The benzoic-imine generated from amine and benzaldehyde groups is an interesting dynamic covalent bond. The bond is stable around neutral pH value (~7.4) arising from the existence of aromatic ring nest to the carbon-nitrogen double bond

while starts to hydrolyze at very mild acidic pH

e.g. the extracellular pH value of solid tumors (6. 5~6. 8). The hydrolysis kinetics can be tunable by the acidity of the environmental conditions

which becomes faster at endosome and lysosome pH values (ca. 4.5~6.5). These merits are promising to design and construct physiological pH responsive materials with tunable morphologies including polymeric aggregates

polymer/inorganic nanocomposites

microgels and bulk injectable hydrogels. Many potential applications have been demonstrated for delivery vehicles and/or scaffolds for tissue engineering. In this review

we summarizes the recent progresses in the design and synthesis of benzoic-imine dynamic bond contained polymeric systems for biomedical applications.