Abstract
Purpose::
The effect of autologous serum eye drops has been established in clinical trials. Serum supports proliferation and migration of corneal epithelial cells. The positive effect is thought to be due to growth factors, vitamins and other nutrients. Platelet releasate (PR) is a cell free solution produced from platelet concentrates (PC). It contains many growth factors at much higher concentrations than serum, e.g. EGF, PDGF or TGF-ß1. In-vitro, PR stimulates proliferation of corneal epithelial cells even better than serum eye drops but serum is superior in supporting migration. We tested mixtures of PR and serum (PR-serum) to investigate, if their wound healing properties are superior that of PR or serum alone.
Methods::
PC and serum (n = 10) were prepared according to a standardised protocol. Serum was diluted with PR to a final concentration of 100, 50, 25, 12.5, 6.25, 3.125 %. SV-40 immortalised human corneal epithelial cells were cultured in 6- and 96-well plates at 37°C, 5% CO2. Proliferation was quantified by means of a luminescence-based ATP-assay. Cell migration was assessed in a colony dispersion assay. In addition differentiation was documented by scanning electron microscopy.
Results::
After 6 h corneal epithelial cells incubated with serum diluted with PR to 12.5% or 6.25% supported proliferation significantly better than 100% PR or 100% serum alone. PR-Serum and pure serum had a similar and strong positive effect on migration, while no migration was observed with 100% PR. Epithelial cells were equally well differentiated when incubated with 25% PR-Serum or undiluted serum.
Conclusions::
Serum diluted with PR has a superior growth supporting effect on corneal epithelial cells than 100% serum or 100% PR alone. The beneficial effect of pure serum on cell migration was not reduced even if it was diluted with PR. The use of PR instead of sodium chloride solutions to dilute serum to the concentration of choice for eye drops may have potential advantages for eyes with persistent ocular surface disease.
Keywords: cornea: tears/tear film/dry eye • cornea: epithelium • wound healing