Abstract
Purpose :
The supposed toxicity in patients of a perfluoro-n-octane (PFO; Alaocta®, Ala Medics®, Germany) originated a sanitary alert in Spain. This PFO had been considered non-toxic by routine in vitro cytotoxicity assays following UNE EN ISO 10993-5 and -12: 2009. Our proposal evaluates the acute cytoxicity of this sanitary product in an organotypic culture of porcine neuroretina.
Methods :
Neuroretina explants were obtained from fresh porcine eyes and exposed to suspected PFO (n=6) for 30 min. PFO were named according to the packing date (DD/MM/YY). Negative and positive controls were exposed to PFO from other manufacturers and to phenol (1.6 mg/ml), respectively. After exposure, explants were cultured for 72 hours. Unexposed controls were cultured in parallel. Each experiment was performed in triplicate. Samples were processed for epoxy resin embedding. Semithin sections (1μm) were stained with toluidine blue and evaluated by light microscopy. Subjective scoring of tissue/cell modifications was performed (grade 0 to 4). Numerical ranking greater than 2 is considered cytotoxic according to UNE EN ISO10993-5: 2009.
Results :
Fresh samples showed preserved neuroretina architecture with initial modifications (grade 0-1). Unexposed and negative controls presented partial loss of photoreceptor and incipient retina vacuolization (grade 1) at 72 hours of culture. Positive controls revealed total retina degeneration (grade 4). Neuroretina explants exposed to Ala Medics® PFO and cultured 72 hours showed different degenerative patterns: low (grade 2; PFO200114), mild (grade 3; PFO150414, PFO050514 and PFO070714), and severe (grade 4; PFO061014 and PFO171214).
Conclusions :
Ala Medics® PFO time-dependent cytoxicity (grade>2) has been confirmed in porcine neuroretina cultures. This study shows that ISO routine premarket methods used to detect PFO toxicity have failed, and proposes a suitable and more sensitive method to determine intravitreal medical devices potential toxicity.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.