Micelle based on non-linear polyethylene glycol-polylactic acid block copolymer and preparation method thereof

Abstract

The invention relates to a micelle based on non-linear polyethylene glycol-polylactic acid block copolymer and a preparation method thereof. The preparation method comprises the following steps: using a single-end hydroxyl or a double-end-group modified polyethylene glycol to induce lactide for ring-opening polymerization, thereby obtaining a non-linear spindle polyethylene glycol-polylactic acid block copolymer, and then obtaining a micron-sized spindle micelle with high stability through self-assembly in aqueous solution. The particle sizes can be controlled through adjusting the molecular weights of polyethylene glycol and the polylactic acid, the critical micelle concentration is as high as 3.72*10-4g / L, and the drug loading rate and the drug encapsulation rate of the micelle are respectively up to 39.9 percent and 70.8 percent by mass percent, superior to a spherical micelle formed through assembly of a linear polyethylene glycol-polylactic acid block copolymer with an identical molecular weight. Simultaneously, the micelle coated with oil-soluble drugs demonstrates controllable release properties to drug molecules in phosphate buffer saline with the pH value of 7.4. The micelle can be used for slow release and targeted delivery of drugs, enhancement of drug effects and the like.

Description

A kind of micelle based on nonlinear polyethylene glycol-polylactic acid block copolymer and its preparation method technical field The invention relates to a micelle based on a non-linear polyethylene glycol-polylactic acid block copolymer and a preparation method thereof. technical background In recent years, biodegradable polymers have been widely used in the fields of tissue engineering, drug controlled release and environmental material engineering. Polycaprolactone (PCL), poly-L-lactide (PLLA) and its combination with polyethylene glycol Aliphatic polyesters represented by (PEG) block copolymers exhibit excellent biocompatibility, drug permeability and biodegradability, and are favored by more and more researchers. At present, the most researched amphiphilic block copolymers for drug release systems mainly focus on di-block and tri-block polymers. The hydrophilic block of the amphiphilic block copolymer is mainly polyethylene glycol (PEG) or polyoxyethylene (PEO), ...

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Problems solved by technology

The micelle morphology formed by these amphiphilic block copolymers of linear structure is relatively simple, and the drug loading capacity is usually low as a drug carrier (J.Polym.Sci.Poly.Chem.2007, 45, 5256; J. Controlled Release 2006, 111, 271)

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