu ◽  
Huayao Chen ◽  
...  
Keyword(s):  
Weibull Model ◽  
Decomposition Temperature ◽  
Comparison Study ◽  
Release Behavior ◽  
Scanning Calorimetry ◽  
Release Process ◽  
Acid Sensitivity ◽  
Ph Values ◽  
Model Drug ◽  
Zeta Potential Analysis

By using dopamine (DA) as the monomer, the model drug avermectin (AVM) was loaded on polydopamine microspheres (AVM/PDAMS) and polydopamine microcapsules (AVM@PDAMC) by the method of impregnation and encapsulation, respectively. The materials’ structures were systematically characterized using Fourier transform infrared spectroscopy (FTIR), zeta potential analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The comparison of antiultraviolet capability as well as release behaviors under different pH values of the materials were studied. The results showed that a spherical appearance was observed from both materials. The use of AVM/PDAMS and AVM@PDAMC made the decomposition temperature of AVM increase to 235°C and 245°C, respectively. After being exposed to ultraviolet light for 1400 min, the residual ratios of AVM of AVM/PDAMS and AVM@PDAMC were 42% and 54%, respectively. Both AVM/PDAMS and AVM@PDAMC showed acid sensitivity. AVM/PDAMS and AVM@PDAMC took about 13 h and 60 h to reach the release rate of 50% under pH 3. The release process of AVM/PDAMS could be explained by the Weibull model at pH 3, while the release behavior of AVM@PDAMC fitted the Baker–Lonsdale equation. At pH 7 and pH 9, both of the delivery materials followed the Korsmeyer–Peppas model and belonged to the Fick diffusion.

Modeling Equilibrium Swelling of a Dual pH- and Temperature-Responsive Core/Shell Hydrogel

2016 ◽  
Vol 08 (03) ◽  
pp. 1650039 ◽  
Author(s):  
N. Hamzavi ◽  
A. D. Drozdov ◽  
Y. Gu ◽  
E. Birgersson
Keyword(s):  
Ph Sensitivity ◽  
Core Shell ◽  
Polymer Gel ◽  
Stimuli Responsive ◽  
Degree Of Ionization ◽  
High Ph ◽  
The Core ◽  
Ionic Core ◽  
Ph Values ◽  
Equilibrium Swelling

The equilibrium swelling of a dual stimuli-responsive core/shell hydrogel is studied by a thermodynamic model. This hydrogel shows thermo-sensitivity as well as pH-sensitivity. The model captures the inhomogeneous swelling of core/shell hydrogels and also, accounts for temperature and pH sensitivity. The predictions of this model are verified with the swelling experiments of a core/shell microgel comprising poly N-isopropyl acrylamide (pNIPAM) and acrylic acid (AAc). The model calculates the equilibrium swelling within the ionic core and the neutral shell. Simulation results can reproduce the equilibrium swelling-temperature curves of this microgel at different pH values considering the delay in the volume phase transition temperature (VPTT) of the ionic polymer gel (pNIPAM-co-AAc) in the core. Two transition points are found in the equilibrium swelling behavior of the hydrogel akin to the VPTTs of the core and shell domains at high pH values of bath solutions. Likewise, the degree of ionization in the core domain is predicted to have a two-step transition behavior corresponding to the VPTTs of the core and shell domains at high pH values of bath solutions. It is shown that the equilibrium swelling of the ionic core is mainly influenced by the electrostatic repulsion between bound charges rather than the ionic pressure. Furthermore, it is determined that the maximum radial stress occurs at the core/shell interface and reaches its maximum value about the VPTT of the core.

Electric Charge Dependence of Controlled Dye-Release Behavior in Glass Ionomer Cement Containing Nano-Porous Silica Particles

2018 ◽  
Vol 18 (1) ◽  
pp. 75-79 ◽  
Author(s):  
Yosuke Bando ◽  
Ko Nakanishi ◽  
Shigeaki Abe ◽  
Shuichi Yamagata ◽  
Yasuhiro Yoshida ◽  
...  
Keyword(s):  
Electric Charge ◽  
Glass Ionomer Cement ◽  
Porous Silica ◽  
Silica Particles ◽  
Glass Ionomer ◽  
Release Behavior ◽  
Dye Release ◽  
Charge Dependence ◽  
Ionomer Cement

