Figure 6.

A schematic exhibiting the synthesis procedure of pHEMA-PMMA-magnetite (Fe₃O₄) (A); the TEM micrographs of the cross-linked pHEMA nanogel (chemically) (a), the cross-linked pHEMA microgel (physically and chemically) (b), Fe₃O₄-coated cross-linked pHEMA-methotrexate (c), pHEMA-PMMA-Fe₃O₄ (Janus) (d) (B); the release trends of methotrexate from pHEMA-PMMA-Fe₃O₄ nanoparticles (C); the magnetic hysteresis loops of bare Fe₃O₄ and final pHEMA-PMMA-Fe₃O₄ nanoparticles (a) plus separation of pHEMA-PMMA-Fe₃O₄ nanoparticles in water by a magnet (b) (D). Reprinted from [15], with permission from the American Chemical Society. (Red arrow: in Figure (b) show coagulation of cross-linked pHEMA nanogel).