Sulistio, Adrian, et al. Biomacromolecules, 2011, 12(10), 3469-3477.
A core cross-linked star (CCS) polymer has been successfully synthesized, which shows potential for targeted drug delivery. The star polymer was synthesized via a one-pot, arm-first approach using sequential ring-opening polymerization (ROP) of amino acid N-carboxyanhydride (NCA) derivatives initiated with N-(trimethylsilyl)allylamine. Then, the incorporation of allyl functionalities at the star periphery allowed for postpolymerization functionalization with thiolated PEG derivatives via "thiol ene" click chemistry.
Synthesis of CCS Polymers 1 with N-(trimethylsilyl)allylamine
· First, lys NCA (1.00 g, 3.26 mmol) was dissolved in anhydrous DMF (10 mL) in a flame-dried, argon-purged two-necked flask. N-(Trimethylsilyl)allylamine (M/I = 40, 13.7 μL, 0.0817 mmol) was added, and the mixture was stirred at room temperature for 12 h to afford poly(Z-L-lysine) (PZLL) (Mw = 9.67 kDa, PDI = 1.12).
· Cys NCA (MI/CL = 30, 0.716 g, 2.45 mmol) was added, and the mixture was stirred for a further 6 h to afford the crude CCS polymer (Mw = 358 kDa, PDI = 1.73, f = 22).
· This solution was added to AMP (0.283 g, 2.35 mmol) dissolved in DMF (20 mL), stirred for 3 h, and then precipitatied in methanol (250 mL).
· The precipitate was isolated via centrifugation, washed with chloroform (100 mL) and THF (100 mL), and dried in vacuo to afford CCS polymer 1.
