Premium
Immunoisolation of transplants by entrapment in 19 F‐labelled alginate gels: production, biocompatibility, stability, and long‐term monitoring of functional integrity
Author(s) -
Hillgärtner M.,
Zimmermann H.,
Mimietz S.,
Jork A.,
Thürmer F.,
Schneider H.,
Nöth U.,
Hasse C.,
Haase A.,
Fuhr G.,
Rothmund M.,
Zimmermann U.
Publication year - 1999
Publication title -
materialwissenschaft und werkstofftechnik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.285
H-Index - 38
eISSN - 1521-4052
pISSN - 0933-5137
DOI - 10.1002/(sici)1521-4052(199912)30:12<783::aid-mawe783>3.0.co;2-#
Subject(s) - biocompatibility , chemistry , biocompatible material , biomedical engineering , transplantation , nanotechnology , biophysics , materials science , surgery , medicine , biology , organic chemistry
Transplantation studies with immunoisolated foreign cells / tissues (encapsulated in Ba 2+ ‐cross‐linked alginate) show that several obligatory requirements have to be met before this immunoisolation technique can be used for routine clinical trials. We present chemical procedures and technical developments which could address and solve the current problems and limitations of the microencapsulation technique. Large‐scale production of highly purified (biocompatible) alginate is possible and this material does not evoke any foreign body reactions under implantation conditions. Atomic force microscopy (AFM) studies suggest that geometric inhomogeneities may lead to immunological reactivity of the cross‐linked alginate. Material traces released from fibroblasts, macrophages and / or lymphocytes migrating over surfaces can also be studied by AFM and may initiate the primary foreign body reactions. Long‐term stability of the alginate beads can be improved by incorporating proteins or (medically approved) perfluorocarbons during the cross‐linking process and by subsequent treatment with 6 mM sulphate. Long‐term stability and local oxygen supply can be monitored in vivo using non‐invasive 19 F‐nuclear magnetic resonance imaging (MRI) of perfluorocarbon‐loaded alginate beads. These improvements and developments allow clinical trials with allogenic (and xenogenic) tissue by alginate immunoisolation.