AMPHIPHILIC POLYMER AND METHOD FOR PREPARING THE SAME

1 . An amphiphilic polymer having the following formula (I):

wherein Z is a hydroxyl-substituted aliphatic group having formula (Z1) or (Z2):

wherein R 11 and R 21 are independently hydrogen, hydroxyl, hydroxymethyl, methyl, or a C 1 -C 20 alkyl group, and R 12 , R 13 , R 14 , R 22 , R 23 , and R 24 are independently hydrogen, hydroxyl, or a sugar moiety;

X is a C 1 -C 6 divalent aliphatic group; and

Y is a biodegradable polyester block having a repeating unit represented by the following formula (II):

wherein, in each repeating unit, R is hydrogen or a C 1 -C 18 alkyl group, m is an integer ranging from 0 to 5, and n is an integer ranging from 10 to 300.

2 . The amphiphilic polymer of claim 1 , wherein R 12 , R 13 , R 14 , R 22 , R 23 , and R 24 are independently hydrogen.

3 . The amphiphilic polymer of claim 2 , wherein R 11 and R 21 are independently a hydroxymethyl, hydrogen, or methyl group.

4 . The amphiphilic polymer of claim 3 , wherein Z is a hydroxyl-substituted aliphatic group having the formula (Z2), and, in formula (Z2), R 21 is a hydroxymethyl group; R 22 and R 23 are independently a hydroxyl group; and R 24 is

wherein a is an integer ranging from 1 to 9.

5 . The amphiphilic polymer of claim 1 , wherein Z is a hydroxyl-substituted aliphatic group having the formula (Z2), and, in formula (Z2), R 21 is

R 22 , R 23 , and R 24 are independently a hydroxyl group.

6 . The amphiphilic polymer of claim 1 , wherein X is a C 1 -C 6 alkylene group.

7 . The amphiphilic polymer of claim 1 , wherein said biodegradable polyester block is derived from one selected from the group consisting of poly(lactic acid), poly(glycolic acid), poly(hydroxy butyrate), polycaprolactone, and poly(hydroxy valerate).

8 . The amphiphilic polymer of claim 1 , wherein said biodegradable polyester block is derived from one selected from the group consisting of poly(lactic acid) and polycaprolactone.

9 . The amphiphilic polymer of claim 1 , wherein R of formula (II) is a methyl group or a hydrogen group, and m is an integer ranging from 0 to 4.

10 . A method for preparing an amphiphilic polymer of claim 1 , comprising the following steps:

(a) reacting a diamine compound of formula (V):

H 2 N—X—NH 2   (V)

 with a sugar having formula (III) or (IV):

 so as to form a compound having formula (VI),

wherein Z is a hydroxyl-substituted aliphatic group having formula (Z1) or (Z2):

wherein R 11 of formulae (III) and (Z1) and R 21 of formulae (IV) and (Z2) are independently hydrogen, hydroxyl, hydroxymethyl, methyl, or a C 1 -C 20 alkyl group, and R 12 , R 13 , R 14 of formulae (III) and (Z1) and R 22 , R 23 , and R 24 of formulae (IV) and (Z2) are independently hydrogen, hydroxyl, or a sugar moiety; and

(b) reacting a biodegradable polyester block of formula (VII):

 with the compound having formula (VI) so as to form the amphiphilic polymer,

wherein, R is hydrogen or a C 1 -C 18 alkyl group, m is an integer ranging from 0 to 5, and n is an integer ranging from 10 to 300.

11 . The method of claim 10 , wherein the step (a) is conducted in the presence of a reducing agent, the reducing agent being selected from the group consisting of sodium borohydride, sodiumcyanoborohydride, and the combination thereof.

12 . The method of claim 10 , further comprising, before step (b), a step of activating the biodegradable polyester block using an activator in the presence of a solvent, the activator being selected from the group consisting of N,N′-dicyclohexylcarbodiimide, N,N′-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and combinations thereof, the solvent being selected from the group consisting of dimethyl sulfoxide, dimethylformamide, and combinations thereof.

13 . The method of claim 10 , wherein the sugar of formula (III) or (IV) has a molecular weight ranging from 180 to 20,000.

14 . The method of claim 10 , wherein the biodegradable polyester block of formula (VII) has a molecular weight ranging from 500 to 25,000.