Gelatin-mediated gallium-doped SrHA composite coatings with sequential antimicrobial and osteogenic functions for infected bone defect repair.

In this study, gallium- and gelatin-modified strontium-doped hydroxyapatite (SrHA-Gel-Ga) bilayer coatings were prepared on titanium substrates by electrodeposition and spin-coating techniques. The results showed that gallium and gelatin were uniformly doped into the SrHA coatings, which exhibited good hydrophilicity and bioactivity. Furthermore, SrHA-Gel-Ga demonstrated good antimicrobial properties against E. coli and S. aureus, especially S. aureus. The co-doping of Sr and gelatin in the coatings was effective in mitigating the cytotoxicity of Ga. SrHA-Gel-Ga was better able to promote the adhesion, proliferation and early differentiation of MC3T3-E1 cells. This study provides a new strategy for the development of anti-infective bone repair coatings.

The Aesthetic Evaluation of the Brow-Eye Continuum After Correction of Severe Congenital Ptosis in Children With Extended Frontalis Muscle Advancement Technique.

BACKGROUND: Severe congenital ptosis is a common ocular deformity in pediatric patients that can significantly impact visual development and aesthetic appearance, leading to negative psychosocial outcomes. The frontalis muscle advancement technique is a well-established surgical treatment for severe congenital ptosis. Aesthetic changes of the brow-eye continuum often plays an important role in ptosis surgery. METHODS: We conducted a single-center retrospective case series study of patients with severe congenital ptosis who underwent the frontalis muscle advancement technique at the Department of Plastic and Reconstructive Surgery, Xijing Hospital, Fourth Military Medical University between April 2020 and June 2021. The study aimed to evaluate the aesthetic changes of the eyebrow-eyelid continuum after surgery. The main outcome measurements included marginal reflex distance 1, palpebral fissure height, eyebrow position, upper eyelid to lower eyebrow distance, lower eyelid to upper eyebrow distance, and nasal base to lower eyelid distance. RESULTS: The study included 48 patients (66 eyelids), with 30 unilateral and 18 bilateral patients. Our analysis found that eyebrow height decreased by an average of 4.8% postoperatively relative to preoperatively in all patients. CONCLUSIONS: The frontalis muscle advancement technique has demonstrated effectiveness in achieving aesthetically pleasing outcomes in children with severe ptosis. It is crucial to pay careful attention to the brow-eye continuum during the correction process, as its harmony can greatly impact the final result.

Porous surface with fusion peptides embedded in strontium titanate nanotubes elevates osteogenic and antibacterial activity of additively manufactured titanium alloy.

It is still a big challenge in orthopedics to treat infected bone defects properly using medical metals. The use of three-dimensional (3D) scaffold materials that simultaneously mimic the skeletal hierarchy and induce sustainable osteogenic and antibacterial functions are a promising solution with an increasing appeal. In this study, we first designed a bifunctional fusion peptide (HHC36-RGD, HR) by linking antimicrobial peptide (HHC36) and arginine-glycine-aspartate (RGD) peptide via 6-aminohexanoic acid. Then the 3D scaffold was fabricated by additive manufacturing, and the strontium titanate nanotube structure (3D-STN) was constructed on its surface. Finally, the HR was anchored to the 3D-STN with the aid of polydopamine (PDA, P), forming the 3D-STN-P-HR scaffold. The results showed that the scaffold exhibited an ordered 3D porous structure, and that the surface was covered by a dense HHC36-RGD layer. Expectedly, the adsorption of PDA effectively slowed down the release of HR. Moreover, the functionalized scaffold had a significant inhibitory effect on Staphylococcus aureus and Escherichia coli, and its antibacterial rate could reach more than 95%. The results of in vitro cell culture experiments demonstrated that the 3D-STN-P-HR scaffold possessed excellent cytocompatibility and could promote the transcription of osteogenic differentiation-related genes and the expression of related proteins. In conclusion, the functionally modified 3D porous titanium alloy scaffold (3D-STN-P-HR) has a balanced antibacterial and osteogenic function, which bodes well for future potential in the customized functional reconstruction of complex-shaped infected bone defects.

