Magnetic upconverting fluorescent NaGdF4:Ln3+ and iron-oxide@NaGdF4:Ln3+ nanoparticles

CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPEMA - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MARANHÃOFAPEAL - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE ALAGOASMicrowave assisted solvothermal method has been employed to synthesize multifunctional upconverting beta-NaGdF4:Ln(3+) and magnetic-upconverting Fe3O4/gamma-Fe2O3@ NaGdF4:Ln3+ ( Ln = Yb and Er) nanoparticles. The powder x-ray diffraction data confirms the hexagonal structure of NaGdF4:Ln(3+) and high resolution transmission electron microscopy shows the formation of rod shaped NaGdF4:Ln(3+) (similar to 20 nm) and ovoid shaped Fe3O4/gamma-Fe2O3@NaGdF4:Ln(3+) (similar to 15 nm) nanoparticles. The magnetic hysteresis at 300 K for beta-NaGdF4:Ln(3+) demonstrates paramagnetic features, whereas iron-oxide@beta-NaGdF4:Ln(3+) exhibits superparamagnetic behavior along with a linear component at large applied field due to paramagnetic NaGdF4 matrix. Both nanoparticle samples provide an excellent green emitting [(H-2(11/ 2), S-4(3/2))-> I-4(15/2) (similar to 540 nm)] upconversion luminescence emission under excitation at 980 nm. The energy migration between Yb and Er in NaGdF4 matrix has been explored from 300-800 nm. Intensity variation of blue, green and red lines and the observed luminescence quenching due to the presence of Fe3O4/gamma-Fe2O3 in the composite has been proposed. These kinds of materials contain magnetic and luminescence characteristics into single nanoparticle open new possibility for bioimaging applications.8516CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPEMA - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MARANHÃOFAPEAL - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE ALAGOASCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPEMA - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MARANHÃOFAPEAL - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE ALAGOAS62. Annual Conference on Magnetism and Magnetic Materials2017Pittsburgh, PAIEEE Magnetics SocietyAIP PublishingAgências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

What NIR photodynamic activation offers molecular targeted nanomedicines: Perspectives into the conundrum of tumor specificity and selectivity

Near infrared (NIR) photodynamic activation is playing increasingly critical roles in cutting-edge anti-cancer nanomedicines, which include spatiotemporal control over induction of therapy, photodynamic priming, and phototriggered immunotherapy. Molecular targeted photonanomedicines (mt-PNMs) are tumor-specific nanoscale drug delivery systems, which capitalize on the unparalleled spatio-temporal precision of NIR photodynamic activation to augment the accuracy of tumor tissue treatment. mt-PNMs are emerging as a paradigm approach for the targeted treatment of solid tumors, yet remain highly complex and multifaceted. While ligand targeted nanomedicines in general suffer from interdependent challenges in biophysics, surface chemistry and nanotechnology, mt-PNMs provide distinct opportunities to synergistically potentiate the effects of ligand targeting. This review provides what we believe to be a much-need demarcation between the processes involved in tumor specificity (biomolecular recognition events) and tumor selectivity (preferential tumor accumulation) of ligand targeted nanomedicines, such as mt-PNMs, and elaborate on what NIR photodynamic activation has to offer. We discuss the interplay between both tumor specificity and tumor selectivity and the degree to which both may play central roles in cutting-edge NIR photoactivable nanotechnologies. A special emphasis is made on NIR photoactivable biomimetic nanotechnologies that capitalize on both specificity and selectivity phenomena to augment the safety and efficacy of photodynamic anti-tumor regimens

Insight into dual-modality of triply doped magnetic-luminescent iron-oxide/NaGdF4:RE3+ (RE = Ce, Tb, Dy) nanoparticles

CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPEMA - FUNDAÇÃO DE AMPARO À PESQUISA E AO DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO DO MARANHÃOFAPEAL - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE ALAGOASGreen emitting iron-oxide@NaGdF4:RE3+ (RE = 5%Ce, 5%Tb, 5%Dy) nanoparticles have been synthesized using microwave assisted solvothermal method. The Rietveld analysis of powder X-ray diffraction and high-resolution transmission electron microscopy provides an average crystallite size (similar to 20 nm) and the hexagonal crystal structure. Magnetic hysteresis loops at 300 K display superparamagnetic behavior along with paramagnetic feature for the reference NaGdF4:RE3+, further validated through magnetization versus temperature curves taken in an external magnetic field of 100 Oe. The photoluminescence investigation of the nanoparticles, suggest a down-converting energy transfer. The excitation spectra consist of a dominant broad band at around 254 nm due to Ce3+(4f-5d) along with f-f transitions due to Gd3+, Tb3+ and Dy3+ ions. The strong emission color lines due to characteristic transitions of Tb3+ (D-5(4) -gt; F-7(J), J = 6-3), and Dy3+ (F-4(9/2)-H-6(15/2), H-6(13/2)), were observed. The luminescence quenching in iron-oxide/NaGdF4: RE3+ through leakage path provided by iron-oxide to excite electrons has been confirmed and explained by comparing the time decay analysis.213358361CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPEMA - FUNDAÇÃO DE AMPARO À PESQUISA E AO DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO DO MARANHÃOFAPEAL - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE ALAGOASCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPEMA - FUNDAÇÃO DE AMPARO À PESQUISA E AO DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO DO MARANHÃOFAPEAL - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE ALAGOASAgências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

