Synthetic amphiphilic polymers based micelles have been extensively applied for site-specific delivery of bioactive therapeutic and imaging agents.Despite the wide pre-/clinical studies of polymeric micelles for these purposes, several drawbacks including their instability and unideal surface chemistry are still unsolved which seriously lower the in vitro/vivo performance.To enhance the micellar stability, π-π stacking interactions were introduced by copolymerizing aromatic monomers in the polymers.Based on these aromatic polymers, a platform technology for loading hydrophobic aromatic compounds in micelles was developed.Hydrophobic drugs, i.e., paclitaxel and docetaxel, and a photodynamic therapy agent, Si(sol)2Pc,were encapsulated in the micelles with high loading capacities, as well as significantly enhanced drug retention.Apart from that, by the π-π stacking between the polymer chains and Si(sol)2Pc,the micelles could molecularly load around 200 times more Si(sol)2Pc in its active form (i.e.non-aggregated form), which increased the singlet oxygen generation by the Si(sol)2Pc in the aromatic micelles.Consequently, the Si(sol)2 Pcencapsulated in the aromatic micelles showed high cytotoxicity under light irradiation to B16F10 cells.In a follow-up in vivo study, paclitaxel loaded polymeric micelles showed significantly enhanced tumor accumulation and therapeutic efficacy.Two types of micelles with a non-PEG stealth corona were prepared from di/triblock amphiphilic thermo-sensitive polymer synthesized by RAFT polymerization, with p(HPMA) hydrophilic block and thermo-sensitive blocks based on HPMA derivatives.These polymers form micelles by heating an aqueous polymer solution to 50 ℃ and paclitaxel could be loaded in the micelles.Moreover, the triblock copolymer based micelles were crosslinked via pH-seusitive hydrazone linkers.Hydrolysis of the polymeric micelles to a water-soluble p(HPMAm) which is biocompatible and biodegradable and can be excreted by renal filtration.Fluorescent labelling of polymeric micelles for noninvasive in vivo imaging has been increasingly interesting.We have developed a post-polymerization procedure capable of chemical entrapment of multiple fluorophores in crosslinked micelles, which were sequentially crosslinked by reduction-sensitive cystamine.The micelles after i.v.injection into CT26-tumor bearing mice showed tumor accumulation of around 4-6% by a hybrid μCT-FMT imaging of the NIR fluorophore.By 3D two-photon laser scanning microscopy utilizing the blue excitation fluorophore, the intra-tumor localization of the micelles was revealed and it showed deep penetration of the micelles into the tumor tissues from the local blood vessels.The overall results show that the synthesized polymeric micelles are a versatile system for delivering imaging agents and potential tumor-targeted drug delivery system.To conclude, the current problems of polymeric micelles as delivery systems can be improved by tailoring the polymer chemistry of the micelle-forming polymers, and the above-mentioned polymeric micelles show a high potential for further pharmaceutical applications.