Premium
Binding and leakage of barium in alginate microbeads
Author(s) -
Mørch Yrr A.,
Qi Meirigeng,
Gundersen Per Ole M.,
Formo Kjetil,
Lacik Igor,
SkjåkBræk Gudmund,
Oberholzer Jose,
Strand Berit L.
Publication year - 2012
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.34237
Subject(s) - barium , materials science , divalent , calcium , leakage (economics) , calcium alginate , radiochemistry , nuclear chemistry , chemistry , metallurgy , economics , macroeconomics
Abstract Microbeads of alginate crosslinked with Ca 2+ and/or Ba 2+ are popular matrices in cell‐based therapy. The aim of this study was to quantify the binding of barium in alginate microbeads and its leakage under in vitro and accumulation under in vivo conditions. Low concentrations of barium (1 m M ) in combination with calcium (50 m M ) and high concentrations of barium (20 m M ) in gelling solutions were used for preparation of microbeads made of high‐G and high‐M alginates. High‐G microbeads accumulated barium from gelling solution and contained higher concentrations of divalent ions for both low‐ and high‐Ba exposure compared with high‐G microbeads exposed to calcium solely and to high‐M microbeads for all gelling conditions. Although most of the unbound divalent ions were removed during the wash and culture steps, leakage of barium was still detected during storage. Barium accumulation in blood and femur bone of mice implanted with high‐G beads was found to be dose‐dependent. Estimated barium leakage relevant to transplantation to diabetic patients with islets in alginate microbeads showed that the leakage was 2.5 times lower than the tolerable intake value given by WHO for high‐G microbeads made using low barium concentration. The similar estimate gave 1.5 times higher than is the tolerable intake value for the high‐G microbeads made using high barium concentration. To reduce the risk of barium accumulation that may be of safety concern, the microbeads made of high‐G alginate gelled with a combination of calcium and low concentration of barium ions is recommended for islet transplantation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:2939–2947, 2012.