31 research outputs found
Imparting Functionality to MOF Nanoparticles by External Surface Selective Covalent Attachment of Polymers
Selective
functionalization of the external surface of porous nanoparticles
is of great interest for numerous potential applications in the field
of nanotechnology. Regarding metal–organic frameworks (MOFs),
few methods for such modifications have been reported in the literature.
Herein, we focus on the covalent attachment of functional polymers
on the external surface of MIL-100(Fe) nanoparticles in order to implement
properties such as increased chemical and colloidal stability or dye-labeling
for the investigation of the particles by fluorescence based techniques.
We prove covalent nanoparticles-polymer bond formation by liquid NMR
after dissolution of the functionalized MOF under mild conditions
and estimate the amount of covalently attached polymer by UV–vis
spectroscopy. The functionalization of the MOF nanoparticles with
fluorescently labeled polymers enables the investigation of nanoparticle
uptake into tumor cells by fluorescence microscopy. Furthermore, the
influence of the polymer shell on the magnetic resonance imaging activity
of MIL-100(Fe) is investigated in detail. The functionalization approach
presented here is expected to enable the fabrication of hybrid nanomaterials,
extending the enormous chemical space of MOFs into polymer materials
Column charts of SI<sub>10min</sub> in the therapy and control group at follow-up.
<p>Note the significant difference (p < 0.05) between the mean values of SI<sub>10min</sub> between the therapy and the control group at the follow-up.</p
Line regression analysis for the correlation between CEUS parameter of VEGFR2-specific binding and immunohistochemical VEGFR2 expression.
<p>Note the significant correlation between the values of SI<sub>8min</sub> and the number of VEGFR2 positive stained vessels (Spearman´s ρ = 0.66, p = 0.003) for the therapy and the control group.</p
Representative CEUS images of a rat with a subcutaneous tumor xenograft (white arrows) under treatment.
<p>Therapy group (red) and control group (blue) at baseline and follow-up. Left side: early vascular phase with BR55 as a functional imaging biomarker; right side: late phase of VEGFR2-specific binding with BR55 as a molecular imaging biomarker 8 minutes after contrast injection. Note the significant lower number of circulating microbubbles in the early vascular phase as well as the significant lower number of bound microbubbles in the late phase at follow-up in the therapy group, compared to baseline and compared to the control group.</p
Correlations between functional CEUS values and immunohistochemistry.
<p>Correlations between functional CEUS values and immunohistochemistry.</p
Individual values of functional parameters of tumor microcirculation in the therapy group at baseline and follow-up.
<p>Note: F<sub>p</sub>: plasma flow [mL/100 mL/min]; V<sub>p</sub>: plasma volume [%]; PS: permeability-area surface product [mL/100 mL/min]; <sup>a</sup>baseline; <sup>b</sup>follow-up.</p
Correlations between molecular CEUS values and immunohistochemistry.
<p>Correlations between molecular CEUS values and immunohistochemistry.</p