Upconversion Nanoparticles for Bioimaging and Regenerative Medicine

Abstract

Nanomaterials are proving useful for regenerative medicine in combination with stem cell therapy. Nanoparticles (NPs) can be administrated and targeted to desired tissues or organs and subsequently be used in non-invasive real-time visualization and tracking of cells by means of different imaging techniques, can act as therapeutic agent nanocarriers, and can also serve as scaffolds to guide the growth of new tissue. NPs can be of different chemical nature, such as gold, iron oxide, cadmium selenide, and carbon, and have the potential to be used in regenerative medicine. However, there are still many issues to be solved, such as toxicity, stability, and resident time. Upconversion NPs have relevant properties such as (i) low toxicity, (ii) capability to absorb light in an optical region where absorption in tissues is minimal and penetration is optimal (note they can also be designed to emit in the near-infrared region), and (iii) they can be used in multiplexing and multimodal imaging. An overview on the potentiality of upconversion materials in regenerative medicine is given.

Ultra-sensitive Nanoprobe Modified with Tumor Cell Membrane for UCL/MRI/PET Multimodality Precise Imaging of Triple-Negative Breast Cancer

“…The tumor-bearing mice were first injected with N 3 -DSPE-PEG-CCm 231 -UCNPs, N 3 -DSPE-PEG-RBCm-UCNPs, or N 3 -DSPE-PEG, and then 24 h after the injection, Al[ 18 F]F-L-NETA-DBCO was subsequently injected into the tumor-bearing mice via tail vein. First, L-NETA-DBCO was successfully radiolabeled with 18 F via Al-18 F chelation [33], and then, 18 F-labeled aza-dibenzocyclooctyne (DBCO) radioligands (Al[ 18 F] F-L-NETA-DBCO) were conjugated with azide-modified UCNPs by in vivo strain-promoted alkyne azide cycloaddition (SPAAC), which enables PET imaging [34]. PET static imaging was performed at 0.5, 1, 2, and 4 h after the injection of Al [ 18…”

A simple neridronate-based surface coating strategy for upconversion nanoparticles: highly colloidally stable125I-radiolabeled NaYF4:Yb3+/Er3+@PEG nanoparticles for multimodalin vivotissue imaging

“…10 Other advantages of the particles include minimum autofluorescence, a large anti-Stokes shift, narrow emission bandwidths and low scattering, which strongly decreases with increasing wavelength (∼1/λ 4 ). 11 The upconversion nanoparticles composed of a NaYF 4 crystal host lattice and doped by an optically active Yb 3+ /Er 3+ ion pair are able after the sequential absorption of two or more low-energy NIR photons to convert them into high-energy visible emission, which may subsequently serve for efficient photodynamic or photothermal therapy in situ. 12,13 Upconversion nanoparticles are thus highly promising for various applications in biological fields, such as in vitro cell labelling, 14 in vivo multimodal imaging and cell tracking, 15 controlled drug delivery, 16 photodynamic therapy, photoacoustic therapy, 17 and photothermal therapy.…”

Phthalocyanine‐Conjugated Upconversion NaYF4:Yb3+/Er3+@SiO2 Nanospheres for NIR‐Triggered Photodynamic Therapy in a Tumor Mouse Model

“…Recently,u pconversion nanomaterials have shown great promise for av ariety of applications ranging from solar energy conversion [1,2] and security areas [3] and even to biomedicine [4] for nanothermometry, [5] drug delivery, [6] early-stage in vivo bioimaging, [7,8] andt reatment of canceru sing photothermal [9] and photodynamic therapy (PDT). [10,11] PDT is an alternative to conventional treatments,s uch as surgery,c hemotherapy,a nd radiotherapy,d ue to its low toxicity andm inimal side effects on normalcells.…”