Automatic analysis framework based on 3D-CT multi-scale features for accurate prediction of Ki67 expression levels in substantial renal cell carcinoma.

PURPOSE: To investigate the effectiveness of an automatic analysis framework based on 3D-CT multi-scale features in predicting Ki67 expression levels in substantial renal cell carcinoma (RCC). METHODS: This retrospective study was conducted using multi-center cohorts consisting of 588 participants with pathologically confirmed RCC. The participants were divided into an internal training set (n = 485) and an external testing set (n = 103) from four and one local hospitals, respectively. The proposed automatic analytic framework comprised a 3D kidney and tumor segmentation model constructed by 3D UNet, a 3D-CT multi-scale features extractor based on the renal-tumor feature, and a low or high Ki67 prediction classifier using XGBoost. The framework was validated using a fivefold cross-validation strategy. The Shapley additive explanation (SHAP) method was used to determine the contribution of each feature. RESULTS: In the prediction of low or high Ki67, the combination of renal and tumor features achieved better performance than any single features. Internal validation using a fivefold cross-validation strategy yielded AUROC values of 0.75 ± 0.1, 0.75 ± 0.1, 0.83 ± 0.1, 0.77 ± 0.1, and 0.87 ± 0.1, respectively. The optimal model achieved an AUROC of 0.87 ± 0.1 and 0.82 ± 0.1 for low vs. high Ki67 prediction in the internal validation and external testing sets, respectively. Notably, the tumor first-order-10P was identified as the most influential feature in the model decision. CONCLUSIONS: Our study suggests that the proposed automatic analysis framework based on 3D-CT multi-scale features has great potential for accurately predicting Ki67 expression levels in substantial RCC. CRITICAL RELEVANCE STATEMENT: Automatic analysis framework based on 3D-CT multi-scale features provides reliable predictions for Ki67 expression levels in substantial RCC, indicating the potential usage of clinical applications.

A Novel Bio-Adhesive Mesh System for Medical Implant Applications: In Vivo Assessment in a Rabbit Model.

Injectable surgical sealants and adhesives, such as biologically derived fibrin gels and synthetic hydrogels, are widely used in medical products. While such products adequately adhere to blood proteins and tissue amines, they have poor adhesion with polymer biomaterials used in medical implants. To address these shortcomings, we developed a novel bio-adhesive mesh system utilizing the combined application of two patented technologies: a bifunctional poloxamine hydrogel adhesive and a surface modification technique that provides a poly-glycidyl methacrylate (PGMA) layer grafted with human serum albumin (HSA) to form a highly adhesive protein surface on polymer biomaterials. Our initial in vitro tests confirmed significantly improved adhesive strength for PGMA/HSA grafted polypropylene mesh fixed with the hydrogel adhesive compared to unmodified mesh. Toward the development of our bio-adhesive mesh system for abdominal hernia repair, we evaluated its surgical utility and in vivo performance in a rabbit model with retromuscular repair mimicking the totally extra-peritoneal surgical technique used in humans. We assessed mesh slippage/contraction using gross assessment and imaging, mesh fixation using tensile mechanical testing, and biocompatibility using histology. Compared to polypropylene mesh fixed with fibrin sealant, our bio-adhesive mesh system exhibited superior fixation without the gross bunching or distortion that was observed in the majority (80%) of the fibrin-fixed polypropylene mesh. This was evidenced by tissue integration within the bio-adhesive mesh pores after 42 days of implantation and adhesive strength sufficient to withstand the physiological forces expected in hernia repair applications. These results support the combined use of PGMA/HSA grafted polypropylene and bifunctional poloxamine hydrogel adhesive for medical implant applications.

Tough Bioplastics from Babassu Oil-Based Acrylic Monomer, Hemicellulose Xylan, and Carnauba Wax.

