Macromolecules, phagocytic uptake

On the other hand, large macromolecules are subjected to nonspecific phagocytic uptake. This can occur in liver and blood by means of scavenger cells (i.e., reticuloendothelial system [RES] cells). Large proteins such as adenosine deaminase (170 kDa) and somatotropin (192 kD a) accumulate in the liver and are cleared by RES cells (Table 13.4). 

Phagocytic processes are also finding applications in oral drag delivery and targeting. Specialized epithelial cells known as M cells, which overly lymphoid sections of the gastrointestinal tract, may be involved in the phagocytic uptake of macromolecules and microparticles from the gut (see Section 6.2.2). 

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