UiO-66/AgNPs Coating for Dental Implants in Preventing Bacterial Infections

Titanium (Ti)-based biomaterials lack inherent antimicrobial activities, and the dental plaque formed on the implant surface is one of the main risk factors for implant infections. Construction of an antibacterial surface can effectively prevent implant infections and enhance implant success. Silver nanoparticles (AgNPs) exhibit broad antibacterial activity and a low tendency to induce drug resistance, but AgNPs easily self-aggregate in the aqueous environment, which significantly impairs their antibacterial activity. In this study, UiO-66/AgNP (U/A) nanocomposite was prepared, where zirconium metal-organic frameworks (UiO-66) were employed as the confinement matrix to control the particle size and prevent aggregation of AgNPs. The bactericidal activity of U/A against methicillin-resistant Staphylococcus aureus and Escherichia coli increased nearly 75.51 and 484.50 times compared with individually synthesized Ag. The antibacterial mechanism can be attributed to the enhanced membrane rupture caused by the ultrafine AgNPs on UiO-66, leading to protein leakage and generation of intracellular reactive oxygen species. Then, U/A was loaded onto Ti substrates (Ti-U/A) by using self-assembly deposition methods to construct an antibacterial surface coating. Ti-U/A exhibited excellent antibacterial activities and desired biocompatibility both in vitro and in vivo. The U/A nanocomposite coating technique is thus expected to be used as a promising surface modification strategy for Ti-based dental implants for preventing dental implant infections.

Near-infrared light responsive gold nanoparticles coating endows polyetheretherketone with enhanced osseointegration and antibacterial properties

Polyetheretherketone (PEEK) is considered as a promising dental implant material owing to its excellent physicochemical and mechanical properties. However, its wide range of applications is limited by its biologically inert nature. In this study, a near-infrared (NIR) light responsive bioactive coating with gold nanoparticles (AuNPs) and metronidazole adhered to the PEEK surface via dopamine polymerization. Compared to pure PEEK, the hydrophilicity of the treated PEEK surface was significantly improved. In addition, under NIR light, the surface coating exhibited photothermal conversion effect, and gold nanoparticles and the antibiotic can be released from the coating. This improved the antibacterial properties of PEEK materials. Moreover, the coating was more conducive to the early adhesion of bone mesenchymal stem cells. The results of in vitro and in vivo osteogenic activity studies showed that the developed coating promoted osseointegration of PEEK implants, and NIR light irradiation further improved the antibacterial ability and osteogenic activity of PEEK implants. Through RNA sequencing, the potential underlying mechanism of promoting bone formation of the AuNPs coating combined metronidazole was interpreted. In summary, the developed coating is a potential surface treatment strategy that endows PEEK with enhanced osseointegration and antibacterial properties.

CeO2 Nanoparticles to Promote Wound Healing: A Systematic Review

Cerium (Ce) is a hot topic in the field of materials research due to its electronic layer structure and the unique antioxidant abilities of its oxide (CeO2 ). Cerium oxide nanoparticles (CeO2 NPs) demonstrate their potential as an antioxidant and antibacterial agent. Current research focuses on whether they can be used to promote wound healing and in what manner. This article provides a systematic review of the various forms of CeO2 NPs that are used in wound-healing materials over the past decade, as well as the effectiveness demonstrated by in vivo and in vitro experiments, with a focus on the relationship between concentration and effectiveness. CeO2 NPs are expected to become effective ingredients in dressings that require antibacterial, antioxidant, and wound healing promoting properties. This article serves as a reference for further research and clinical applications of nano-sized CeO2 in wound healing.

Genome editing in rice using CRISPR/Cas12i3

The CRISPR/Cas type V-I is a family of programmable nuclease systems that prefers a T-rich protospacer adjacent motif (PAM) and is guided by a short crRNA. In this study, the genome-editing application of Cas12i3, a type V-I family endonuclease, was characterized in rice. We developed a CRIPSR/Cas12i3-based Multiplex direct repeats (DR)-spacer Array Genome Editing (iMAGE) system that was efficient in editing various genes in rice. Interestingly, iMAGE produced chromosomal structural variations with a higher frequency than CRISPR/Cas9. In addition, we developed base editors using deactivated Cas12i3 and generated herbicide-resistant rice plants using the base editors. These CRIPSR/Cas12i3-based genome editing systems will facilitate precision molecular breeding in plants.

