Format

Send to:

Choose Destination
See comment in PubMed Commons below
Biomaterials. 1996 Jun;17(11):1069-79.

Alginate polycation microcapsules. II. Some functional properties.

Author information

  • 1Norwegian Biopolymer Laboratory, Department of Biotechnology, Norwegian Institute of Technology, University of Trondheim, Norway.

Abstract

The main cause of alginate polycation capsule breakage under physiological conditions is probably the osmotic swelling of the alginate core owing to the Donnan equilibrium set up by the negative charges of the carboxyl groups not involved in cooperative binding of counterions in the junction zones of the network. In the present paper we show how capsules can be stabilized extensively by reducing their swelling capacity in various ways. Alginate polycation capsules with good chemical and mechanical stability have been made by controlling their swelling behaviour through selection of capsule material according to chemical structure and molecular weight, as well as by controlling the kinetics of the capsule formation. Stable capsules have been made either by increasing the strength of the polyanion-polycation membrane, or by keeping a low-swelling gel network in the core. The latter capsules are made from an alginate rich in guluronic acid both in the core and in an outer coating, and with anisotropic distribution of the polymer material in the core where the concentration at the surface is higher than that in the centre of the capsule. Some functional properties of these capsules, such as porosity, have also been studied.

PMID:
8718966
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk