title: Microencapsulation of human parathyroid cells: an "in vitro" study.
abstract: 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.
  
  
  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.
authors.affiliation: Surgery Unit, Department of Clinical Physiopathology, University of Florence, 50139 Florence, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Picariello
authors.forename: S
authors.initials: S
authors.lastname: Benvenuti
authors.forename: R
authors.initials: R
authors.lastname: Recenti
authors.forename: L
authors.initials: L
authors.lastname: Formigli
authors.forename: A
authors.initials: A
authors.lastname: Falchetti
authors.forename: A
authors.initials: A
authors.lastname: Morelli
authors.forename: L
authors.initials: L
authors.lastname: Masi
authors.forename: F
authors.initials: F
authors.lastname: Tonelli
authors.forename: P
authors.initials: P
authors.lastname: Cicchi
authors.forename: M L
authors.initials: ML
authors.lastname: Brandi
mesh_terms: D000236:Adenoma; D002122:Calcium Chloride / Q000494:pharmacology; D002455:Cell Division; D002470:Cell Survival; D017690:Cell Transplantation / Q000379:methods; D015925:Cryopreservation; D004058:Diffusion; D004339:Drug Compounding / Q000379:methods*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000637:transplantation; D006801:Humans; D007011:Hypoparathyroidism / Q000628:therapy*; D066298:In Vitro Techniques; D010280:Parathyroid Glands / Q000166:cytology* / Q000637:transplantation*; D010281:Parathyroid Hormone / Q000378:metabolism; D010282:Parathyroid Neoplasms; D014407:Tumor Cells, Cultured
chemical_list: D010281:Parathyroid Hormone; D002122:Calcium Chloride