We describe here the fabrication, characterization, and properties of tough bioplastics made of a babassu oil-based acrylic polymer (PBBM), hemicellulose xylan grafted with PBBM chains, and carnauba wax (CW). The plastic was primarily designed to obtain bioderived materials that can replace low-density polyethylene (LDPE) in certain food packaging applications. To obtain plastic, the radical polymerization of an original babassu oil-based acrylic monomer (BBM) in the presence of xylan macromolecules modified with maleic anhydride (X-MA) was conducted. The polymerization resulted in a material (PBBM-X) mostly consisting of highly branched PBBM/X-MA macromolecules. PBBM-X has a glass transition of 42 °C, a storage modulus of 130 MPa (at 25 °C, RT), and a Young's modulus of 30 MPa at RT. To increase the moduli, we blended PBBM-X with carnauba wax, a natural material with a high modulus and a melting temperature of ~80 °C. It was found that PBBM-X is compatible with the wax, as evidenced by the alternation of the material's thermal transitions and the co-crystallization of BBM side alkyl fragments with CW. As a result, the PBBM-X/CW blend containing 40% of the wax had a storage modulus of 475 MPa (RT) and a Young's modulus of 248 MPa (RT), which is close to that of LDPE. As polyethylene, the PBBM-X and PBBM-X/CW bioplastics have the typical stress-strain behavior demonstrated by ductile (tough) plastics. However, the bioplastic's yield strength and elongation-at-yield are considerably lower than those of LDPE. We evaluated the moisture barrier properties of the PBBM-X/(40%)CW material and found that the bioplastic's water vapor permeability (WVP) is quite close to that of LDPE. Our bioderived material demonstrates a WVP that is comparable to polyethylene terephthalate and lower than the WVP of nylon and polystyrene. Taking into account the obtained results, the fabricated materials can be considered as polyethylene alternatives to provide sustainability in plastics production in the packaging areas where LDPE currently dominates.

Systematic Study of the Sensory Quality, Metabolomics, and Microbial Community of Fresh-Cut Watermelon Provides New Clues for Its Quality Control and Preservation.

As a popular form of fruit consumption, fresh-cut watermelon is of great convenience for its consumers. Owing to the lack of comprehensive knowledge about the quality changes of fresh-cut watermelon during its shelf life, guidelines and standards are unavailable currently. To clarify the deterioration process and its underlying mechanism in fresh-cut watermelon, the sensory parameters, metabolomics, and microbial community of fresh-cut watermelon during a three-day storage at both room temperature (RT) and refrigerator temperature were systematically studied in this work. Results revealed that the whole property of the watermelon stored at refrigerator temperature kept stable, while pulps stored at RT had substantially deteriorated after 36 h. The decay was reflected in the significant decrease in soluble solid contents, firmness, pH, and color parameters in the sensory perspective. At the metabolic level, significantly declined malate, citrate, uridine, uridine 5-monophosphate, and amino acids, and increased ethanol and lactate contents, were observed as deterioration markers, which partially resulted from the activities of pyruvate dehydrogenase and alcohol dehydrogenase and the burst of genera Enterobacteriaceae and Leuconostocaceae. This study unveiled the underlying mechanisms of quality changes in fresh-cut watermelon under its primary storage conditions to provide fundamental information and potential clues for its quality control and preservation.

Cobalt-doping of molybdenum phosphide nanofibers for trapping-diffusion-conversion of lithium polysulfides towards high-rate and long-life lithium-sulfur batteries.

Rational design of separators is especially critical to solve the "shuttle effect" of lithium polysulfides (LiPSs) and the sluggish redox kinetics in lithium-sulfur batteries (LSBs). Here, the multi-functional nanocomposite involving Co-doped molybdenum phosphide (Co-MoP) nanofibers and porous carbon nanofibers (PCNFs) is designed and prepared through electro-blow spinning and phosphating process, which possesses multiple adsorption and catalytic sites and is acted as the functional material for LSBs separators. In this multifunctional nanocomposite, the prepared Co-MoP nanofibers can provide internal adsorption and catalytic sites for LiPSs conversion. And the interconnected nitrogen-doped PCNFs can be elaborated an efficient LiPSs mediator and accommodate the huge volume changes in the reaction process for LSBs. Benefiting from the multiple adsorptive and catalytic sites of the developed functional materials, the assembled LSBs with a Co-MoP/PCNFs modified separator display outstanding electrochemical performances, including an admirable capacity retention of 770.4 mAh g-1 after 400 cycles at 1.0 C, only 0.08 % capacity decay per cycle at 2.0 C, rate performance up to 5 C, and also decent areal capacity even under a high sulfur loading of 4.9 mg cm-2. The work provides a facile pathway towards multifunctional separators in LSBs, and it may also help deepen preparation method of MoP through the electrostatic blowing/electrospinning technology in other related energy storage fields.

