Toggle Main Menu Toggle Search

Open Access padlockePrints

Pulsatile release from a flat self-oscillating chitosan macrogel

Lookup NU author(s): Dr Anna Isakova, Dr Katarina Novakovic



This is the authors' accepted manuscript of an article that has been published in its final definitive form by Royal Society of Chemistry, 2018.

For re-use rights please refer to the publisher's terms and conditions.


Coupling oscillatory chemical reactions to smart materials which can respond to external stimuli has long been considered an answer to the long-standing issue of pulsatile drug delivery. Although a number of coupled architectures exist, there are no systems reporting pH-controlled pulsed drug release based on chemical oscillators. In this paper, we report for the first time a proof-of-concept self-oscillatory chitosan macrogel, employing the palladium-catalysed oxidative carbonylation reaction as the driving force of its oscillations. The reported hydrogel is composed of highly biocompatible components and a novel imine-functionalised chitosan-palladium catalyst with zero leaching rates. This macrogel was shown to rhythmically release not only the products of the reaction, but also fluorescein, which is used as an FDA-approved model drug. The step-wise release pattern corresponded to the step-wise dynamics of pH decrease in methanol:water, while in pure methanol, the changes in pH had an oscillatory mode, accompanied by mirrored oscillations in fluorescein concentration. This proof-of-concept system significantly expands the horizons of pulsatile delivery materials for future research.

Publication metadata

Author(s): Isakova A, Novakovic K

Publication type: Article

Publication status: Published

Journal: Journal of Materials Chemistry B

Year: 2018

Volume: 6

Issue: 30

Pages: 5003-5010

Print publication date: 14/08/2018

Online publication date: 20/07/2018

Acceptance date: 14/07/2018

Date deposited: 16/07/2018

ISSN (print): 2050-750X

ISSN (electronic): 2050-7518

Publisher: Royal Society of Chemistry


DOI: 10.1039/C8TB00781K


Altmetrics provided by Altmetric


Funder referenceFunder name