Preparation of Layer-by-Layer Films Composed of Polysaccharides and Poly(Amidoamine) Dendrimer Bearing Phenylboronic Acid and Their pH- and Sugar-Dependent Stability

Abstract

Layer-by-layer films composed of polysaccharides and poly(amidoamine) dendrimer bearing phenylboronic acid (PBA-PAMAM) were prepared to study the deposition behavior of the films and their stability in buffer solutions and in sugar solutions. Alginic acid (AGA) and carboxymethylcellulose (CMC) were employed as counter-polymers in constructing LbL films. AGA/PBA-PAMAM films were successfully prepared at pH 6.0–9.0, whereas the preparation of CMC/PBA-PAMAM film was unsuccessful at pH 8.0 and 9.0. The results show that the LbL films formed mainly through electrostatic affinity between PBA-PAMAM and polysaccharides, while, for AGA/PBA-PAMAM films, the participation of boronate ester bonds in the films was suggested. AGA/PBA-PAMAM films were stable in the solutions of pH 6.0–9.0. In contrast, CMC/PBA-PAMAM films decomposed at pH 7.5–9.0. The AGA/PBA-PAMAM films decomposed in response to 5–30 mM fructose at pH 7.5, while the films were stable in glucose solutions. Thus, AGA is useful as a counter-polymer for constructing PBA-PAMAM films that are stable at physiological pH and decompose in response to fructose.

Sugar-Responsive Layer-by-Layer Film Composed of Phenylboronic Acid-Appended Insulin and Poly(vinyl alcohol)

“…[7][8][9][10] In this study, we also used PVA with PBA-appended insulin incorporated directly in the LbL film. The fabrication process of the LbL films was monitored with QCM using a flow-through cell.…”

“…[4][5][6][7][8][9][10] PBA derivatives show binding ability for the 1,2-diol, and 1,3-diol of sugars, which can result in the formation of a cyclic ester even in aqueous solution. 11,12) The cyclic ester formation is a reversible reaction, which is suitable for stimuli-responsive LbL films.…”

Nanoarchitectonics beyond perfect order – not quite perfect but quite useful

“…126 Besides, hydrogen-bonding interactions, [127][128][129] biospecific interactions, 130 charge transfer interactions, 131 electrochemical reactions, 132 metal coordination, 133 stereo-complex formation, 134 sol/gel reactions, 135 molecular interactions, 136 or covalent bonding formation 137 can also act as driving forces of LbL assembly. Another property of LbL assembly is pH-, [138][139][140][141] salt-, 142,143 redox, 144 ionic strength 145 responsiveness, and crosslinking capability. 146 LbL assembly exhibits the unique characteristics of facile and inexpensive procedures, which can be divided into three mature operational strategies.…”

Supramolecular dendrimer-containing layer-by-layer nanoassemblies for bioapplications: current status and future prospects

“…120 It has been demonstrated that several physicochemical parameters, including the solution pH and ionic strength and the intrinsic properties of the polyelectrolytes such as the concentration, molecular weight and charge density play a key role in the deposition, stability, structure, properties and functions of the assembled multilayered structures, as described below. 83,121 2.1.1 Factors governing the growth of LbL assemblies 2.1.1.1 Influence of solution pH. Many dendritic families include tertiary amines at the interior and primary amines on the surface and, as such, their conformation in aqueous solution is affected by changes in the pH, which in turn influence the preparation of dendrimer-based LbL films assembled via electrostatic interactions.…”