Fig. 6.
Chitosan nanoparticle in vivo uptake. Fluorescence microscopy of ocular surface structures of sham-treated (A, D), CSNP-treated (B, E), and contralateral control (C, F) rabbit eyes. Representative corneal (A–C) and conjunctival (D–F) sections are shown. No fluorescence was detected in sham control corneas (A) or conjunctivas (D). (B) Corneal epithelial cells of CSNP-treated rabbits were uniformly fluorescent. (B, inset): enlargement showing a detail of corneal epithelial fluorescence pattern. (E) Fluorescence in conjunctival epithelial cells was intense in apical cell membranes and positive along the basolateral cell membrane. (E, inset) Enlargement showing the basolateral membrane fluorescence staining in goblet and non–goblet cells. (C, F) Some fluorescence was detected in corneal and conjunctival epithelial cells from contralateral control eye (OS), although much less intense than in the treated (OD) eye. Scale bar (A–F) 50 μm; insets: 10 μm). The in vivo uptake by conjunctival and corneal epithelia was confirmed from these fluorescence microscopy images of eyeball and lids sections confirmed. [Reprinted from De Salamanca, Amalia Enrique, et al. “Chitosan nanoparticles as a potential drug delivery system for the ocular surface: toxicity, uptake mechanism and in vivo tolerance.” Investigative ophthalmology & visual science 47.4 (2006): 1416–1425. Copyright © Association for Research in Vision and Ophthalmology.]