Astrocyte growth and glial cell line-derived neurotrophic factor secretion in three-dimensional polyethylene terephthalate fibrous matrices

The ability of human astrocytes grown in nonwoven fibrous matrices to produce glial cell line-derived neurotrophic factor (GDNF) was studied. GDNF has the ability to selectively nourish and regenerate dopaminergic neurons and thus can provide a new treatment of Parkinson's disease. Compressed polyethylene terephthalate (PET) fabrics (porosity, 88.8%; mean pore diameter, 64 microm), treated with boiling NaOH, was effective in supporting high-density growth of astrocytes with stable GDNF production over the entire period of 18 days studied. Treatment of PET with NaOH renders the fiber surface more hydrophilic, thereby facilitating attachment and spreading of cells, whereas matrix compression allows cells to grow along and also between the fibers of these matrices to a higher density. The average production of GDNF by cells grown in these matrices (approximately 2 cm in diameter) was 21.7 pg/mL x day, with an average high concentration of 64.6 pg/mL, which is well above the effective concentration of 40 pg/mL. This work shows promise in culturing astrocytes in PET matrices as the first step in developing a potential implantable tissue-engineering device for treating patients with Parkinson's disease.