Effects of immunological adjuvants on the mouse complement system — II. Anti-complementary effects of surface-active compounds

Klerx, J.P.A.M.; Dijk, Hans van; Kouwenberg, E. A.; Maaden, W. J. Van Der; Willers, J. M. N.

doi:10.1016/0192-0561(86)90072-x

Cited by 8 publications

(1 citation statement)

References 24 publications

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“…Surface-localized PEG chains reduce nonspecific protein adsorption (and false positive results) in solid phase diagnostics and on polystyrene latex microspheres used in biomedical assays . They may improve the biocompatibility of materials used in implant and extracorporeal therapies. , They can also be used to control wall wetting plus reduce the variable, pH-sensitive electroosmosis and adsorption phenomena which compromise free solution, (capillary) electrophoresis. − Coatings of other uncharged, water-soluble polymers, such as polyglucose-based dextran or alkyl−ether modified celluloses, behave similarly ,, although some polymers, including PEG−PPG block copolymers, may activate serum complement and related immune mechanisms. , …”

Section: Introductionmentioning

confidence: 99%

Poly(ethylene glycol) Amphiphiles: Surface Behavior of Biotechnical Significance

Alstine

Malmsten

1997

Langmuir

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The interfacial behavior of surface localized, poly(ethylene glycol) (PEG) esterified fatty acid amphiphiles was comparatively studied at microparticle surfaces via phase partition and at flat surfaces via in situ null ellipsometry. Ellipsometry was performed on methylsilane (MeSi), phosphatidic acid (PA), and phosphatidylcholine (PC) coated silica slides, while human erythrocyte and PC liposomes were subjected to partition in aqueous PEG, dextran two-phase systems. Analogous results from both methods suggest that PEG−amphiphile adsorption can be relatively independent of the underlying surface. Ellipsometry indicated that members of a series of PEG-fatty acid esters of the type C i : j −EO151 (16 ≤ i ≤ 18, 0 ≤ j ≤ 2) adsorb similarly at MeSi-, PC-, and PA-coated surfaces, reaching a plateau (≈0.1 PEG chains·nm-2) independent of micelle formation. When normalized for acyl tail hydrophobicity, PEG−amphiphile adsorption is relatively noncooperative and independent of the acyl tail; saturation is largely determined by repulsive PEG interchain interactions. At saturation, EO151−ester layers were 10−15 nm thick, suggesting close packed PEG molecules unfolded normal to the target surface. Ellipsometry also indicated the average PEG concentration in the layer was ≈0.07 g·cm-3, and greater than in the PEG-enriched phase of many two-phase systems. This suggests that the partition of PEG-coated colloids reflects interfacial free energy differences between solution- and surface-localized, polymer-enriched phases. PEG−ester adsorption (mg·m-2) isotherms determined on flat slides via ellipsometry correlate directly with those reflected by the partition of analogous microparticles. These results help explain previous observations that changes in partition induced by surface-localized PEG mirror the effects of such localization on the physiological behavior of bioactive colloids.

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