Microencapsulation of human parathyroid cells: an "in vitro" study.

BACKGROUND

Patients affected by hypoparathyroidism of variable etiology are currently treated with exogenously administered vitamin D and calcium. Human parathyroid transplantation has long been investigated as a possible mean of treating these patients to prevent long-term hypocalcemia. However, the main obstacle for this treatment is represented by tissue rejection. A reliable method to efficiently protect the transplanted tissue from rejection and to allow long-term survival of the graft is the encapsulation of tissues or cells in alginate-polylysine-alginate membranes, which were successfully used for encapsulation of islets of Langerhans. The microencapsulation of parathyroid tissue fragments or of parathyroid cells becomes, therefore, a potential approach for the successful treatment of permanent symptomatic hypoparathyroidism without pharmacological immunosuppression.

MATERIALS AND METHODS

We describe microencapsulation of differentiated human parathyroid cells derived from adenoma or hyperplastic glands. Long-term viability, cell growth, and parathyroid hormone production of microencapsulated cells were evaluated together with responsiveness to extracellular Ca(2+).

RESULTS

Microencapsulated parathyroid cells maintained proliferative and differentiative properties for a long term in culture with a good response to extracellular Ca(2+) concentration.

CONCLUSIONS

These findings represent a crucial step toward the construction of functional bioartificial parathyroid organoids for the treatment of hypoparathyroidism in humans.