Encapsulation of parathyroid cells in hollow fibers: a preliminary report

The purpose of experiments was to evaluate the survival and functioning of human parathyroid cells after encapsulation in hollow fibers (HFs). The polypropylene HFs K600(PP Accurel (Akzo-Nobel, Germany) of inner diameter 0.6 mm, wall thickness 0.2 mm, original or surface modified were used for encapsulation. Production of parathormone (PTH) by encapsulated cells was measured in vitro. HF were filled with parathyroid cell suspension and tightly closed. Encapsulated cells were cultured for 9 or 33 days in RPMI 1640 containing 10% FCS or in Chang's medium. The level of PTH, produced by encapsulated cells was evaluated in the culture medium with radioimmunoassay test (RIA). The assays were performed every 2-4 days. The result of PTH assay was similar in both types of tested media as well as with unmodified and modified HFs, being 2-4 pg/ml of culture medium per 10(3) encapsulated cells. In conclusion, encapsulation in original or modified HFs ensures diffusion of nutrients from culture medium to encapsulated cells and allows for functioning of cells for at least 33 days in vitro.