To analyze whether plasma rich in growth factors (PRGFs) eye drops preserve their activity and biological properties after storage for 9 and 12 months at −20°C, and at 4°C, and at room temperature (RT) for 3 and 7 days in comparison to fresh samples (t0).
PRGF eye drops were obtained from 6 healthy donors. Then, they were stored for 9 and 12 months at −20°C. At each time, different PRGF eye drops samples were thawed and maintained at RT or at 4°C for 3 and 7 days. Platelet-derived growth factor-AB, epidermal growth factor, transforming growth factor-β1, vascular endothelial growth factor, angiopoietin-1, and thrombospondin-1 were analyzed at each time and temperature of storage. In addition, the pH level, the microbial contamination, and the proliferative potential on primary human corneal stromal fibroblasts human keratocytes of each obtained PRGF eye drops were also evaluated.
All growth factor levels were preserved at each time and storage condition. No differences were observed on the human keratocytes proliferation after treatment with PRGF eye drops at any studied time or temperature. No microbial contamination was observed in any of the PRGF eye drops. Finally, the pH levels increased significantly after 9 and 12 months of storage at −20°C compared with t0.
PRGF eye drops can be stored for up to 12 months without reduction of the main growth factors and proteins and without any microbial contamination. Furthermore, the biological activity of the PRGF eye drops is maintained after storing for 3 and 7 days at 4°C or at RT.