Multimodal fluorescently labeled polymer-coated GdF3 nanoparticles inhibit degranulation in mast cells

Cu-In-S/ZnS:Gd3+ quantum dots with isolated fluorescent and paramagnetic modules for dual-modality imaging in vivo

Gd³⁺-doped quantum dots (QDs) have been widely used as small-sized bifunctional contrast agents for fluorescence/magnetic resonance (FL/MR) dual-modality imaging. However, Gd³⁺ doping will always compromise the FL of host QDs. Therefore, balancing the Gd³⁺ doping and the optical properties of QDs is crucial for constructing high-performance bifunctional nanoprobes. Additionally, most paramagnetic QDs are synthesized in the organic phase and need to be transferred to the aqueous phase for bioimaging. Herein, ingeniously designed shell-doped Cu-In-S/ZnS:Gd³⁺ QDs have been prepared in the aqueous phase. It has been demonstrated that isolating paramagnetic Gd³⁺ from fluorescent Cu-In-S core via doping Gd³⁺ into ZnS shell not only avoided the decrease of FL quantum yield (QY), but also ensured the water accessibility of paramagnetic Gd³⁺ ions, by which the FL QY and r₁ relaxivity of Cu-In-S/ZnS:Gd³⁺ QDs achieved as much as 15.6% and 15.33 mM^-1·s^-1, respectively. These high-performance QDs with excellent stability, low biotoxicity, and good tumor permeability were successfully applied for in vivo tumor FL/MR dual-modality imaging, and have shown significant potential in the precision detection and diagnosis of diseases.

Surface Biofunctionalization of Gadolinium Phosphate Nanobunches for Boosting Osteogenesis/Chondrogenesis Differentiation

In order to achieve smart biomedical micro/nanomaterials, promote interaction with biomolecules, improve osteogenic/chondrogenic differentiation, exhibit better dispersion in bone implants and ultimately maximize functionality, we innovatively and successfully designed and synthesized polymer PBLG-modified GdPO₄·H₂O nanobunches by hydroxylation, silylation and glutamylation processes. The effects of different feeding ratios on the surface coating of GdPO₄·H₂O with Si-OH, the grafting γ-aminopropyltriethoxysilane (APS) and the in situ ring-opening polymerization reaction of poly(g-benzyl-L-glutamate) (PBLG) were investigated, and the physical and chemical properties were characterized in detail. When GdPO₄·H₂O@SiO₂-APS:NCA = 4:1, the PBLG-g-GdPO₄·H₂O grafting rate was 5.93%, with good stability and dispersion in degradable polymeric materials. However, the MRI imaging signal was sequentially weakened as the modification process proceeded. Despite this, the biological effects had surprising findings. All the modifiers at appropriate concentrations were biocompatible and biologically active and the biomacromolecules of COL I and COL II in particular were expressed at least 3 times higher in GdPO₄·H₂O@SiO₂ compared to the PLGA. This indicates that the appropriate surface modification and functionalization of gadolinium-containing micro/nanomaterials can promote interaction with cells and encourage bone regeneration by regulating biomacromolecules and can be used in the field of biomedical materials.

PMVEMA-coated upconverting nanoparticles for upconversion-linked immunoassay of cardiac troponin

Surface engineering of upconverting nanoparticles (UCNPs) is crucial for their bioanalytical applications. Here, an antibody specific to cardiac troponin I (cTnI), an important biomarker for acute myocardial infection, was covalently immobilized on the surface of UCNPs to prepare a label for the detection of cTnI biomarker in an upconversion-linked immunoassay (ULISA). Core-shell UCNPs (NaYF₄:Yb,Tm@NaYF₄) were first coated with poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) and then conjugated to antibodies. The morphology (size and uniformity), hydrodynamic diameter, chemical composition, and amount of coating on the of UCNPs, as well as their upconversion luminescence, colloidal stability, and leaching of Y³⁺ ions into the surrounding media, were determined. The developed ULISA allowed reaching a limit of detection (LOD) of 0.13 ng/ml and 0.25 ng/ml of cTnI in plasma and serum, respectively, which represents 12- and 2-fold improvement to conventional enzyme-linked immunosorbent based on the same immunoreagents.