Dynamics of an RNase H-Responsive Tetrahedral DNA Nanostructure for Efficient Intracellular microRNA Inhibition

Area of Science:

• Biotechnology
• Nanomedicine
• Molecular Biology

Background:

• Tetrahedral DNA nanostructures (TDNs) are advanced platforms for therapeutic oligonucleotide delivery.
• Current methods often require external handles, limiting functionalization and flexibility.

Purpose of the Study:

• To develop a novel TDN strategy embedding antisense oligonucleotide (ASO) sequences directly into the structural framework.
• To create a TDN-gapmer for autonomous delivery and efficient targeting of microRNA-21 (miR-21) in glioblastoma.

Main Methods:

• Engineered a TDN-gapmer incorporating a gapmer design for structural reconfiguration upon cellular entry.
• Validated autonomous delivery into glioblastoma cells without transfection agents.
• Investigated mechanism using mechanistic studies and coarse-grained modeling.
• Assessed stability in serum.

Main Results:

• Achieved autonomous delivery of TDN-gapmer into glioblastoma cells.
• Demonstrated robust inhibition of microRNA-21 (miR-21).
• Mechanistic studies suggest recruitment of ribonuclease H (RNase H) for RNA cleavage and target suppression.
• Coarse-grained modeling predicted structural transitions facilitating strand displacement and catalytic reconfiguration.
• TDN-gapmer showed stability in serum while retaining therapeutic potential.

Conclusions:

• The integrated TDN-gapmer design offers a versatile platform for precision RNA-targeting therapeutics.
• This approach enhances ASO accessibility and target engagement, bypassing the need for transfection agents.
• The structural integration allows for potential multifunctionalization, expanding therapeutic applications.