Novel carboxyl-and amino-functionalized copolyesters, based on poly(e-caprolactone)-block-poly(butylene fumarate)-block-poly(epsilon-caprolactone), were efficiently synthesized via Michael-type thiol-ene click chemistry. The resulting amphiphilic copolyesters with controllable molecular weights and abundant positively or negatively charged groups could spontaneously form pH-sensitive micelles in aqueous solutions, as confirmed by transmission electron microscopy, dynamic light scattering, fluorescence probing technique, and zeta potential analyses. Importantly, charge-reversal hybrid micelles can be obtained by co-assembly of carboxyl- and amino-functionalized copolyesters. The surface charges of hybrid micelles reversed rapidly from negative to positive at isoelectric point via protonation of surface carboxyl and amino groups. Interestingly, the hybrid micelles showed apparent pH-triggered Nile red-release behavior in acidic condition resembling tumor intracellular environment, which is fairly desirable for drug delivery. Our work indicates that co-assembly is a facile but efficient way to prepare charge-reversal micelles, which have great potential to be used as intelligent drug delivery systems for cancer therapy. (C) 2015 Wiley Periodicals, Inc.