Investigation of bacteria and detergent residues on undergraduate students' dinner plates in dormitories during university lockdown.

The COVID-19 outbreak has disrupted undergraduate students' experiments since their access to the laboratory is limited. To address this problem, the bacteria and detergent residues on undergraduate students' dinner plates were investigated by the students in the dormitories. Five different types of dinner plates from 50 students were collected, which were cleaned with detergent and water in the same way and naturally dried. Then, Escherichia coli (E. coli) test papers and sodium dodecyl sulfonate test kits were used to understand the bacteria and detergent residuals. Commonly available equipment such as a yogurt maker was used for bacterial culture; detergent analyses were performed using centrifugation tubes. Effective sterilization methods and safety protection were achieved by dormitory available methods. According to the investigated results, the students found the differences in bacteria and detergent residuals between different dinner plates and made suitable choices for the future.

Effects of simvastatin on immunoreaction and inflammation in rats with asthma by regulating NOTCH signaling pathway.

To investigate the effect of simvastatin on the immunoreaction and inflammation in rats with asthma through the NOTCH signaling pathway, a total of 36 Sprague-Dawley (SD) rats were enrolled and randomly divided into the normal group (n=12), model group (n=12) and simvastatin group (n=12). The rats in the normal group were fed normally, those in the model group were prepared into models of asthma, and those in the simvastatin group were prepared into models of asthma and intervened with simvastatin. Next, the morphology of airway tissues was observed via hematoxylin-eosin (HE) staining assay. Besides, immunohistochemistry was employed to determine the expression of interferon-γ (INF-γ), and the relative protein expression levels of NOTCH2 and NOTCH3 were measured by Western blotting (WB). Additionally, enzyme-linked immunosorbent assay (ELISA) and quantitative polymerase chain reaction (qPCR) assay were carried out to detect the content of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) and the relative mRNA expression levels of INF-γ, IL-6 and TNF-α, respectively. HE staining results uncovered that the airway tissues displayed normal morphology in the normal group and disordered morphology and obvious inflammatory infiltration in the model group. In comparison with the model group, the simvastatin group exhibited significantly improved morphology of airway tissues. Based on immunohistochemistry, the average optical density of INF-γ positive expression was increased in the model group and simvastatin group compared with that in the normal group (P<0.05), and it was distinctly lower in the simvastatin group than that in the model group (P<0.05). The results of WB showed that compared with those in the normal group, the relative protein expression levels of NOTCH2 and NOTCH3 were elevated in model group and simvastatin group (P<0.05), whereas they were overtly reduced in simvastatin group compared with those in model group (P<0.05). It was found through ELISA that the model group and simvastatin group had raised content of IL-6 and TNF-α in comparison with the normal group (P<0.05), while the simvastatin group exhibited markedly decreased content of IL-6 and TNF-α in comparison with the model group (P<0.05). The results of qPCR revealed that the relative mRNA expression levels of INF-γ, IL-6 and TNF-α were distinctly up-regulated in the model group and simvastatin group compared with those in the normal group, displaying statistically significant differences (P<0.05), whereas they were markedly lowered in simvastatin group compared with those in the model group, showing statistically significant differences (P<0.05). Simvastatin represses the immunoreaction and inflammation in rats with asthma by down-regulating the NOTCH signaling pathway.

Mucosal immunity of mannose-modified chitosan microspheres loaded with the nontyepable Haemophilus influenzae outer membrane protein P6 in BALB/c mice.

