This article briefly describes some new approaches to stimuli-sensitive polymeric micelles and hoHow spheres

which were developed in the authors’laboratory in recent years．(1)Self-assembly of component polymers via specific interactions to construct non-covaienfly connected micelles (NCCM)．For example

in water

PCL and PAA formed core-shell particles driven by interpolymer hydrogen bonding．After erosslinking the PAA shell and removing the PCL core

“nanoeages”made of PAA network were obtained．This hollow structure shows perfect reversible size-pH dependence．(2) Simultaneous in-situ polymerization of monomers and self-assembly of the polymers．In this approach

PNIPAM network were formed by radical polymerization covering PCL particles Hollow spheres of PNIPAM network was then obtained by biodegradation of the PCL core．Both the core-shell spheres and hollow spheres show reversible size dependence on temperature change because of PNIPAM undergoing phase transition around 32℃．(3) Complexation-induced mieellization and transition between the micelles and hollow spheres Graft copolymers of hydmxylethyl cellulose (HEC) and PAA were prepared by free radicai polymerization．The copolymers showed pH dependent micellization

i．e．mieelles formed when pH of the graft copelymer solution decreased to around 3．The mieellar structure could be loeked by crosslinking PAA grafts．The resultant cross-linked mieelles undergo pH-dependent transition between the micelles and hollow sphere

which accompanies a remarkable particle size change．Both the micellization and the structure transition were found to be reversible and associated with H-bonding complexation between the main chain and grafts．