Abstract
Purpose:
We evaluated whether plasma rich in growth factors (PRGF) eye drops maintain their composition and biological activity after storage of 3 months at -20 0C and then maintaining the eye drops for 72 hours either at 40C or room temperature.
Methods:
Eye drops were obtained using the Endoret (PRGF) Ophthalmology kit (BTI Biotechnology Institute, S.L., Vitoria, Spain). Briefly, after informed consent was obtained, blood was collected from eight healthy donors into 9 mL tubes. Blood was centrifuged at 580g for 8 minutes, whole plasma column was drawn off avoiding the buffy coat, and incubated at 37 0C for one hour, and finally, the released supernatants were collected by aspiration, filtered and aliquoted. Eye-drops were kept fresh or stored at -20 0C for 3 months. After 3 months of storage, two aliquots were kept at room temperature or at 4 0C for 72 hours. EGF, PDGF-AB, VEGF, TGF-β1, Angiopoietin and Thrombospondin-1 were quantified in each type of eye-drop. Proliferative potential of each eye drop was assayed on primary human keratocytes.
Results:
All growth factors and proteins levels analyzed in this study remained constant at each time and storage condition. In addition, no differences were observed in the proliferative activity of keratocytes after treatment with the eye-drops at any time or temperature. No microbial contamination was observed in any of the eye-drops.
Conclusions:
Protein composition and biological activity of the PRGF-Endoret eye drops were preserved in all the protocols evaluated. No contamination was observed in any of the cases. Thus, we recommend a dosage of one dispenser for 72h at room temperature for a final treatment of 3 months.