Purchase this article with an account.
Dirk de Korte, Jos Lorinser, Pieter van der Meer, Hans Van Der Heiden; Changes in Growth Factor Content of Human Serum for Use as Eye Drops during Frozen Storage for 1 Year. Invest. Ophthalmol. Vis. Sci. 2017;58(8):452.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Growth factors are thought to be among the active components in serum used for treatment of dry-eye syndrome. The purpose of this study is to demonstrate stability of growth factor content in human serum during long-time storage at -18°C or <-25 to >-35°C packed in a new micro dose device for single use as eye drops. If these single use products can be stored at -18°C it will be feasible to store this product in household freezers, making the product more user-friendly for patients in need of serum eye drops.
Serum produced from 500 mL whole blood donations from non-remunerated healthy donors was quickly frozen. After frozen storage at <-25°C for 3-12 months and controlled thawing, six different sera were used to fill a large number of small (140 µl) containers, which were refrozen and stored at either -180C or <-25°C. During storage at 3 months intervals, samples were tested for several growth factors, using Magpix® Luminex Multiplex assays and compared to control samples stored at <-80°C. Growth factors tested were PDGF-AA&AB/BB, TGF-ß1/2/3, VEGF, EGF, FGF2. The study was a fact-finding study, without preset acceptance criteria.
PDGF-AB/BB and TGF-ß1 were the most abundant growth factors, on average 35, resp. 40 ng/mL. Also PDGF-AA was detected at relatively high concentration in human serum, on average 11 ng/mL. TGF-ß2, EGF and VEGF were detected at relatively low values, resp. 3 ng/mL, 0.5 ng/mL and 0.3 ng/mL. Average levels of FGF2 and TGF-ß3 were close to detection limit (< 0.2 ng/mL). The controls stored at <-80°C showed for all growth factors close to 100 % of the initial values in fresh human serum samples at T=0. For serum stored at <-25°C for up to 12 months, less than 10% decrease was found for all tested growth factors. For serum stored at -18°C this 10 % decrease was reached after 6 months, after 12 months the decrease was 10-20%.
Human serum eye drops can be stored in the new micro dose device at -180C (household 3-star freezers) or <-25°C (professional freezers) for at least one year after preparation without large decreases in growth factor content. It is yet unknown if the tested components add to the in vivo effectiveness of serum eye drops and what the minimal concentration is to ensure in vivo effectiveness. Further stability testing in combination with in vitro and in vivo application is required to extend the shelf-life beyond 1 year.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
This PDF is available to Subscribers Only