Chondroitin Sulfate-Coated Heteroduplex-Molecular Spherical Nucleic Acids

Area of Science:

• Nanotechnology and Drug Delivery
• Neuroscience and Molecular Biology

Background:

• Molecular Spherical Nucleic Acids (MSNAs) are dendritic nanostructures with potential as oligonucleotide delivery vehicles.
• The radial structure and outer sphere conjugates of MSNAs can be modulated to influence delivery properties.
• Antisense oligonucleotides (ASOs) are used for gene silencing, but their delivery to target cells remains a challenge.

Purpose of the Study:

• To investigate fullerene-based MSNAs as carriers for a Tau-ASO.
• To evaluate the impact of chondroitin sulfate (CS) conjugation and decoration on MSNA-mediated delivery and activity of Tau-ASO.
• To assess the formation, stability, cellular uptake, and Tau-suppression activity of these novel MSNA-ASO conjugates in vitro.

Main Methods:

• Synthesis of [60]fullerene-based MSNAs carrying DNA and RNA sequences.
• Conjugation of Tau-ASO with chondroitin sulfate tetrasaccharides (CS) with varying sulfation patterns.
• Characterization of MSNA-ASO conjugate formation and stability using UV melting, PAGE, DLS, and SEC-MALS.
• In vitro assessment of cellular uptake via confocal microscopy and Tau-suppression activity via Western blot in hippocampal neurons.

Main Results:

• Heteroduplex ASO-MSNAs were successfully formed and characterized for stability.
• The MSNA carriers and CS-moieties influenced the cellular uptake and Tau-suppression activity of the Tau-ASO.
• CS-decorations on MSNAs modulated the delivery efficiency and biological activity of the Tau-ASO in hippocampal neurons.

Conclusions:

• Fullerene-based MSNAs are effective hybridization-mediated carriers for antisense oligonucleotides.
• Chondroitin sulfate conjugation and decoration represent a viable strategy to enhance MSNA-mediated gene silencing.
• These findings highlight the potential of tailored MSNA-ASO conjugates for therapeutic applications in neuroscience.