Design, Synthesis and Characterization of A Novel Cationic Polymer Poly(lactic acid-b-L-lysine)

Abstract

A novel biodegradable block copolymer poly(lactic acid-b-lysine) (PLA-b-PLL) has been synthesized and characterized in this study. This product was synthesized via a five-step reaction: Synthesis of hydroxyl-tailed poly(lactic acid) (PLA) by the ring-opening polymerization (ROP) of D,L-lactide in the presence of stannous octoate (Sn(OCt) 2 ) as initiator; coupling N-t-butoxycarbonyl-Lphenylalanine to hydroxyl-tailed PLA using dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP); the aminotailed PLA was obtained through de-protection of the Boc-protective group in trifluoroacetic acid (TFA) solution; and then ringopening polymerization of N ε -(Z)-lysine-N-carboxyanhydride (NCA) using the amino-tailed PLA as macro-initiator; finally removal of the Cbz-protective group of PLA-b-poly(N ε -(Z)-L-lysine) (PLA-b-PLL(Z) in a mixed hydrobromic acid/acetic acid solution to give the target copolymer. The characterization of this copolymer and its precursors were performed by 1 H-NMR, FTIR and GPC. The block copolymer PLA-b-PLL, combining the characteristics of an aliphatic polyester and poly(amino acids), could be of potential interest in a variety of medical applications, such as the fields of targeted drug delivery and gene delivery systems.

Preparation of a Thermosensitive Gel Composed of a mPEG-PLGA-PLL-cRGD Nanodrug Delivery System for Pancreatic Tumor Therapy

“…The drug in NPs can be taken up by cells through endocytosis to avoid being recognized and effluxed . mPEG-PLGA-PLL-cRGD is a material synthesized in our laboratory. , NPs made of this material have been studied in our earlier work. − The ability to reverse drug resistance is an important characteristic of the NPs . The cRGD is a targeting group to integrin α v β 3 , which was expressed on Aspc-1 cell .…”

“…40 mPEG-PLGA-PLL-cRGD is a material synthesized in our laboratory. 30,31 NPs made of this material have been studied in our earlier work. 41−44 The ability to reverse drug resistance is an important characteristic of the NPs.…”

“…mPEG-PLGA-PLL-cRGD (PEG M w = 5000, 20%) was synthesized according to our previous protocol. , The paclitaxel (PTX) standard was obtained from the National Institutes for Food and Drug Control. The bulk PTX was obtained from Jiangsu YEW Biotechnology CO., Ltd. Acetonitrile (of chromatographic purity) was obtained from CNW (GER).…”

Stimulus-Responsive Degradable Polylactide-Based Block Copolymer Nanoassemblies for Controlled/Enhanced Drug Delivery

“…Most diblock copolymers consisting of PLA and poly­(amino acid) blocks have been synthesized by ROP of an α-amino acid N -carboxyanhydride from NH 2 -terminated polymer, followed by the hydrolysis for deprotection of groups to the corresponding amino acids. A diblock copolymer of PLA- b -poly­( l -lysine) was synthesized by ROP of N -carbonylbenzoxy- l -lysine in the presence of NH 2 -PLA initiator . The synthesis of a triblock copolymer of PEG- b -poly­( l -serine) grafted with PLA has been reported.…”

“…A diblock copolymer of PLA-b-poly(L-lysine) was synthesized by ROP of N-carbonylbenzoxy-L-lysine in the presence of NH 2 -PLA initiator. 47 The synthesis of a triblock copolymer of PEG-b-poly(L-serine) grafted with PLA has been reported. The approach involves the ROP of o-(t-butyl)-Lserine in the presence of PEG-NH 2 and following hydrolytic cleavage of pendant t-butoxy groups to the corresponding OH groups.…”