Modified Upconverting Nanoparticles
Upconversion nanoparticles - a new generation of fluorophores - convert near-infrared radiation to visible radiation through a nonlinear optical process. These UCNPs have been developed as alternative fluorescent labels with great potential for imaging and bioassays for in vitro and in vivo applications.
Alfa Chemistry provides modified upconverting nanoparticles, including the following:
SiO2 coated Upconverting Nanoparticles, mesoporous silica coated upconverting nanomaterials, excite at 975-980 nm and emit either blue or violet light. The mesoporous silica can be used as a carrier for drug delivery.
TiO2 coated Upconverting Nanoparticles, titanium dioxide coated upconverting nanomaterials, excitation wavelength 975-980 nm, particle size 40 nm.
PEG-COOH modified Upconverting Nanoparticles, using a near-infrared continuous laser as the excitation source, have a deep light penetration depth, no background fluorescence interference, and little damage to biological tissues.
PEG-NH2 Modified Upconverting Nanoparticles, PEG-NH2 Modified Upconverting Nanoparticles, have an excitation wavelength of 975-980 nm.
Upconverting nanoparticles have superior photostability and have been widely used in biomedical applications, including in vivo bioimaging, bioassays, immunohistochemistry, microarray detection, photodynamic therapy, and photocontrolled drug activation.
Kowalik et al. coated rare earth ion-doped NaYF4 nanoparticles with a silicon oxide shell (NaYF4:20% Yb, 0.2% Tm@SiO2) for biological and medical applications (e.g., cancer cell imaging and nanoscale therapy). The wide range of upconversion emission at 980 nm excitation allows one to use nanoparticles for photodynamic therapy (PDT) of cancer cells (4T1) without photosensitizers. Reactive oxygen species (ROS) are generated by Tm/Yb ion upconversion emission (blue and UV light). 4T1 cells incubated with NaYF4:20%Yb, 0.2%Tm@SiO2 nanoparticles were tested for in vitro PDT and irradiated with NIR light. After 24 h, cell survival decreased to less than 10%, showing very good therapeutic efficiency. the high modification sensitivity of SiO2 shell allows the attachment of biomolecules (specific antibodies). Anti-human IgG antibodies were attached to silane-PEG-NHS modified NaYF4:20%Yb,0.2%Tm@SiO2 nanoparticles and a specially labeled membrane model was attached by bioconjugation. Thus, it is possible to perform a selective search (a high quality optical approach with very low levels of organic background) and eventually damage the target cancer cells. The study focused on the therapeutic properties of NaYF4:20%Yb, 0.2%Tm@SiO2 nanoparticles and demonstrated their potential for targeted therapy after biofunctionalization.
Fig.1 EDX maps of UCNPs@SiO2 elements. (Kowalik et al., 2021)
Phototherapeutic Agents for Tumors
A single laser-excited activatable photothermal nanocomposite (UCNPs-D-MQ) was developed by Yang et al. Upconversion nanoparticles (UCNPs) excited at 808 nm were used as a matrix and programmed to assemble with the amphiphilic compound DSPE-PEG-COOH, the near-infrared absorbing polymer DPP, and the pro-photosensitizer MBQB. Upon endocytosis by cancer cells and excitation by 808 nm laser, UCNPs-D-MQ can generate high yield of reactive oxygen species (ROS) as a result of monoclinic oxygen generation transferred to methylene blue, GSH depletion and photoactivated ROS generation. In vitro and in vivo experiments demonstrated that the nanocomposite had significant therapeutic effects and minimal photodamage to normal cells. These results suggest that UCNPs-D-MQ is a powerful tumor phototherapeutic agent.
Fig.2 Schematic diagram of a novel photodiagnostic nanocomposite (UCNPs-D-MQ). (Yang et al., 2021)
Alfa Chemistry can provide a variety of complex and customized fluorescent quantum dot products. Our products involve perovskites precursors, perovskites quantum dots, quantum dot kit, single layer quantum dots, upconverting nanoparticles and other fluorescent quantum dots. Alfa Chemistry provides products with high fluorescence quantum yield, stable quality and relatively low price. Our products are constantly updated. If the product you need is not in our catalog, please feel free to contact us, we provide relevant custom services.
- Kowalik, P. , et al. The ROS-generating photosensitizer-free NaYF4:Yb,Tm@SiO2 upconverting nanoparticles for photodynamic therapy application[J]. Nanotechnology, 2021.
- Yang, Yang, Tao Zhang, and Da Xing. Single 808 nm near-infrared-triggered multifunctional upconverting phototheranostic nanocomposite for imaging-guided high-efficiency treatment of tumors[J]. Journal of Biophotonics, 2021, 14(9): e202100134.
* It should be noted that our service is only used for research, not for clinical use.