Surface modification of polymer latex particles by AGET ATRP of a styrene derivative bearing a lactose residue

Grafting of a styrene derivative bearing a lactose residue, i.e., N-2-4-(vinylbenzenesulfonamido)ethyl lactobionamide (VBSAELA), onto polymer latex particles was carried out in aqueous media by activator generated electron transfer atom transfer radical polymerization (AGET ATRP). The core polymer latex particles having α-chloroester groups as ATRP-initiating groups were prepared by miniemulsion polymerization of styrene and 2-chloropropionyloxyethyl methacrylate (CPEM) in the presence of a polymerizable surfactant, i.e., N,N-dimethyl-N-dodecyl-N-2-methacryloyloxyethylammonium bromide (C₁₂Br). AGET ATRP was initiated with tris[(2-pyridylmethyl)amine] copper (II) dichloride and l-ascorbic acid. Dynamic light scattering (DLS) revealed that the P(St-CPEM)-g-P(VBSAELA) particles possess graft layers of 10 nm in thickness on the core particles of 91 nm in diameter. Critical coagulation concentration measurement revealed that the dispersion stability of the particles in water increased due to hydrated P(VBSAELA) shell layers. Adsorption of bovine serum albumin (BSA) onto the particles was considerably suppressed by the hydrated shell layers.