Cationic and biocompatible mucoadhesive CDNs have been developed for sustained drug delivery to the ocular surface. The CDNs were stable to lysozyme and showed prolonged adherence to the corneal surface.

No abstract

Objective: Sulforhodamine B (SRB) is a hydrophilic tracer whose fluorescence is unaffected by pH unlike that of carboxyfluorescein. Therefore, SRB may serve as a better tracer when there are significant changes in pH. Thus, in this study, the suitability of SRB to assess the barrier properties of the cellular layers of the cornea was examined using a custom-built confocal scanning micro-fluorometer (CSMF). Methods:The dye solution (0.1% SRB) was prepared in PBS-Ca 2+ Results: SRB penetrated the corneal endothelium readily into the stroma following injection into the anterior chamber in a time-dependent manner. Despite accumulation in the stroma, SRB did not partition into the epithelium. In agreement with these findings, the dye did not cross the epithelium after topical administration. Co-administration with Tween 20 and injury to the epithelium with microneedles, however, led to penetration of the dye into the stroma. and three experiments were performed ex vivo using freshly isolated porcine eyes. First, we investigated the penetration of SRB across the endothelium by injection of the dye into the anterior chamber. Next, we measured the penetration of SRB across the epithelium after exposing the ocular surface to the dye. Finally, we examined the penetration after exposure to the dye with detergent (Tween 20) and exposure to the dye concomitant with microneedle injuries. The dye concentration profiles across the cornea were measured using CSMF.Conclusions: SRB is a hydrophilic dye that can be used as an alternative fluorescent tracer to assess the barrier function of the cellular layers of the cornea.

No abstract

No abstract