Sustained subconjunctival protein delivery using a thermosetting gel delivery system

Area of Science:

• Ophthalmology
• Biomaterials Science
• Drug Delivery Systems

Background:

• Posterior eye diseases require effective therapeutic delivery to ocular tissues.
• Current treatments often involve invasive procedures or frequent administration.
• Macromolecule delivery to the posterior segment remains a significant challenge.

Purpose of the Study:

• To evaluate a thermosetting gel for sustained delivery of proteins to the posterior eye segment.
• To assess the ability of the gel to deliver Alexa 647 ovalbumin to rat choroid and retina.
• To compare in vitro and in vivo release rates of ovalbumin from the gel.

Main Methods:

• Subconjunctival injection of thermosetting gel loaded with Alexa 647 ovalbumin in rats.
• Spectrophotometric assays and fluorescence microscopy to quantify ovalbumin in ocular tissues (sclera, choroid, retina) over 14 days.
• In vitro and in vivo release studies of ovalbumin from the gel.

Main Results:

• Measurable ovalbumin concentrations were sustained in rat sclera, choroid, and retina for up to 14 days.
• A concentration gradient of ovalbumin was observed, decreasing from sclera to choroid to retina.
• In vitro and in vivo ovalbumin release profiles demonstrated similar release kinetics.

Conclusions:

• The thermosetting gel system offers a feasible approach for sustained protein delivery to the posterior eye.
• This method is safe, minimally invasive, and convenient for treating posterior segment eye diseases.
• The gel facilitates prolonged therapeutic agent availability in choroidal and retinal tissues.