---The results show the potential of ligand free UCNPs for further functionalization and the potential for NaGdF4:Er3+, Yb3+ upconverting nanoparticles in targeting and delivery of heparinbinding growth factors and imaging of cancer cells.
---Survival rate of HeLa cells after 24 h of incubation with heparin coated and bFGF heparin functionalized UCNPs. Concentration of solution 0.5 mg mL1 in PBS.
Accepted 14th May 2012 Nanoscale
Junhua Gu Xiaojuan wang 2012.11.1
Outline
Background
---Ligand-free UNCPs
Ligand-free NaGdF4:Er3+,Yb3+ upconverting nanoparticle with heparin and basic fibroblastgrowth factor (bFGF) can be used to obtain high-contrast images of HeLa cells, which reveal that the heparin-bFGF functionalized nano particles show specific binding to the cell membrane.
---Absorption spectrum of BSA protein (0.2, 0.8, 1.6 and 2 mg mL1)–dye complex and absorption spectrum of heparinbFGFfunctionalized UCNPs. Inset: Bradford calibration curve at 590 nm. Right: Coomassie brilliant blue changes from grey to dark blue due to the presence of bFGF on the surface of the UCNPs.
Conclusion
---Ligand free NaGdF4:Er3+, Yb3+ upconverting nanoparticles may be functionalized with heparin, a biocompatible polysaccharide which plays an important role in protein and cell interactions, drug delivery and cancer diagnosis. ---The resulting water dispersible heparin-coated UCNPs were further functionalized with bFGF and both exhibited excellent luminescent properties. ---The HeLa cell images obtained after incubation with heparin coated and bFGF–heparin UCNPs clearly showed the nonspecific binding of the heparin coated UCNPs and the specific binding of the bFGF–heparin functionalized UCNPs to the cell membrane.
---Optical transmission image (top row), fluorescence image (middle row), and the overlay image (bottom row), of a group of HeLa cancer cells incubated at 37 C with a PBS solution (control) or a PBS solution containing 5 mg mL1 of ligand free, heparin and bFGF–heparin coated UCNPs.
Bio-functionalization of ligand-free upconverting lanthanide doped nanoparticles for bio-imaging and cell targeting
-Nicoleta Bogdan, Emma Martin Rodriguez, Francisco Sanz-Rodriguez, M Carmen Iglesias de la Cruz, Angeles Juarranz, Daniel Jaque, Jose Garcia Sole and Joha A, Capobianco
---Fourier transform infrared (FTIR) spectroscopy
It is used to characterize the functional groups
Experiment
Chemical structure of repeating units of the heparin sodium salts
---Absorption spectrum of Nile blue dye (D), heparin (H)–Nile blue dye (D) complex at various H/D ratios and absorption spectrum of heparin-coated Ln3+-UCNPs (HNP/D). Right: Nile blue dye solution and the same solution in presence of Ln3+-UCNPs after modification with heparin. The presence of heparin on theUCNPssurface causes the color of the dye to change from blue to purple.
The –NHSO3-,-CH2OSO3-,-O-SO3- and –COOgroups on the repeating disaccharide group cause the high negative charge density.
Experiment
Preparation of herarin-coated and bFGF-heperin coated Ln3+UCNPs
ห้องสมุดไป่ตู้
Results & discussion
---FTIR spectrum of heparin (black line), ligand free UCNPs (green line), heparin coated UCNPs (red line) and bFGF–heparin coated UCNPs (blueline).
---Imaging cells
Novel biocompatible luminescent probes and multiphoton fluorescence microscopy have a significant impact on imaging cells, both in vivo and in vitro.