A robust high selectivity fluorescence turn-on nanoprobe for peroxynitrite detection in inflammatory cells and mice.

Changed levels of intracellular peroxynitrite anion (ONOO-) are closely related to the occurrence and development of inflammation. Specific imaging of ONOO- at sites of inflammation can be of great significance not only for inflammation diagnosis but also for obtaining a deeper understanding of the role of ONOO- in inflammation. Therefore, there is an urgent need for constructing some reliable tools to study the relationship between ONOO- and inflammation in biosystems. In this work, we developed a robust high selectivity fluorescence turn-on nanoprobe (Rhb-ONOO) for inflammation-targeted imaging of ONOO-. The Rhb-ONOO was obtained by self-assembly of amphiphilic Rhb-ONOO, which was constructed by the condensation reaction of the hydrophobic, ONOO--response and deep red-emitting fluorophore (Rhb) with hydrophilic biopolymer glycol chitosan (GC). Rhb-ONOO showed rapid response towards ONOO- during 60 s, high sensitivity with 19-fold enhancement of fluorescence intensity ratio (I628/I0), and excellent selectivity towards ONOO- over other analytes as well as a good linear relationship was observed between the I628/I0 and the ONOO- concentration range 0-1 µM, with an excellent limit of detection (LOD) of 33 nM. Impressively, it was successfully employed Rhb-ONOO for ONOO- imaging in living inflammatory cells and drug-induced inflammatory mice, illustrating nanoprobe Rhb-ONOO has excellent potential for further study ONOO--related inflammatory diseases.

Fabrication of multilevel porous structure networks on Nb-Ta-Ti alloy scaffolds and the effects of surface characteristics on behaviors of MC3T3-E1 cells.

Porous Nb-25Ta-25Ti alloys (60% porosity and 100-600 µm pore size) for bone implant applications were manufactured combining impregnation and sintering methods. Surfaces with porous micro-nanostructured networks on Nb-Ta-Ti alloys were successfully modified by various surface pre-treatments (acid etching, alkali-heat treatment and annealing treatment). Surface characteristics and Ca-P layer deposition behaviors of the multilevel structured porous Nb-Ta-Ti alloys were investigated by conducting various tests, including x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray, atomic force microscopy and optical contact angle measurement. In particular, bulk Nb-Ta-Ti alloys were also used as mutual control. The results demonstrated that the porous alloy exhibited a unique multilevel porous structure with macro-networks and micro-pits after pre-treatments. The surface passive TiO2/Nb2O5/Ta2O5layers on Nb-Ta-Ti alloys were partially dissolved by the corrosive attack of hydroxyl ions during alkali heat treatment. In addition, subsequent annealing treatment increased the density of the gel layers formed during alkali heat treatment. After immersion in SBF for 14 d, a continuous relatively uniform apatite layer was formed on the multilevel structured surfaces. Moreover, the mechanism of surface mineralization can be construed as electrostatic interactions between substrates and ions. Furthermore,in vitrocell culture showed that Nb-Ta-Ti alloys had a good biocompatibility and the multilevel porous structure could enhance the cellular behaviors including: cell adhesion and spreading.

Bone response in vivo of Ti-45Zr alloy as dental implant material.

Ti-Zr alloys have gained increasing attention as a new metallic biomaterial, being used as implants for both orthopedics and dentistry. More recently, our group found promising results for the Ti-45Zr alloy, which presented a low elastic modulus, a pronounced and excellent mechanic character, and excellent cell compatibility in vitro. However, its biocompatibility and potential to promote osteogenesis in vivo remained unclear. In the present study, the biocompatibility, osteointegration ability, and immune response effects of the Ti-45Zr alloy were evaluated in animal experiments. The results showed that the alloy had good blood compatibility and no body side effects. After implantation in vivo, the inflammation turned out well and was beneficial to the polarization of macrophages. Additionally, the Ti-45Zr alloy presented a good osteointegration ability. Overall, these results confirmed that the Ti-45Zr alloy can be used as a dental implant material.

Microstructure, mechanical properties and osseointegration ability of Ta-20Zr alloy used as dental implant material.

