Up‐conversion (UC) luminescent porous silica fibers decorated with NaYF4:Yb3+, Er3+ nanocrystals (NCs) (denoted as NaYF4:Yb3+, Er3+@silica fiber) are prepared by the electrospinning process using ...cationic surfactant P123 as a template. Monodisperse and hydrophobic oleic acid capped β‐NaYF4: Yb3+, Er3+ NCs are prepared by thermal decomposition methodology. Then, these NCs are transferred into aqueous solution by employing cetyltrimethylammonium bromide (CTAB) as secondary surfactant. The water‐dispersible β‐NaYF4:Yb3+, Er3+ NCs are dispersed into precursor electrospinning solution containing P123 and tetraethyl orthosilicate (TEOS), followed by preparation of precursor fibers via electrospinning. Finally, porous α‐NaYF4:Yb3+, Er3+@silica fiber nanocomposites are obtained after annealing the precursor fibers containing β‐NaYF4:Yb3+, Er3+ at 550 °C. The as‐prepared α‐NaYF4:Yb3+, Er3+@silica fiber possesses porous structure and UC luminescence properties simultaneously. Furthermore, the obtained nanocomposites can be used as a drug delivery host carrier and drug storage/release properties are investigated, using ibuprofen (IBU) as a model drug. The results indicate that the IBU–loaded α‐NaYF4:Yb3+, Er3+@silica fiber nanocomposites show UC emission of Er3+ under 980 nm NIR laser excitation and a controlled release property for IBU. Meanwhile, the UC emission intensity of IBU–α‐NaYF4:Yb3+, Er3+@silica fiber system varies with the released amount of IBU.
Electrospinning derived α‐NaYF4:Yb3+, Er3+ decorated silica fibers, which combine porous structure and red up‐conversion luminescence, can be used as a drug‐delivery vehicle. The IBU‐loaded silica fiber system shows a controlled release property for IBU. In addition, the up‐conversion emission intensities of the drug carrier system vary with the amount of IBU released.
Compared with traditional photodynamic therapy (PDT), ultrasound (US) triggered sonodynamic therapy (SDT) has a wide application prospect in tumor therapy because of its deeper penetration depth. ...Herein, a novel MnSiO3-Pt (MP) nanocomposite composed of MnSiO3 nanosphere and noble metallic Pt was successfully constructed. After modification with bovine serum albumin (BSA) and chlorine e6 (Ce6), the multifunctional nanoplatform MnSiO3-Pt@BSA-Ce6 (MPBC) realized the magnetic resonance imaging (MRI)-guided synergetic SDT/chemodynamic therapy (CDT). In this nanoplatform, sonosensitizer Ce6 can generate singlet oxygen (1O2) to kill cancer cells under US irradiation. Meanwhile, the loaded Pt has the ability to catalyze the decomposition of overexpressed hydrogen peroxide (H2O2) in tumor microenvironment (TME) to produce oxygen (O2), which can conquer tumor hypoxia and promote the SDT-induced 1O2 production. In addition, MP can degrade in mildly acidic and reductive TME, causing the release of Mn2+. The released Mn2+ not only can be used for MRI, but also can generate hydroxyl radical (∙OH) for CDT by Fenton-like reaction. The multifunctional nanoplatform MPBC has high biological safety and good anticancer effect, which displays the great latent capacity in biological application.
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Multifunctional nanoplatform MnSiO3-Pt@BSA-Ce6 (MPBC) was successfully constructed for magnetic resonance imaging (MRI)-guided catalysis-enhanced sonodynamic therapy (SDT)/chemodynamic therapy (CDT), in vitro and in vivo data showed MPBC-based combined therapy could kill tumor safely and effectively.
Up‐conversion (UC) luminescent and porous NaYF4:Yb3+, Er3+@SiO2 nanocomposite fibers are prepared by electrospinning process. The biocompatibility test on L929 fibrolast cells reveals low ...cytotoxicity of the fibers. The obtained fibers can be used as anti‐cancer drug delivery host carriers for investigation of the drug storage/release properties. Doxorubicin hydrochloride (DOX), a typical anticancer drug, is introduced into NaYF4:Yb3+, Er3+@SiO2 nanocomposite fibers (denoted as DOX‐NaYF4:Yb3+, Er3+@SiO2). The release properties of the drug carrier system are examined and the in vitro cytotoxicity and cell uptake behavior of these NaYF4:Yb3+, Er3+@SiO2 for HeLa cells are evaluated. The release of DOX from NaYF4:Yb3+, Er3+@SiO2 exhibits sustained, pH‐sensitive release patterns and the DOX‐NaYF4:Yb3+, Er3+@SiO2 show similar cytotoxicity as the free DOX on HeLa cells. Confocal microscopy observations show that the composites can be effectively taken up by HeLa cells. Furthermore, the fibers show near‐infrared UC luminescence and are successfully applied in bioimaging of HeLa cells. The results indicate the promise of using NaYF4:Yb3+, Er3+@SiO2 nanocomposite fibers as multi‐functional drug carriers for drug delivery and cell imaging.
