Scaffolds for parathyroid tissue engineering

Parathyroid glands are compact glandular bodies attached to the thyroid gland and have a major function of producing parathyroid hormone (PTH), which regulates calcium and phosphate homeostasis. Over- or underproduction of PTH leads to “hyperparathyroidism” or “hypoparathyroidism,” respectively; of the two, hypoparathyroidism occurs more frequently due to surgical/radiational operations for thyroid/laryngeal disorder. Hypoparathyroidism results in severe chronic hypocalcemia that is fatal to humans. A few therapeutic approaches, including lifetime intake of calcium and vitamin D, recombinant PTH injection, and autograft of parathyroid tissues, have been developed. Recently, the use of stem cell engineering using human embryonic stem cells and mesenchymal stem cells derived from adipocytes and particularly tonsils, in combination with scaffold systems, has become an appealing option, offering improved biocompatibility. This chapter overviews the new paradigm of parathyroid regeneration using stem cell engineering with scaffolds and its potential therapeutic applications in the treatment of hypoparathyroidism. Recent publication employing a scaffold-free system is also reviewed.