Cleavable

Cleavable refers to the property of being able to be split or cleaved into smaller parts. In chemistry and related fields, cleavable describes bonds or linkers that are stable under normal conditions but break under defined stimuli, such as chemical, enzymatic, photolytic, or mechanical triggers.

In bioconjugation and pharmacology, cleavable linkers are used to attach payloads (drugs, imaging agents, or polymers) to other molecules (such as antibodies or carriers) with release triggered by specific conditions. Common cleavable bonds include disulfide bonds cleaved in reducing environments like the intracellular cytosol, esters and amides cleaved by hydrolysis or enzymatic activity, and hydrazone or oxime linkers that respond to pH changes. Peptide sequences can be cleaved by proteases, providing enzyme-specific release. Photocleavable groups release cargo upon exposure to light.

In mineralogy and geology, cleavage describes the tendency of a mineral to break along smooth, flat planes rather than irregular fractures. A mineral can be described as cleavable if cleavage is a defining property. Examples include muscovite, which has perfect basal cleavage; halite, with cubic cleavage; and calcite, with rhombohedral cleavage. Cleavability differs from fracture, which is a non-planar break.

In materials science, cleavable linkers and bonds are used to create stimuli-responsive systems, including drug delivery platforms and degradable polymers, where controlled rupture under specific conditions enables release or disassembly.