Geometrical effects, compartmentalized

Another specifity of in vivo conditions is given by the compartmental nature of the body discussed above, Pinocytosis or phagocytosis represent a transport of the polymer in the interior of the cell only in the geometrical sense because the polymer remains physiologically isolated from the cytoplasma by the lysosomal membrane. There are techniques which can open the membrane for macromolecules, e.g. osmotic manipulation or fusing with liposomes However, as far as we know, they have not yet been employed in the study of the effects of synthetic polymers in the cell interior. Although all in vitro studies of the direct interaction of synthetic polymers with nucleic acids, mitochondria, intracellular enzymes, etc., are of undeniable theoretical importance, they yield little information on the effect of these polymers in vivo. 

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