Provided herein are nanoplexes comprising a payload selected from a protein and/or a polynucleic acid； and a plurality of copolymers comprising a first copolymer that is poly(N,N′；-bis(acryloyl)cystamine-poly(aminoalkyl)) (PBAP), a second copolymer that is poly(C2-3 akylene glycol)-PBAP-poly(C2-3 akylene glycol), and a third copolymer that is TG-poly(C2-3 akylene glycol)-PBAP-poly(C2-3 akylene glycol)-TG wherein TG at each occurrence is independently a targeting ligand, a cell penetrating peptide, an imaging agent or a capping group, provided that a plurality of TG groups is a targeting ligand； wherein the payload is non-covalently complexed to one or more of the copolymers, one or more of the first, second, and/or third copolymers comprises an endosomal escape group having a pKa of about 4.5 to about 6.5, and optionally one or more of the first, second, and/or third copolymers comprises a host and a guest non-covalent crosslinker.