Customized Structure Design and Functional Mechanism Analysis of Carbon Spheres for Advanced Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) are attracting much attention due to their high theoretical energy density and are considered to be the predominant competitors for next-generation energy storage systems. The practical commercial application of LSBs is mainly hindered by the severe "shuttle effect" of the lithium polysulfides (LiPSs) and the serious damage of lithium dendrites. Various carbon materials with different characteristics have played an important role in overcoming the above-mentioned problems. Carbon spheres (CSs) are extensively explored to enhance the performance of LSBs owing to their superior structures. The review presents the state-of-the-art advances of CSs for advanced high-energy LSBs, including their preparation strategies and applications in inhibiting the "shuttle effect" of the LiPSs and protecting lithium anodes. The unique restriction effect of CSs on LiPSs is explained from three working mechanisms: physical confinement, chemical interaction, and catalytic conversion. From the perspective of interfacial engineering and 3D structure designing, the protective effect of CSs on the lithium anode is also analyzed. Not only does this review article contain a summary of CSs in LSBs, but also future directions and prospects are discussed. The systematic discussions and suggested directions can enlighten thoughts in the reasonable design of CSs for LSBs in near future.

YF3/CoF3 co-doped 1D carbon nanofibers with dual functions of lithium polysulfudes adsorption and efficient catalytic activity as a cathode for high-performance Li-S batteries.

Lithium-sulfur (Li-S) batteries have attracted extensive attention in the field of energy storage due to their high energy density and low cost. However, conundrums such as severe polarization, poor cyclic performance originating from shuttle effect of lithium polysulfides and sluggish sulfur redox kinetics are stumbling blocks for their practical application. Herein, a novel sulfur cathode integrating sulfur and polyvinylpyrrolidone(PVP)-derived N-doped porous carbon nanofibers (PCNFs) with embedded CoF3 and YF3 nanoparticles are designed and prepared though the electrostatic blowing technology and carbonization process. The unique flexible PCNFs with embedded polar CoF3 and YF3 nanoparticles not only offer enough voids for volume expansion to maintain the structural stability during the electrochemical process, but also promote the physical encapsulation and chemical entrapment of all sulfur species. Moreover, the uniform distribution of YF3/CoF3 nanoparticles also can expose more binding active sites to lithium polysulfide and present more catalytic sites to the greatest extent. Therefore, the assembled cells with the prepared cathode exhibited stable performances with an outstanding initial capacity of 1055.2 mAh g-1 and an extended cycling stability of 0.029% per cycle during the 300 cycles at 0.5C. Even at a high sulfur loading of 2.1 mg cm-2, The YF3/CoF3 doped-PCNFs exhibited a high discharge specific capacity of 1038 mAh g-1, and the decay rate is also as low as 0.05% over 1000 cycles. This work shares a convenient and safe strategy for the synthesis of multi-dimension, dual-functional and stable superstructure electrode for advanced Li-S batteries.

A potentially valuable nano graphene oxide/USPIO tumor diagnosis and treatment system.

Due to increased requirements for precision cancer treatment, cancer chemotherapy and combination therapies have gradually developed in the direction of diagnosis and treatment integration. In this study, a non-toxic nano carrier that demonstrates integrated MRI signal enhancing performance, as well as better chemotherapy and photothermal conversion performance, was prepared and characterized. Furthermore, the carrier was used to construct an integrated system of tumor diagnosis and treatment. Our in vitro studies showed that this system has a considerable inhibition effect on tumor cells during the treatment of chemotherapy when combined with PTT, and in vivo studies showed that the system could improve the MRI signal of the tumor site with application of a safe dosage. Thus, this system based on NGO/USPIO has the potential to be a multi-functional nano drug delivery system integrating diagnosis and treatment benefits and applications that are worthy of further research.

