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Microgel‐Based Engineered Nanostructures and Their Applicability with Template‐Directed Layer‐by‐Layer Polyelectrolyte Assembly in Protein Encapsulation
Author(s) -
Shenoy Dinesh B.,
Sukhorukov Gleb B.
Publication year - 2005
Publication title -
macromolecular bioscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.924
H-Index - 105
eISSN - 1616-5195
pISSN - 1616-5187
DOI - 10.1002/mabi.200400180
Subject(s) - polyelectrolyte , polymer , scanning electron microscope , materials science , layer by layer , chemical engineering , biopolymer , nanotechnology , layer (electronics) , composite material , engineering
Summary: A novel strategy for the fabrication of microcapsules is elaborated by employing biomacromolecules and a dissolvable template. Calcium carbonate (CaCO 3 ) microparticles were used as sacrificial templates for the two‐step deposition of polyelectrolyte coatings by surface controlled precipitation (SCP) followed by the layer‐by‐layer (LbL) adsorption technique to form capsule shells. When sodium alginate was used for inner shell assembly, template decomposition with an acid resulted in simultaneous formation of microgel‐like structures due to calcium ion‐induced gelation. An extraction of the calcium after further LbL treatment resulted in microcapsules filled with the biopolymer. The hollow as well as the polymer‐filled polyelectrolyte capsules were characterized using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and scanning force microscopy (SFM). The results demonstrated multiple functionalities of the CaCO 3 core – as supporting template, porous core for increased polymer accommodation/immobilization, and as a source of shell‐hardening material. The LbL treatment of the core‐inner shell assembly resulted in further surface stabilization of the capsule wall and supplementation of a nanostructured diffusion barrier for encapsulated material. The polymer forming the inner shell governs the chemistry of the capsule interior and could be engineered to obtain a matrix for protein/drug encapsulation or immobilization. The outer shell could be used to precisely tune the properties of the capsule wall and exterior.Confocal laser scanning microscopy (CLSM) image of microcapsules (insert is after treating with rhodamine 6G to stain the capsule wall).