Facile Noninvasive Retinal Gene Delivery Enabled by Penetratin

Area of Science:

• Ophthalmology
• Gene Therapy
• Biomaterials Science

Background:

• Gene delivery to the posterior eye segment is challenging due to biological barriers, necessitating invasive intravitreal injections.
• Previous research demonstrated penetratin's potential for topical ocular delivery of small molecules.

Purpose of the Study:

• To develop a noninvasive gene delivery system targeting the retina using penetratin-based complexes.
• To evaluate the efficacy of this system for gene expression in the posterior segment of the eye.

Main Methods:

• Designed gene delivery systems by electrostatically binding red fluorescent protein plasmid (pRFP) with penetratin and/or G3 PAMAM dendrimers.
• Optimized formulation, confirmed structure, and characterized the complexes.
• Assessed cellular uptake, transfection efficiency, and intraocular distribution in rat models after topical ocular instillation.

Main Results:

• Penetratin enhanced cellular uptake and transfection, while G3 PAMAM improved plasmid condensation and complex stability.
• The developed complexes penetrated the ocular surface rapidly and reached the retina, persisting for over 8 hours.
• Efficient red fluorescent protein expression was observed in the posterior segment, indicating successful gene delivery via a noncorneal pathway.

Conclusions:

• A facile and noninvasive gene delivery system utilizing penetratin and G3 PAMAM was successfully developed for posterior eye segment targeting.
• This approach demonstrates significant potential for advancing noninvasive gene therapy for posterior segment ocular diseases.