RESUMO
The use and applications of infrared emitting rare-earth luminescent nanoparticles as nanothermometers have attracted a great deal of attention during the last few years. Researchers have regarded rare-earth doped luminescent nanoparticles as appealing systems due to their reliability, sensitivity and versatility for minimally invasive thermal sensing in nanomedicine. The challenge of developing nanothermometers operating over 1000 nm with outstanding brightness and enhanced sensitivity is being constantly addressed. In this sense, this work explores the potential of Tm3+ emissions at around 1.23 and 1.47 µm, under excitation at 690 nm, for ratiometric thermometry in Tm3+ doped LaF3 nanoparticles. The temperature dependence of the 1.23 µm emission band, which cannot be observed in systems such as NaNbO3:Tm, was demonstrated to be very effective and presented a relative thermal sensitivity as high as 1.9% °C-1. The physical mechanisms behind the strong thermal dependences were explained in terms of multiphonon decays and cross-relaxations. As a proof of concept, the nanothermometers presented were capable of accessing the basic properties of tissues in an ex vivo experiment using thermal relaxation dynamics.
RESUMO
There is an urgent need to develop new diagnosis tools for real in vivo detection of first stages of ischemia for the early treatment of cardiovascular diseases and accidents. However, traditional approaches show low sensitivity and a limited penetration into tissues, so they are only applicable for the detection of surface lesions. Here, it is shown how the superior thermal sensing capabilities of near infrared-emitting quantum dots (NIR-QDs) can be efficiently used for in vivo detection of subcutaneous ischemic tissues. In particular, NIR-QDs make possible ischemia detection by high penetration transient thermometry studies in a murine ischemic hindlimb model. NIR-QDs nanothermometers are able to identify ischemic tissues by means of their faster thermal dynamics. In addition, they have shown to be capable of monitoring both the revascularization and damage recovery processes of ischemic tissues. This work demonstrates the applicability of fluorescence nanothermometry for ischemia detection and treatment, as well as a tool for early diagnosis of cardiovascular disease.
Assuntos
Raios Infravermelhos , Isquemia/diagnóstico por imagem , Medições Luminescentes/métodos , Pontos Quânticos/química , Termômetros , Termometria/métodos , Animais , CamundongosRESUMO
Correction for 'Self-monitored photothermal nanoparticles based on core-shell engineering' by Erving C. Ximendes et al., Nanoscale, 2016, 8, 3057-3066.
RESUMO
The recent development of core/shell engineering of rare earth doped luminescent nanoparticles has ushered a new era in fluorescence thermal biosensing, allowing for the performance of minimally invasive experiments, not only in living cells but also in more challenging small animal models. Here, the potential use of active-core/active-shell Nd(3+)- and Yb(3+)-doped nanoparticles as subcutaneous thermal probes has been evaluated. These temperature nanoprobes operate in the infrared transparency window of biological tissues, enabling deep temperature sensing into animal bodies thanks to the temperature dependence of their emission spectra that leads to a ratiometric temperature readout. The ability of active-core/active-shell Nd(3+)- and Yb(3+)-doped nanoparticles for unveiling fundamental tissue properties in in vivo conditions was demonstrated by subcutaneous thermal relaxation monitoring through the injected core/shell nanoparticles. The reported results evidence the potential of infrared luminescence nanothermometry as a diagnosis tool at the small animal level.
