Cell‐Penetrating Poly(disulfide)s

To appreciate 10 years of cell‐penetrating poly(disulfide)s (CPDs), this review comprehensively covers the structures realized by now. CPDs have been introduced as dynamic covalent polymers that i) are obtained from cyclic disulfide monomers by ring‐opening polymerization (ROP) and ii) enter cells by thiol‐mediated uptake. They were discovered in 2014 and have been used since then for diverse delivery applications in vitro and in vivo. The introduction briefly sketches their mode of action, as far as it is known. The main part lists the CPDs realized so far, organized by their structures, with selected examples for biological applications. The final chapters cover the few cyclic monomers other than lipoic acid derivatives that have been explored and links to related topics such as templated ROP of cyclic disulfides in lipoplexes and liposomes and related delivery motifs. We hope this review offers a solid and productive basis for future progress with CPD research and its use in science and society.