Stability of Growth Factors in Autologous Serum Eyedrops After Long-Term Storage

Abstract

Purpose: The purpose of this study is to assess the stability of the growth factors (GF) in autologous serum eyedrops under different storage conditions.

Methods: The concentration of epidermal growth factor (EGF), transforming growth factor-β (TGF-β1), platelet-derived growth factor AB (PDGF-AB), and albumin was measured in fresh and defrosted samples of autologous serum under different storage conditions. The fresh and defrosted samples were cooled at 4 °C, and they were studied immediately after preparation, or after defrosting, and after 1, 2, 3, and 4 weeks. The concentration of GF was also assessed after 1, 3, 6, and 9 months at −20 °C. We also investigated how the different storage conditions influence the biological effects of autologous serum on conjunctival and corneal cell cultures.

Results: The concentration of EGF, TGF-β1, PDGF-AB, and albumin remained stable over the 4 weeks at 4 °C, both in fresh and in defrosted samples. Likewise, no statistically significant differences were found between the GF concentration in fresh samples and after 1, 3, 6, and 9 months of freezing at −20 °C. Moreover, no differences were found on the cell proliferation and differentiation between cultured cells with fresh or defrosted samples after 4 weeks at 4 °C or after 1, 3, 6, or 9 months at −20 °C.

Conclusions: Long-term storage of autologous serum eyedrops at −20 °C does not affect the concentration of GF, simplifies clinical logistics, and reduces the frequency of blood extractions from the patients.

• Autologous serum eyedrops
• conjunctival culture cells
• corneal culture cells
• epitheliotrophic growth factors
• long-term storage
• sodium hyaluronate

Declaration of interest

All authors have contributed to the research and article preparation and they have approved the final version of this work.

This paper was partly funded with the help of the Carlos III Health Institute (Madrid, Spain) and the Mutua Madrileña Foundation (Madrid, Spain). The funding organization had no role in the design or conduct of this research. The authors have no proprietary or commercial interests in any concept or product discussed in this article.