2 research outputs found
Porphyrin-magnetite nanoconjugates for biological imaging
<p>Background: The use of silica coated magnetic nanoparticles as contrast agents has resulted in the production of
highly stable, non-toxic solutions that can be manipulated via an external magnetic field. As a result, the
interaction of these nanocomposites with cells is of vital importance in understanding their behaviour and
biocompatibility. Here we report the preparation, characterisation and potential application of new âtwo-in-oneâ
magnetic fluorescent nanocomposites composed of silica-coated magnetite nanoparticles covalently linked to a
porphyrin moiety.</p>
<p>Method: The experiments were performed by administering porphyrin functionalised silica-coated magnetite
nanoparticles to THP-1 cells, a human acute monocytic leukaemia cell line. Cells were cultured in RPMI 1640
medium with 25 mM HEPES supplemented with heat-inactivated foetal bovine serum (FBS).</p>
<p>Results: We have synthesised, characterised and analysed in vitro, a new multimodal (magnetic and fluorescent)
porphyrin magnetic nanoparticle composite (PMNC). Initial co-incubation experiments performed with THP-1
macrophage cells were promising; however the PMNC photobleached under confocal microscopy study. bmercaptoethanol (b-ME) was employed to counteract this problem and resulted not only in enhanced
fluorescence emission, but also allowed for elongated imaging and increased exposure times of the PMNC in a
cellular environment.</p>
<p>Conclusion: Our experiments have demonstrated that b-ME visibly enhances the emission intensity. No deleterious
effects to the cells were witnessed upon co-incubation with b-ME alone and no increases in background
fluorescence were recorded. These results should present an interest for further development of in vitro biological
imaging techniques.</p>