abstract |
A stable cross-linked alginate gel such as in the form of alginate gel beads encapsulating transplant materials is produced by binding surplus multivalent cations remaining after cross-linking alginate with the cations. A cross-linked alginate gel containing the surplus cations is contacted with a solution of multivalent anions such as sodium sulfate solution to bind the surplus cations. Preferably, a dehydration preventing agent such as protein, bone powder or implant substances is present during cross-linking. A hydrophobic substance such as a perfluoro hydrocarbon or an emulsion may be present during cross-linking to fill spaces between alginate chains. Alginate gel beads produced by the process have long term stability after transplanting. |