Bisphosphonate-Modified Polymer-Coated NaYF₄:Yb,Er,Pr Upconverting Nanoparticles for Cell Imaging: Synthesis,...

Area of Science:

• Nanomedicine
• Biomaterials
• Optical Imaging

Background:

• Upconverting nanoparticles (UCNPs) possess unique photon upconversion properties valuable for nanomedicine.
• However, inherent cytotoxicity of UCNPs limits their biomedical applications.
• Developing biocompatible UCNPs is crucial for advancing nanomedical technologies.

Purpose of the Study:

• To design and synthesize novel UCNPs with improved biocompatibility and dual-region luminescence (visible and NIR-II).
• To evaluate the physicochemical properties, cytotoxicity, and in vivo biosafety of the developed UCNPs.
• To demonstrate the potential of these UCNPs for cellular imaging applications.

Main Methods:

• Synthesis of bisphosphonate-modified poly(isobutylene-alt-maleic acid)-graft-poly(N,N-dimethylacrylamide)-coated NaYF4:Yb,Er,Pr UCNPs (UCNP@PIMAPDMA).
• Characterization using TEM, EDAX, DLS, XRD, spectrofluorometry, and XPS.
• In vitro cytotoxicity assessment using MTT assay on HEK293 cells.
• In vivo biocompatibility studies in mice, monitoring body mass and blood parameters.
• Cellular imaging of rat mesenchymal stem cells and C6 glioblastoma cells via confocal microscopy.

Main Results:

• UCNP@PIMAPDMA nanoparticles exhibited luminescence in both visible and NIR-II regions.
• Characterization confirmed the nanoparticles' structure and properties.
• UCNP@PIMAPDMA showed significantly lower cytotoxicity compared to neat UCNPs.
• In vivo studies revealed no significant adverse effects on mice.
• Successful imaging of cellular cytoplasm was achieved, demonstrating application potential.

Conclusions:

• The developed UCNP@PIMAPDMA nanoparticles demonstrate enhanced biocompatibility and reduced cytotoxicity.
• These modified UCNPs possess dual-region luminescence suitable for advanced biomedical imaging.
• The formation of a protein corona may contribute to the improved biosafety of UCNP@PIMAPDMA.
• UCNP@PIMAPDMA nanoparticles hold promise for future applications in nanomedicine and bioimaging.