Temperature-dependent permeability of polyelectrolyte complex capsule membranes havingN-isopropylacrylamide domains

Kono, Kenji; Okabe, Hideki; Morimoto, Keiji; Takagishi, Toru

doi:10.1002/1097-4628(20000919)77:12<2703::aid-app180>3.0.co;2-p

Cited by 28 publications

(15 citation statements)

References 20 publications

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“…In recent years, poly[( N ‐isopropylacrylamide)‐ co ‐(methacrylic acid)] (P( N ‐iPAAm‐ co ‐MAA)) copolymers have been studied as one type of these temperature‐ and pH‐sensitive materials 17–26. These copolymers show different properties depending on composition and previous swelling treatment,24, 26 which potentially allows one to obtain hydrogels for specific uses.…”

Section: Introductionmentioning

confidence: 99%

Thermo‐ and pH‐sensitive hydrogels based on 2‐(2‐methoxyethoxy)ethyl methacrylate and methacrylic acid

París

García

Quijada‐Garrido

2010

Polymer International

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Hydrogels based on commercially available 2‐(2‐methoxyethoxy)ethyl methacrylate (MEO2MA), with methacrylic acid (MAA) as comonomer, are studied. The incorporation of an ionizable monomer, such as MAA, in a thermosensitive system leads to the formation of hydrogels able to respond to pH and temperature according to their monomeric composition. Thus, at low pH, the acid groups of MAA are protonated, and they do not contribute to increase the hydrophilic balance, and collapse of the hydrogels occurs around room temperature. For temperatures below that of collapse, the degree of swelling increases with increasing MEO2MA content. In contrast, at neutral or basic pH, the ionization of the acid groups contributes to increase the hydrophilicity and the osmotic pressure, leading to polyelectrolyte behaviour. In this regime, the swelling capacity increases and the thermosensitivity decreases with increasing MAA content in the hydrogels. These properties make poly(MEO2MA‐co‐MAA) hydrogels suitable candidates for use in oral controlled delivery of hydrophobic drugs. This possibility is explored using ibuprofen as a model drug, after a complete study of the swelling kinetics. Copyright © 2010 Society of Chemical Industry

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Section: Introductionmentioning

confidence: 99%

Thermo‐ and pH‐sensitive hydrogels based on 2‐(2‐methoxyethoxy)ethyl methacrylate and methacrylic acid

París

García

Quijada‐Garrido

2010

Polymer International

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“…The change is of course attributed to the thermal responsive polymer, which has a lower solution temperature (LCST) of %34 8C. [33][34][35] It is known that below the LCST, PNIPAAm is hydrophilic and soluble in water, which has no extra influence on the permeation of Rd6G. When the temperature is above the LCST, the PNIPAAm chains become hydrophobic and collapse to make the capsule shell denser, and even cover part of the existing pores.…”

Section: Resultsmentioning

confidence: 99%

In Situ Coacervated Microcapsules with Filled Polyelectrolytes and Charge‐Controlled Permeation for Dye Molecules

Wang

Tong

et al. 2008

Macro Chemistry & Physics

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Microcapsules with charge‐controlled permeation for electrolytes were fabricated by an in situ coacervation method in the presence of polyelectrolyte during core removal. A layer of PAH was adsorbed onto PSS‐doped CaCO3 microparticles, followed by crosslinking of the PAH layer with GA and core removal in a solution of EDTA with or without PAH. In the presence of PAH, microcapsules with a larger size, weight and PSS content than with PAH were obtained. Microcapsules produces without PAH showed a unique feature of charge‐controlled permeation for electrolytes: negatively charged probes were completely rejected, but positively charged ones were attracted.magnified image

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“…As there are many cases in which temperature fluctuations occur naturally, and in which the temperature stimuli can be easily designed and artificially controlled, in recent years much attention has been focused on thermo-sensitive microcapsules [3][4][5][6][7][8][9][10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

“…Several types of thermo-sensitive hollow microcapsules have been developed with PNIPAM. These microcapsules can be briefly classified as two main types: (1) microcapsules with membranes modified by PNIPAM [3][4][5][6][7][8], and (2) microcapsules with whole PNI-PAM membranes [9][10][11][12][13][14][15]. To fabricate hollow thermo-sensitive microcapsules with whole PNIPAM membranes, templating method is one of the most common methods [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Preparation of monodisperse thermo-sensitive poly(N-isopropylacrylamide) hollow microcapsules

Cheng

Chu

Ren

et al. 2007

Journal of Colloid and Interface Science

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Temperature-dependent permeability of polyelectrolyte complex capsule membranes havingN-isopropylacrylamide domains

Cited by 28 publications

References 20 publications

Thermo‐ and pH‐sensitive hydrogels based on 2‐(2‐methoxyethoxy)ethyl methacrylate and methacrylic acid

Thermo‐ and pH‐sensitive hydrogels based on 2‐(2‐methoxyethoxy)ethyl methacrylate and methacrylic acid

In Situ Coacervated Microcapsules with Filled Polyelectrolytes and Charge‐Controlled Permeation for Dye Molecules

Preparation of monodisperse thermo-sensitive poly(N-isopropylacrylamide) hollow microcapsules

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