Cholesterol-linked pyrene excimer molecular beacon with enhanced cell permeability

Area of Science:

• Biochemistry
• Molecular Biology
• Nanotechnology

Background:

• Molecular beacons (MBs) are crucial for nucleic acid detection.
• Enhancing cellular delivery of MBs is vital for in vivo applications.
• Cholesterol conjugation is a known strategy to improve biomolecule cell permeability.

Purpose of the Study:

• To develop a novel, covalently labeled pyrene excimer molecular beacon (MB) system.
• To enhance the cellular delivery efficiency of MBs using a cholesterol moiety.
• To evaluate the potential of these cholesterol-linked MBs as in vivo biosensors.

Main Methods:

• Covalent attachment of pyrene units into adenosine within oligonucleotide strands.
• Incorporation of pyrene-labeled oligonucleotides into hairpin structures at specific stem positions.
• Conjugation of a cholesterol unit to a free terminus of the MB hairpin.
• Assessment of MB color change (green to blue) upon duplex formation.
• Evaluation of cellular delivery and cell permeability compared to conventional methods.

Main Results:

• The developed system functions as an effective molecular beacon, exhibiting a distinct color change upon target binding.
• Cholesterol-linked MBs demonstrated enhanced cellular delivery compared to unlabeled MBs.
• The cell permeability of cholesterol-linked MBs was comparable to conventional transfection techniques.
• The cholesterol-based MB systems are structurally simple and can be synthesized efficiently.

Conclusions:

• Cholesterol conjugation effectively enhances the cellular delivery of molecular beacons.
• These cholesterol-linked MBs show significant potential for use in in vivo biosensing applications.
• The efficient synthesis and promising cellular uptake pave the way for advanced biosensor development.