Delivery of 9-Cis retinal to photoreceptors from bovine serum albumin.

Retinoids are labile compounds with less than micromolar solubility in aqueous solutions. They are normally associated with a carrier protein, interphotoreceptor retinoid binding protein, in the interstitial spaces of the retina. In the past, experimental retinoids have been delivered to isolated retinas and photoreceptors using either unprotected ethanolic suspensions or phospholipid vesicles that protect but require burdensome preparation. The objective of these experiments was to characterize the protection of retinoids and their delivery to isolated photoreceptor cells at high concentrations using fatty-acid-free bovine serum albumin (BSA) as a convenient vehicle and protectant. Our results confirm that BSA is a useful protectant and vehicle for delivery of retinoids to isolated retinas and photoreceptors.