Silica Nanoparticles Decorated with Gadolinium Oxide Nanoparticles for Magnetic Resonance and Optical Imaging of Tumors

Abstract

structured nanoprobe that incorporates water-soluble silica and water-interacted gadolinium oxide, endowed with excellent hydrophilicity and high magnetic resonance imaging (MRI) relaxivity. The nanoprobes are monodispersed and uniformed with a superior stability due to the formation of Gd−O−Si bonds. The nanoprobe possesses an MRI relaxivity of 39.08 mM −1 s −1 , 9.3 times that of clinical Gd chelates, gaining a significant MRI enhancement in vivo; the classical Solomon− Bloembergen−Morgan theory is applied to explicate the relaxation enhancement mechanism. Multicolor and enhanced emissions are tunable through adjusting Yb 3+ /Li + -doping concentrations in Gd 2 O 3 :Yb 3+ /Er 3+ /Li + . A theoretical model based on the rate equations of upconversion energy-transfer processes is established to address the nanoprobe's photoluminescence. Cross-linked with folate-PEG, the nanoprobe can be absorbed by nasopharyngeal, cervical, and breast carcinoma cells, rendering a vivid multicolor living cell imaging. The nanoprobe owns a negligible nanotoxicity according to in vitro cytotoxicity and in vivo immunotoxicity, histopathology, and hematology assays. This study demonstrates that folate-PEGylated SiO 2 @Gd 2 O 3 :5%Yb 3+ /2%Er 3+ /6%Li + core@dotted-shell nanoprobes designated for multimodal imaging can achieve simultaneously enhanced MR relaxivity, photoluminescence efficiency, tumor-targeting ability, and biocompatibility. Both designing of nanoprobe and addressing MR/photoluminescence enhancement mechanism facilitate the development of practical multimodal imaging nanoprobes for accurate diagnosis of early tumors.

Click functionalized biocompatible gadolinium oxide core-shell nanocarriers for imaging of breast cancer cells

“…12,13 Also doping the gadolinium oxide particles with mesoporous silica enhanced T1 contrast of gadolinium due to silica geometrical connement. [14][15][16] Recent studies have revealed that the conjugation of Gd 3+ complexes with iron oxide NPs, and the combination of Gd 2 O 3 NPs with other magnetic materials, such as Fe 3 O 4 NPs into single composite particles leads to the enhancement of T1 and T2 contrast in MRI. In case of a thin gadolinium shell, nanocomposites provided higher relativity than a thick shell during MRI examinations.…”

Plasmon-induced double-field-enhanced upconversion nanoprobes with near-infrared resonances for high-sensitivity optical bio-imaging

“…3.0 g of carbamide, 1 mmol of Gd(NO 3 ) 3 •6H 2 O, Ln(NO 3 ) 3 •6H 2 O, and Yb(NO 3 ) 3 •5H 2 O with a relative molar ratio of 83:2:15 were dissolved into the as-prepared AuNSs colloidal solution and heated at 80 °C under water bath with forceful stirring for 5 h. After centrifugation at 8000 rpm for 8 min, the precursors were acquired and washed with deionized water and ethanol followed by drying in a vacuum refrigerant drier at minus 40 °C for 6 h. The AuNSA@Gd 2 O 3 :Yb 3+ /Ln 3+ (A-LnNPs) were successfully fabricated after being heated at 800 °C in a stove for 5 h and cooled down spontaneously (figure S1 (available online at stacks.iop.org/NANO/32/435201/mmedia)). The fabrication of SiO 2 nanocores, AuNSs and SiO 2 @Gd 2 O 3 :Yb 3+ /Ln 3+ NPs (S-LnNPs) [25] are supplied in supporting information.…”

Gadolinium-doped fluorescent carbon quantum dots as MRI contrast agents and fluorescent probes

“…During recent decades, much attention has been devoted to the T1 MRI contrast agents, since the T2 mode of MRI can be confused with hypointense lesions and the blooming effect generated by SPIONs 3 . Different T1 contrast agents based on the Gd 3+ are gadolinium doped iron oxide 4 , gadolinium PGMA-based supramolecular polycations (PGEDGd@PGEAs) 5 , gadolinium oxide nanoparticles (Gd 2 O 3 ) 6 , and gadolinium functionalized carbon materials (graphene oxide 7 , carbon nanotube 8 , fullerene 9 ). However, most of the mentioned T1 contrast agents are single-modal only for MRI 3 .…”