New principle for large-scale preparation of purified human pancreas islets.

Because successful human islet transplantation requires large quantities of viable islets that must be separated from the highly immunogenic exocrine tissue and because handpicking is too time-consuming and laborious to be clinically relevant, a new approach for solving this problem has been established in rat models. It is based on the principle that magnetic microspheres (MMSs) coupled to lectins with binding specificity for the exocrine tissue portion are trapped in an electromagnetic field, thus providing effluent islets of a high degree of purity. In this study our aim was to adapt this principle to human islet preparations. In this context our prime interest was focused on a lectin suitable for human pancreatic tissue. Of 19 different lectins tested, only 1, Wisteria floribunda agglutinin (WFA), is suitable, as shown by immunofluorescence, MMS-lectin binding, and magnetic separation.