Infrared to Visible Up-conversion in Biocellulose–yttrium Vanadate Nanoparticle Composite Membranes. Demonstration of Chloroaluminum Phthalocyanine Light Emission Under Up-converted Light Excitation

Abstract

Biocellulose Chloroaluminum phthalocyanine Yttrium vanadate nanoparticles lanthanide ions photodynamic therapy photosensitizers drug delivery systems biomaterials composite membranes YVO 4 :(Yb 3+ -Er 3+ /Ho 3+ ) nanoparticles were incorporated in biocellulose membranes obtained from Gluconacetobacter xylinus. Materials present the property of converting near-infrared (NIR) into higher-energy visible light. Nanoparticles were prepared by optimizing towards higher emission intensity at the absorption wavelength range of chloroaluminum phthalocyanine (ClAlPc) used as a photosensitizer in the photodynamic therapy. The NIR excitation wavelength is advantageous for biological applications, as it allows deeper penetration into tissues than the UV-visible radiation commonly used for luminescence excitation. Up-conversion emission spectra obtained under excitation at 980 nm showed a preferential green emission for the Yb 3+ -Er 3+ system and a red emission for the Yb 3+ -Ho 3+ one. In the last case, by using mixtures of nanoparticles and ClAlPc the red emission (680 nm) of the phtalocyanine was observed through excitation by the up-converted emission of the nanoparticles (650 nm) which were excited in NIR (980 nm).

Upconversion 3D Printed Composite with Multifunctional Applications for Tissue Engineering and Photodynamic Therapy

“…After sintering, the product was crushed and then wetly ballmilled again for 24 h. The sintering steps and parameters were at 950 °C for 2 h and then at 1100 °C for 48 h, with a heating ramp of 5 °C min -1 and a cooling ramp of 10 °C min -1 down to room temperature. YVO 4 :Yb 3+ :Er 3+ nanoparticles YVO 4 :Yb 3+ :Er 3+ upconversion nanoparticles (UCNPs) were synthesized according to the method previously reported by Nigoghossian et al 40 The method consists in a co-precipitation of sodium citrate 2 M (5 mL) and lanthanide ions. The latter is a mixture of aqueous solutions (1 M) of yttrium nitrate and ytterbium and erbium chlorides in a defined molar ratio (Y:Yb:Er = 77.5:20:2.5).…”

Low Level Energy Photodynamic Therapy for Skin Processes and Regeneration

“…The ability of these compounds to suppress the superoxide production by macrophages seems to modulate the secretion of protein kinases in tumor cell proliferation and induce the expression of anticarcinogenic enzymes [34,35]. Recent studies have demonstrated that PDT is not restricted to visible light; deep tissue penetration in PDT could also be achieved with near-infrared (NIR) laser radiation, followed by upconversion to higher-energy visible or ultraviolet light in the biological medium [36,37].…”

Influence of excitation and detection geometry on optical temperature readouts – reabsorption effects in luminescence thermometry

“…Optical materials containing lanthanide (Ln) ions are widely studied due to their promising potential for application in many fields of science and industry. [1][2][3][4][5][6][7][8][9][10][11] This is because these materials are capable of generating luminescence, 9,12 i.e. emission of light resulting from the excitation of electrons of a given material with radiation from the ultraviolet (UV), visible or near-infrared (NIR) spectral ranges and their subsequent radiative relaxation to the ground states.…”