The aim of this study was to evaluate the application prospect of a tantalum (Ta) and zirconium (Zr) alloy as a dental implant material. The Ta-20Zr (wt.%) alloy was prepared by powder metallurgy, and its microstructure and mechanical properties were analyzed by standard techniques. The effect of Ta-20Zr alloy on inflammation, bone remodeling and osseointegration was analyzed in rat and rabbit models by biochemical, histological and imaging tests. The Ta-20Zr alloy showed excellent mechanical compatibility with the bone tissue on account of similar elastic modulus (49.2 GPa), thereby avoiding the 'stress shielding effect'. Furthermore, Ta-20Zr alloy enhanced the inflammatory response by promoting secretion of interleukin-6 (IL-6) and IL-10, and facilitated the balance between the M1/M2 macrophage phenotypes. Finally, Ta-20Zr also showed excellent osseointegration and osteogenic ability without any systemic side effects, making it an ideal dental implant material.

Cytocompatibility of Ti-xZr alloys as dental implant materials.

Ti-xZr (x = 5, 15, 25, 35, 45% wt%) alloys with low elastic modulus and high mechanical strength were fabricated as a novel implant material. The biocompatibility of the Ti-xZr alloys was evaluated by osteoblast-like cell line (MG63) in terms of cytotoxicity, proliferation, adhesion, and osteogenic induction using CCK-8 and live/dead cell assays, electron microscopy, and real-time PCR. The Ti-xZr alloys were non-toxic and showed superior biomechanics compared to commercially pure titanium (cpTi). Ti-45Zr had the optimum strength/elastic modulus ratio and osteogenic activity, thus is a promising to used as dental implants.

Construct a lysosome-targeting and highly selective fluorescent probe for imaging of hydrogen sulfide in living cells and inflamed tissues.

Since the fluctuation of cellular hydrogen sulfide (H2S) is a very important third endogenously generated gaseous signaling molecule and plays a key role in the development of numerous human disorders, the real-time fluorescence detection of H2S in living systems has attracted plenty of interest during past decade. Although a lot of H2S fluorescent probes have been reported, the relationship between the physiology and pathology of H2S in organelles remains unclear, especially for inflammatory tissue. In this work, by adopting a weakly basic morpholine group as the lysosome-targeting site, a naphthalimide derivative as the signal reporter group and a 4-dinitrobenzene-ether (DNB) as fluorescence signal quencher and H2S-selective recognition moiety, we reported a new lysosome-targeting TP fluorescent probe LyNP-H2S for H2S detection and imaging in living cells and inflamed tissues. The probe LyNP-H2S exhibits very low fluorescence signal in the absence of H2S, and displays a significant 262-fold fluorescence intensity enhancement in the presence of H2S at 540 nm. Moreover, LyNP-H2S has the capability of quantitative detection of H2S at concentrations ranging from 0 to 12.0 µM (limit of detection = 9.8 nM), rapid response, as well as high sensitivity and selectivity toward H2S. Impressively, the results of living cell and inflamed tissues imaging test demonstrate that LyNP-H2S has the potentiality of being an ideal probe for real-time H2S detection in biosystems.

Nb-Ti-Zr alloys for orthopedic implants.

Niobium (Nb), Titanium (Ti), and Zirconium (Zr) have attracted much attention as implant materials due to it's excellent mechanical properties and biocompatibility. However, little attention has been paid to high Nb-containing biomedical alloys. Here, the 50 wt.%Nb-XTi-Zr ternary alloy(x = 20wt.%, 30 wt.%, 40 wt.%) with relative density over 90% was prepared by powder metallurgy method. The massive α(Zr) distributed along the grain boundaries and lamellar ß(Zr) appeared in the grains of ß(Nb) in the 50 wt.%Nb-20wt.%Ti-Zr alloy. The acicular α phase is mainly distributed in the ß-grain of 50 wt.%Nb-30wt.%Ti-Zr alloy. And α(Ti)-colonies in the ß-grains and continuous α(Ti)GB at ß-grain boundary can be observed in the 50 wt.%Nb-40wt.%Ti-Zr alloy. Comparing with Nb-20wt.%Ti-Zr alloy and 50 wt.%Nb-40wt.%Ti-Zr alloy, the 50 wt.%Nb-30wt.%Ti-Zr alloy showed lower Vickers hardness and elastic modulus. Furthermore, the as-sintered 50 wt.%Nb-XTi-Zr alloy promoted the cell proliferation and cell adhesion of MG-63 cells on the surface of alloys. In conclusion, the 50 wt.%Nb-XTi-Zr alloy combines excellent mechanical and biological properties, and the 50 wt.%Nb-30wt.%Ti-Zr alloy with lower elastic modulus (close to the bone) is a more promising candidate for bone implant material.

