Microencapsulation of porcine thyroid cell organoids within a polymer microcapsule construct.

Hypothyroidism is a common condition of hormone deficiency, and oral administration of thyroid hormones is currently the only available treatment option. However, there are some disadvantages with this treatment modality including compliance challenges to patients. Therefore, a physiologically based alternative therapy for hypothyroidism with little or no side-effects is needed. In this study, we have developed a method for microencapsulating porcine thyroid cells as a thyroid hormone replacement approach. The hybrid wall of the polymer microcapsules permits thyroid hormone release while preventing immunoglobulin antibodies from entry. This strategy could potentially enable implantation of the microcapsule organoids containing allogeneic or xenogeneic thyroid cells to secret hormones over time without the need for immunosuppression of recipients. Porcine thyroid cells were isolated and encapsulated in alginate-poly-L-ornithine-alginate microcapsules using a microfluidic device. The porcine thyroid cells formed three-dimensional follicular spheres in the microcapsules with decent cell viability and proliferation. Thyroxine release from the encapsulated cells was higher than from unencapsulated cells ( P < 0.05) and was maintained during the entire duration of experiment (>28 days). These results suggest that the microencapsulated thyroid cell organoids may have the potential to be used for therapy and/or drug screening.