We evaluated whether plasma rich in growth factors eye drops maintain their composition and biological activity after storage for 3 months at −20°C and after storage at 4°C or room temperature (RT) for 24 hours, compared with samples obtained at time 0 (fresh samples).
Blood from 10 healthy donors was collected, centrifuged, and plasma rich in growth factors was prepared by avoiding the collection of the buffy coat. Eye drops were kept fresh or were stored at −20°C for 15, 30, and 90 days. For each time, 2 aliquots were kept at RT or at 4°C for 24 hours. Osmolarity, vitamin A, fibronectin, platelet-derived growth factor-AB, vascular endothelial growth factor, epithelial growth factor, and transforming growth factor-β1 were quantified. The proliferative and migratory potential of the eye drops was assayed on primary human keratocytes.
Platelet-derived growth factor-AB, vascular endothelial growth factor, epithelial growth factor, and vitamin A levels remained constant for each time and for each storage condition, whereas fibronectin, transforming growth factor-β1, and osmolarity values were slightly modified after freezing. Cell proliferation and migration were significantly enhanced with the biological eye drops independently of the time and the storage condition. No microbial contamination was observed in any plasma rich in growth factors eye drops.
Plasma rich in growth factors eye drops can be stored for up to 3 months without any reduction of the main proteins involved in ocular surface healing. Their use during 24 hours either at 4°C or at RT did not alter the composition and the in vitro biological activity of the eye drops.