Figure 3.

Macrophage response to biomaterials depending on the size of the implanted materials. Macrophages respond to small fragments and particles (<10 μm in diameter) by internalization via phagocytosis and intracellular digestion. If the particle size is larger than 10 μm and smaller than 100 μm, the macrophages fuse together forming giant cells which in turn engulf the particles and digest them. If the particles are larger, the bulk digestion is carried out via extracellular degradation by macrophages and macrophage fused giant cells through release of enzymes and/or pH lowering mechanisms [35].