Nontypeable Haemophilus influenzae (NTHi) is a common opportunistic pathogen that colonizes the nasopharynx. NTHi infections result in enormous global morbidity in two clinical settings: otitis media in children and acute exacerbation of chronic obstructive pulmonary disease (COPD) in adults. Thus, there is an urgent need to design and develop effective vaccines to prevent morbidity and reduce antibiotic use. The NTHi outer membrane protein P6, a potential vaccine candidate, is highly conserved and effectively induces protective immunity. Here, to enhance mucosal immune responses, P6-loaded mannose-modified chitosan (MC) microspheres (P6-MCMs) were developed for mucosal delivery. MC (18.75%) was synthesized by the reductive amination reaction method using sodium cyanoborohydride (NaBH3CN), and P6-MCMs with an average size of 590.4±16.2 nm were successfully prepared via the tripolyphosphate (TPP) ionotropic gelation process. After intranasal immunization with P6-MCMs, evaluation of humoral immune responses indicated that P6-MCMs enhance both systemic and mucosal immune responses. Evaluation of cellular immune responses indicated that P6-MCMs enhance cellular immunity and trigger a mixed Th1/Th2-type immune response. Importantly, P6-MCMs also trigger a Th17-type immune response. They are effective in promoting lymphocyte proliferation and differentiation without toxicity in vitro. The results also demonstrate that P6-MCMs can effectively induce MHC class I- and II-restricted cross-presentation, promoting CD4+-mediated Th immune responses and CD8+-mediated cytotoxic T lymphocyte (CTL) immune responses. Evaluation of protective immunity indicated that immunization with P6-MCMs can reduce inflammation in the nasal mucosa and the lung and prevent NTHi infection. In conclusion, MCMs are a promising adjuvant-delivery system for vaccines against NTHi.

"Dual-functional" strontium titanate nanotubes designed based on fusion peptides simultaneously enhancing anti-infection and osseointegration.

Currently, there is an increasing clinical demand for implants that effectively resist bacterial infections while promoting osseointegration. In this study, the fusion peptide technology was used to linearly fuse the antimicrobial peptide (AMP, HHC36) and the bone-promoting peptide (RGD), so that the titanium (Ti)-based implant modified by the polypeptide had the dual function of "antibacterial-promoting bone". Firstly, self-organized vertically-oriented strontium-doped titanium dioxide nanotubes (STN) were manufactured by anodizing and hydrothermal synthesis methods. Secondly, the fusion peptide (HHC36-RGD) was loaded into the tubular structure by a simple vacuum-assisted physical adsorption method. Finally, STN loaded with HHC36-RGD (H-R-STN) was obtained. The characterization results demonstrated that the surface of the H-R-STN had a roughness and hydrophilicity that promoted cell adhesion. Additionally, electrochemical tests showed that H-R-STN coating can reduce the corrosion rate of pure Ti. The fusion peptide and Sr2+ in H-R-STN were released in the initial fast and subsequent slow kinetic model. Expected, H-R-STN can kill more than 99% of clinically common pathogenic bacteria (Staphylococcus aureus and Escherichia coli), and significantly inhibit the formation of bacterial biofilms. Simultaneously, under the synergistic effect of RGD in the fusion peptide and strontium in STN, H-R-STN markedly promoted the adhesion and proliferation of mouse osteoblasts, and significantly promoted osteogenic markers (alkaline phosphatase, runt-related transcription, collagen, mineralization) expression. In summary, the bifunctional titanium-based implant constructed by H-R-STN in this article can effectively prevent bacterial infections and promote early osseointegration. The main advantage of the titanium surface treatment method of the study was that its simplicity, low cost, especially its versatility made it a promising anti-infective bone repair material.

Electrodeposited dopamine/strontium-doped hydroxyapatite composite coating on pure zinc for anti-corrosion, antimicrobial and osteogenesis.

