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6 záznamů v Medvik Filtry

Článek

Poly(N,N-dimethylacrylamide)-coated upconverting NaYF4:Yb,Er@NaYF4:Nd core-shell nanoparticles for fluorescent labeling of carcinoma cells

Oleksa, Viktoriia
Autor Oleksa, Viktoriia Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 40, Prague 2, Czech Republic
Macková, Hana
Autor Macková, Hana Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
Engstová, Hana
Autor Engstová, Hana Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20, Prague 4, Czech Republic
Patsula, Vitalii
Autor Patsula, Vitalii Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
Shapoval, Oleksandr
Autor Shapoval, Oleksandr Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
Velychkivska, Nadiia
Autor Velychkivska, Nadiia Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
Ježek, Petr
Autor Ježek, Petr Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20, Prague 4, Czech Republic
Horák, Daniel
Autor Horák, Daniel Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic. horak@imc.cas.cz

Scientific reports. 2021 ; 11 (1) : 21373. [pub] 20211101

Sci Rep
ISSN 2045-2322
Medvik
Zdroj

Upconverting luminescent lanthanide-doped nanoparticles (UCNP) belong to promising new materials that absorb infrared light able to penetrate in the deep tissue level, while emitting photons in the visible or ultraviolet region, which makes them favorable for bioimaging and cell labeling. Here, we have prepared upconverting NaYF4:Yb,Er@NaYF4:Nd core-shell nanoparticles, which were coated with copolymers of N,N-dimethylacrylamide (DMA) and 2-(acryloylamino)-2-methylpropane-1-sulfonic acid (AMPS) or tert-butyl [2-(acryloylamino)ethyl]carbamate (AEC-Boc) with negative or positive charges, respectively. The copolymers were synthesized by a reversible addition-fragmentation chain transfer (RAFT) polymerization, reaching Mn ~ 11 kDa and containing ~ 5 mol% of reactive groups. All copolymers contained bisphosphonate end-groups to be firmly anchored on the surface of NaYF4:Yb,Er@NaYF4:Nd core-shell nanoparticles. To compare properties of polymer coatings, poly(ethylene glycol)-coated and neat UCNP were used as a control. UCNP with various charges were then studied as labels of carcinoma cells, including human hepatocellular carcinoma HepG2, human cervical cancer HeLa, and rat insulinoma INS-1E cells. All the particles proved to be biocompatible (nontoxic); depending on their ξ-potential, the ability to penetrate the cells differed. This ability together with the upconversion luminescence are basic prerequisites for application of particles in photodynamic therapy (PDT) of various tumors, where emission of nanoparticles in visible light range at ~ 650 nm excites photosensitizer.

Článek

UV-Mediated Photofunctionalization of Indirect Restorative Materials Enhances Bonding to a Resin-Based Luting Agent

BioMed research international. 2021 ; 2021 (-) : 9987860. [pub] 20210529

Biomed Res Int
ISSN 2314-6141
Medvik
Zdroj

Purpose: The potential of UV-mediated photofunctionalization to enhance the resin-based luting agent bonding performance to aged materials was investigated. Methods: Sixty samples of each material were prepared. Yttria-stabilized zirconia (YZr) and Pd-Au alloy (Pd-Au) plates were fabricated and sandblasted. Lithium disilicate glass-ceramic (LDS) was CAD-CAM prepared and ground with #800 SiC paper. Half of the specimens were immersed in machine oil for 24 h to simulate the carbon adsorption. Then, all of the specimens (noncarbon- and carbon-adsorbed) were submitted to UV-mediated photofunctionalization with a 15 W UV-LED (265 nm, 300 mA, 7692 μW/cm2) for 0 (control groups), 5, and 15 min and subjected to contact angle (Ɵ) measurement and bonded using a resin cement (Panavia™ V5, Kuraray Noritake, Japan). The tensile bond strength (TBS) test was performed after 24 h. The Ɵ (°) and TBS (MPa) data were statistically analyzed using two-way ANOVA and Bonferroni correction tests (α = 0.05). Results: In the carbon-adsorbed groups, UV-mediated photofunctionalization for 5 min significantly decreased Ɵ of all materials and increased TBS of YZr, and UV for 15 min significantly increased the TBS of LDS and Pd-Au. In noncarbon-adsorbed groups, UV-photofunctionalization did not significantly change the Ɵ or TBS except YZr specimens UV-photofunctionalized for 15 min. Conclusion: UV-mediated photofunctionalization might have removed the adsorbed hydrocarbon molecules from the materials' surfaces and enhanced bond strengths of Panavia™ V5 to YZr, LDS, and Pd-Au. Additionally, UV-mediated photofunctionalization improved the overall TBS of YZr. Further investigation on the optimum conditions of UV photofunctionalization on indirect restorative materials should be conducted.

Článek

Phthalocyanine-Conjugated Upconversion NaYF4 :Yb3 /Er3+ @SiO2 Nanospheres for NIR-Triggered Photodynamic Therapy in a Tumor Mouse Model

ChemMedChem. 2017 ; 12 (24) : 2066-2073. [pub] 20171205

ISSN 1860-7187
Medvik
Zdroj

Photodynamic therapy (PDT) has garnered immense attention as a minimally invasive clinical treatment modality for malignant cancers. However, its low penetration depth and photodamage of living tissues by UV and visible light, which activate a photosensitizer, limit the application of PDT. In this study, monodisperse NaYF4 :Yb3+ /Er3+ nanospheres 20 nm in diameter, that serve as near-infrared (NIR)-to-visible light converters and activators of a photosensitizer, were synthesized by high-temperature co-precipitation of lanthanide chlorides in a high-boiling organic solvent (octadec-1-ene). The nanoparticles were coated with a thin shell (≈3 nm) of homogenous silica via the hydrolysis and condensation of tetramethyl orthosilicate. The NaYF4 :Yb3+ /Er3+ @SiO2 particles were further functionalized by methacrylate-terminated groups via 3-(trimethoxysilyl)propyl methacrylate. To introduce a large number of reactive amino groups on the particle surface, methacrylate-terminated NaYF4 :Yb3+ /Er3+ @SiO2 nanospheres were modified with a branched polyethyleneimine (PEI) via Michael addition. Aluminum carboxyphthalocyanine (Al Pc-COOH) was then conjugated to NaYF4 :Yb3+ /Er3+ @SiO2 -PEI nanospheres via carbodiimide chemistry. The resulting NaYF4 :Yb3+ /Er3+ @SiO2 -PEI-Pc particles were finally modified with succinimidyl ester of poly(ethylene glycol) (PEG) in order to alleviate their future uptake by the reticuloendothelial system. Upon 980 nm irradiation, the intensive red emission of NaYF4 :Yb3+ /Er3+ @SiO2 -PEI-Pc-PEG nanoparticles completely vanished, indicating efficient energy transfer from the nanoparticles to Al Pc-COOH, which generates singlet oxygen (1 O2 ). Last but not least, NaYF4 :Yb3+ /Er3+ @SiO2 -PEI-Pc-PEG nanospheres were intratumorally administered into mammary carcinoma MDA-MB-231 growing subcutaneously in athymic nude mice. Extensive necrosis developed at the tumor site of all mice 24-48 h after irradiation by laser at 980 nm wavelength. The results demonstrate that the NaYF4 :Yb3+ /Er3+ @SiO2 -PEI-Pc-PEG nanospheres have great potential as a novel NIR-triggered PDT nanoplatform for deep-tissue cancer therapy.