Breakthroughs in medicine and bioimaging with up-conversion nanoparticles (original) (raw)
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Materials, 2022
Upconverting luminescent nanoparticles (UCNPs) are “new generation fluorophores” with an evolving landscape of applications in diverse industries, especially life sciences and healthcare. The anti-Stokes emission accompanied by long luminescence lifetimes, multiple absorptions, emission bands, and good photostability, enables background-free and multiplexed detection in deep tissues for enhanced imaging contrast. Their properties such as high color purity, high resistance to photobleaching, less photodamage to biological samples, attractive physical and chemical stability, and low toxicity are affected by the chemical composition; nanoparticle crystal structure, size, shape and the route; reagents; and procedure used in their synthesis. A wide range of hosts and lanthanide ion (Ln3+) types have been used to control the luminescent properties of nanosystems. By modification of these properties, the performance of UCNPs can be designed for anticipated end-use applications such as phot...
Nanomaterials, 2014
Lanthanide-doped upconversion-luminescent nanoparticles (UCNPs), which can be excited by near-infrared (NIR) laser irradiation to emit multiplex light, have been proven to be very useful for in vitro and in vivo molecular imaging studies. In comparison with the conventionally used down-conversion fluorescence imaging strategies, the NIR light excited luminescence of UCNPs displays high photostability, low cytotoxicity, little background auto-fluorescence, which allows for deep tissue penetration, making them attractive as contrast agents for biomedical imaging applications. In this review, we will mainly focus on the latest development of a new type of lanthanide-doped UCNP material and its main applications for in vitro and in vivo molecular imaging and we will also discuss the challenges and future perspectives.
Upconversion nanoparticles in biological labeling, imaging, and therapy
Analyst, 2010
Upconversion refers to non-linear optical processes that convert two or more low-energy pump photons to a higher-energy output photon. After being recognized in the mid-1960s, upconversion has attracted significant research interest for its applications in optical devices such as infrared quantum counter detectors and compact solid-state lasers. Over the past decade, upconversion has become more prominent in biological sciences as the preparation of high-quality lanthanide-doped nanoparticles has become increasingly routine. Owing to their small physical dimensions and biocompatibility, upconversion nanoparticles can be easily coupled to proteins or other biological macromolecular systems and used in a variety of assay formats ranging from bio-detection to cancer therapy. In addition, intense visible emission from these nanoparticles under near-infrared excitation, which is less harmful to biological samples and has greater sample penetration depths than conventional ultraviolet excitation, enhances their prospects as luminescent stains in bio-imaging. In this article, we review recent developments in optical biolabeling and bio-imaging involving upconversion nanoparticles, simultaneously bringing to the forefront the desirable characteristics, strengths and weaknesses of these luminescent nanomaterials.
High resolution fluorescence imaging of cancers using lanthanide ion-doped upconverting nanocrystals
2012
During the last decade inorganic luminescent nanoparticles that emit visible light under near infrared (NIR) excitation (in the biological window) have played a relevant role for high resolution imaging of cancer. Indeed, semiconductor quantum dots (QDs) and metal nanoparticles, mostly gold nanorods (GNRs), are already commercially available for this purpose. In this work we review the role which is being played by a relatively new class of nanoparticles, based on lanthanide ion doped nanocrystals, to target and image cancer cells using upconversion fluorescence microscopy. These nanoparticles are insulating nanocrystals that are usually doped with small percentages of two different rare earth (lanthanide) ions: The excited donor ions (usually Yb 3+ ion) that absorb the NIR excitation and the acceptor ions (usually Er 3+ , Ho 3+ or Tm 3+), that are responsible for the
Nanoscale, 2012
