Figure 6. The bio-inspired 3D detoxifier.

(a) Rational design of the liver-mimetic 3D structure. The modified liver lobule topology allows toxins to enter the 3D matrix efficiently. (b) The masks that are used for printing liver-mimetic 3D structure. By alternatively using these masks in DOPsL technology, a bio-inspired detoxifier with four layers of liver-mimetic structure is created. (c) The 3D structure of the detoxifier measured by laser confocal microscopy. Incubated with melittin (50 μg ml⁻¹, 300 μl), the red fluorescence of PDA allows the reconstruction of the microstructure of the detoxifier in 3D. (d) Scanning electron microscope image of this detoxifier. Scale bar, 50 μm. (e) Dynamic test on the neutralization efficiency with comparison between the liver-mimetic structure (3D structure) and slab control (that is, with the same total volume). After the incubation of melittin solution with detoxifier for different times, the neutralization efficiency was tested by the haemolytic assay. (f) Centrifuged RBCs after incubation with normal saline (control), melittin (5 μg ml⁻¹), detoxifier-treated melittin or PDA nanoparticles-treated melittin. The red colour indicates the cytolysis of RBCs. (g) Neutralization efficiency of the 3D detoxifier. Equivalent amount of PDA nanoparticles is used for comparison.