Assuntos
Medições Luminescentes/instrumentação , Nanopartículas/química , Neodímio/química , Termômetros , Itérbio/química , Administração Cutânea , Animais , Temperatura Corporal , Raios Infravermelhos , Luminescência , Camundongos , Nanopartículas/administração & dosagem , Neodímio/administração & dosagem , Fenômenos Fisiológicos da Pele , Itérbio/administração & dosagemRESUMO
The continuous development of nanotechnology has resulted in the actual possibility of the design and synthesis of nanostructured materials with pre-tailored functionabilities. Nanostructures capable of simultaneous heating and local thermal sensing are in strong demand as they would constitute a revolutionary solution to several challenging problems in bio-medicine, including the achievement of real time control during photothermal therapies. Several approaches have been demonstrated to achieve simultaneous heating and thermal sensing at the nanoscale. Some of them lack of sufficient thermal sensitivity and others require complicated synthesis procedures for heterostructure fabrication. In this study, we demonstrate how single core/shell dielectric nanoparticles with a highly Nd(3+) ion doped shell and an Yb(3+),Er(3+) codoped core are capable of simultaneous thermal sensing and heating under an 808 nm single beam excitation. The spatial separation between the heating shell and sensing core provides remarkable values of the heating efficiency and thermal sensitivity, enabling their application in single beam-controlled heating experiments in both aqueous and tissue environments.
Assuntos
Európio/química , Neodímio/química , Itérbio/química , Espectroscopia de Ressonância de Spin Eletrônica , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Espectrometria por Raios X , TemperaturaRESUMO
The future perspective of fluorescence imaging for real in vivo application are based on novel efficient nanoparticles which is able to emit in the second biological window (1000-1400 nm). In this work, the potential application of Nd(3+) -doped LaF(3) (Nd(3+) :LaF(3) ) nanoparticles is reported for fluorescence bioimaging in both the first and second biological windows based on their three main emission channels of Nd(3+) ions: (4) F(3/2) â(4) I(9/2) , (4) F(3/2) â(4) I(11/2) and (4) F(3/2) â(4) I(13/2) that lead to emissions at around 910, 1050, and 1330 nm, respectively. By systematically comparing the relative emission intensities, penetration depths and subtissue optical dispersion of each transition we propose that optimum subtissue images based on Nd(3+) :LaF(3) nanoparticles are obtained by using the (4) F3/2 â(4) I11/2 (1050 nm) emission band (lying in the second biological window) instead of the traditionally used (4) F(3/2) â(4) I(9/2) (910 nm, in the first biological window). After determining the optimum emission channel, it is used to obtain both in vitro and in vivo images by the controlled incorporation of Nd(3+) :LaF(3) nanoparticles in cancer cells and mice. Nd(3+) :LaF(3)nanoparticles thus emerge as very promising fluorescent nanoprobes for bioimaging in the second biological window.
Assuntos
Diagnóstico por Imagem/métodos , Fluoretos , Lantânio , Nanopartículas , Neodímio , Absorção , Administração Intravenosa , Animais , Sobrevivência Celular , Galinhas , Fluorescência , Fluoretos/administração & dosagem , Células HeLa , Humanos , Injeções Subcutâneas , Lantânio/administração & dosagem , Camundongos , Nanopartículas/administração & dosagem , Nanopartículas/ultraestrutura , Neodímio/administração & dosagem , Imagem Óptica , Tamanho da Partícula , SoluçõesRESUMO
In this work, we report the multifunctional character of neodymium-doped LaF3 core/shell nanoparticles. Because of the spectral overlap of the neodymium emission bands with the transparency windows of human tissues, these nanoparticles emerge as relevant subtissue optical probes. For neodymium contents optimizing the luminescence brightness of Nd³âº:LaF3 nanoparticles, subtissue penetration depths of several millimeters have been demonstrated. At the same time, it has been found that the infrared emission bands of Nd³âº:LaF3 nanoparticles show a remarkable thermal sensitivity, so that they can be advantageously used as luminescent nanothermometers for subtissue thermal sensing. This possibility has been demonstrated in this work: Nd³âº:LaF3 nanoparticles have been used to provide optical control over subtissue temperature in a single-beam plasmonic-mediated heating experiment. In this experiment, gold nanorods are used as nanoheaters while thermal reading is performed by the Nd³âº:LaF3 nanoparticles. The possibility of a real single-beam-controlled subtissue hyperthermia process is, therefore, pointed out.