NaYF4:Yb3+, Er3+@SiO2 nanocomposite fibers, which are used as a novel anticancer drug carrier, are prepared using an electrospinning process. The fibers show the attractive properties of regular morphology, porous structure, good biocompatibility, and up‐conversion emission. The drug loading and release properties, cytotoxicity, cellular uptake, and cell imaging of nanocomposite fibers are investigated.
ZnGa2O4 and ZnGa2O4: Mn2+/Eu3+ with uniform nanosphere (diameter about 400 nm) morphology have been synthesized via a facile hydrothermal approach. XRD, Raman spectra, XPS, FT‐IR, SEM, TEM, ...photoluminescence (PL), and cathodoluminescecne (CL) spectra are used to characterize the resulting samples. The controlled experiments indicate the dosage of trisodium citrate and pH values are responsible for shape determination of the ZnGa2O4 products. The possible fast crystallization–dissolution–recrystallization formation mechanism for these nanospheres is presented. Under UV light and low‐voltage electron beam excitation, ZnGa2O4, ZnGa2O4: Mn2+ and ZnGa2O4: Eu3+ emit bright blue, green, and red luminescence, respectively. Based on density functional theory calculations from first principles, the green and red emission are caused by the Mn 3d and Eu 4f electronic structures, respectively. Besides, the dependence of the CL intensity on the calcination temperature and electrical conductivity of the samples is presented. The ZnGa2O4: Mn2+ nanospheres have a higher CL intensity than that of bulk samples under the same excitation condition. The realization of three primary colors from a single host material suggests that full color display based on ZnGa2O4 nanospheres might be achievable, showing that these materials have potential applications in lighting and display fields.
ZnGa2O4: Mn2+/Eu3+ with uniform nanospheric morphology (diameter about 400 nm) are synthesized via a facile hydrothermal approach. The electronic properties, chemical bonding, and mechanisms of electron transitions in ZnGa2O4 and Mn2+/Eu3+‐doped ZnGa2O4 systems are studied based on the density functional theory (DFT) calculations from first principles.
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► 4 Magnetic Fe3O4@MS with different morphologies and pore structures were synthesized. ► 4 Low cytoxicity of these magnetic composites make them potential drug carriers. ► 4 Fe3O4@MS ...with large pore sizes can be vectors for aspirin and BSA.
Magnetic Fe3O4@mesoporous silica (MS) composites were synthesized by generating Fe3O4 nanoparticles in the mesoporous silica matrix using the sol–gel method in nitrogen atmosphere. The mesoporous silica hosts include SBA-15 particles owning highly ordered p6mm mesostructure, siliceous mesostructured cellular foams (MCFs), and fiber-like mesoporous silica (FMS) with unique pore structures. The X-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 adsorption/desorption results show that Fe3O4 functionalized MCFs and FMS possess suitable mesoporous structure for the adsorption of both small-molecular drug and large biomolecules. The biocompatibility tests on L929 fibroblast cells using MTT assay reveal low cytotoxicity of these systems. These Fe3O4@mesoporous silica composites show sustained release properties for aspirin in vitro. The release of the aspirin molecules from the pores of the Fe3O4@mesoporous silica composites is basically a diffusive process. Fe3O4@MCFs and Fe3O4@FMS owning larger pore size are good candidates for the adsorption of bovine serum albumin (BSA). These magnetic composites can be potential vectors for drug delivery and bioadsorption.
Highly uniform and well‐dispersed CaF2 hollow spheres with tunable particle size (300–930 nm) have been synthesized by a facile hydrothermal process. Their shells are composed of numerous ...nanocrystals (about 40 nm in diameter). The morphology and size of the CaF2 products are strongly dependent on experimental parameters such as reaction time, pH value, and organic additives. The size of the CaF2 hollow spheres can be controlled from 300 to 930 nm by adjusting the pH value. Nitrogen adsorption–desorption measurements suggest that mesopores (av 24.6 nm) exist in these hollow spheres. In addition, Ce3+/Tb3+‐codoped CaF2 hollow spheres can be prepared similarly, and show efficient energy transfer from Ce3+ to Tb3+ and strong green photoluminescence of Tb3+ (541 nm, 5D4→7F5 transition of Tb3+, the highest quantum efficiency reaches 77 %). The monodisperse CaF2:Ce3+/Tb3+ hollow spheres also have desirable properties as drug carriers. Ibuprofen‐loaded CaF2:Ce3+/Tb3+ samples still show green luminescence of Tb3+ under UV irradiation, and the emission intensity of Tb3+ in the drug‐carrier system varies with the released amount of ibuprofen, so that drug release can be easily tracked and monitored by means of the change in luminescence intensity. The formation mechanism and luminescent and drug‐release properties were studied in detail.