Zinc-based biometal is expected to become a new generation of biodegradable implants. Due to its antibacterial and biocompatibility in vivo, zinc metals is recently considered to be the most promising biodegradable metal, However, cytotoxicity is the thorny problem that currently restrict its application, due to the excessive Zn ions released during degradation. In order to solve these problems, dopamine modified strontium-doped hydroxyapatite coating (SrHA/PDA) was fabricated on alkali-treated pure zinc to improve its corrosion rate and cytocompatibility by electrodeposition for the first time. The obtained coating showed a dense structure and high crystallinity, which was attributed to the attraction of Ca2+ ions by polydopamine. The results showed that the SrHA/PDA coating delayedthe degradation rate of zinc metal, which reduced the release of Zn2+, thereby reducing its cytotoxicity. Additionally, electrochemical tests showed that SrHA/PDA coating can reduce the corrosion rate of pure zinc. In vitro cell viability showed that even at high Zn2+ concentrations (3.11 mg/L), preosteoblasts (MC3T3-E1) cells proliferated at a high rate on SrHA/PDA, thus confirming that Sr2+ counteracted the cytotoxic effects of Zn2+ and promoted cell differentiation. Moreover, the SrHA/PDA coating still maintained excellent antibacterial effects against pathogenic bacterial strains (Escherichia coli and Staphylococcus aureus). Mild pH changes had no significant effect on the viability of cells and bacterias. Collectively, the present study elucidated that by coating SrHA/PDA/Zn(OH)2 on Zn, a controllable corrosion rate, original antibacterial properties and better cell compatibility can be achieved. This provided a new strategy for the surface modification of biodegradable Zn.

Mg/Cu-doped TiO2 nanotube array: A novel dual-function system with self-antibacterial activity and excellent cell compatibility.

Many studies were conducted to change the surface morphology and chemical composition of Ti implants for the improvement of antibacterial ability and osseointegration between medical Ti and surrounding bone tissue. In this study, we successfully prepared a novel dual-function coating on pure Ti surface, i.e. Cu and Mg-co-doped TiO2 nanotube (TN) coating, by combining anodisation and hydrothermal treatment (HT), which could act as a delivery platform for the sustained release of Cu and Mg ions. Results showed that the amounts of Cu and Mg were about 5.43 wt%-6.55 wt% and 0.69 wt%-0.73 wt%, respectively. In addition, the surface morphology of Cu and Mg-co-doped TN (CuMTN) coatings transformed into nanoneedles after HT for 1 h. Compared with TN, CuMTN had no change in roughness and remarkable improved hydrophilicity. Antibacterial tests revealed that CuMTN had an antibacterial rate of more than 93% against Escherichia coli and Staphylococcus aureus, thereby showing excellent antibacterial properties. In addition, CuMTN could induce the formation of apatite well after being immersed in simulated body fluid, showing good biological activity. Preosteoblasts (MC3T3-E1) cultured on CuMTN-coated Ti demonstrated better proliferation and osteogenic differentiation than pristine and as-anodised specimens. To the best of our best knowledge, this study had successfully attempted to combine anodisation and HT, introduce Cu/Mg elements and functionalise Ti-based implant surfaces with enhanced hydrophilicity, osteogenesis and antimicrobial properties that can meet clinical needs for the first time.

Assembly of Carbon Dots into Frameworks with Enhanced Stability and Antibacterial Activity.

Carbon dots (CDs) have been widely used as antimicrobials due to their active surface, but some CDs suffer instability. Therefore, the relative applications such as the antibacterial activity may not be reliable for long-term use. Herein, we synthesize CDs with blue fluorescence by a hydrothermal process. Thereafter, polyethylenimine was applied for the assembly of CDs into CDs-based frameworks (CDFs). The CDFs exhibited quenched fluorescence but showed more stable properties based on the scanning electron microscope and zeta potential investigations. Both CDs and CDFs show antibacterial activity toward Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), but CDFs exhibited better antibacterial performance, and S. aureus could be completely inhibited with the minimum inhibitory concentration of 30 µg/mL. This reveals CDFs magnify both the stability and antibacterial activity, which would be more promising for practical applications.

The characteristics and risk factors of in-stent restenosis in patients with percutaneous coronary intervention: what can we do.