Naphthalimide-based a highly selective two-photon fluorescent probe for imaging of hydrogen sulfide in living cells and inflamed tissue of mouse model.

Hydrogen sulfide (H2S) is a very important third endogenously generated gaseous signaling molecule and plays a key role in physiological and pathological regulation processes of living biosystems. Although a lot of H2S fluorescent probes have been reported, the relationship between the physiology and pathology of H2S in inflamed tissues remains unclear. Herein, by adopting a donor-π-acceptor (D-π-A)-structured naphthalimide derivative as the two-photon (TP) fluorophore and a 4-dinitrobenzene-ether (DNB) with a strong intramolecular charge transfer (ICT) effect as the recognition moiety, we reported a novel TP bioimaging probe NP-H2S for H2S with improved sensitivity. The NP-H2S exhibits very low background fluorescence in the absence of H2S, and a significant 258-fold fluorescence intensity enhancement was observed in the presence of H2S, resulting in a high sensitivity and selectivity to H2S in aqueous solutions with a detection limit of 18.8 nM observed. The probe also shows a wide linear response concentration range (0-10.0 µM) to H2S with high selectivity. All these features are favorable for direct monitoring of H2S in complex biological samples. It was then applied for direct TP imaging of H2S in tissues of inflammation model with satisfactory sensitivity, indicating it has the latent capability in further biological applications for investigation of the interaction H2S with inflammation.

Cytocompatibility, stability and osteogenic activity of powder metallurgy Ta-xZr alloys as dental implant materials.

Tantalum (Ta) and zirconium (Zr) alloys were found to had low elastic modulus and similar biomechanical characteristics as the human bone. However, the biocompatibility and osteogenic potential of Ta-xZr alloyswith different proportions (20, 30, 40 and 50% Zr by atom) remains to be investigated. In this study, the biocompatibility of Ta-xZr alloys and commercially pure titanium (cpTi) was evaluated in vitro by cell counting kit-8 assay. The adhesion of MG63 osteoblasts to the surface of the alloys was observed by fluorescence microscopy, and their morphology was analyzed by scanning electron microscopy (SEM). The expressions of alkaline phosphatase (ALP), Ki67, osteocalcin (OC), collagen-I (Col-I) and Integrin ß1 mRNA in the cultured cells were determined by RT-PCR. As a result, Ta-xZr (x = 20, 30, 40 and 50 at%) alloys were non-toxic and supported proliferation of the MG63 cells. The osteoblasts adhered to the Ta-xZr alloys, and subsequently spread and proliferated rapidly. Furthermore, the cells grown on Ta-20Zr and Ta-30Zr expressed high levels of ALP, Col I and OC, indicating that the Ta-xZr alloys can induce osteogenesis. In conclusion, Ta-xZr alloys promoted the adhesion, proliferation and osteogenic differentiation of MG63 cells. The Ta-xZr composites with a higher proportion of Ta exhibited superior osteogenic activity, and Ta-30Zr is therefore a promising alternative for Ti implants.

Construction of a lysosome-targetable ratiometric fluorescent probe for H2O2 tracing and imaging in living cells and an inflamed model.

Hydrogen peroxide (H2O2), an important reactive oxygen species (ROS) with unique destructive oxidation properties, can be produced in lysosomes to fight off pathogens. Although many fluorescent probes have been developed for the detection and imaging of H2O2, the development of a ratiometric fluorescent probe for H2O2 detection and imaging in lysosomes and an inflammation model remains rather scarce. Therefore, it is important to develop an efficient tool for monitoring H2O2 in inflamed tissues to evaluate the physiological and pathological relationship between inflammation and lysosomal H2O2. In this work, a new naphthalimide-based lysosome-targeting fluorescent probe (NPT-H2O2) for ratiometric detection and imaging was developed in vitro and in vivo. The probe exhibited two well-resolved emission peaks separated by 125 nm, rapid response (<40 s), and high selectivity and sensitivity toward H2O2, as well as low cytotoxicity in vitro. Inspired by prominent features of these results, we further successfully applied NPT-H2O2 for H2O2 imaging with a dual-channel in living cells, demonstrating that our probe NPT-H2O2 was targeted in the lysosomes. Finally, NPT-H2O2 was used for H2O2 detection in inflamed tissues and achieved satisfactory results. We predict that our probe can be used as a powerful tool to reveal the relationship between physiology and pathology of inflammation and lysosomal H2O2.

