FITC-horseradish peroxidase

Jain et al. (33) used the microemulsion system Triton X-100/cyclo-hexane/hexanol/water/ammonia to prepare silica nanoparticles with entrapped bioactive macromolecules fluorescein isothiocyanate-dextran (FITC-Dx) (mol. mass 19.6 kD), [125I]tyraminylinulin (mol. mass 5 kD), and horseradish peroxidase (HRP) (mol. mass 40 kD). The biomolecules were first solubilized in the microemulsion, and the alkoxide (TMOS) was then added. To ensure small particle sizes, the reaction was conducted under ice-cold temperatures (in a refrigerator for 72 h). 

Pitkanen et al. [51] reported the isolated bovine RPE-choroid was up to 20 times more permeable to lipophilic than hydrophilic beta-blockers. Furthermore, the in vitro permeability of bovine RPE-choroid to hydrophilic compounds and macromolecules was 10 to 100 times less compared to sclera, whereas the permeability for lipophilic molecules was in the same range for both tissues. The isolated bovine RPE-choroid also exhibited differential permeation by molecular weight and Stokes radius. The permeation rate of 4, 10, and 20 kDa FITC dextrans was moderate compared to a good permeation rate for the 376 Da carboxyfluor-escein and a poor penetration rate for 40 and 80 kDa FITC-dextrans. The permeability to carboxyfluorescein was 35 times more than to 80 kDa FITC-dextran [51]. In a study on the permeability of the human ciliary epithelium to a horseradish peroxidase, Tonjum and Pedersen [52] reported that ciliary and iridial epithelium contained a system of paracellular zonulae occludentes. Peroxidase was applied on the stromal side of ciliary body and iris specimens obtained from freshly enucleated eyes. The 40 kDa peroxidase was blocked apically in the lateral intercellular spaces of the CNPE whereas in the iris the progression of peroxidase was blocked apically in the lateral intercellular spaces of the IPE. Freddo [53] studied the intercellular junctions in the posterior IPE cells of the rhesus monkey by electron microscopy, freeze-fracture, and horseradish peroxidase. Intravenously injected horseradish... 

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