Synthesis and characterization of biodegradable amphiphilic triblock copolymers methoxy-poly(ethylene glycol)-b-poly(L-lysine)-b-poly(L-lactic acid)

Abstract

Starting from MPEG-NH 2 , a series of amphiphilic triblock copolymers MPEG-b-PLL-b-PLA were synthesized through PEG-NH 2 -initiated ring-open polymerization of N ε-benzyloxycarbonyl-L-lysine, followed by acylation coupling between the amino-terminated MPEG-b-PZLL-NH 2 and carboxyl-terminal PLA and the deprotection of amines. The block copolymers were characterized by FT-IR, 1 H NMR, GPC, DSC and TEM. The copolymer functional groups, molecular and block structures were verified by FT-IR, 1 H NMR and DSC, respectively. The GPC results indicate that the chain lengths of each block can be controlled by varying the feed ratios of the monomer and initiator, providing the polymer samples with a narrow molecular weight distribution (M w /M n 01.10~1.25). The TEM analysis shows that the triblock polymers can self-assemble into polymeric micelles in aqueous solution with spherical morphology. The cellcytotoxicity assay indicates that the triblock polymers show no obvious cytotoxicity against Bel7402 human hepatoma cells.

Temperature-Sensitive Gold Nanoparticle-Coated Pluronic-PLL Nanoparticles for Drug Delivery and Chemo-Photothermal Therapy

“…The benzyloxycarbonyl group of the polymer can be removed in a HBr/acetic acid solution. 32 The deprotection was confirmed by 1 H NMR as shown in Fig. 1 (E).…”

Mechanical properties, crystallization characteristics, and foaming behavior of polytetrafluoroethylene-reinforced poly(lactic acid) composites

“…The cell density (N c ) was calculated on the basis of Eq. 3 [47], in which q f (g/cm 3 ) was the apparent density of the foam samples and q p (g/cm 3 ) was the density of the PLA and its composites. Both were measured using a pycnometer.…”

Poly(ethylene oxide) (PEO)-based ABC triblock terpolymers – synthetic complexity vs. application benefits

“…107 Biodegradable amphiphilic poly(ethylene oxide)-block-poly-(L-lysine)-block-poly(lactic acid) (PEO-b-PLL-b-PLA) or poly-(ethylene oxide)-block-poly(L-lactide)-block-poly(3-caprolactone) (PEO-b-PLLA-b-PCL) triblock terpolymers form multilayered micelles where paclitaxel could be successfully encapsulated. 108,109 Another system which is closely related to drug delivery approaches is poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(3-caprolactone) (PEO-b-PPO-b-PCL). Depending on the block length of the PCL segment spherical micelles or worm-like structures can be observed and used to encapsulate hydrophobic compounds such as pyrene.…”