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.
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.
A low toxic multifunctional nanoplatform, integrating both mutimodal diagnosis methods and antitumor therapy, is highly desirable to assure its antitumor efficiency. In this work, we show a ...convenient and adjustable synthesis of multifunctional nanoparticles NaYF4:Yb, Er@mSiO2@Fe3O4-PEG (MFNPs) based on different sizes of up-conversion nanoparticles (UCNPs). With strong up-conversion fluorescence offered by UCNPs, superparamagnetism properties attributed to Fe3O4 nanoparticles and porous structure coming from the mesoporous SiO2 shell, the as-obtained MFNPs can be utilized not only as a contrast agent for dual modal up-conversion luminescence (UCL)/magnetic resonance (MR) bio-imaging, but can also achieve an effective magnetically targeted antitumor chemotherapy both in vitro and in vivo. Furthermore, the UCL intensity of UCNPs and the magnetic properties of Fe3O4 in the MFNPs were carefully balanced. Silica coating and further PEG modifying can improve the hydrophilicity and biocompatibility of the as-synthesized MFNPs, which was confirmed by the in vitro/in vivo biocompatibility and in vivo long-time bio-distributions tests. Those results revealed that the UCNPs based magnetically targeted drug carrier system we synthesized has great promise in the future for multimodal bio-imaging and targeted cancer therapy.
Hydroxyapatite (Ca5(PO4)3OH) nano- and microcrystals with multiform morphologies (separated nanowires, nanorods, microspheres, microflowers, and microsheets) have been successfully synthesized by a ...facile hydrothermal process. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL) spectra, kinetic decay, and electron paramagnetic resonance (EPR) were used to characterize the samples. The experimental results indicate that the obtained Ca5(PO4)3OH samples show an intense and bright blue emission under long-wavelength UV light excitation. This blue emission might result from the CO2 •− radical impurities in the crystal lattice. Furthermore, the organic additive (trisodium citrate) and pH values have an obvious impact on the morphologies and luminescence properties of the products to some degree. The possible formation and luminescent mechanisms for Ca5(PO4)3OH nano- and microcrystals are presented in detail.
One-dimensional YVO4:Ln and Y(V, P)O4:Ln nanofibers and quasi-one-dimensional YVO4:Ln microbelts (Ln = Eu3+, Sm3+, Dy3+) have been prepared by a combination method of sol−gel process and ...electrospinning. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric and differential thermal analysis (TG−DTA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL), low-voltage cathodoluminescence (CL), and time-resolved emission spectra as well as kinetic decays were used to characterize the resulting samples. Due to an efficient energy transfer from vanadate groups to dopants, YVO4:Ln phosphors showed their strong characteristic emission under ultraviolet excitation (280 nm) and low-voltage electron beam excitation (1−3 kV). The energy transfer process was further studied by the time-resolved emission spectra as well as kinetic decay curves of Eu3+ upon excitation into the VO4 3− ion. Furthermore, the PL emission color of YVO4:Ln nanofibers can be tuned from blue to green, orange-red, and red easily by partial replacement VO4 3− with PO4 3− and changing the doping concentrations (x) of Ln, making the materials have potential applications in fluorescent lamps and field emission displays (FEDs).
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.
A multifunctional, dual-drug carrier platform was successfully constructed. Core-sheU structured NaGdF4：Yb/Er@NaGdF4：Yb@mSiO2-polyethylene glycol （abbreviated as UCNPS） nanopartides loaded with the ...antiturnor drug, doxorubicin （DOX） were incorporated into poly（~-caprolactone） （PCL） and gelatin loaded with antiphlogistic drug, indomethacin （MC） to form nanofibrous fabrics （labeled as MC/UCNPS/DOX） via electrospinning process. The resultant multifunctional spinning pieces can be surgically implanted directly at the tumor site of mice as an orthotopic chemotherapy by controlled-release DOX from mesoporous silicon dioxide （SiO2） and upconversion fluorescence/magnetic resonance dual-model imaging through NaGdF4：Yb/Er@NaGdF4：Yb embedded in MCfldCNPS/DOX invivo.
Novel multifunctional poly(ε-caprolactone)-gelatin encapsulating upconversion core/shell silica nanoparticles (NPs) composite fibers as dual drugs delivery system (DDDS), with indomethacin (IMC) and ...doxorubicin (DOX) releasing in individual release properties, have been designed and fabricated via electrospinning process. Uniform and monodisperse upconversion (UC) luminescent NaYF4:Yb3+, Er3+ nanocrystals (UCNCs) were encapsulated with mesoporous silica shells, resulting in the formation of core/shell structured NaYF4:Yb3+, Er3+@mSiO2 (UCNCs@mSiO2) NPs, which can be performed as DOX delivery carriers. These UCNCs@mSiO2 NPs loading DOX then were dispersed into the mixture of poly(ε-caprolactone) (PCL) and gelatin-based electrospinning solution containing IMC, followed by the preparation of dual drug-loaded composite fibers (DDDS) via electrospinning method. The drugs release profiles of the DDDS were measured, and the results indicated that the IMC and DOX released from the electrospun composite fibers showed distinct properties. The IMC in the composite fibers presented a fast release manner, while DOX showed a sustained release behavior. Moreover, the UC luminescent intensity ratios of 2H11/2/4S3/2–4I15/2 to 4F9/2–4I15/2 from Er3+ vary with the amounts of DOX in the system, and thus drug release can be tracked and monitored by the luminescence resonance energy transfer (LRET) mechanism.
The in situ photopolymerization method was applied to synthesize bulk nanocomposites consisting of hydrophobic NaYF4:Yb3+, Er3+ (Tm3+) nanoparticles as the filler and poly(methyl methacrylate) (PMMA) ...as the host material. The oleic acid stabilized NaYF4:Yb3+, Er3+ (Tm3+) nanoparticles and NaYF4:Yb3+, Er3+ (Tm3+)/PMMA nanocomposites have been well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), the thermogravimetric analysis (TGA), flexural tests, UV/vis transmission spectra, upconversion photoluminescence spectra, and luminescence decays. The well-crystallized NaYF4:Yb3+, Er3+ (Tm3+) nanoparticles are spherical with a mean diameter of 40 nm. The obtained solid NaYF4:Yb3+, Er3+ (Tm3+)/PMMA nanocomposites have similar mechanical properties to that of pure polymer. NaYF4:Yb3+, Er3+/PMMA and NaYF4:Yb3+, Tm3+/PMMA nanocomposites are transparent in the visible spectral region and exhibit strong green and blue upconversion photoluminescence upon 980 nm laser excitation due to the integration of luminescent NaYF4:Yb3+, Er3+ and NaYF4:Yb3+, Tm3+ nanoparticles, respectively.
