Enhancing the near-infrared upconversion photocatalytic activity of ZnO/Bi3Ti2O8F:Yb3+, Er3+ by modulating the internal electric field through Z-scheme heterojunction construction.

Exploring strategies to improve the near-infrared response of photocatalysts is an urgent challenge that can be overcome by utilizing upconversion (UC) luminescence to enhance photocatalysis. This paper reports the fabrication of a ZnO/Bi3Ti2O8F:Yb3+, Er3+ (ZnO/BTOFYE) Z-scheme heterojunction based on a Bi3Ti2O8F:Yb3+, Er3+ (BTOFYE) UC photocatalyst via electrostatic self-assembly. Fermi energy difference at the interface of BTOFYE and ZnO generates a strong internal electric field (IEF) in the Z-scheme heterojunction, offering a novel charge transfer mode that promotes carrier transfer and separation while retaining the strong redox capability. These results are confirmed through in situ X-ray photoelectron spectroscopy, in situ Kelvin probe force microscopy, electron spin resonance, and density functional theory calculations. In addition, the effect of the IEF on the UC luminescence process of Er3+ enhances the luminescence intensity, considerably improving the UC utilization efficiency. The optimal ZnO/BTOFYE degrades 64 % of ciprofloxacin in 120 min, which is 2.3 times more than that degraded by BTOFYE. Overall, the results of this study offer a reference for the rational development of high efficiency UC photocatalysts by generating IEF in Z-scheme heterojunctions.

SEA Anemone-inspired Conducting Polymer Sensing Platform for Integrated Detection of Tumor Protein Marker and Circulating Tumor Cell.

Combining the detection of tumor protein markers with the capture of circulating tumor cells (CTCs) represents an ultra-promising approach for early tumor detection. However, current methodologies have not yet achieved the necessary low detection limits and efficient capture. Here, we introduced a novel polypyrrole nanotentacles sensing platform featuring anemone-like structures capable of simultaneously detecting protein biomarkers and capturing CTCs. The incorporation of nanotentacles significantly enhanced the electrode surface area, providing abundant active sites for antibody binding. This enhancement allowed detecting nucleus matrix protein22 (NMP22) and bladder tumor antigen (BTA) with 2.39 and 3.12 pg/mL detection limit, respectively. Furthermore, our developed sensing platform effectively captured MCF-7 cells in blood samples with a detection limit of fewer than 10 cells/mL, attributed to the synergistic multivalent binding facilitated by the specific recognition antibodies and the positive charge on the nanotentacles surface. This sensing platform demonstrated excellent detection capabilities and outstanding capture efficiency, offering a simple, accurate, and efficient strategy for early tumor detection. This article is protected by copyright. All rights reserved.

Docosahexaenoic Acid-Loaded Nanostructured Lipid Carriers for the Treatment of Peri-Implantitis in Rats.

Being the most common cause of implant failure, peri-implantitis is defined as a pathological condition associated with the occurrence of peri-implant plaque, characterized by peri-implant mucosal inflammation and progressive loss of the supporting bone tissue attributed to the persistence of pro-inflammatory cytokines. Docosahexaenoic acid (DHA), which is a type of omega-3 polyunsaturated fatty acid, is generally used for the treatment of many inflammatory diseases. However, a suitable form for dosing and its therapeutic effect on peri-implantitis remain unclear. In this study, a novel nanostructured lipid carrier (NLC) loaded with squalene and DHA was fabricated (DHA-loaded NLC). The encapsulation efficiency and drug loading efficiency values of the DHA-loaded NLC were 78.13% ± 1.85% and 28.09% ± 0.48%, respectively. The release of DHA was gradual and steady until 144 h. In addition, the free-radical-scavenging rate of DHA-loaded NLC (0.57 ± 0.03) was much higher than that of sole DHA (0.17 ± 0.003). By inhibiting nuclear factor-κB p65 nuclear translocation, DHA-loaded NLC prevented the activation of nuclear factor-κB downstream inflammatory pathways and exerted anti-inflammatory effects on macrophages. Moreover, DHA-loaded NLC showed better effects on preventing alveolar bone resorption of rat peri-implantitis model than sole DHA. Hence, DHA-loaded NLC enhanced the anti-inflammatory bioavailability of DHA, offering a novel approach for the treatment of peri-implantitis.

