title: Preservation of Biological Activity of Plasma and Platelet-Derived Eye Drops After Their Different Time and Temperature Conditions of Storage.
abstract: OBJECTIVE
  To analyze whether plasma rich in growth factors (PRGF) eye drops preserve their biological characteristics and activity after storage for 3 and 6 months at -20°C, at 4°C, and at room temperature for 72 hours, compared with fresh samples (t0).
  
  
  METHODS
  Blood from 6 healthy donors was harvested and centrifuged to obtain PRGF free of leukocytes. Resulting PRGF eye drops were stored for 3 and 6 months at -20°C. At each time, 2 aliquots were maintained at room temperature or at 4°C for 72 hours. Platelet-derived growth factor-AB, transforming growth factor-β1, vascular endothelial growth factor, epidermal growth factor, insulin-like growth factor-1, angiopoietin-1, and thrombospondin-1 were quantified at each time and temperature of storage. Also, the effect of PRGF eye drops on proliferation of primary human keratocytes was evaluated.
  
  
  RESULTS
  All the analyzed growth factor levels remained constant at each time and storage condition. No differences were observed in the proliferative activity of keratocytes after treatment with PRGF eye drops at any studied time or temperature. Finally, there was no microbial contamination in any of the PRGF eye drops.
  
  
  CONCLUSIONS
  The preservation of the PRGF eye drops at -20°C for up to 3 and 6 months does not mean reduction of the main growth factors and proteins implicated in ocular surface wound healing. Eye drop characteristics and in vitro biological activity were not affected by their usage and conservation for 72 hours at 4°C or at room temperature.
authors.affiliation: *Fundación Eduardo Anitua, Vitoria, Spain; †BTI Biotechnology Institute, Vitoria, Spain; and ‡Fundación de Investigación Oftalmológica, Instituto Oftalmológico Fernández-Vega, Oviedo, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Anitua
authors.forename: María
authors.initials: M
authors.lastname: de la Fuente
authors.forename: Ana
authors.initials: A
authors.lastname: Riestra
authors.forename: Jesús
authors.initials: J
authors.lastname: Merayo-Lloves
authors.forename: Francisco
authors.initials: F
authors.lastname: Muruzábal
authors.forename: Gorka
authors.initials: G
authors.lastname: Orive
mesh_terms: D000328:Adult; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism; D001782:Blood Donors; D049109:Cell Proliferation / Q000502:physiology; D002478:Cells, Cultured; D060527:Corneal Keratocytes / Q000187:drug effects / Q000378:metabolism; D015925:Cryopreservation; D004355:Drug Stability; D004356:Drug Storage; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008875:Middle Aged; D009883:Ophthalmic Solutions; D010949:Plasma / Q000737:chemistry* / Q000502:physiology; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D053657:Platelet-Rich Plasma / Q000737:chemistry* / Q000502:physiology; D012259:Ribonuclease, Pancreatic / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C583557:IGF1 protein, human; D009883:Ophthalmic Solutions; D010982:Platelet-Derived Growth Factor; C481348:SPZ1 protein, human; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A; C095477:platelet-derived growth factor AB; D007334:Insulin-Like Growth Factor I; C046366:angiogenin; D012259:Ribonuclease, Pancreatic