Magnetic upconverting fluorescent NaGdF4:Ln3+ and iron-oxide@NaGdF4:Ln3+ nanoparticles

Microwave assisted solvothermal method has been employed to synthesize multifunctional upconverting β-NaGdF4:Ln3+ and magnetic-upconverting Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (Ln = Yb and Er) nanoparticles. The powder x-ray diffraction data confirms the hexagonal structure of NaGdF4:Ln3+ and high resolution transmission electron microscopy shows the formation of rod shaped NaGdF4:Ln3+ (∼ 20 nm) and ovoid shaped Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (∼ 15 nm) nanoparticles. The magnetic hysteresis at 300 K for β-NaGdF4:Ln3+ demonstrates paramagnetic features, whereas iron-oxide@β-NaGdF4:Ln3+ exhibits superparamagnetic behavior along with a linear component at large applied field due to paramagnetic NaGdF4 matrix. Both nanoparticle samples provide an excellent green emitting [(2H11/2, 4S3/2)→4I15/2 (∼ 540 nm)] upconversion luminescence emission under excitation at 980 nm. The energy migration between Yb and Er in NaGdF4 matrix has been explored from 300-800 nm. Intensity variation of blue, green and red lines and the observed luminescence quenching due to the presence of Fe3O4/γ-Fe2O3 in the composite has been proposed. These kinds of materials contain magnetic and luminescence characteristics into single nanoparticle open new possibility for bioimaging applications

What NIR photodynamic activation offers molecular targeted nanomedicines: Perspectives into the conundrum of tumor specificity and selectivity

Near infrared (NIR) photodynamic activation is playing increasingly critical roles in cutting-edge anti-cancer nanomedicines, which include spatiotemporal control over induction of therapy, photodynamic priming, and phototriggered immunotherapy. Molecular targeted photonanomedicines (mt-PNMs) are tumor-specific nanoscale drug delivery systems, which capitalize on the unparalleled spatio-temporal precision of NIR photodynamic activation to augment the accuracy of tumor tissue treatment. mt-PNMs are emerging as a paradigm approach for the targeted treatment of solid tumors, yet remain highly complex and multifaceted. While ligand targeted nanomedicines in general suffer from interdependent challenges in biophysics, surface chemistry and nanotechnology, mt-PNMs provide distinct opportunities to synergistically potentiate the effects of ligand targeting. This review provides what we believe to be a much-need demarcation between the processes involved in tumor specificity (biomolecular recognition events) and tumor selectivity (preferential tumor accumulation) of ligand targeted nanomedicines, such as mt-PNMs, and elaborate on what NIR photodynamic activation has to offer. We discuss the interplay between both tumor specificity and tumor selectivity and the degree to which both may play central roles in cutting-edge NIR photoactivable nanotechnologies. A special emphasis is made on NIR photoactivable biomimetic nanotechnologies that capitalize on both specificity and selectivity phenomena to augment the safety and efficacy of photodynamic anti-tumor regimens

Binary activated iron oxide/SiO2/NaGdF4:RE (RE = Ce, and Eu; Yb, and Er) nanoparticles: Synthesis, characterization and their potential for dual: T 1- T 2 weighted imaging

We report the microwave-assisted synthesis of binary doped optical-magnetic up/downconverting NaGdF4:RE and iron oxide/SiO2/NaGdF4:RE nanoparticles. The morphological characteristics were finely tuned from elongated rod-shaped to ovoidal nanoparticles. The (Yb, and Er) activated particles provided an excellent up/down conversion luminescence emission in the green and mid-infrared region under excitation of 980 nm, whereas the (Ce, and Eu) activated systems exhibited a strong red emission via the Gd3+ sublattice upon excitation in the UV region. The magnetic hysteresis at 300 K for β-NaGdF4:RE showed typical signatures of a paramagnetic system, whereas iron oxide/SiO2/β-NaGdF4:RE exhibited superparamagnetic behavior along with a Curie-like component. The luminescence quenching effects induced by the presence of iron oxide phase have been validated through comparing the emission/lifetime decay curves. In addition to the excellent optical and magnetic properties, these materials show remarkably high longitudal and transverse relaxivity values (for Fe and Gd) and thus are potential candidates for T1 and T2-weighted bioimaging. This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique