Contact lenses co-releasing dexamethasone and the cell-penetrating peptide penetratin significantly increased drug levels in the cornea and aqueous humor compared to drug-only lenses in rabbits.
Significant increasein corneal and aqueous humor drug levels with penetratin co-delivery vs drug-only lenses
What the researchers found
Co-delivery of dexamethasone with penetratin from contact lenses significantly increased drug concentrations in the cornea and aqueous humor after 6 hours of wear in rabbits.
Why it matters
Getting drugs past the eye's tissue barriers to treat conditions like macular degeneration or uveitis is a major clinical challenge. Cell-penetrating peptides in contact lenses could offer a non-invasive alternative to eye injections.
The numbers in context
Co-released dexamethasone sodium phosphate and penetratin (cell-penetrating peptide) from contact lens platform.
How the study worked
Development and characterization of HEMA-based hydrogel contact lenses functionalized with AAc and/or APMA, with in vitro release kinetics, biocompatibility testing, and in vivo ocular distribution in rabbits after 6 hours of CL wearing.
Who was studied
In vitro ocular tissue permeation models
What this study cannot tell us
Rabbit eye model may not fully predict human ocular drug distribution; only one drug-peptide combination tested; long-term safety of repeated penetratin exposure to ocular tissues unknown; posterior segment drug levels not specifically measured; small animal study.
How to read the evidence
Preliminary preclinical evidence from a rabbit model. Well-designed study with in vitro and in vivo validation, but human translation remains to be demonstrated.
When this study was published
Published in 2024, representing current innovation in peptide-enhanced ocular drug delivery.
The bigger picture
If validated clinically, this approach could transform how posterior eye diseases are treated — replacing painful, repeated eye injections with comfortable daily contact lens wear that delivers drugs past tissue barriers via cell-penetrating peptides.
Questions still open
- Can penetratin-enhanced contact lens delivery reach therapeutic drug levels in the retina?
- What is the long-term safety profile of repeated penetratin exposure to the cornea?
- Can this platform be extended to other ophthalmic drugs beyond corticosteroids?
Common questions
Could contact lenses replace eye injections?
How does the peptide help the drug get into the eye?
Read the original research
Dexamethasone phosphate and penetratin co-eluting contact lenses: a strategy to enhance ocular drug permeability.
International journal of pharmaceutics, 650, 123685
Citation
Toffoletto, Nadia; Salema-Oom, Madalena; Nicoli, Sara; Pescina, Silvia; González-Fernández, Felipe M; Pinto, Carlos A; Saraiva, Jorge A; Alves de Matos, António P; Vivero-Lopez, Maria; Huete-Toral, Fernando; Carracedo, Gonzalo; Saramago, Benilde; Serro, Ana Paula. (2024). Dexamethasone phosphate and penetratin co-eluting contact lenses: a strategy to enhance ocular drug permeability.. International journal of pharmaceutics, 650, 123685. https://doi.org/10.1016/j.ijpharm.2023.123685