Hanks buffer salt solution

Ex vivo cultures were prepared according to published protocols (Amato et al., 2016 (link)). Briefly, retinas were dissected, cut into four fragments and transferred onto Millicell-CM culture inserts (Merck Millipore, Burlington, MA, United States) with ganglion cells up. The retinal explants were cultured in 1 mL of serum-free culture medium composed of 50% MEM/HEPES (Sigma Aldrich) containing 6 mM D-glucose, 25% Hank’s buffer salt solution (Sigma Aldrich) 25% PBS, 25 U/mL penicillin, 25 mg/mL streptomycin, 1 μg/mL amphotericin B, and 200 μM L-glutamine. The explants were incubated for 5 days at 37°C under a humidified 95%/5% (v/v) mixture of air and CO₂. OS treatment consisted in adding H₂O₂ to a final concentration of 100 μM. 1 μM OCT, 4.9 μg/mL MNPs, or 1 μM MNP-OCT were added to the culture medium. The medium was changed every other day. The dose-response experiment was performed by adding 1 μM, 0.1 μM, 0.01 μM, or 0.001 μM OCT or equivalent amounts of MNP-OCT to the culture medium. Retinal explants were then incubated for 3 days without changing the medium.