Self-assembly of carboxymethyl konjac glucomannan-g-poly(ethylene glycol) and (α-cyclodextrin) to biocompatible hollow nanospheres for glucose oxidase encapsulation

The self-assembly of rod-coil carboxymethyl konjac glucomannan-graft-poly(ethylene glycol) (CKGM-g-PEG) and alpha-cyclodextrin (alpha-CD) complexes were investigated and used as encapsulating hollow nanospheres for the enzyme glucose oxidase (GOX) in aqueous solution. These hollow nanospheres exhibited cell-like semi-permeability allowing enzyme substrates to pass through the surface while restricting the encapsulated enzyme (i.e. GOX) to the interior. Encapsulated GOX exhibited higher thermostability, optimal enzymatic activity over a wider pH range and improved storage stability in comparison to free un-encapsulated GOX. In addition, these CKGM-g-PEG/alpha-CD hollow nanospheres showed in vitro biocompatibility when exposed to L929 cells when tested using MIT viability assay. These studies suggested that self-assembly of CKGM-g-PEG and alpha-CD to form stable nanospheres may be an effective method for enzyme encapsulation with numerous biomedical applications. (C) 2011 Elsevier Ltd. All rights reserved.