Surface modified polystyrene particles as model carriers

Surface-modified Polystyrene Particles as Model Carriers 

The particle size of the polystyrene particles is also important. Both 60 and 150 nm particles coated with Poloxamer 407 were not sequestered by the macrophages in the bone marrow (they avoided capture by the Kupffer cells), whereas 250 nm particles (also coated with Poloxamer 207) were sequestered by the spleen and liver and only a small portion reached the bone marrow. 

3 Surface modified polystyrene particles as model carriers 

Two methods for surface modification could be applied (i) Adsorption of block copolymers of PEO-PPO-PEO, namely Poloxamers, or Poloxamines that are made of polyethylene diamine with four branches of PEG chains. The molecular weight of the 

PEG chain and hence the adsorbed layer thickness was crucial in preventing phagocytosis. For example, Poloxeimer 338 (with PEG chains of M = 5600) Wcts more efficient in preventing phagocytosis when compared with Poloxamer 108 (with PEG M, = 1800). A long PPO cheiin was also important to ensure anchoring of the block copolymer to the surface. 

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