Carboxylic acid modified pH-responsive composite polymer particles

2019 ◽  
Vol 39 (7) ◽  
pp. 671-678
Author(s):  
Nur E. Jannat ◽  
Md. Ashraful Alam ◽  
M.A. Rahman ◽  
M.M. Rahman ◽  
M.K. Hossain ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Methacrylic Acid ◽  
Ph Value ◽  
Ethylene Glycol Dimethacrylate ◽  
Glycol Dimethacrylate ◽  
Ph Responsive ◽  
Composite Polymer ◽  
Polymer Particles ◽  
Ph Values ◽  
Composite Polymer Particles

Abstract pH-responsive polymers are attracting much interest from researchers because of their wide application potentials in areas like biosensor, bioseparator, bioreactor, biocatalysis, drug delivery, and water treatments. In this investigation a two-step process is evaluated to prepare carboxyl(–COOH) functional submicrometer-sized pH-responsive composite polymer particles. First, submicrometer-sized polystyrene (PS) particles are prepared by a modified conventional dispersion polymerization. In the second step, PS/poly(methacrylic acid-acrylamide-ethylene glycol dimethacrylate) [PS/P(MAA-AAm-EGDMA)] composite polymer particles are synthesized by seeded co-polymerization of methacrylic acid, acrylamide, and ethylene glycol dimethacrylate in the presence of PS seed particles. The size distributions and morphologies analyzed by electron micrographs suggested that seeded copolymerization smoothly occurred without formation of any secondary tiny copolymer particles. The surface composition and functionality are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. The hydrodynamic diameter increased with the increase in pH values as part of the carboxyl groups are deprotonated, which favored the swelling of copolymer layer formed around the surface of PS particles. The adsorption of cationic and anionic surfactants at two different pH values showed that adsorption of cationic surfactant is favored at higher pH value whereas that of anionic surfactant is favored at lower pH value.

scholarly journals Three-Dimensional Hydrazone-Functionalized Covalent Organic Frameworks as pH-Triggered Rotary Switches

2021 ◽  
Author(s):  
Wenjuan Zhao ◽  
Chengyang Yu ◽  
Fengqian Chen ◽  
Xinyu Guan ◽  
Hui Li ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Drug Carriers ◽  
Covalent Organic Frameworks ◽  
Stimuli Responsive ◽  
Disease Treatment ◽  
Ph Values ◽  
First Case ◽  
Synthesis Strategy ◽  
Potential Applications ◽  
Model Drug

<i>The property expansion of three-dimensional (3D) functionalized covalent organic frameworks (COFs) is important for developing their potential applications. Herein, we report the first case of 3D hydrazone-decorated COFs as pH-triggered molecular switches, and explore their application in the stimuli-responsive drug delivery system. These functionalized COFs with hydrazone groups on the channel walls were obtained via a multi-component bottom-up synthesis strategy. They exhibit a reversible E/Z isomerization at various pH values, confirmed by UV-vis absorption spectroscopy and proton conduction. Remarkably, after loading cytarabine (Ara-C) as a model drug molecule, these pH-responsive <a></a><a>COFs showed an </a>excellent and intelligent sustained-release effect with an almost <a></a><a>4-fold</a> increase in the Ara-C release at pH = 4.8 than at pH = 7.4,</i> <i>which will effectively improve drug-targeting and reduce drug side effects. Thus, these results open a way toward designing 3D stimuli-responsive functionalized COF materials and promote their potential application as drug carriers in <a></a><a>the field of </a>disease treatment.</i>

Temperature- and pH-responsive poly(N-isopropylacrylamide-co-methacrylic acid) microgels as a carrier for controlled protein adsorption and release

Soft Matter ◽  
2021 ◽  
Author(s):  
Priyanshi Agnihotri ◽  
Sangeeta Jangra ◽  
Shikha Aery ◽  
Abhijit Dan
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Protein Adsorption ◽  
Methacrylic Acid ◽  
Bovine Serum ◽  
Ph Responsive ◽  
Ph Values ◽  
Different Temperatures ◽  
Adsorption And Release

Herein, we report controlled protein adsorption and delivery of thermo- and pH-responsive poly(N-isopropylacrylamide-co-methacrylic acid) (PNIPAM-co-MAA) microgels at different temperatures, pH values and ionic strengths by employing bovine serum albumin (BSA)...

