Thermo-sensitive tri-block copolymer having sol-gel conversion characteristic and preparation thereof

A technology of block copolymer and diblock copolymer, which is applied in the field of triblock copolymer and its preparation, can solve the problems of high critical gel concentration, large relative molecular mass, non-biodegradable, etc., and achieve controllable properties , good biocompatibility and easy operation

Inactive Publication Date: 2011-10-19
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the critical gel concentration of poloxamers is high, the gel strength is weak, and they cannot be biodegraded. These shortcomings limit the wide application of poloxamers in the biomedical field.
[0005] The Chinese patent application No. 03100434.2 discloses a polycaprolactone (PCL) copolymer modified by a polyethylene glycol (PEG) block, wherein it is specifically disclosed that the relative molecular mass is 2000, 4000 PCL and relative The PEG (2000, 4000)-PCL (8000, 4000)-PEG (2000, 4000) amphiphilic tri-block copolymer synthesized by PEG with a molecular mass of 2000, 4000 has a large relative molecular mass. The polymer disclosed in this invention Polycaprolactone (PCL) copolymer modified with ethylene glycol (PEG) block is formulated into a solution with an organic solvent, and then self-assembled into nanoparticles or micelles in water. The nanoparticles can be degraded in vivo, and the degradation products are non-toxic Harmless, its nanoparticles can be dispersed in water to form a stable dispersion, "is an excellent excipient for the development of long-acting sustained-release preparations of hydrophobic drugs", the disadvantage is that the PEG-PCL-PEG copolymer is insoluble in water

Method used

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  • Thermo-sensitive tri-block copolymer having sol-gel conversion characteristic and preparation thereof
  • Thermo-sensitive tri-block copolymer having sol-gel conversion characteristic and preparation thereof
  • Thermo-sensitive tri-block copolymer having sol-gel conversion characteristic and preparation thereof

Examples

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Embodiment 1

[0038] Example 1 Synthesis and verification of PEG-PCL-PEG copolymer of the present invention

[0039] 1) Synthesis of PEG-PCL-PEG copolymer of the present invention

[0040] The brief synthetic route of the PEG-PCL-PEG copolymer of the present invention is as follows:

[0041]

[0042] where X and Y are positive integers.

[0043] According to the synthetic route of the above formula, a certain amount of polyethylene glycol monomethyl ether (MPEG) and caprolactone (ε-CL) were added to a three-necked flask equipped with a stirrer, and stannous octoate was used as a catalyst. The reaction was carried out under nitrogen protection for 6 hours, cooled to 80° C., and the cross-linking agent isophorone diisocyanate (IPDI) was added to continue the reaction for 6 hours to obtain the product, which was cooled to room temperature for purification, and dried. In addition, suitable diisocyanates also include: toluene diisocyanate, 1,6-hexamethylene diisocyanate, diphenylmethane-4,4...

Embodiment 2

[0055] Example 2 Study on the sol-gel transition characteristics of the PEG-PCL-PEG copolymer of the present invention

[0056] In the present invention, the gel-sol transition temperature is measured by the test tube method. When the system is in a flowing liquid state, it is called a sol state (Sol); when the system is in a non-flowing solid state, it is called a gel state (Gel); when the system is in a milky white suspension state, it is called a suspension state state (Sus); when the water phase and the polymer phase are separated in the system, it is called the precipitation state (Prep)

[0057] 1. Preparation of PEG-PCL-PEG copolymer aqueous solution of the present invention

[0058] Weigh the PEG-PCL-PEG copolymers with different molecular weights prepared in Example 1 above, and add them to the PEG-PCL-PEG copolymers at different concentrations of 10%, 15%, 20%, 25%, 30%, 35%, and 40% by weight. Fully and uniformly dissolve in sub-distilled water (ie double distille...

Embodiment 3

[0066] Example 3 Preparation and release experiment of PEG-PCL-PEG copolymer-drug complex

[0067] In this example, the copolymer prepared in the above example was loaded with 3 kinds of drugs to prepare a PEG-PCL-PEG copolymer-drug complex, including macromolecular protein drug (model drug is bovine serum albumin BSA), small Molecular hydrophilic drug (model drug is VB 12 ), small molecule hydrophobic drugs (model drug Honokiol and Honokiol).

[0068] 1. Small molecule hydrophilic drugs (vitamin B 12 ) PEG-PCL-PEG complex preparation and drug release behavior

[0069] First prepare 200 microliters of PEG-PCL-PEG (E 550 -C 2200 -E 550 ) solution (the weight content of PEG-PCL-PEG is 30% wt or 20% wt), and then 0.8 mg and 2 mg of the small-molecule hydrophilic drug VB were added to the PEG-PCL-PEG aqueous solution, respectively. 12,well mixed. Then, the resulting solution was added to a 5 ml EP tube and kept at 37°C for 12 hours to make a gel. Then 2 ml of phosphate buff...

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Abstract

The present invention relates to medical polymers field, especially a temperature sensitive and biodegradable triblock copolymer with gel-sol transformation characteristics and preparation method thereof and usage. The triblock copolymer is PEG-PCL-PEG copolymer, the aqueous solution thereof performs Sol-Gel phase transformation along with the temperature rise and the phase transformation temperature is 25-35 degree. The PEG-PCL-PEG copolymer has a variety of excellent features to provide a new choice in field which is in need of temperature sensitive material.

Description

technical field [0001] The invention relates to the field of medical polymer materials, in particular to a temperature-sensitive, biodegradable triblock copolymer with sol-gel transition characteristics and a preparation method and application thereof. Background technique [0002] In recent years, biodegradable environment-sensitive hydrogels have received extensive attention from scholars at home and abroad due to their good sensitivity, biodegradability and biocompatibility. Environmentally sensitive hydrogels, also known as smart hydrogels, refer to their ability to sense changes or stimuli in the external environment (such as temperature, pH value, light, electricity, pressure, etc.) and generate corresponding physical structures and chemical structures. A class of polymer hydrogels with changing properties. Among them, temperature-sensitive physical hydrogels have attracted much attention due to their broad application prospects in the fields of drug controlled releas...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G81/00C08G63/91C08G63/08C08G63/85C08K5/29A61K47/34A61L31/06
Inventor 钱志勇魏于全赵霞
Owner SICHUAN UNIV
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