Provided are synthetic schemes for the synthesis of a derivatized chitosan polymer, grafted with polyethylene glycol (PEG) and a peptide such as a cell-targeting/cell penetrating peptide. In alternative embodiments, provided are synthetic schemes for the preparation of a peptide tagged PEGylated phthaloyl chitosan (CS-O-PEG-peptide), or a CS-O-PEG-TAT if the peptide is a TAT. Provided are synthetic schemes for the preparation of a PEGylated Phthaloyl Chitosan (CS-PH-O-PEG-peptide), or a CS-PH-O-PEG-TAT if the peptide is a TAT. In alternative embodiments, provided are protocols and synthetic schemes for the preparation of a phthaloyl chitosan and a homo-functional di-carboxylic acid polyethylene glycol (COOH-PEG-COOH). Provided are protocols and synthetic schemes for the preparation of a peptide tagged PEGylated chitosan (CS-O-PEG-peptide). Provided are peptide-tagged PEGylated chitosan (CS-O-PEG-peptide) (optionally CS-O-PEG-TAT if the peptide is a TAT) made by a method or synthetic scheme as provided herein.