FA-GAN: Fused attentive generative adversarial networks for MRI image super-resolution.

High-resolution magnetic resonance images can provide fine-grained anatomical information, but acquiring such data requires a long scanning time. In this paper, a framework called the Fused Attentive Generative Adversarial Networks(FA-GAN) is proposed to generate the super- resolution MR image from low-resolution magnetic resonance images, which can reduce the scanning time effectively but with high resolution MR images. In the framework of the FA-GAN, the local fusion feature block, consisting of different three-pass networks by using different convolution kernels, is proposed to extract image features at different scales. And the global feature fusion module, including the channel attention module, the self-attention module, and the fusion operation, is designed to enhance the important features of the MR image. Moreover, the spectral normalization process is introduced to make the discriminator network stable. 40 sets of 3D magnetic resonance images (each set of images contains 256 slices) are used to train the network, and 10 sets of images are used to test the proposed method. The experimental results show that the PSNR and SSIM values of the super-resolution magnetic resonance image generated by the proposed FA-GAN method are higher than the state-of-the-art reconstruction methods.

Recent Progress in High-Performance Lithium Sulfur Batteries: The Emerging Strategies for Advanced Separators/Electrolytes Based on Nanomaterials and Corresponding Interfaces.

Lithium-sulfur (Li-S) batteries, possessing excellent theoretical capacities, low cost and nontoxicity, are one of the most promising energy storage battery systems. However, poor conductivity of elemental S and the "shuttle effect" of lithium polysulfides hinder the commercialization of Li-S batteries. These problems are closely related to the interface problems between the cathodes, separators/electrolytes and anodes. The review focuses on interface issues for advanced separators/electrolytes based on nanomaterials in Li-S batteries. In the liquid electrolyte systems, electrolytes/separators and electrodes system can be decorated by nano materials coating for separators and electrospinning nanofiber separators. And, interface of anodes and electrolytes/separators can be modified by nano surface coating, nano composite metal lithium and lithium nano alloy, while the interface between cathodes and electrolytes/separators is designed by nano metal sulfide, nanocarbon-based and other nano materials. In all solid-state electrolyte systems, the focus is to increase the ionic conductivity of the solid electrolytes and reduce the resistance in the cathode/polymer electrolyte and Li/electrolyte interfaces through using nanomaterials. The basic mechanism of these interface problems and the corresponding electrochemical performance are discussed. Based on the most critical factors of the interfaces, we provide some insights on nanomaterials in high-performance liquid or state Li-S batteries in the future.

Functionalized Graphene Oxide as Drug Delivery Systems for Platinum Anticancer Drugs.

Graphene Oxide, prepared by the modified Hummer's method, was modified with a series of high polymers (polyethyleneimine, polyethylene glycol, chitosan) and Folic Acid for the delivery of platinum anticancer drugs including Cisplatin, Carboplatin, Oxaliplatin and Eptaplatin. Nanocarriers were successfully prepared and characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscope. Measurement of drug loading efficiency showed that these nanocarriers had the ability for effective delivery of the platinum anticancer drugs. The Maximum loading ratios of Cisplatin, Carboplatin, Oxaliplatin and Eptaplatin were 25.72, 161.08, 345.21 and 67.80 µg/mg. Drug release experiments in the acid environment showed that the cumulative release rate of platinum anticancer drugs from nanocarriers was higher than that in the neutral environment. The cumulative release of all three nanocarriers in the acid environment reached above 60%. In vitro cytotoxicity assay showed that those nanocarriers had a low toxicity. The cell viability rates were above 80% for all three nanocarriers. Investigation of the anticancer activity in vitro showed that those drug delivery systems had the ability to inhibit the growth of the SKOV3 cell line. These results showed that those nanocarriers were suitable for the delivery of platinum anticancer drugs. Providing preliminary advice on the potential application of the combination of platinum anticancer drugs and the functionalized Graphene Oxide nanocarriers.