Evaluation of biocompatibility and osseointegration of Nb-xTi-Zr alloys for use as dental implant materials.

The aim of this study was to evaluate the biocompatibility and osteogenic potential of 50%Nb-xTi-Zr (NTZ,x= 20%, 30%, 40% by weight) alloys as compared with dental commercial pure titanium (cpTi). Cell cytotoxicity assay, fluorescence microscopy and electron microscopy were used to measure thein vitrobiocompatibility of NTZ. The expression of alkaline phosphatase (ALP), integrin ß1, osteocalcin (OC), Ki67 and collagen-I (Col-I) at the mRNA level was measured by real-time reverse transcription-polymerase chain reaction. Osseointegration ability was determined using x-ray evaluation and histological analysisin vivo. Compared with the MG63 cells grown on cpTi on day 3, the viability, adherence and proliferation rates of cells cultured on NTZ alloys were significantly improved (p< 0.05). Furthermore, similar expression levels of Ki67, Col-I, OC and ALP were found in the MG63 cells grown on NTZ alloys and those grown on cpTi. The Cbfα1 level was significantly higher for the 50%Nb-30%Ti-Zr (NTZ3) than for the cpTi group on day 6 (p< 0.01), indicating that NTZ alloys can induce osteogenesis. A considerable amount of new bone formation and osseointegration was observed around NTZ3 implants compared with cpTi implantsin vivo. Collectively, NTZ3 showed superior biocompatibility and osteogenic activity; therefore, NTZ3 may be an excellent replacement for dental Ti implants.

[Cephalometric analysis of the soft tissue profile in Hunan Han adults with normal occlusion].

OBJECTIVE: To analyze the characteristics soft tissue profile in Hunan Han adults with normal occlusion and to explore the differences of the soft tissue profile in gender, region and race. METHODS: Lateral cephalometric radiographs were performed for 323 volunteers (164 females and 159 males) from Hunan Province. The digital cephalometric radiographs were imported into the WinCeph8.0 measurement and analysis system in a same computer. According to the Holdaway analysis method, the mean and standard deviation were calculated. Then the results were compared to the data from Liaoning, Nepalese, Japanese, North American Caucasians. RESULTS: The normal value of cephalometric facial soft tissue profile in Han population adults with normal occlusion in Hunan Province were obtained. There were significant differences in subnasale to H line (Sn-H), upper lip tension, lower lip sulcus depth (Si-PgsLs), and soft tissue chin thickness (Pg-Pgs) between males and females (all P<0.05). Compared with Liaoning Province, significant regional differences in soft tissue facial angle (FH-NsPgs), upper lip sulcus depth (Ss-Ls), Sn-H, lower lip thickness, upper lip thickness, H angle, lower lip to H line (Li-PgsLs), Si-PgsLs, and Pg-Pgs were found in Hunan Province (all P<0.05). Compared with the Japan, significant regional differences in FH-NsPgs, nose prominence (Sn-Pn), lower lip thickness, upper lip tensity, H angle, Li-PgsLs, Si-PgsLs, and Pg-Pgs were found in Hunan Province (all P<0.05). Compared with the Nepalese, significant regional differences in Sn-Pn, Ss-Ls, Sn-H, skeletal profile convexity (A-NPs), basic upper lip thickness, upper lip tensity, H angle, Li-PgsLs and Pg-Pgs were found in Hunan Province (all P<0.05). Compared with the North America, significant regional differences in Sn-Pn, Ss-Ls, Sn-H, A-NPs, basic upper lip thickness, upper lip tensity, H angle, Li-PgsLs, Si-PgsLs and Pg-Pgs were found in Hunan Province (all P<0.05). CONCLUSION: There are both similarities and differences in facial soft tissue profile between males and females with normal occlusion in Hunan Province. The characteristics of facial soft tissue profile in Hunan Province are different from that in Liaoning area, Nepal, Japan and North America.