Effectively enhanced photocatalytic performance of layered perovskite Bi2NdO4Cl by coupling piezotronic effect.

The coupling between piezoelectricity and photoexcitation is an attractive method for improving the photocatalytic efficiency of semiconductors. Herein, a novel layered perovskite photocatalyst Bi2NdO4Cl (BNOC) has been successfully prepared via solid-state reaction. PFM results confirm that BNOC has piezoelectricity, and its piezo-photocatalytic degradation performance was evaluated for the first time using tetracycline hydrochloride (TH) as a pollutant model. The results show that the piezo-photocatalytic degradation rate constant is about 1.5 times higher than the sum of the individual photo- and piezo-catalytic components. This synergistic enhancement can be attributed to the band tilting-induced piezoelectric polarization charges and formation of a piezoelectric field, which accelerates the photoinduced charge carrier separation and effectively enhanced the photocatalytic performance. This work may facilitate the development of novel piezoelectric photocatalytic materials that are highly sensitive to the mechanical energy of discrete fluids, and offer ideas for piezo-photocatalysis in environmental applications.

Involvement of ferroptosis in Porphyromonas gingivalis lipopolysaccharide-stimulated periodontitis in vitro and in vivo.

OBJECTIVES: Ferroptosis is associated with multiple inflammatory diseases. Periodontitis is an inflammatory disease mainly caused by oral opportunistic pathogens. However, the ferroptosis-periodontitis relationship has not been thoroughly described. We here analyzed whether ferroptosis is involved in periodontitis. MATERIALS AND METHODS: Human gingival fibroblasts (HGFs) were stimulated with P. gingivalis-LPS and ferrostatin-1 (Fer-1, a ferroptosis inhibitor), and changes in mitochondrial morphology, ferroptosis-related factors, and inflammation levels were detected. After the rat experimental periodontitis model was established, changes in ferroptosis-related factors and inflammation levels were re-evaluated in the same manner. RESULTS: Porphyromonas gingivalis-LPS-induced mitochondrial shrinkage, an increase in mitochondrial membrane density, and upregulation of reactive oxygen species in HGFs. The expression of prostaglandin-endoperoxide synthase 2, transferrin receptor 1, and malondialdehyde and inflammation levels were upregulated, whereas the expression of solute carrier family seven member 11, glutathione peroxidase 4, superoxide dismutase, and glutathione were downregulated. Fer-1 attenuated these aforementioned changes and inflammation levels induced by P. gingivalis-LPS. The in vivo experiment results were consistent with the in vitro experiment results. CONCLUSIONS: Ferroptosis is involved in inflammatory processes in HGFs upon P. gingivalis-LPS stimulation. Ferroptosis is observed in the gingival tissue of periodontitis rats.

Janus electro-microenvironment membrane with surface-selective osteogenesis/gingival healing ability for guided bone regeneration.

Guided bone regeneration is widely applied in clinical practice to treat alveolar bone defects. However, the rate of healing of severe alveolar bone defects is slow, and there is a high incidence of soft tissue wound dehiscence. In this study, we propose a barrier membrane with a Janus electro-microenvironment (JEM) to achieve side-selective bone regeneration and soft tissue healing. The JEM membrane was constructed using a polarized polyvinylidene fluoride ferroelectric membrane with different surface potentials on either side. It promoted osteogenic differentiation and bone regeneration on the negatively polarized side (JEM-) and soft tissue regeneration on the positively polarized side (JEM+). Further investigation revealed that the JEM-mediated promotion of bone formation was related to mitochondrial autophagy, as indicated by depolarization of the mitochondrial membrane potential and the expression of LC3, Pink I, and Parkin. Moreover, the gingival healing promoted by JEM+ was related to oxidative phosphorylation in mitochondria, as indicated by the upregulation of mitochondrial complexes I-V and an increase in ATP generation. The design concept of the JEM provides a new avenue for regulating tissue regeneration between different tissue interfaces.

Self-doping induced oxygen vacancies and lattice strains for synergetic enhanced upconversion luminescence of Er3+ ions in 2D BiOCl nanosheets.

