Patent ID: 7615233

Claim:
A particulate construct, comprising: an external solid phase containing a first and a second polyhydroxyalkanoate that are different; and an internal phase incorporated in said external solid phase, wherein said internal phase is at least one of a solid phase, a liquid phase or a gaseous phase, wherein the external solid phase has a gradient structure in which the monomer unit composition of said polyhydroxyalkanoates changes along a direction from the inner side to the outer side of said particulate construct, and wherein said first polyhydroxyalkanoate comprises at least one monomer unit selected from the group consisting of monomer units represented by chemical formulae: wherein R1 and a are selected from the group of combinations consisting of: R1 is a hydrogen atom (H) and a is 0 or any of integers from 3 to 10; R1 is a halogen atom and a is any of integers from 1 to 10; R1 is a chromophore and a is any of integers from 1 to 10; R1 is a carboxyl group or a salt thereof and a is any of integers from 1 to 10; and R1 is and a is any of integers from 1 to 7; wherein b represents any of integers from 0 to 7 and R2 is selected from a group consisting of a hydrogen atom (H), a halogen atom, —CN, —NO 2 , —CF 3 , —C 2 F 5 , and —C 3 F 7 ); wherein c represents any of integers from 1 to 8 and R3 is selected from a group consisting of a hydrogen atom (H), a halogen atom, —CN, —NO 2 , —CF 3 , —C 2 F 5 , and —C 3 F 7 ; wherein d represents any of integers from 0 to 7 and R4 is selected from a group consisting of a hydrogen atom (H), a halogen atom, —CN, —NO 2 , —CF 3 , —C 2 F 5 , and —C 3 F 7 ; wherein e represents any of integers from 1 to 8 and R5 is selected from a group consisting of a hydrogen atom (H), a halogen atom, —CN, —NO 2 , —CF 3 , —C 2 F 5 , —C 3 F 7 , —CH 3 , —C 2 H 5 , and —C 3 H 7 ; wherein f represents any of integers from 0 to 7; wherein g represents any of integers from 1 to 8; wherein h represents any of integers from 1 to 7 and R6 is selected from a group consisting of a hydrogen atom (H), a halogen atom, —CN, —NO 2 , —COOR′, —SO 2 R″, CH 3 , —C 2 H 5 , —C 3 H 7 , —CH(CH 3 ) 2 , and —C(CH 3 ) 3 , wherein R′ is selected from a group consisting of a hydrogen atom (H), Na, K, —CH 3 , and —C 2 H 5 , and R″ is selected from a group consisting of —OH, —ONa, —OK, a halogen atom, —OCH 3 , and —OC 2 H 5 ; wherein i represents any of integers from 1 to 7 and R7 is selected from a group consisting of a hydrogen atom (H), a halogen atom, —CN, —NO 2 , —COOR′, —SO 2 R″, wherein R′ is selected from a group consisting of a hydrogen atom (H), Na, K, —CH 3 , and —C 2 H 5 , and R″ is selected from a group consisting of —OH, —ONa, —OK, halogen atoms, —OCH 3 , and —OC 2 H 5 ; and wherein j represents any of integers from 1 to 9.