Beilstein J. Nanotechnol.2022,13, 538–548, doi:10.3762/bjnano.13.45
substituents compared to PHEG-Tyr nanogel [25]. This assumption is also supported by the DH dependence (Figure 3a) showing a DH maximum at pH 7.4.
Adsorption and release of BSA and AAT
Next, optimization studies of in vitro loading of 125I-radiolabeled BSA as a model protein and its release from PHEG-Tyr and
Nα-Lys-NG nanogels were performed. 125I-radiolabeled BSA was loaded onto PHEG-Tyr nanogel at pH 4.7 and 25 °C as PHEG-Tyr nanogel exhibits the most swollen state and a negative charge under these conditions (Figure 2). The uptake of BSA was found to be more efficient at or below the isoelectric point
of BSA (pI 4.7) and, thus, BSA adsorption is driven by electrostatic and hydrophobic interactions [30][31]. PHEG-Tyr nanogel was incubated with three different 125I-radiolabeled BSA concentrations (1, 0.75, and 0.5 mg/mL), and the loading efficiency was found to be low, that is, 2.1% (21 µg/mL), 1.9
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Figure 1:
TEM images of PHEG-Tyr (a) and Nα-Lys-NG (b) nanogels prepared by HRP/H2O2-mediated crosslinking in...
Beilstein J. Nanotechnol.2015,6, 36–46, doi:10.3762/bjnano.6.5
surface was modified by PEGylation with mono- or bifunctional poly(ethylene oxide)amines (PEG). Using 125I-labeled test proteins (transferrin, albumin), the binding and exchange of corona proteins was studied first in vitro. Incubation with 125I-transferrin showed that with increasing grade of PEGylation
proteins. If non-labeled transferrin was used as preformed corona and excess 125I-labeled albumin was added to the reaction mixtures with different SPIOs, a substantial amount of label was bound to the particles with initially adsorbed transferrin but little or even zero with covalently bound transferrin
. These in vitro experiments show a clear difference in the stability of a preformed hard corona with adsorbed or covalently bound protein. This difference seems, however, to be of minor importance in vivo when polymer-coated 59Fe-SPIOs with adsorbed or covalently bound 125I-labeled mouse transferrin were
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Figure 1:
Synthesis and characterization of polymer-coated SPIOs with different surface charge due to PEGylat...