In situ imaging miRNAs using multifunctional linear DNA nanostructure

Area of Science:

• Biotechnology
• Molecular Diagnostics
• Nanomedicine

Background:

• MicroRNAs (miRNAs) are crucial biomarkers for disease diagnosis.
• Sensitive and specific intracellular quantification of miRNA expression remains a challenge.

Purpose of the Study:

• To develop a multifunctional linear DNA nanostructure (MLN) for detecting and imaging miRNA-21 within living cells.
• To overcome the limitations of current miRNA detection methods.

Main Methods:

• Designed a DNA nanostructure (MLN-MB) comprising an aptamer (AS1411), MLN, and molecular beacon (MB-21).
• Utilized the aptamer for non-transfection cellular entry.
• Employed MB-21 hybridization with intracellular miRNA-21 for fluorescence signal enhancement.
• Ensured an enzyme-free, autonomous, and continuous detection process.

Main Results:

• Achieved sensitive detection of miRNA-21 with a limit of 320 pM in 10 minutes.
• Demonstrated high specificity for miRNA-21 against other miRNAs.
• Confirmed stable detection of miRNA-21 in complex biological matrices.
• Showcased biocompatibility and cellular uptake of the MLN-MB system.

Conclusions:

• The MLN-MB system provides a sensitive, specific, and simple approach for intracellular miRNA-21 detection and imaging.
• This technology holds significant potential for early cancer diagnosis through specific cancer cell identification.
• The enzyme-free and autonomous nature simplifies the detection process.