Rational Design of Poly(disulfide)s as a Universal Platform for Delivery of CRISPR-Cas9 Machineries toward Therapeutic Genome Editing

We synthesized a series of poly­(disulfide)­s by ring-opening polymerization and demonstrated that the copolymerization of monomer 1 containing diethylenetriamine moieties and monomer 2 containing guanidyl ligands could generate an efficient delivery platform for different forms of CRISPR-Cas9-based genome editors, including plasmid, mRNA, and protein. The excellent delivery performance of designed poly­(disulfide)­s stems from their delicate molecular structures to interact with genome-editing biomacromolecules, unique delivery pathways to mediate the cellular uptake of CRISPR-Cas9 cargoes, and strong ability to escape the endosome. The degradation of poly­(disulfide)­s by intracellular glutathione not only promotes the timely release of CRISPR-Cas9 machineries into the cytosol but also minimizes the cytotoxicity that nondegradable polymeric carriers often encounter. These merits collectively account for the excellent ability of poly­(disulfide)­s to mediate different forms of CRISPR-Cas9 for their efficient genome-editing activities in vitro and in vivo.