Cornea-SELEX-derived DNA aptamers for preparing spherical nucleic acids and corneal staining

Area of Science:

• Biotechnology
• Nanotechnology
• Ophthalmology

Background:

• Topical eye drops have limited therapeutic efficacy due to poor bioavailability.
• Rapid tear clearance and corneal barriers hinder drug absorption.
• Aptamers offer potential for targeted ocular delivery and extended drug retention.

Purpose of the Study:

• To develop aptamer-functionalized gold nanoparticles (AuNPs) for enhanced ocular drug delivery.
• To investigate the binding capabilities of these aptamer-AuNP conjugates (spherical nucleic acids, SNAs) to corneal tissues and cells.
• To identify the optimal aptamer for targeted ocular applications.

Main Methods:

• Selection and synthesis of six aptamers with poly-adenine tails.
• Functionalization of gold nanoparticles (AuNPs) with aptamers to form spherical nucleic acids (SNAs) via thermal evaporation.
• Assessment of SNA colloidal stability and binding affinity to porcine corneal tissues and human corneal epithelial cells (HCECs).
• Flow cytometry to determine the dissociation constant (Kd) of the best-performing SNA.

Main Results:

• The aptamer-Cornea-S5 functionalized AuNPs (SNAs) demonstrated superior colloidal stability.
• Cornea-S5 SNAs exhibited optimal binding to both corneal tissues and HCECs.
• Specific staining of scarred corneal regions was observed.
• The dissociation constant (Kd) of Cornea-S5 to HCECs was determined to be 169 nM.

Conclusions:

• Aptamer-AuNP conjugates, specifically SNAs, show significant potential for targeted ocular drug delivery.
• The Cornea-S5 aptamer-AuNP conjugate offers enhanced corneal binding and retention, improving therapeutic efficacy.
• These aptamer-AuNP conjugates are promising for both ocular drug delivery and diagnostic applications.