Nanoparticles comprise a drug, a first block polymer and a second block polymer. The first block polymer has a poly(ethylene oxide) (PEO) block and a polycarbonate block bearing a side chain aromatic nitrogen-containing heterocycle (N-heterocycle). The N-heterocycle can be in the form of a base, a hydrosalt of the base, a sulfobetaine adduct of the base, or a combination thereof. The second block polymer has a PEO block and a polycarbonate block bearing a side chain catechol group, which can be present as a catechol, oxidized form of a catechol, and/or a polymerized form of a catechol. The nanoparticles can be dispersed in water and are capable of controlled release of the drug.