Polylactic Acid Sealed Polyelectrolyte Multilayer Microchambers for Entrapment of Salts and Small Hydrophilic Molecules Precipitates

Meiyu Gai; Johannes Frueh; Valeriya L Kudryavtseva; Alexey M Yashchenok; Gleb B Sukhorukov

doi:10.1021/acsami.7b03451

Polylactic Acid Sealed Polyelectrolyte Multilayer Microchambers for Entrapment of Salts and Small Hydrophilic Molecules Precipitates

ACS Appl Mater Interfaces. 2017 May 17;9(19):16536-16545. doi: 10.1021/acsami.7b03451. Epub 2017 May 5.

Authors

Meiyu Gai¹, Johannes Frueh², Valeriya L Kudryavtseva³, Alexey M Yashchenok⁴, Gleb B Sukhorukov¹

Affiliations

¹ School of Engineering and Materials Science, Queen Mary University of London , Mile End, Eng, 215, London E1 4NS, United Kingdom.
² State Key laboratory of Micro/Nano Technology Research Centre, Harbin Institute of Technology , Yikuang Street 2, Harbin 150080, China.
³ RASA Center in Tomsk, Department of Experimental Physics, National Research Tomsk Polytechnic University , Tomsk 634050, Russia.
⁴ Remote Controlled Theranostic Systems Lab, Educational Research Institute of Nanostructures and Biosystem, Saratov State University , 83 Astrakhanskaya Street, Saratov 410012, Russia.

PMID: 28452456
DOI: 10.1021/acsami.7b03451

Abstract

Efficient depot systems for entrapment and storage of small water-soluble molecules are of high demand for wide variety of applications ranging from implant based drug delivery in medicine and catalysis in chemical processes to anticorrosive systems in industry where surface-mediated active component delivery is required on a time and site specific manner. This work reports the fabrication of individually sealed hollow-structured polyelectrolyte multilayer (PEM) microchamber arrays based on layer-by-layer self-assembly as scaffolds and microcontact printing. These PEM chambers are composed out of biocompatible polyelectrolytes and sealed by a monolayer of hydrophobic biocompatible and biodegradable polylactic acid (PLA). Coating the chambers with hydrophobic PLA allows for entrapment of a microair-bubble in each chamber that seals and hence drastically reduces the PEM permeability. PLA@PEM microchambers are proven to enable prolonged subaqueous storage of small hydrophilic salts and molecules such as crystalline NaCl, doxicycline, and fluorescent dye rhodamine B. The presented microchambers are able to entrap air bubbles and demonstrate a novel strategy for entrapment, storage, and protection of micropackaged water-soluble substances in precipitated form. These chambers allow triggered release as demonstrated by ultrasound responsiveness of the chambers. Low-frequency ultrasound exposure is utilized for microchamber opening and payload release.

Keywords: air bubble entrapment; controlled release; hydrophobization; polyelectrolyte multilayer; small hydrophilic molecules; stimuli responsive; ultrasound.