A Noncovalent Click-to-Release Strategy to Control Bond Cleavage and Prodrug Activation

Area of Science:

• Supramolecular Chemistry
• Chemical Biology
• Materials Science

Background:

• Click-to-release chemistry offers precise control over molecular release.
• Existing methods often rely on covalent ligation, limiting scope.
• Bioorthogonal strategies are crucial for in vivo applications.

Purpose of the Study:

• To develop a noncovalent click-to-release strategy.
• To utilize cucurbit[7]uril-adamantane (CB-Ad) host-guest complex for controlled release.
• To demonstrate proof-of-concept for therapeutic applications.

Main Methods:

• Formation of a cucurbit[7]uril (CB) host-guest complex with a self-immolative guest (SIG).
• Initiation of noncovalent click reaction via introduction of a high-affinity adamantane (Ad) guest.
• Displacement of SIG by Ad, triggering self-immolation and cargo release.
• In vitro evaluation using a prototype prodrug (SIG2) for photodynamic therapy.

Main Results:

• Successful demonstration of noncovalent click-to-release mechanism.
• Controlled release of cargo triggered by CB-Ad association.
• Effective regulation of in vitro photodynamic cell killing using a prodrug.
• The SIG remains inert until triggered by the CB-Ad reaction.

Conclusions:

• The noncovalent click-to-release strategy expands bioorthogonal cleavage methods.
• This approach offers promising potential for stimuli-responsive materials.
• Significant implications for advanced biomedical applications and drug delivery systems.