BACKGROUND: Percutaneous coronary intervention (PCI) is a common treatment for patients with coronary heart disease, and intra-stent restenosis (ISR) is a serious complication after PCI. It's necessary to identify the potential risk factors to provide evidence for the prevention of ISR. METHODS: The patients who underwent coronary angiography 1 year after PCI in our hospital from January 2017 to May 2019 were selected. The characteristics and results of clinical examination of ISR and no-ISR patients were compared, Multivariate logistic regression analyses were performed to identify the risk factors. RESULTS: A total of 209 patients were included, the incidence of ISR after PCI was 30.62%. There were significant differences on the hypertension, diabetes, number of coronary artery lesions, reasons for stent implantation, the diameter of stent, the length of stent and stent position between ISR group and no-ISR patients (all p < 0.05). The LDL-C in ISR groups was significantly higher than that of no-ISR group (p = 0.048), there were no significant differences between two groups in FPG, TG, TC, HDL-C, Apo A1, Apo B, LP-a and glycated haemoglobin (all p > 0.05). The hypertension (OR 4.30, 95% CI 1.12-9.34), diabetes (OR 5.29, 95% CI 1.25-9.01), number of coronary artery lesions ≥ 2 (OR 4.84, 95% CI 1.21-9.55), LDL-C ≥ 1.9 mmol/L (OR 5.93, 95% CI 2.29-10.01), unstable angina (OR 2.92, 95% CI 1.20-4.55), left anterior descending artery (OR 4.01, 95% CI 1.73-7.58), diameter of stent ≥ 3 mm (OR 5.42, 95% CI 1.24-10.84), the length of stent > 20 mm (OR 3.06, 95% CI 1.19-5.22) were the independent risk factor for ISR (all p < 0.05). CONCLUSION: It is necessary to take preventive measures against these risk factors to reduce ISR, and studies with larger sample size and longer follow-up on this issue are needed in the future.

Cockroach as a Vector of Blastocystis sp. is Risk for Golden Monkeys in Zoo.

Blastocystis sp. is a kind of protozoa living in the intestinal tract of human and animals, which will cause intestinal diseases such as diarrhea, abdominal distension and vomiting. This paper was aimed to understand the infection of Blastocystis sp. In golden monkeys and the transmission path in North China. Thirty-seven feces samples from golden monkeys and 116 cockroach samples from Shijiazhuang Zoo were collected from July to October 2019 for PCR analysis of Blastocystis sp. Genetic diversity analysis was further conducted on the samples with positive PCR results. The results showed that the infection rate was 48.7% (18/37) in golden monkeys and 82.8% (96/116) in cockroaches, respectively. The genetic evolution analysis based on small subunit ribosomal RNA demonstrated that three subtypes (ST) of Blastocystis sp. including ST1, ST2, and ST3 existed in the intestinal tract of golden monkeys, while only ST2 was detected in the intestinal tract of cockroaches. This paper may provide supports for the quarantine and control of Blastocystis sp. for the zoo in Northern China.

Planctomonas psychrotolerans sp. nov., isolated from rhizosphere soil of Suaeda salsa.

A psychrotolerant actinobacterium, designated strain J5903T, was isolated from an alkaline soil sample from the rhizosphere of Suaeda salsa collected in desertification land surrounding Jiuliancheng Nur in Hebei Province, PR China. Cells of the isolate were Gram-stain-positive, aerobic, non-motile and non-spore-forming cocci. Strain J5903T grew optimally at 20‒25 °C, at pH 7.0‒7.5 and with <1 % (w/v) NaCl. The cell-wall peptidoglycan type was B2γ with d-2,4-diaminobutyric acid and l-2,4-diaminobutyric acid as diagnostic amino acids. The muramyl residue was acetyl type. The menaquinones were MK-11, MK-12, MK-10 and MK-13. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and one unidentified glycolipid. The major whole-cell fatty acids were anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. The genomic DNA G+C content was 69.1 mol%. It shared the highest average nucleotide identity and digital DNA-DNA hybridization values with Planctomonas deserti 13S1-3T. Phylogenies based on genome sequence showed that strain J5903T and P. deserti 13S1-3T formed a robust cluster with high bootstrap support. Strain J5903T shared typical chemotaxonomic characteristics with P. deserti 13S1-3T. Combining the polyphasic taxonomic evidence, strain J5903T represents a novel species of the genus Planctomonas, for which the name Planctomonas psychrotolerans sp. nov. is proposed. The type strain is J5903T (=DSM 101894T=CGMCC 1.15523T).

