Gum Arabic coated magnetic nanoparticles with affinity ligands specific for antibodies

Abstract

A novel magnetic support based on gum Arabic (GA) coated iron oxide magnetic nanoparticles (MNP) has been endowed with affinity properties towards immunoglobulin G (IgG) molecules. The success of the in situ triazine ligand synthesis was confirmed by fluorescence assays. Two synthetic ligands previously developed for binding to IgG, named as ligand 22/8 (artificial Protein A) and ligand 8/7 (artificial Protein L) were immobilized on to MNPs coated with GA (MNP_GA). The dimension of the particles core was not affected by the surface functionalization with GA and triazine ligands. The hydrodynamic diameters of the magnetic supports indicate that the coupling of GA leads to the formation of larger agglomerates of particles with about 1 microm, but the introduction of the triazine ligands leads to a decrease on MNPs size. The non-functionalized MNP_GA bound 28 mg IgG/g, two times less than bare MNP (60 mg IgG/g). MNP_GA modified with ligand 22/8 bound 133 mg IgG/g support, twice higher than the value obtained for ligand 8/7 magnetic adsorbents (65 mg/g). Supports modified with ligand 22/8 were selected to study the adsorption and the elution of IgG. The adsorption of human IgG on this support followed a Langmuir behavior with a Q(máx) of 344 mg IgG/g support and K(a) of 1.5 x 10(5) M. The studies on different elution conditions indicated that although the 0.05 M citrate buffer (pH 3) presented good recovery yields (elution 64% of bound protein), there was occurrence of iron leaching at this acidic pH. Therefore, a potential alternative would be to elute bound protein with a 0.05 M glycine-NaOH (pH 11) buffer.

Biofunctional Composites of Polysaccharides Containing Inorganic Nanoparticles

“…For example dextran coated magnetic nanoparticles functionalized with different ligands were tested for the separation of lectins from legume extracts, using high-gradient magnetic separation technique (Heebøll-Nielsen et al, 2004). Gum Arabic coated iron oxide nanoparticles were functionalized with triazine ligands with specificity towards antibodies and successfully used for the antibody immobilization (Batalha et al, 2010). Due to the intrinsic ability of the polysaccharides to coordinate to metal ions, polysaccharide based magnetic nanocomposites have been explored in magnetically assisted water purification (Ambashta & Sillanpää, 2010;Liu et al, 2009).…”

Bioinspired and sustainable chitosan-based monoliths for antibody capture and release

“…In this work, the density of ligand 22/8 immobilized in chitosan-based monoliths was 10-fold the value reported for ligand 22/8 immobilized in agarose beads, 5,6 70-fold on cellulose membranes, 7 and less than 2-fold on magnetic nanoparticles. 8 It can also be noted that, in general, the density of immobilized ligand 22/8 is quite high when compared to the values obtained for immobilized natural ligands. 23,28 To the best of our knowledge, this is the first report on the preparation of affinity monoliths with such a high ligand density.…”

“…5 Ligands based on a triazine scaffold, in particular ligand 22/8 or artificial protein A, and are known to be low cost and highly resistant to the harsh conditions employed during cleaning-in-place (CIP) and sterilization-in-place (SIP). 5,6 Ligand 22/8 has been immobilized on agarose, 5 cellulose membranes, 7 and magnetic particles, 8 and shown to selectively bind to human Immunoglobulin G (hIgG) when employed in chromatographic processes. With the need to treat large volumes of concentrated antibody solutions, fast processes with high selectivity are desired.…”

Phosphocholine-Modified Magnetic Nanoparticles for Isolation of C-Reactive Protein from Human Serum

“…dye-ligand (5-6); 2. transition metal for the chelation of proteins (7)(8); and 3. specific ligand complementary to the target molecule (9)(10)(11)(12)(13)(14).…”