Factors associated with alveolar bone depth mesial to the mandibular third molars after orthodontic protraction.

INTRODUCTION: The objective of this research was to study the factors associated with the alveolar bone depth mesial to the mandibular third molars (M8) after the mandibular second (M7) and third molars were protracted into the space of the mandibular first molars (M6), which were newly extracted for orthodontic treatment or extracted more than 1 year before treatment. METHODS: This retrospective study included 57 adult patients (mean age 23.40 ± 4.40 years) in whom M6 were newly extracted for orthodontic treatment or extracted more than 1 year before treatment. The alveolar bone depth mesial to M8 was measured on posttreatment panoramic radiographs. The vertical, horizontal, and angular changes of M8 were measured on both pre- and posttreatment panoramic radiographs. Linear correlation and regression analyses were conducted to explore the factors associated with the alveolar bone depth mesial to M8. RESULTS: The alveolar bone conditions of M6 (R= -0.391, P <0.001) and the vertical movement directions of M8 (R= -0.433, P <0.001) were significant factors associated with the alveolar bone depth mesial to M8 after orthodontic protraction. CONCLUSIONS: Without considering the pretreatment periodontal status of M8, patients with M6 extracted exceeding 1 year before treatment and with M8 extruded after orthodontic protraction may exhibit deeper alveolar bone depth mesial to M8.

Towards a Long-Chain Perfluoroalkyl Replacement: Water and Oil Repellent Perfluoropolyether-Based Polyurethane Oligomers.

Original perfluoropolyether (PFPE)-based oligomeric polyurethanes (FOPUs) with different macromolecular architecture were synthesized (in one step) as low-surface-energy materials. It is demonstrated that the oligomers, especially the ones terminated with CF3 moieties, can be employed as safer replacements to long-chain perfluoroalkyl substances/additives. The FOPU macromolecules, when added to an engineering thermoplastic (polyethylene terephthalate, PET) film, readily migrate to the film surface and bring significant water and oil repellency to the thermoplastic boundary. The best performing FOPU/PET films have reached the level of oil wettability and surface energy significantly lower than that of polytetrafluoroethylene, a fully perfluorinated polymer. Specifically, the highest level of the repellency is observed with an oligomeric additive, which was made using aromatic diisocyanate as a comonomer and has CF3 end-group. This semicrystalline oligomer has a glass transition temperature (Tg) well above room temperature, and we associate the superiority of the material in achieving low water and oil wettability with its ability to effectively retain CF3 and CF2 moieties in contact with the test wetting liquids.

Functionalised molybdenum disulfide nanosheets for co-delivery of doxorubicin and siRNA for combined chemo/gene/photothermal therapy on multidrug-resistant cancer.

OBJECTIVE: Molybdenum disulfide (MoS2) has been developed for medical uses due to its excellent medically beneficial characteristics. This research was designed to develop a multifunctional nano-drug delivery system based on the nano-structure of MoS2 for combined chemo/gene/photothermal therapy targeting multidrug-resistant cancer. METHODS: MoS2 nanosheets were prepared by a hydrothermal reaction and modified. Afterward, the nanocarrier was characterised. In vitro cytotoxicity of the drug delivery systems on human breast adenocarcinoma cell lines was assessed. KEY FINDINGS: The nanocarrier was a flake-like structure with a uniform hydrodynamic diameter and possessing good colloidal stability. The nanocarrier showed the capacity to be deployed for co-delivery of Doxorubicin (DOX) and siRNA. The release of DOX could be triggered and enhanced by pH and application of near-infrared (NIR) laser. The nanocarrier had a good photothermic response and stability. The nanocarrier had little effect on the cells and exhibited good biocompatibility. Measurement of the therapeutic efficacy showed that synergistic therapy combining chemo-, gene- and photothermal therapy deploying this drug delivery system will achieve a better anticancer effect on drug-resistant cancer cells than DOX alone. CONCLUSIONS: Our results suggest that this drug delivery system has potential application in the therapeutic strategy for drug-resistant cancer.

