Viral capsid DNA aptamer conjugates as multivalent cell-targeting vehicles

Area of Science:

• Bioconjugation Chemistry
• Nanomedicine
• Molecular Targeting

Background:

• Nucleic acid aptamers are versatile targeting moieties for drug delivery applications.
• Viral capsids serve as robust carriers for therapeutic payloads.
• Efficient methods are needed to conjugate aptamers to viral capsid surfaces.

Purpose of the Study:

• To develop an efficient oxidative coupling strategy for attaching aptamers to viral capsids.
• To characterize the stability and functionality of aptamer-functionalized viral capsids.
• To evaluate the potential of aptamer-labeled capsids for targeted drug delivery.

Main Methods:

• Periodate-mediated oxidative coupling of phenylene diamine-modified oligonucleotides with aniline-functionalized viral capsids.
• Characterization of DNA strand attachment density and retention of base-pairing capabilities.
• Cellular binding assays using Jurkat T cells and a tyrosine kinase receptor-targeting aptamer.
• Confocal microscopy for colocalization studies and assessment of cellular uptake and trafficking.

Main Results:

• Successfully attached up to 60 DNA aptamer strands per viral capsid using the oxidative coupling method.
• Demonstrated retention of aptamer base-pairing capabilities and capsid protein stability post-conjugation.
• Confirmed specific binding of aptamer-functionalized capsids to target cells (Jurkat T cells).
• Observed endocytosis and lysosomal trafficking of the aptamer-capsid complexes.

Conclusions:

• The developed oxidative coupling strategy provides an efficient means to create aptamer-functionalized viral capsids.
• Aptamer-labeled viral capsids can specifically target cells and undergo endocytosis.
• These aptamer-capsid constructs hold potential for targeted drug delivery, particularly for acid-labile prodrugs released in lysosomes.