Hollow Microcapsules Through Layer-by-Layer Self-Assembly of Chitosan/Alginate on E. coli
- PDF / 473,966 Bytes
- 7 Pages / 432 x 648 pts Page_size
- 93 Downloads / 163 Views
MRS Advances © 2020 Materials Research Society DOI: 10.1557/adv.2020.261
Hollow Microcapsules Through Layer-byLayer Self-Assembly of Chitosan/Alginate on E. Coli Michael Y. Yitayew1 and Maryam Tabrizian1,2 1
Department of Biomedical Engineering, McGill University, 3775 Rue University, Montreal, QC H3A 2B4 Canada
2
Faculty of Dentistry, McGill University, 2001 Avenue McGill College, Montreal, QC H3A 1G1 Canada
ABSTRACT
Hollow microcapsules prepared via layer-by-layer (LbL) self-assembled polyelectrolytes are prevalent biomaterials in the synthesis of biocompatible delivery systems for drugs, imaging probes, and other macromolecules to control biodistribution and lower toxicity in vivo. The use of LbL self-assembly for the synthesis of these capsules provides several benefits including ease of fabrication, abundance in choice of substrates and coating material, as well as application-specific tunability. This study explores the development of hollow microcapsules by LbL assembly of chitosan and alginate onto live E. coli cells, and also provides a proof-of-concept of this capsule as a delivery platform through the encapsulation of quantum dots as a cargo. The study found that robust bilayers of chitosan/alginate can be formed onto the core substrate (E. coli) containing quantum dots as demonstrated with zeta potential analysis. Confocal microscopy was used to verify cell viability and the internalization of quantum dots into the cells as well as confirmation of the coating using fluorescein-labelled chitosan. Furthermore, transmission electron microscopy (TEM) was used to analyse cells coated with four-bilayers and showed a uniform coating morphology with a capsule thickness of 10-20 nm, which increased to 2050 nm for hollow capsules after cell lysis. Quantum dot retention in the capsules was demonstrated using fluorescence measurements. Overall, the study shows promising results of a novel fabrication method for hollow microcapsules that uses biocompatible 1
Downloaded from https://www.cambridge.org/core. Macquarie University, on 30 May 2020 at 04:28:10, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1557/adv.2020.261
polymers and mild core dissolution conditions using cell templates with applications in sustained release of therapeutics and imaging probes.
INTRODUCTION The synthesis of hollow microcapsules has been of great interest in the development of new delivery systems as a result of their ability to encapsulate and mediate controlled release of a wide-variety of drugs, nanoparticles, and other macromolecules [1]. Their use became prominent due to their capacity to incorporate polar molecules with improved stability and permeability compared to liposomes [2]. The most established method to fabricate such capsules uses inorganic substrates such as calcium carbonate, silica, or polystyrene microspheres as a template for polymer encapsulation. Hollow capsules are formed through dissolution and removal of the template using excess chelat
Data Loading...
