(Problems) The object of the present invention is to provide an inverted-opal structure which is excellent in biodegradability,
biocompatibility, and pH responsiveness, has specific
light reflection property due to three-dimensionally-ordered-pores formed therein, is capable of releasing a
drug autonomously and intermittently by responding rapidly to pH change, and is capable of measuring the
drug-release associated with its
biodegradation by an optical means rapidly in a simple and easy way; a method for manufacturing the inverted-opal structure; a medical
implant comprising the inverted-opal structure; a method for enlarging the
pore diameter; and a method for measuring the release-amount of a
drug held in the inverted-opal structure.(Means for Solving Problems) The present invention provides a biodegradable inverted-opal structure comprising an aliphatic
polyester; and a method for manufacturing a biodegradable inverted-opal structure, comprising the steps of: (1) producing a
colloidal crystal from a
silica particle or a
polystyrene particle; (2) immersing the
colloidal crystal in a solution including a
monomer from which the aliphatic
polyester is formed; (3) thermally-polymerizing the
monomer under a pressurized condition in order to obtain a composition of the
colloidal crystal coated with the aliphatic
polyester; and (4) removing the
silica particle from said composition by
etching, or removing the
polystyrene particle from said composition by eluting the
polystyrene particle with an
organic solvent in order to obtain the biodegradable inverted-opal structure.