0000000000402234
AUTHOR
M. Laudes
Improved yield and functionality of parathyroid cells separated by using collagenase-digestion with cold pre-incubation.
Preparation of cells from solid organs often induces a functional impairment due to the proteolytic cell damage by the applied digestive enzyme like collagenase, trypsin or dispase. To preserve the tissue and to enhance the yield of cells, Laue et al. reported an islet cell isolation with pre-incubation at 4 C permitting the enzyme to diffuse into the tissue and explicite activity equally throughout the whole particle. The aim of this study was to investigate whether this procedure can be applied to parathyroid glands. Therefore porcine parathyroid glands were dissected into 1 mm3 pieces. Subsequently one group of these pieces was incubated 22 h at 4 C in 2 mg/ml collagenase before activati…
Xenotransplantation of parathyroids in rats using barium-alginate and polyacrylic acid multilayer microcapsules
The integrity and function of encapsulated parathyroid tissue following xenotransplantation is limited by oxygen and nutrition supply and capsule fibrosis. Since some of these factors depend on stability and biocompatibility of the coating material, multilayer microcapsules have been developed. Parathyroid tissue pieces and digested single cells from pigs were encapsulated in barium-alginate and in polyacrylic acid (PAA) multilayer capsules. After 7 days of culture the function of the encapsulated cells were assessed. Subsequently, in a part of the cultured microcapsules the viability was directly assessed whereas the other part was transplanted in dark animal [DA] rats for 30 days. After e…
Effect of media composition on long-term in vitro stability of barium alginate and polyacrylic acid multilayer microcapsules.
For a number of applications stability of microcapsules is a critical factor. Since the maintenance of polyelectrolyte complexes depends considerably on the ion composition we tested the physical properties of barium alginate capsules and searched for conditions to improve stability by a multilayer coating with polyethylenimine (PEI) and polyacrylic acid (PAA). Mechanical stability and diameters were determined in barium alginate capsules and compared with multilayer capsules. Multilayer coating resulted in smaller capsules than barium complexing alone. The difference was more pronounced when CaCl2 was used instead of NaCl during coating. Barium alginate capsules and application of CaCl2 du…