In vivo photodynamic therapy using upconversion nanoparticles as remote-controlled nanotransducers

Abstract

Conventional photodynamic therapy (PDT) is limited by the penetration depth of visible light needed for its activation. Here we used mesoporous-silica-coated upconversion fluorescent nanoparticles (UCNs) as a nanotransducer to convert deeply penetrating near-infrared light to visible wavelengths and a carrier of photosensitizers. We also used the multicolor-emission capability of the UCNs at a single excitation wavelength for simultaneous activation of two photosensitizers for enhanced PDT. We showed a greater PDT efficacy with the dual-photosensitizer approach compared to approaches using a single photosensitizer, as determined by enhanced generation of singlet oxygen and reduced cell viability. In vivo studies also showed tumor growth inhibition in PDT-treated mice by direct injection of UCNs into melanoma tumors or intravenous injection of UCNs conjugated with a tumor-targeting agent into tumor-bearing mice. As the first demonstration, to the best of our knowledge, of the photosensitizer-loaded UCN as an in vivo-targeted PDT agent, this finding may serve as a platform for future noninvasive deep-cancer therapy.

808 nm driven Nd3+-sensitized upconversion nanostructures for photodynamic therapy and simultaneous fluorescence imaging

“…[11][12][13] For in vivo bioapplications, upconversion nanoparticles that are excitable at 980 nm have previously been the focus. This is because this excitation wavelength falls in the so-called "optical window" of tissue and the biological environment is hardly excited, leading to high quality as well as relatively deep depth imaging.…”

Tailored Near‐Infrared Photoemission in Fluoride Perovskites through Activator Aggregation and Super‐Exchange between Divalent Manganese Ions

“…Besides, luminescent materials that emit in the NIR (700–1100 nm) themselves are attractive for a variety of applications. Recently, the most vibrant field of interest in this context has been in the area of biomedical imaging, where cells and tissue exhibit weak autofluorescence and low transmission loss for optical signals just within the NIR 22, 23. It has hence been crucial to design (nano) materials that exhibit both emission and excitation of luminescence in the NIR region for in vitro and in vivo imaging applications 24, 25.…”

Optimizing infrared to near infrared upconversion quantum yield of β-NaYF4:Er3+ in fluoropolymer matrix for photovoltaic devices

“…[3][4][5][6][7][8][9] UC refers to an anti-Stokes type nonlinear optical emission process in which one higher energy photon is emitted for every two or more absorbed lower energy photons. 10 Since the first experimental demonstration in 1966, 11 this effect has received renewed interest due to its ever expanding application base in, for example, lasing, 12 laser cooling, 13 temperature sensing, 14 biomedical imaging and therapy, 15,16 3D displays, 17 and, more recently, for broadening the spectral response of PV devices. [4][5][6][7][8][9] In the context of Si PV devices, the UC of the sub-bandgap photons (k > 1100 nm) into above-bandgap photons (k < 1100 nm) increases the theoretical efficiency limit of a single-junction Si solar cell from near 30% up to 40% when illuminated under non-concentrated light.…”