Interactions of serum proteins and alkaline phosphatase with poly(styrene/α‐tert‐butoxy‐ω‐vinylbenzyl‐polyglycidol) microspheres with various surface concentrations of polyglycidol

Abstract

Interactions of human serum albumin, gamma globulins and alkaline phosphatase with surface of hydrophilic microspheres are described. Relation between the composition of particles surface layer and adsorption/covalent immobilization and activity of proteins is elucidated. The set of poly(styrene/α‐tert‐butoxy‐ω‐vinylbenzyl‐polyglycidol) microspheres (poly(S/PGly)) was synthesized via emulsion copolymerization of styrene and α‐tert‐butoxy‐ω‐vinylbenzyl‐polyglycidol (PGL) macromonomer (Mn = 3000, Mw/Mn = 1.08). The way of addition of PGL macromonomer was different in particular subsets of syntheses; however, the total concentration of all compounds added to the polymerization mixture was kept constant. Namely, PGL was continuously injected beginning injection at various stages of styrene conversion or it was added together with styrene at the beginning of the polymerization. The syntheses yielded microspheres with a number average diameter measured by SEM in a range from 300 to 564.7 nm, and dispersities (Dw/Dn) lower than 1.004, depending on the method of addition of PGL to the polymerization mixture. Studies of proteins' adsorption allowed for determination of relation between the surface concentration of adsorbed protein and chemical composition of the particles interfacial layer. Activation of hydroxyl groups in polyglycidol by 1,3,5‐trichlorotriazine allowed for the controlled covalent immobilization of proteins onto particles. The accompanying physical adsorption was low. Studies of the activity of alkaline phosphatase covalently bonded to the surface of the poly(S/PGly) particles with the fraction of PGL in the particles' interfacial layer (fPGL = 20.6 mol% revealed that the activity of the covalently immobilized enzyme was 4.6 times higher than activity of the enzyme adsorbed on the surface of the polystyrene microspheres. Copyright © 2014 John Wiley & Sons, Ltd.

Gamma Globulins Adsorption on Carbofunctional Polysiloxane Microspheres

“…weight of c-globulins equal 160 kDa, the dimensions 23/2.5/2.5 nm and assuming their vertical orientation with contracted F(ab) fragment [25]. Data in Table 2 indicate that in some cases the degree of coverage exceeds 100 %, suggesting formation of a protein layer thicker than the monolayer.…”

“…These proteins were selected for the studies because they are well defined and show a high affinity to surfaces of many materials [22][23][24][25]. They are often used in studies of protein adsorption [22,[24][25][26]. Gamma globulins are present in biological fluids where they play important physiological roles [27].…”

Characterization methods of polymer core–shell particles

“…The presence of hydrophilic or hydrophobic [31] polymers on a particle's surface creates opportunities for specific applications. Moreover, shell-building polymers can exhibit specific properties, such as thermosensitivity in the case of PNIPAM [30] and PNVIBA, antifouling behaviour of poly(ethylene glycol) (PEG) [32,33] and polyglycidol [22] or conductivity in the case of polypyrrole [4,34] and polyaniline [35]. To examine the surface composition, direct and indirect methods can be applied.…”

“…It has been shown that an increase in the molar fraction of polyglycidol macromonomer during synthesis resulted in the increased amount of polyglycidol fraction in the surface. The authors also examined the influence of changes in the particles' synthesis conditions, namely from batch (all reagents introduced from the beginning of the process) to continuous (polyglycidol macromonomer was added in a continuous manner to the reaction mixture) polymerization [22].…”

“…In addition to the XPS method, the presence of polyglycidol on the surface of poly(styrene/polyglycidol) particles was also demonstrated through protein adsorption studies [22,49]. Particles were obtained by emulsion polymerization of styrene and macromonomer α-tert-butoxy-ω-vinylbenzyl-polyglycidol in water.…”