Readily Accessible Strained Difunctionalized trans-Cyclooctenes with Fast Click and Release Capabilities

Area of Science:

• Bioorthogonal chemistry
• Chemical biology
• Drug delivery systems

Background:

• The click reaction between trans-cyclooctene (TCO) and tetrazine (Tz) is valuable for bioorthogonal conjugation and payload release.
• The synthesis of difunctionalized TCOs is challenging, limiting their application.
• Improved accessibility of difunctionalized TCOs is crucial for advancing novel applications.

Purpose of the Study:

• To develop a scalable and accessible synthesis for a novel bioorthogonal difunctionalized TCO.
• To evaluate the TCO-Tz click reaction kinetics and payload release efficiency.
• To demonstrate the potential of this system in targeted drug delivery.

Main Methods:

• A four-step synthesis of difunctionalized TCO from commercially available starting materials.
• Kinetic assessment of the TCO-Tz click reaction.
• Demonstration of payload release (carbonate and carbamate) triggered by tetrazine.
• In vitro cellular toxicity studies.

Main Results:

• Successful scalable synthesis of a new difunctionalized TCO in four high-yielding steps.
• Excellent kinetic rates observed for the TCO-Tz click reaction.
• Up to 100% release efficiency for carbonate and carbamate payloads.
• A >20-fold increase in cytotoxicity demonstrated through local drug release in cellular studies.

Conclusions:

• The developed synthesis provides accessible difunctionalized TCOs for bioorthogonal applications.
• The TCO-Tz click chemistry enables efficient and triggered payload release.
• This system shows significant potential for targeted drug delivery and enhanced therapeutic efficacy.