Luminescent hollow spheres as drug carriers: Monodisperse CaF2 and CaF2:Ce3+/Tb3+ hollow spheres with tunable size (see depicted SEM and TEM images) have been synthesized by a facile hydrothermal method. The CaF2:Ce3+/Tb3+ hollow spheres show strong green photoluminescence under UV excitation (see spectrum). They also have desirable properties as drug carriers see cumulative release curve for ibuprofen (IBU).
Hollow and porous structured GdVO4:Dy3+ spheres were fabricated via a facile self-sacrificing templated method. The large cavity allows them to be used as potential hosts for therapeutic drugs, and ...the porous feature of the shell allows guest molecules to easily pass through the void space and surrounding environment. The samples show strong yellow-green emission of Dy3+ (485 nm, 4F9/2 → 6H15/2; 575 nm, 4F9/2 → 6H13/2) under UV excitation. The emission intensity of GdVO4:Dy3+ was weakened after encapsulation of anticancer drug (doxorubicin hydrochloride, DOX) and gradually restored with the cumulative released time of DOX. These hollow spheres were nontoxic to HeLa cells, while DOX-loaded samples led to apparent cytotoxicity as a result of the sustained release of DOX. ICP measurement indicates that free toxic Gd ions can hardly dissolate from the matrix. The endocytosis process of DOX-loaded hollow spheres is observed using confocal laser scanning microscopy (CLSM). Furthermore, GdVO4:Dy3+ hollow spheres can be used for T 1-weighted magnetic resonance (MR) imaging. These results implicate that the luminescent GdVO4:Dy3+ spheres with hollow and porous structure are promising platforms for drug storage/release and MR imaging.
Bilayer thermosensitive P(NIPAm-co-AAm) hydrogel discs were prepared by a facile UV light initiation process from N-isopropylacrylamide (NIPAm) and acrylamide (AAm) monomers’ cross-linking ...copolymerization. Poly(ethylene glycol) (PEG) as a pore-forming agent was added in order to form a porous structure and improve the water content in the hydrogel. Functional materials of NaYF4:Yb3+/Er3+ nanoparticles and multiwalled carbon nanotubes (MWCNTs) were incorporated into different layers of the P(NIPAm-co-AAm) hydrogel for the purpose of up-conversion luminescence labeling and the NIR light antenna effect, respectively. Significantly improved drug release from composite hydrogels was achieved in response to 980 nm NIR light irradiation by using lysozyme as a macromolecular drug. The multifunctional hydrogel reported here provides a platform for simultaneous NIR luminescence labeling and NIR-driven drug release.
The multicolor patterned luminescent films of CaWO4:Eu3+ (red), CaWO4:Tb3+ (green), and pure CaWO4 (blue) on quartz substrates were fabricated by the facile and low-cost microcontact printing (μCP) ...method combining with the Pechini sol–gel route. On the basis of the μCP process, a hydrophobic self-assembled monolayer (SAM) was first created on the hydrophilic surface of quartz substrates by poly(dimethylsiloxane) (PDMS) mold printing, and then, the multicolor patterned luminescent films were selectively deposited on the hydrophilic regions via a spin coating process and heating treatment. The X-ray diffraction, optical microscopy, scanning electron microscopy, and photoluminescence (PL) spectra were used to characterize the structure and fluorescence properties of the corresponding samples. The results demonstrate that the μCP process can be used for patterning the inorganic phosphor materials and have potential for fabricating rare-earth luminescent pixels for the applications of display devices.
Nearly monodisperse and well-defined one-dimensional (1D) Gd2O3:Eu3+ nanorods and microrods were successfully prepared through a large-scale and facile hydrothermal method followed by a subsequent ...heat treatment process, without using any catalyst or template. X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TGA−DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), photoluminescence (PL) and cathodoluminescence (CL) spectra as well as kinetic decays were used to characterize the samples. The size of the Gd2O3:Eu3+ rods could be modulated from micro- to nanoscale with the increase of pH value using ammonia solution. The as-formed product via the hydrothermal process, Gd(OH)3:Eu3+, could transform to cubic Gd2O3:Eu3+ with the same morphology and a slight shrinking in size after a postannealing process. The formation mechanism for the Gd(OH)3 rods has been proposed. Both the Gd2O3:Eu3+ nanorods and microrods exhibit the same strong red emission corresponding to 5D0 → 7F2 transition (610 nm) of Eu3+ under UV light excitation (257 nm) and low-voltage electron beam excitation (1−5 kV), which have potential applications in fluorescent lamps and field emission displays.