Si, Sr, Ag co-doped hydroxyapatite/TiO2 coating: enhancement of its antibacterial activity and osteoinductivity.

A multifaceted coating with favourable cytocompatibility, osteogenic activity and antibacterial properties would be of great significance and value due to its capability for improving osseointegration and alleviating prosthesis loosening. This study marks the first report on the coating of TiO2 nanotubular (TNT) arrays with Sr-and-Si-substituted hydroxyapatite (SSHA) endowed with antibacterial characteristics using silver ions. This TNT layer coated with Ag-substituted SSHA (SSAgHA) formed a composite coating with an interconnected microporous structure and a homogeneous distribution of Sr, Si and Ag; such a coating promoted cell adhesion and osteogenic potential. The anchoring effect of the TNT layer improved the adhesion strength of the SSAgHA/TNT coating to 16.9 ± 3.1 MPa, which was higher than the 15 MPa set in the ISO standard 13 779-4:2002. Moreover, the bio-corrosion resistance of the underlying Ti substrate was greatly enhanced by the composite coating. Hydroxyapatite (HA) and SSAgHA coatings provided a suitable environment for the adhesion, spreading and proliferation of mouse osteoblasts. The SSAgHA coating excellently inhibited bacterial activity and enhanced osteoinductivity with higher osteogenic differentiation compared with the HA coating. Sr and Si dopants increased the expression levels of the genes related to osteogenesis and successfully offset the potential cytotoxicity of Ag ions. Super-osteoinductivity was attributed to the rough and superhydrophilic surface of the composite coating. Therefore, the present study demonstrated the potential of the electrodeposited SSAgHA/TNT composite coating as a promising metallic implant with great intrinsic antibacterial activity and osteointegration ability.

Photo-Induced Multiple-State Memory Behaviour in Non-Volatile Bipolar Resistive-Switching Devices.

The recent discovery of non-volatile resistive-switching memory is a promising phenomenon for the semiconductor industry and electronic device technology. In our work, CaWO4 nanoparticles were synthesised through a one-step hydrothermal reaction. A resistive-switching memory device with Ag/CaWO4/fluorine-doped tin oxide structure was prepared. This device presents photo-induced multiple-state memory behaviour at room temperature. This study is valuable for exploring multi-functional materials and their applications in photo-controlled multiple-state non-volatile memories.

Biofunctional Sr- and Si-loaded titania nanotube coating of Ti surfaces by anodization-hydrothermal process.

BACKGROUND: Two frequent problems associated with titanium (Ti) surfaces of bone/dental implants are their corrosion and lack of native tissue integration. METHODS: Here, we present an anodization-hydrothermal method for coating Ti surfaces with a layer of silicon (Si)- and strontium (Sr)-loaded titania nanotubes (TNs). The Ti surfaces coated with such a layer (Si-Sr-TNs) were characterized with different techniques. RESULTS: The results indicate that the Si4+ and Sr2+ ions were evenly incorporated into the TNs and that the Si-Sr-TN layer provides good protection against corrosive media like simulated body fluid. The excellent cytocompatibility of the coating was confirmed in vitro by the significant growth and differentiation of MC3T3-E1 osteoblastic cells. CONCLUSION: Being easily and economically fabricated, the Si-Sr-TN surfaces may find their niche in clinical applications, thanks to their excellent biological activity and corrosion resistance.

CXCR3 knockdown protects against high glucose-induced podocyte apoptosis and inflammatory cytokine production at the onset of diabetic nephropathy.