Rare earth (RE) ions combined with two-dimensional (2D) semiconductors can exhibit unexpected optical properties. However, fluorescence quenching has always been inevitable due to defects associated with the synthesis and doping of 2D materials. In this work, we reported an efficient upconversion (UC) enhancement of Er3+ doped BiOCl nanosheets, utilizing a defect engineering strategy conversely rather than eliminating defects. Experiments and theoretical calculations provide evidence that oxygen vacancies (OVs) and lattice strain are simultaneously formed in the BiOCl:Er3+ nanosheets through self-doping of Cl- ions. Under 980 nm excitation, samples doped with 300 mol% Cl- ions exhibit the best luminescent emission, and the green and red UC emissions are enhanced 3.5 and 15 times, respectively. We showed that the OVs in the 2D semiconductor can act as energy bridges to transfer charges to the Er3+ energy level, enriching the electron population at the excited levels; while, the lattice strain enhances the energy transfer and charge accumulation, which synergistically enhance the UC luminescence. This research provides a new insight into the development of defect engineering for UC PL in 2D nanomaterials.

Advances and Prospects in Antibacterial-Osteogenic Multifunctional Dental Implant Surface.

In recent years, dental implantation has become the preferred protocol for restoring dentition defects. Being the direct contact between implant and bone interface, osseointegration is the basis for implant exerting physiological functions. Nevertheless, biological complications such as insufficient bone volume, poor osseointegration, and postoperative infection can lead to implant failure. Emerging antibacterial-osteogenic multifunctional implant surfaces were designed to make up for these shortcomings both during the stage of forming osseointegration and in the long term of supporting the superstructure. In this mini-review, we summarized the recent antibacterial-osteogenic modifications of the dental implant surface. The effects of these modifications on biological performance like soft tissue integration, bone osteogenesis, and immune response were discussed. In addition, the clinical findings and prospects of emerging antibacterial-osteogenic implant materials were also discussed.

Enhancement of solar-driven photocatalytic activity of oxygen vacancy-rich Bi/BiOBr/Sr2LaF7:Yb3+,Er3+ composites through synergetic strategy of upconversion function and plasmonic effect.

For better use of solar energy, the development of efficient broadband photocatalyst has attracted extraordinary attention. In this study, a ternary composite consisting of Sr2LaF7:Yb3+,Er3+ upconversion (UC) nanocrystals and Bi nanoparticles loaded BiOBr nanosheets with oxygen vacancies (OVs, SLFBB) was designed and synthesized by multistep solvent-thermal method. Mechanisms of in-situ formation of Bi nanoparticles and OVs in BiOBr/Sr2LaF7:Yb3+,Er3+ composites (SFLB) are clarified. The Bi metal and OVs enhanced the light-harvesting capacity in the region of visible-near-infrared (Vis-NIR), and promoted the separation of electron-hole (e-/h+) pairs. Furthermore, the surface plasmon resonance (SPR) effect of Bi metal can improve the energy transfer from Sr2LaF7:Yb3+,Er3+ to BiOBr via nonradiative energy transfer process, resulting in enhancing the light utilization from upconverting NIR into Vis light. Due to the synergistic effects of UC function, SPR and OVs, the SFLBB exhibited obviously enhanced photocatalytic ability for the degradation of BPA with a rate of 8.9 × 10-3 min-1, which is about 2.78 times higher than 3.2 × 10-3 min-1 of BiOBr (BOB) under UV-Vis-NIR light irradiation. This work provides a novel strategy for the project of high-efficiency Bismuth-based broadband photocatalysts, which is helpful to further understand the mechanism of enhanced photocatalysis by UC function and plasmonic effect.

Intermediate excited state suppression and upconversion enhancement of Er3+ ions by carbon-doping boosting photocarrier separation in bismuth oxychloride nanosheets.

Low luminescence efficiency of rare-earth ions dopedupconversion (UC) nanomaterials is still a major limitation for their applications.Here, based on bismuth oxychloride nanosheets that show efficient photocarriers separation due to combining spontaneous polarization and layered semiconductor, we report a new carbon heterovalent doping strategy for efficient UC luminescence enhancement by suppressing the intermediate excited states of Er3+ ions. The first-principles calculations and photoelectrochemical characterizations provide evidences that the replacement of C ions for Cl strengthen the spontaneous polarization and inter electric field (IEF) of bismuth oxychloride nanosheets, which further improve the photocarriers separation efficiency. Under 808 or 980 nm excitation, the emission intensity of 4I13/2 energy level of Er3+ ions (1550 nm) increase slightly with C doping, but the its decay time and the visible UC emission are improved tremendously at the same time. We show that the recombination rate of intermediate excited state electrons of Er3+ ions with the ground state is inhibited by the enhanced IEF, which promotes the energy reabsorption transition to upper energy levels, thus enhancing the visible UC emission. This work not only may provide a new insight into the method for engineering of UC emissions but also deepen the understanding for layered semiconducting material to modify the transition of Lanthanide ions.

