Co-assembled phenolic particles with metal ions and small molecule drugs. (a) The chemical structures of building blocks (Pt–OH, PEG-b-PPOH) and schematic illustration of a phenolic particle prepared by co-polymerization. (b) TEM image of the as-prepared phenolic particles. (a and b) Reproduced with permission. Copyright 2020, Wiley-VCH. (c) Schematic illustration of synthesis of PDA-coated and NIR-responsive carrier-free “nanobomb” (DNPs/N@PDA). (d) TEM images of the DOX nanoparticles (DNPs), PDA-coated DNPs (DNPs@PDA), and NH4HCO3-loaded DNPs@PDA (DNPs/N@PDA). (c–f) Reproduced with permission. Copyright 2018, Wiley-VCH.