Chemokines and their receptors play an important role in the pathogenesis of acute and chronic diabetic nephropathy (DN). However, their expression pattern and function in glomerular podocytes have not been investigated as of yet. In the present study, we investigated whether CXCR3 could protect podocytes from high glucose-induced apoptosis and inflammatory cytokine production and explored the possible mechanism. Cell viability, cell cycle and apoptosis were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry, respectively. The level of intracellular reactive oxygen species (ROS) and mitochondrial membrane potential (∆Ψm) was measured using a dichlorofluorescein diacetate (DCFH-DA) ortetrechloro-tetraethylbenzimidazol carbocyanine iodide (JC-1) fluorescent probe, respectively. Quantitative real-time PCR was used to determine the gene expression of CXCR3. Western blots were carried out for the related protein expression in podocytes, including CXCR3, Nephrin, Podocin, Bcl-2, Bax, and Caspase-3. Firstly, we found that CXCR3 expression was significantly up-regulated and cell viability was decreased in high glucose (HG)-treated mouse podocytes in a dose-dependent manner. Secondly, knockdown of CXCR3 in mouse podocytes significantly suppressed HG-induced viability decrease, cell cycle arrest, ROS generation and ∆Ψm reduction. Moreover, knockdown of CXCR3 reduced the podocytes injury in cell apoptosis and inflammation through increasing the expression of Nephrin, Podocin and Bcl-2, and decreasing the expression of Bax and Caspase-3. In conclusion, CXCR3 knockdown protected podocytes from HG-induced apoptosis and inflammation in vitro, suggesting that inhibition of CXCR3 may have a therapeutic potential in DN treatment.

Chain elongation analog of resveratrol as potent cancer chemoprevention agent

Resveratrol is identified as a natural cancer chemoprevention agent. There has been a lot of interest in designing and developing resveratrol analogs with cancer chemoprevention activity superior to that of parent molecule and exploring their action mechanism in the past several decades. In this study, we have synthesized resveratrol analogs of compounds A-C via conjugated chain elongation based on isoprene unit retention strategy. Remarkably, cytotoxic activity analysis results indicated that compound B possesses the best proliferation inhibition activity for NCI-H460 cells in all the test compounds. Intriguingly, compound B displayed a higher cytotoxicity against human non-small cell lung cancer cells (NCI-H460) compared to normal human embryonic lung fibroblasts (MRC-5). Afterward, flow cytometry analysis showed that compound B would induce cell apoptosis. We further researched the action mechanism. When NCI-H460 cells were incubated by compound B for 6 or 9 h, respectively, the intracellular reactive oxygen species (ROS) level was enhanced obviously. With elevation of intracellular ROS level, flow cytometry measurement verified mitochondrial transmembrane potential collapse, which was accompanied by the up-regulation of Bax and down-regulation of Bcl-2. More interestingly, compound B increased the expression of caspase-9 and caspase-3, which induced cell apoptosis. Moreover, compound B arrested cell cycle in G0/G1 phase. These are all to provide useful information for designing resveratrol-based chemoprevention agent and understanding the action mechanism (AU)

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[Preparation and Characterization of Manganese and Fluorine Co-Modified Hydroxyapatite Composite Coating].

Titanium and titanium alloys have been widely used as orthopedic, dental implants and cardiovascular stents owing to their superior physical properties. However, titanium surface is inherently bio-inert, thus could not form efficient osseointegration with surrounding bone tissue. Therefore, to improve the surface property of titanium implant is significantly important in clinical application. Manganese and fluorine co-doped hydroxyapatite (FMnHAP) coatings were prepared on titanium substrate by electrochemical deposition technique. The as-prepared coatings were examined by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) tests. The results indicated that the FMnHAP coatings take the morphology of nanoscale-villous-like, the composite coating becomes more compact. The FTIR test indicated that the symmetry of bending vibration modes of hydroxyl changed, simulated body fluid immersion test proved that the FMnHAP coatings had induce carbonate-apatite formation, indicating that the composite coating possess excellent biocompatibility. In the electrochemical corrosion testing, the FMnHAP coatings showed stronger corrosion resistance than pure Ti.