scholarly journals Three-Dimensional Hydrazone-Functionalized Covalent Organic Frameworks as pH-Triggered Rotary Switches

2021 ◽  
Author(s):  
Wenjuan Zhao ◽  
Chengyang Yu ◽  
Fengqian Chen ◽  
Xinyu Guan ◽  
Hui Li ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Drug Carriers ◽  
Covalent Organic Frameworks ◽  
Stimuli Responsive ◽  
Disease Treatment ◽  
Ph Values ◽  
First Case ◽  
Synthesis Strategy ◽  
Potential Applications ◽  
Model Drug

<i>The property expansion of three-dimensional (3D) functionalized covalent organic frameworks (COFs) is important for developing their potential applications. Herein, we report the first case of 3D hydrazone-decorated COFs as pH-triggered molecular switches, and explore their application in the stimuli-responsive drug delivery system. These functionalized COFs with hydrazone groups on the channel walls were obtained via a multi-component bottom-up synthesis strategy. They exhibit a reversible E/Z isomerization at various pH values, confirmed by UV-vis absorption spectroscopy and proton conduction. Remarkably, after loading cytarabine (Ara-C) as a model drug molecule, these pH-responsive <a></a><a>COFs showed an </a>excellent and intelligent sustained-release effect with an almost <a></a><a>4-fold</a> increase in the Ara-C release at pH = 4.8 than at pH = 7.4,</i> <i>which will effectively improve drug-targeting and reduce drug side effects. Thus, these results open a way toward designing 3D stimuli-responsive functionalized COF materials and promote their potential application as drug carriers in <a></a><a>the field of </a>disease treatment.</i>

scholarly journals Thermoresponsive Polymer Grafted Porous Silicas as Smart Nanocarriers

2018 ◽  
Vol 71 (7) ◽  
pp. 477 ◽  
Author(s):  
Sushilkumar A. Jadhav ◽  
Dominique Scalarone
Keyword(s):  
Porous Silica ◽  
Silica Particles ◽  
Stimuli Responsive ◽  
Thermoresponsive Polymer ◽  
Thermoresponsive Polymers ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Pharmaceutical Nanocarriers ◽  
Improved Performance ◽  
Thermally Triggered

Porous silica particles grafted with various stimuli-responsive polymers are investigated with great interest for their use as smart pharmaceutical nanocarriers in advanced drug delivery systems (DDS). In particular, porous silica particles grafted with thermoresponsive polymers that exhibit thermally triggered on/off gating mechanisms have shown improved performance as hybrid DDS capable of controlling the release of different drugs in various mediums which resemble complex biological environments. In addition, the tuning of the drug release profiles as per requirements has proved possible with modifications to the porous core and the grafted thermoresponsive polymers. This highlight presents a brief discussion of basic preparation techniques and some recent significant developments in the field of thermoresponsive polymer grafted porous silica particles as smart pharmaceutical nanocarriers.

scholarly journals A Brief Overview of Recent Progress in Porous Silica as Catalyst Supports

2021 ◽  
Vol 5 (3) ◽  
pp. 75
Author(s):  
Preeti S. Shinde ◽  
Pradnya S. Suryawanshi ◽  
Kanchan K. Patil ◽  
Vedika M. Belekar ◽  
Sandeep A. Sankpal ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
High Surface ◽  
High Surface Area ◽  
Porous Silica ◽  
Textural Properties ◽  
Silica Particles ◽  
Catalyst Supports ◽  
Silica Supports ◽  
Low Degree ◽  
Transfer Properties

Porous silica particles have shown applications in various technological fields including their use as catalyst supports in heterogeneous catalysis. The mesoporous silica particles have ordered porosity, high surface area, and good chemical stability. These interesting structural or textural properties make porous silica an attractive material for use as catalyst supports in various heterogeneous catalysis reactions. The colloidal nature of the porous silica particles is highly useful in catalytic applications as it guarantees better mass transfer properties and uniform distribution of the various metal or metal oxide nanocatalysts in solution. The catalysts show high activity, low degree of metal leaching, and ease in recycling when supported or immobilized on porous silica-based materials. In this overview, we have pointed out the importance of porous silica as catalyst supports. A variety of chemical reactions catalyzed by different catalysts loaded or embedded in porous silica supports are studied. The latest reports from the literature about the use of porous silica-based materials as catalyst supports are listed and analyzed. The new and continued trends are discussed with examples.

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