Biodegradable polymer microparticle for filler, manufacturing method thereof, freeze-dried body including the same, and filler injection including the same

1. A biodegradable polymer microparticle group, comprising:

a first biodegradable polymer microparticle having a core and a shell; and

a second biodegradable polymer microparticle having a core and a shell,

wherein the cores of the first biodegradable polymer microparticle and the second biodegradable polymer microparticle contain secondary particles including aggregates of a plurality of primary particles,

wherein the shells of the first biodegradable polymer microparticle and the second biodegradable polymer microparticle have a raspberry shaped structure,

wherein the first biodegradable polymer microparticle and the second biodegradable polymer microparticle comprise polydioxanone,

wherein the content concentration in the core of the first biodegradable polymer microparticle is higher than the content concentration in the shell of the first biodegradable polymer microparticle, and the difference in the content concentrations between the core and the shell of the first biodegradable polymer microparticle is 0.01 to 3% by weight,

wherein the second biodegradable polymer microparticle has the same content concentration in the core and in the shell,

wherein the content of the second biodegradable polymer microparticle (B) is 6 to 8% by weight based on the total weight of the first biodegradable polymer microparticle (A) and the second biodegradable polymer microparticle (B),

and wherein the average particle diameter of the plurality of primary particles is 3 to 15 μm, the average particle diameter of the secondary particles is 80 to 150 μm, the cores of the first biodegradable polymer microparticle and the second biodegradable polymer microparticle are 60 to 95% by volume, and the shells of the first biodegradable polymer microparticle and the second biodegradable polymer microparticle are 5 to 40% by volume with respect to the total volume.

2. The biodegradable polymer microparticle group according to claim 1 , wherein the polydioxanone has a weight average molecular weight of 50,000 to 200,000 Daltons.

3. The biodegradable polymer microparticle group according to claim 1 , wherein the first biodegradable polymer microparticle and the second biodegradable polymer microparticle have a porosity of 2 to 85%.

4. A freeze-dried body, comprising: the biodegradable polymer microparticle group of claim 1 ; and a biocompatible carrier.

5. The freeze-dried body according to claim 4 , wherein the biocompatible carrier is one or more selected from Alginic acid and salt thereof, hyaluronic acid and salt thereof, carboxymethyl cellulose and salt thereof, collagen, Gelatin, and Elastin.

6. An injectable composition, comprising: the biodegradable polymer microparticle group of claim 1 ; and one or more selected from injection water, sterilized water, and distilled water.

7. The injectable composition according to claim 6 , further comprising: a biocompatible carrier,

wherein the mixing weight ratio of the biodegradable polymer microparticle group and the biocompatible carrier is 80:20 to 20:80.

8. A method for manufacturing the biodegradable polymer microparticle group of claim 1 , the method comprising:

a first operation of mixing a first composition containing organic solvent miscible with water and biodegradable polymers and a second composition containing first surfactant and water, and preparing a third composition containing biodegradable polymer microparticle precursors for a filler and stirring them;

a second operation of adding and mixing a fourth composition containing the first composition containing the biodegradable polymers, second surfactant, and water to a product of the first operation, and stirring them to prepare a fifth composition containing biodegradable polymer microparticle group;

and a third operation of separating the biodegradable polymer microparticle group from the fifth composition,

wherein in the second operation, the feed rate of the fourth composition is faster than the feed rate of the second composition of the first operation,

wherein the total content of the first surfactant and the second surfactant is 30 to 50 parts by weight with respect to 100 parts by weight of the total content of the biodegradable polymer microparticle group,

wherein the stirring speed of the second operation is slower than the stirring speed of the first operation,

wherein in the second operation, the content of the second surfactant is more than the content of the first surfactant in the first operation, and

wherein the content of the first surfactant in the first operation is 5 to 20 parts by weight with respect to 100 parts by weight of the total content of the biodegradable polymer microparticle group, and the content of the second surfactant in the second operation is 25 to 30 parts by weight with respect to 100 parts by weight of the total content of the biodegradable polymer microparticle group.

9. The method according to claim 8 , wherein in the first operation, the second operation, and the third operation, the reaction temperature is 20 to 25° C., the stirring speed is 300 to 500 rpm, and the pH is controlled to be 4 to 6.

10. The method according to claim 8 , wherein the first surfactant and the second surfactant are independently selected from polyvinyl alcohol, polyoxyethylene sorbitan and salt thereof, soy Lecithin, and monoglyceride.

11. A method for manufacturing the freeze-dried body according to claim 5 , the method comprising:

a first operation of mixing a first composition containing organic solvent miscible with water and biodegradable polymers and a second composition containing first surfactant and water, and preparing a third composition containing biodegradable polymer microparticle precursors for a filler and stirring them;

a second operation of adding and mixing a fourth composition containing the first composition containing the biodegradable polymers, second surfactant, and water to a product of the first operation, and stirring them to prepare a fifth composition containing biodegradable polymer microparticle group;

a third operation of separating the biodegradable polymer microparticle group from the fifth composition,

wherein in the second operation, the feed rate of the fourth composition is faster than the feed rate of the second composition of the first operation,

wherein the total content of the first surfactant and the second surfactant is 30 to 50 parts by weight with respect to 100 parts by weight of the total content of the biodegradable polymer microparticle group,

wherein the stirring speed of the second operation is slower than the stirring speed of the first operation,

wherein in the second operation, the content of the second surfactant is more than the content of the first surfactant in the first operation, and

wherein the content of the first surfactant in the first operation is 5 to 20 parts by weight with respect to 100 parts by weight of the total content of the biodegradable polymer microparticle group, and the content of the second surfactant in the second operation is 25 to 30 parts by weight with respect to 100 parts by weight of the total content of the biodegradable polymer microparticle group; and

a fourth operation of preparing a sixth composition by mixing the biodegradable polymer microparticle group and a biocompatible carrier after the third operation,

wherein the biocompatible carrier is one or more selected from Alginic acid and salt thereof, hyaluronic acid and salt thereof, carboxymethyl cellulose and salt thereof, collagen, Gelatin, and Elastin.