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Using a Laminating Technique to Perform Confocal Microscopy of the Human Sclera
Published on: May 6, 2016
Diffusion of macromolecules through sclera.
Heng Miao1, Bi-Dong Wu, Yong Tao
1Department of Ophthalmology, People's Hospital, Peking University, Beijing, China.
Acta Ophthalmologica
|September 25, 2012
Summary
Porcine sclera permeability to macromolecules is lower in thicker posterior regions. Permeability decreases with increasing molecular weight and scleral thickness, impacting drug delivery.
Area of Science:
- Ocular Pharmacology
- Biomaterials Science
- Drug Delivery Systems
Background:
- The sclera, a crucial outer layer of the eye, presents a significant barrier to drug delivery.
- Understanding scleral permeability is vital for developing effective transscleral drug delivery strategies.
Purpose of the Study:
- To quantify the in vitro permeability coefficient of porcine sclera to macromolecules.
- To investigate how topographical location and molecular weight influence scleral permeability.
Main Methods:
- Porcine sclera from equatorial and posterior regions was used in a two-chamber diffusion apparatus.
- Permeability to fluorescein isothiocyanate (FITC)-conjugated dextrans (40-150 kDa) was measured using fluorescence spectrophotometry.
- Scleral thickness and macromolecule surface enrichment were analyzed via microscopy.
Main Results:
- Scleral permeability coefficient (Pc) was significantly higher in the equatorial region compared to the posterior region.
- A significant negative relationship was observed between Pc and scleral thickness for all tested molecular weights.
- Permeability decreased significantly with increasing macromolecule molecular weight, with larger molecules accumulating on the scleral surface.
Conclusions:
- Scleral permeability is inversely related to scleral thickness and the molecular weight of macromolecules.
- Topographical variations in scleral thickness influence permeability, with potential pharmacokinetic implications for transscleral drug delivery.
- Macromolecule accumulation on the scleral surface increases with molecular size.
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