Effects of Smad4 on the expression of caspase­3 and Bcl­2 in human gingival fibroblasts cultured on 3D PLGA scaffolds induced by compressive force.

Human gingival fibroblasts (HGFs) are the main cells that comprise gingival tissue, where they transfer mechanical signals under physiological and pathological conditions. The exact mechanism underlying gingival tissue reconstruction under compressive forces remains unclear. The present study aimed to explore the effects of Smad4, caspase­3 and Bcl­2 on the proliferation of HGFs induced by compressive force. HGFs were cultured on poly(lactide­co­glycolide) (PLGA) scaffolds under an optimal compressive force of 25 g/cm2. Cell viability was determined via Cell Counting Kit­8 assays at 0, 12, 24, 48 and 72 h. The expression levels of Smad4, caspase­3 and Bcl­2 were measured via reverse transcription­quantitative PCR and western blotting. The application of compressive force on HGFs for 24 h resulted in a significant increase in cell proliferation and Bcl­2 expression, but a significant decrease in the expression of Smad4 and caspase­3; however, inverse trends were observed by 72 h. Subsequently, a lentivirus was used to overexpress Smad4 in HGFs, which attenuated the effects of compressive force on HGF proliferation and Bcl­2 expression, but enhanced caspase­3 expression, suggesting that Smad4 may regulate compressive force­induced apoptosis in HGFs. In conclusion, these findings increased understanding regarding the mechanisms of compressive force­induced HGF proliferation and apoptosis, which may provide further insight for improving the efficacy and stability of orthodontic treatment.

Highly Oil-Repellent Thermoplastic Boundaries via Surface Delivery of CF3 Groups by Molecular Bottlebrush Additives.

We fabricated thermoplastic surfaces possessing extremely limited water and oil wettability without employment of long-chain perfluoroalkyl (LCPFA) substances. Namely, by taking advantage of the structure and behavior of original oleophobic perfluoropolyether (PFPE) methacrylate (PFM) molecular bottlebrush (MBB) additive we obtained polymeric surfaces with oil contact angles well above 80° and surface energy on the level of 10 mN/m. Those angles and surface energies are the highest and the lowest respective values reported to date for any bulk solid flat organic surface not containing LCPFA. We show experimentally and computationally that this remarkable oil repellency is attributed to migration of small quantities of the oleophobic MBB additives to the surface of the thermoplastics. Severe mismatch in the affinity between the densely grafted long side chains of MBB and a host matrix promotes stretching and densification of mobile side chains delivering the lowest surface energy functionalities (CF3) to the materials' boundary. Our studies demonstrate that PFM can be utilized as an effective low surface energy additive to conventional thermoplastic polymers, such as poly(methyl methacrylate) and Nylon-6. We show that films containing PFM achieve the level of oil repellency significantly higher than that of polytetrafluoroethylene (PTFE), a fully perfluorinated thermoplastic. The surface energy of the films is also significantly lower than that of PTFE, even at low concentrations of PFM additives.

Synthesis, characterization and antibacterial properties of novel cellulose acetate sorbate.

In this paper, cellulose acetate (CA) with different degree of substitution (DS) of 2.17∼1.75 were obtained through hydrolysis of cellulose diacetate (CDA). Furthermore, novel cellulose acetate sorbate (CASA) were synthesized by esterification of CA and sorbic acid (SA). The DS of sorbyl groups varied within 0.12-1.20 by adjusting composition ratio, reaction time and temperature. Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance spectroscopy (NMR) and elemental analysis were used to determine the chemical structure. Scanning electron microscopy (SEM) indicated CASA showed denser surface morphology than CA. Thermal properties and crystallization of CASA were slightly decrease but did not affect their service performance. Specifically, all CASA showed excellent antibacterial ability, the maximum relative bactericidal rate reached 81.5 % for Escherichia coli (E. coli) and 95.4 % for Staphylococcus aureus (S. aureus), respectively. Moreover, the obtained CASA films using casting technique possessed good mechanical properties. These antibacterial CASA exhibited potential application in healthcare fields.