Emergence of photoluminescence enhancement of Eu3+ doped BiOCl single-crystalline nanosheets at reduced vertical dimensions.

Here, we report that a reduction in scale leads to an enhancement in the photoluminescence (PL) of Eu3+ doped BiOCl nanosheets, challenging the long-standing notion that PL is inevitably suppressed at a scale of tens of nanometers. The oriented depolarization effect of layered ferroelectrics was utilized for the first time to improve the PL efficiency of lanthanide doped nanomaterials. The probing effect of the electric dipole transitions of the Eu3+ ions and their PL measurements provides evidence that the depolarization field and the PL of Eu3+ ions increase synchronously as the thickness of the BiOCl single-crystalline nanosheets decreases from hundreds to tens of nanometers. We show that the scale-dependent internal electric field (IEF) induced by the depolarization field as well as its excitation field enhancement are responsible for the appearance of an abnormal scale-dependent PL enhancement. This finding may be useful for the development of low-dimensional material systems with enhanced photophysical properties, relevant for use in new nano-optoelectronic devices.

Ti nanorod arrays with a medium density significantly promote osteogenesis and osteointegration.

Ti implants are good candidates in bone repair. However, how to promote bone formation on their surface and their consequent perfect integration with the surrounding tissue is still a challenge. To overcome such challenge, we propose to form Ti nanorods on their surface to promote the new bone formation around the implants. Here Ti nanorod arrays (TNrs) with different densities were produced on pure Ti surfaces using an anodizing method. The influence of TNr density on the protein adsorption as well as on the adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 pre-osteoblastic cells were assessed. The TNrs were also implanted into the bone defects in rabbits to test their application in promoting bone formation and osteointegration at the implant-bone interface. TNrs with the medium density were found to show the best capability in promoting the protein adsorption from surrounding medium, which in turn efficiently enhanced osteogenic differentiation in vitro and osteointegration in vivo. Our work suggests that growing TNrs with a medium density on the surface of traditional Ti implants is an efficient and facile method for promoting bone formation and osteointegration in bone repair.

[Synthesis and Luminescence Properties of BiOCL: Dy3⁺Phosphors for NUV Excited White Light-Emitting Diodes].

Abstract In the present paper, we reported the luminescence properties of BiOCl:Dy(3+) and BiOCl:Dy(3+), Li+ phosphor synthesized by conventional solid state method. X-ray diffraction (XRD) and excitation and emission spectroscopy were used to characterize the samples. Results show that pure tetragonal BiOCl:Dy(3+) crystals can be synthesized successfully at 500 °C, and Li+ ion dopant improves the crystallinity of samples furtherly. Under near UV light excitation, the samples,give the characteristic luminescence of Dy(3+) ions located at 478 (blue) and 574 nm (yellow), which show a low yellow-to-blue intensity ratio (Y/B) of Dy(3+) emission and white light emission. Moreover, codoping of Li+ ion can realize the enhancement of emission intensity and the adjustment of emission color. The characteristics of BiOCl:Dy(3+) phosphor, low temperature preparation, good near ultraviolet excitation and white light emission make it to a promising near-ultraviolet WLED phosphor.

Investigation on the upconversion emission in 2D BiOBr:Yb(3+)/Ho(3+) nanosheets.

As lanthanide doped upconverting host, two dimensional (2D) nanostructure materials have remarkable advantages compare with the bulk materials, but excellent 2D upconversion nanohost is still few up to date. In this work, Yb(3+)/Ho(3+) co-doped BiOBr nanosheets have been successfully prepared via a facile hydrothermal method, which were characterized by X-ray diffraction, transmission electron microscopy, Atomic Force Microscope, Raman spectra, Fourier transform infrared absorption and UC luminescence spectra. Under excitation at 980 nm, bright green UC emission centered at 550 nm accompanied with weak red (663 nm) and near infrared (NIR) UC emissions (760 nm) were observed. Power dependence studies revealed that NIR and red UC emissions were both dominated by a two and one-photon process due to saturation effects that is related to the special crystal structure of BiOBr nanosheets, and a different UC mechanism of NIR emission from Ho(3+) was proposed accordingly.