All chemicals used in the synthesis of the nanoparticles were purchased from Sigma-Aldrich and used as received. Millipore water was used in the preparation of all aqueous solutions used in the characterization of the samples. Synthesis of Oleate-Capped-Ln 3+-UCNPs. Oleate-capped NaGdF 4 :Er 3+ 2%, Yb 3+ 20% nanoparticles (oleate-capped-Ln 3+-UCNPs) were synthesized via the thermal decomposition procedure 1, 2. In the first step, the precursors (Solution A) were prepared by mixing 0.975 mmol Gd 2 O 3 (99.99 %), 0.25 mmol Yb 2 O 3 (99.99 %), and 0.025 mmol Er 2 O 3 (99.99 %) with 5 mL trifluoroacetic acid (99 %) and 5 mL of distilled water in a 100 mL three-neck round-bottom flask. The solution was stirred and refluxed at 80 °C for 12 h or until a clear solution was obtained and the temperature was lowered to 60 °C to slowly evaporate excess trifluoroacetic acid and water. In the second step, 2.5 mmol sodium trifluoroacetic acid CF 3 COONa (98 %) was added to the dried lanthanide trifluoroacetate precursors and mixed with 7.5 mL each of oleic acid and 1-octadecene (Solution A). In a separate three-neck round bottom flask 12.5 mL each of the coordinating ligand oleic acid (90 %) and the non-coordinating solvent 1-octadecene (90 %) were added (Solution B). Both solutions were placed under vaccum at a temperature of 150 °C, degassed to remove residual water and oxygen with stirring for 30 minutes. Solution B was heated under argon flow at a rate of approximately 8 °C/min, to 310 °C. Solution A was added to Solution B using a mechanical pump system at a rate of 1.5 mL/min (Harvard Apparatus Econoflow). The solution was maintained at 310 °C and stirred vigorously for 2 h to form the oleate-capped NaGdF 4 :Er 3+ 2%, Yb 3+ 20% nanoparticles. After 2 h, the mixture was allowed to cool to room temperature, and the oleate-capped-Ln 3+-UCNPs were precipitated by the addition of hexane/ethanol (1:4 v/v) and isolated via centrifugation at 3000 rpm for 15 minutes. The resulting pellet was then washed once with ethanol and further purified by dispersing in a minimum amount of hexane and precipitated with excess ethanol. The resulting pellet was subsequently washed with acetone and isolated via centrifugation. The resulting oleate-capped-Ln 3+-UCNPs were dried.
REVIEW Lanthanide-doped up-converting nanoparticles: Merits and challenges
Due to exceptional photo-physical properties, up-converting nanoparticles (UCNPs) are promising and advantageous alternative to conventional fluorescent labels used in many bio-medical applications. The first part of this review aims at presenting these properties as well as the current state-of-the-art in the up-conversion enhancement, NPs surface functionalization and bioconjugation. In the second part of the paper, the applications of UCNPs and currently available detection instrumentation are discussed in the view of the distinctive properties of these markers. Because the growing widespread use of the biofunctionalized NPs, scarce instrumentation for up-conversion detection is reviewed. Finally, the challenges and future perspectives of the UCNPs are discussed.
Near-Infrared-Triggered Upconverting Nanoparticles for Biomedicine Applications
Biomedicines, 2021
Due to the unique properties of lanthanide-doped upconverting nanoparticles (UCNP) under near-infrared (NIR) light, the last decade has shown a sharp progress in their biomedicine applications. Advances in the techniques for polymer, dye, and bio-molecule conjugation on the surface of the nanoparticles has further expanded their dynamic opportunities for optogenetics, oncotherapy and bioimaging. In this account, considering the primary benefits such as the absence of photobleaching, photoblinking, and autofluorescence of UCNPs not only facilitate the construction of accurate, sensitive and multifunctional nanoprobes, but also improve therapeutic and diagnostic results. We introduce, with the basic knowledge of upconversion, unique properties of UCNPs and the mechanisms involved in photon upconversion and discuss how UCNPs can be implemented in biological practices. In this focused review, we categorize the applications of UCNP-based various strategies into the following domains: neuromodulation, immunotherapy, drug delivery, photodynamic and photothermal therapy, bioimaging and biosensing. Herein, we also discuss the current emerging bioapplications with cutting edge nano-/biointerfacing of UCNPs. Finally, this review provides concluding remarks on future opportunities and challenges on clinical translation of UCNPs-based nanotechnology research.
Synthesis strategy and application of Rare earth doped upconverting Nanoparticles in Bio-Imaging
2015
Upconversion luminescence, a nonlinear process, which re-emits a photon at a shorter wavelength by the absorption of more than one photon, successively at longer wavelengths via long-lived intermediate energy states, is useful for important applications in various fields like fluorescence bio-imaging and lasers. This NIR up-conversion nanoparticle provides high penetration depth into biological tissue and results in high contrast optical imaging due to absence of an auto fluorescence background and decreased light scattering. Excitation at long wavelengths also minimizes damage to biological tissues. Herein, we report, the different mechanisms for the Upconversion process of rare-earth (Er3+, Ho3+, Tm3+) doped nanoparticle and different methods are used to synthesize and decorate up converting nanoparticle.