Preparation and anti-cancer activity of transferrin/folic acid double-targeted graphene oxide drug delivery system.

In this study, a transferrin/folic acid double-targeting graphene oxide drug delivery system loaded with doxorubicin was designed. Graphene oxide was prepared by ultrasound improved Hummers method and was modified with Pluronic F68, folic acid, and transferrin to decrease its toxicity and to allow dual-targeting. The results show that the double target drug delivery system (TFGP*DOX) has good and controllable drug delivery performance with no toxicity. Moreover, TFGP*DOX has a better inhibitory effect on SMMC-7721 cells than does a single target drug delivery system (FGP*DOX). The results of drug release analysis and cell inhibition studies showed that TFGP*DOX has a good sustained release function that can reduce the drug release rate in blood circulation over time and improve the local drug concentration in or near a targeted tumor. Therefore, the drug loading system (TFGP*DOX) has potential application value in the treatment of hepatocellular carcinoma.

Potential Role of Integrin α5ß1/Focal Adhesion Kinase (FAK) and Actin Cytoskeleton in the Mechanotransduction and Response of Human Gingival Fibroblasts Cultured on a 3-Dimension Lactide-Co-Glycolide (3D PLGA) Scaffold.

BACKGROUND The stability of orthodontic treatment is thought to be significantly affected by the compression and retraction of gingival tissues, but the underlying molecular mechanism is not fully elucidated. The objectives of our study were to explore the effects of mechanical force on the ECM-integrin-cytoskeleton linkage response in human gingival fibroblasts (HGFs) cultured on 3-dimension (3D) lactide-co-glycolide (PLGA) biological scaffold and to further study the mechanotransduction pathways that could be involved. MATERIAL AND METHODS A compressive force of 25 g/m² was applied to the HGFs-PLGA 3D co-cultured model. Rhodamine-phalloidin staining was used to evaluate the filamentous actin (F-actin) cytoskeleton. The expression level of type I collagen (COL-1) and the activation of the integrin alpha5ß1/focal adhesion kinase (FAK) signaling pathway were determined by using real-time PCR and Western blotting analysis. The impacts of the applied force on the expression levels of FAK, phosphorylated focal adhesion kinase (p-FAK), and COL-1 were also measured in cells treated with integrin alpha5ß1 inhibitor (Ac-PHSCN-NH 2, ATN-161). RESULTS Mechanical force increased the expression of integrin alpha5ß1, FAK (p-FAK), and COL-1 in HGFs, and induced the formation of stress fibers. Blocking integrin alpha5ß1 reduced the expression of FAK (p-FAK), while the expression of COL-1 was not fully inhibited. CONCLUSIONS The integrin alpha5ß1/FAK signaling pathway and actin cytoskeleton appear to be involved in the mechanotransduction of HGFs. There could be other mechanisms involved in the promotion effect of mechanical force on collagen synthesis in addition to the integrin alpha5ß1 pathway.

Novel porous iron phthalocyanine based metal-organic framework electrochemical sensor for sensitive vanillin detection.

Vanillin is widely used as a flavor enhancer and is known to have numerous other interesting properties, including antidepressant, anticancer, anti-inflammatory, and antioxidant effects. However, as excess vanillin consumption can affect liver and kidney function, simple and rapid detection methods for vanillin are required. Herein, a novel electrochemical sensor for the sensitive determination of vanillin was fabricated using an iron phthalocyanine (FePc)-based metal-organic framework (MOF). Scanning electron microscopy and transmission electron microscopy showed that the FePc MOF has a hollow porous structure and a large surface area, which impart this material with high adsorption performance. A glassy carbon electrode modified with the FePc MOF exhibited good electrocatalytic performance for the detection of vanillin. In particular, this vanillin sensor had a wide linear range of 0.22-29.14 µM with a low detection limit of 0.05 µM (S/N = 3). Moreover, the proposed sensor was successfully applied to the determination of vanillin in real samples such as vanillin tablets and human serum.