Tuning nano-architectures and improving bioactivity of conducting polypyrrole coating on bone implants by incorporating bone-borne small molecules.

Citric acid, a molecule present in fresh bone, was introduced into template-free electrochemical polymerization to form biocompatible coating made of polypyrrole (PPy) nano-cones on bone implants. It served not only as a dopant to tune the nano-architectures but also as a promoter to enhance bioactivity of the PPy-coated implants.

Surface-dependent self-assembly of conducting polypyrrole nanotube arrays in template-free electrochemical polymerization.

One-dimensional conducting polymer nanostructure arrays could provide short ion transport paths, thus delivering superior chemical/physical performance and having large potential as intelligent switching materials. In this work, in situ electrochemical atomic force microscopy is employed to monitor the self-assembly of conducting polypyrrole nanotube arrays in template-free electrochemical polymerization. The specific spreading behavior of pyrrole micelles on the conductive substrate is important to large-area self-assembly of conducting polypyrrole nanotube arrays and the insight into self-assembly of conducting polypyrrole nanotube arrays is discussed. Moreover, compared with unoriented nanostructured polypyrrole, the conducting polypyrrole nanotube arrays possess enhanced electrical and electrochemical performances.

Controlled oxidative nanopatterning of microrough titanium surfaces for improving osteogenic activity.

To further enhance the biological properties of acid-etched microrough titanium surfaces, titania nanotextured thin films were produced by simple chemical oxidation, without significantly altering the existing topographical and roughness features. The nanotextured layers on titanium surfaces can be controllably varied by tuning the oxidation duration time. The oxidation treatment significantly reduced water contact angles and increased the surface energy compared to the surfaces prior to oxidation. The murine bone marrow stromal cells (BMSCs) were used to evaluate the bioactivity. In comparison, oxidative nanopatterning of microrough titanium surfaces led to improved attachment and proliferation of BMSCs. The rate of osteoblastic differentiation was also represented by the increased levels of alkaline phosphatase activity and mineral deposition. These data indicated that oxidative nanopatterning enhanced the biological properties of the microrough titanium surfaces by modulating their surface chemistry and nanotopography. Based on the proven mechanical interlocking ability of microtopographies, enhancement of multiple osteoblast functions attained by this oxidative nanopatterning is expected to lead to better implant osseointegration in vivo.

Preparation and upconversion emission modification of Yb, Er co-doped Y2SiO5 inverse opal photonic crystals.

Yb, Er co-doped Y2SiO5 inverse opal photonic crystals with three-dimensionally ordered macroporous were fabricated using polystyrene colloidal crystals as the template. Under 980 nm excitation, the effect of the photonic stopband on the upconversion luminescence of Er3+ ions has been investigated in the Y2SiO5:Yb, Er inverse opals. Significant suppression of the green or red UC emissions was detected if the photonic band-gap overlaps with the Er3+ ions emission band.

Enhancement of the short wavelength upconversion emission in inverse opal photonic crystals.

Upconversion luminescence properties of Yb-Tb codoped Bi4Ti3O12 inverse opals have been investigated. The results show that the upconversion emission can be modulated by the photonic band gap. More significantly, in the upconversion inverse opals, the excited-state absorption of Tb3+ is greatly enhanced by the suppression of upconversion spontaneous emissions of the intermediate excited state, and thus the short wavelength upconversion emission from Tb3+ is considerably improved. We believe that the present work will be valuable for not only the foundational study of upconversion emission modifications but also new optical devices in upconversion displays and short wavelength upconversion lasers.

Alpha-NaYF4:Nd3+ nanocrystal with near-infrared to near-infrared luminescence for bioimaging applications.

Nd3+ doped alpha-NaYF4 nanocrystals with size of about 15 nm were successfully synthesized through hydrothermal method. Nearly pure near-infrared to near-infrared (NIR-to-NIR) luminescence can be realized. Moreover, the excitation and the emission at 880 and 1060 nm, respectively, are away from the visible region. These are beneficial to deeper tissue penetration and reduced auto-fluorescence. This material exhibits an excellent NIR-to-NIR emission performance and is thus potentially applicable as a high-contrast in vitro and in vivo imaging probe.