Layer-by-layer assembled thin films composed of carboxyl-terminated poly(amidoamine) dendrimer as a pH-sensitive nano-device

Tomita, Shigeru; Sato, Katsuhiko; Anzai, Jun‐ichi

doi:10.1016/j.jcis.2008.06.054

Cited by 65 publications

(48 citation statements)

References 30 publications

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“…19,20 Carboxylated poly(amidoamine) dendrimer and tannic acid have also been used as components of hydrogenbonding LbL films. [21][22][23] Hydrogen-bonding LbL films are constructed by an alternate deposition of hydrogen donor and acceptor polymers from aqueous solutions, in a similar manner as that for the preparation of electrostatic bonded LbL films. A unique feature of hydrogen-bonded LbL films is their pH-dependent instability, in contrast to the high stability of electrostatic bonded LbL films.…”

Section: ·2 Hydrogen Bonding Lbl Fimsmentioning

confidence: 99%

Layer-by-layer Thin Films and Microcapsules for Biosensors and Controlled Release

2012

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We present an overview of the preparation and properties of layer-by-layer (LbL) deposited thin films and microcapsules in relation to their use in the development of biosensors and controlled release systems. Enzyme biosensors can be constructed by immobilizing enzymes on the surface of electrodes by LbL deposition without loss of their catalytic activity. In addition to synthetic polymers, binding proteins, such as avidin and lectin, are also used for constructing LbL films through avidin-biotin and lectin-sugar interactions. The performance characteristics of LbL film-based biosensors can be tuned by controlling the number of layers and by the choice of film components. The permeability of polyelectrolyte LbL films to ions and molecules is discussed in relation to the use of the films for eliminating interference in biosensors. The possible use of polysaccharide LbL film-coated electrodes for the construction of biosensors is highlighted, and examples of LbL film-and microcapsule-based optical sensors are described. We then focus on the use of LbL films and microcapsules as vehicles for controlled release, in particular on recent progress in the controlled release of insulin from LbL films and microcapsules. LbL films composed of insulin and polymers are sensitive to environmental pH, and release insulin in response to pH changes, suggesting that insulin LbL films can be used in the development of orally administered insulin. The construction of glucose-dependent insulin release systems using LbL insulin microcapsules functionalized with phenylboronic acid, lectin, and glucose oxidase is also examined.

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Section: ·2 Hydrogen Bonding Lbl Fimsmentioning

confidence: 99%

Layer-by-layer Thin Films and Microcapsules for Biosensors and Controlled Release

2012

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“…The permeability of [Ru(NH 3 ) 6 ]Cl 3 across (PAH-PSS) 5 film was higher than that across (PAH-PSS) 5 PAH film. On the other hand, the opposite trend was observed for K 3 [Fe(CN) 6 ], suggesting that the surface charge of the LbL film had a predominant effect. It is reasonable to assume that Fe(CN) 6 3− ions undergo significant Donnan exclusion at the negatively charged surface of the (PAH-PSS) 5 film.…”

Section: Ion Permeationmentioning

confidence: 92%

“…nanotubes [5,6], proteins [7,8], and polysaccharides [9,10]. LbL films have been used for constructing molecular architectures [11][12][13], stimuli-sensitive systems [2,[14][15][16][17], optical and electrochemical devices [5,10,[18][19][20][21][22], and controlled release systems [23][24][25][26][27][28].…”

Section: Open Accessmentioning

confidence: 99%

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Ion Permeability of Free-Suspended Layer-by-Layer (LbL) Films Prepared Using an Alginate Scaffold

2013

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Abstract:Layer-by-layer (LbL) films were prepared over an aperture (diameter 1-5 mm) on a glass plate to study ion permeation across free-suspended LbL films. LbL films were prepared by depositing alternating layers of poly(allylamine hydrochloride) (PAH) and poly(styrene sulfonate) (PSS) on the surface of a glass plate with an aperture filled with an alginate gel, followed by dissolution of the alginate gel. PAH-PSS films prepared in this way showed permeability to inorganic salts, depending on the size and charge. Permeability to alkali metal chlorides depended on the Stokes radius of the alkali metal cations. The effect of the type of halide was negligible because of the halides' smaller ionic radii. Permeation of multivalent ions such as Ru(NH 3 ) 6 3+ and [Fe(CN) 6 ] 3− was severely suppressed owing to Donnan exclusion.

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“…Polyelectrolyte layer-by-layer (LbL) films can be prepared by an alternate and repeated deposition of polymeric materials on a solid surface through electrostatic interactions [1,2], hydrogen binding [3,4], host-guest complexation [5,6], and biological affinity [7]. A recent review has summarized biocompatible LbL films for smart materials [8].…”

Section: Introductionmentioning

confidence: 99%

pH-Dependent Release of Insulin from Layer-by-Layer-Deposited Polyelectrolyte Microcapsules

et al. 2015

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Insulin-containing microcapsules were prepared by a layer-by-layer (LbL) deposition of poly(allylamine hydrochloride) (PAH) and polyanions, such as poly(styrenesulfonate) (PSS), poly(vinyl sulfate) (PVS), and dextran sulfate (DS) on insulin-containing calcium carbonate (CaCO3) microparticles. The CaCO3 core was dissolved in diluted HCl solution to obtain insulin-containing hollow microcapsules. The microcapsules were characterized by scanning electron microscope (SEM) and atomic force microscope (AFM) images and ζ-potential. The release of insulin from the microcapsules was faster at pH 9.0 and 7.4 than in acidic solutions due to the different charge density of PAH. In addition, insulin release was suppressed when the microcapsules were constructed using PAH with a lower molecular weight, probably owing to a thicker shell of the microcapsules. The results suggested a potential use of the insulin-containing microcapsules for developing insulin delivery systems.

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Layer-by-layer assembled thin films composed of carboxyl-terminated poly(amidoamine) dendrimer as a pH-sensitive nano-device

Cited by 65 publications

References 30 publications

Layer-by-layer Thin Films and Microcapsules for Biosensors and Controlled Release

Layer-by-layer Thin Films and Microcapsules for Biosensors and Controlled Release

Ion Permeability of Free-Suspended Layer-by-Layer (LbL) Films Prepared Using an Alginate Scaffold

pH-Dependent Release of Insulin from Layer-by-Layer-Deposited Polyelectrolyte Microcapsules

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