Structure-Switching Aptamer Triggering Hybridization Chain Reaction on the Cell Surface for Activatable Theranostics.

Area of Science:

• Biotechnology
• Molecular Biology
• Theranostics

Background:

• Probing low-abundance biomolecules and targeted drug delivery are crucial for biological research and theranostics.
• Existing methods often lack sensitivity or real-time activation for effective tumor imaging and therapy.

Purpose of the Study:

• To develop a novel, activatable theranostic platform using aptamers and hybridization chain reaction (HCR) for enhanced fluorescence imaging and targeted therapy.
• To enable real-time activation and signal amplification for sensitive detection and treatment of tumors.

Main Methods:

• Designed a structure-switching aptamer probe that triggers HCR only upon binding to target cells.
• Utilized HCR to amplify fluorescence signals for imaging and to accumulate high-load prodrugs for targeted therapy.
• Validated the approach using in vitro assays for protein tyrosine kinase-7 (PTK7) detection and live cell studies for imaging and drug delivery.

Main Results:

• Achieved efficient signal amplification for fluorescence detection of PTK7 with a 1 pM detection limit.
• Demonstrated high-contrast fluorescence imaging and sensitive detection of tumor cells.
• Showcased high-efficiency drug delivery into tumor cells via endocytosis, leading to cisplatin conversion.

Conclusions:

• The developed aptamer-HCR platform offers real-time activation and amplification for sensitive tumor imaging and targeted therapy.
• This approach holds significant potential for early-stage cancer diagnosis and precise therapeutic interventions.
• The platform enables simultaneous fluorescence detection and drug delivery, advancing theranostic capabilities.