A novel DAD type and folic acid conjugated fluorescent monomer as a targeting probe for imaging of folate receptor overexpressed cells.

We describe a modification and post-functionalization technique for a donor-acceptor-donor type monomer; 6-(4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2H-benzo[d][1,2, 3]triazol-2-yl)hexan-1-amine. Folic acid was attached to the fluorescent structure. The conjugation was confirmed via NMR and Fourier transform infrared analyses. Cytotoxicity was investigated and the comparison of association of targeted monomeric structures in tumor cells was monitored via fluorescence microscopy.

Biofunctional quantum dots as fluorescence probe for cell-specific targeting.

We describe here the synthesis, characterization, bioconjugation, and application of water-soluble thioglycolic acid TGA-capped CdTe/CdS quantum dots (TGA-QDs) for targeted cellular imaging. Anti-human epidermal growth factor receptor 2 (HER2) antibodies were conjugated to TGA-QDs to target HER2-overexpressing cancer cells. TGA-QDs and TGA-QDs/anti-HER2 bioconjugates were characterized by fluorescence and UV-Vis spectroscopy, X-ray diffraction (XRD), hydrodynamic sizing, electron microscopy, and gel electrophoresis. TGA-QDs and TGA-QDs/anti-HER2 were incubated with cells to examine cytotoxicity, targeting efficiency, and cellular localization. The cytotoxicity of particles was measured using an MTT assay and the no observable adverse effect concentration (NOAEC), 50% inhibitory concentration (IC50), and total lethal concentration (TLC) were calculated. To evaluate localization and targeting efficiency of TGA-QDs with or without antibodies, fluorescence microscopy and flow cytometry were performed. Our results indicate that antibody-conjugated TGA-QDs are well-suited for targeted cellular imaging studies.

From invisible structures of SWCNTs toward fluorescent and targeting architectures for cell imaging.

Single-walled carbon nanotubes (SWNTs) are unique nanostructures used as cargo systems for variety of diagnostic and therapeutic agents. For taking advantage of these structures in biological processes, they should be visible. Therefore, fluorescence labeling of SWCNTs with various probes is a significant issue. Herein, we demonstrate a simple approach for cell specific imaging and diagnosis by combining SWCNTs with a copolymer poly(para-phenylene) (PPP) containing polystyrene (PSt) and poly(ε-caprolactone) (PCL) side chains (PPP-g-PSt-PCL). In this approach PPP-g-PSt-PCL is noncovalently attached on carboxyl functional SWCNTs. The obtained fluorescent probe is bound to folic acid (FA) for targeted imaging of folate receptor (FR) positive HeLa cells. In vitro studies demonstrate that this conjugate can specifically bind to HeLa cells and indicate great potential for targeting and imaging studies.

Folic acid-modified clay: targeted surface design for cell culture applications.

Here we report the preparation, characterization and application of folic acid modified Montmorillonite clay (FA-Mont) as a cell culture material. Clays exhibit unique properties such as good mechanical and chemical stabilities, high surface area, low toxicity and easy combination with functional organic groups. FA was used as a modifier to facilitate adhesion of folate positive cells on the clay surface. FA-Mont was characterized using FT-IR, XRD, zeta potential measurements as well as thermogravimetric analyses. Finally, the usage potential of FA-Mont as a receptor mediated cell adhesion material was successfully proved by using folate receptor (FR) rich HeLa and FR poor A-549 cells. The cell adhesion studies were monitored and imaged by fluorescence and scanning electron microscopy techniques.