Zeolite imidazolate framework-8 in bone regeneration: A systematic review

Zeolite imidazolate framework-8 (ZIF-8) is a biomaterial that has been increasingly studied in recent years. It has several applications such as bone regeneration, promotion of angiogenesis, drug loading, and antibacterial activity, and exerts multiple effects to deal with various problems in the process of bone regeneration. This systematic review aims to provide an overview of the applications and effectiveness of ZIF-8 in bone regeneration. A search of papers published in the PubMed, Web of Science, Embase, and Cochrane Library databases revealed 532 relevant studies. Title, abstract, and full-text screening resulted in 39 papers being included in the review, including 39 in vitro and 22 animal studies. Appropriate concentrations of nano ZIF-8 can promote cell proliferation and osteogenic differentiation by releasing Zn2+ and entering the cell, whereas high doses of ZIF-8 are cytotoxic and inhibit osteogenic differentiation. In addition, five studies confirmed that ZIF-8 exhibits good vasogenic activity. In all in vivo experiments, nano ZIF-8 promoted bone formation. These results indicate that, at appropriate concentrations, materials containing ZIF-8 promote bone regeneration more than materials without ZIF-8, and with characteristics such as promoting angiogenesis, drug loading, and antibacterial activity, it is expected to show promising applications in the field of bone regeneration. STATEMENT OF SIGNIFICANCE: This manuscript reviewed the use of ZIF-8 in bone regeneration, clarified the biocompatibility and effectiveness in promoting bone regeneration of ZIF-8 materials, and discussed the possible mechanisms and factors affecting its promotion of bone regeneration. Overall, this study provides a better understanding of the latest advances in the field of bone regeneration of ZIF-8, serves as a design guide, and contributes to the design of future experimental studies.

Surface modification of titanium implants with Mg-containing coatings to promote osseointegration

Titanium (Ti) and Ti alloys are commonly used in dental implants, which have good biocompatibility, mechanical strength, processability, and corrosion resistance. However, the surface inertia of Ti implants leads to delayed integration of Ti and new bone, as well as problems such as aseptic loosening and inadequate osseointegration. Magnesium (Mg) ions can promote bone regeneration, and many studies have used Mg-containing materials to modify the Ti implant surface. This systematic review summarizes the methods, effects, and clinical applications of surface modification of Ti implants with Mg-containing coatings. Database collection was completed on Janury 1, 2023, and a total of 29 relevant studies were ultimately included. Mg can be compounded with different materials and coated to the surface of Ti implants using different methods. In vitro and in vivo experiments have shown that Mg-containing coatings promote cell adhesion and osteogenic differentiation. On the one hand, the surface roughness of implants increases with the addition of Mg-containing coatings, which is thought to have an impact on the osseointegration of the implant. On the other hand, Mg ions promote cell attachment through binding interactions between the integrin family and FAK-related signaling pathways. And Mg ions could induce osseointegration by activating PI3K, Notch, ERK/c-Fos, BMP-4-related signaling pathways and TRPM7 protein channels. Overall, Mg-based coatings show great potential for the surface modification of Ti implants to promote osseointegration. STATEMENT OF SIGNIFICANCE: The inertia surface of titanium (Ti) implants leads to delayed osseointegration. Magnesium (Mg) ions, known for promoting bone regeneration, have been extensively studied to modify the surface of Ti implants. However, no consensus has been reached on the appropriate processing methods, surface roughness and effective concentration of Mg-containing coatings for osseointegration. This systematic review focus on the surface modification of Ti implants with Mg-containing compounds, highlighting the effects of Mg-containing coatings on the surface properties of Ti implants and its associated mechanisms. Besides, we also provide an outlook on future directions to promote the clinical application of Mg-modified implants.

Mechanical properties, in vitro biodegradable behavior, biocompatibility and osteogenic ability of additively manufactured Zn-0.8Li-0.1Mg alloy scaffolds

Alloying and structural design provide flexibility to modulate performance of biodegradable porous implants manufactured by laser powder bed fusion (L-PBF). Herein, bulk Zn-0.8Li-0.1Mg was first fabricated to indicate the influence of the ternary alloy system on strengthening effect. Porous scaffolds with different porosities, including 60 % (P60), 70 % (P70) and 80 % (P80), were designed and fabricated to study the influence of porosity on mechanical properties, in vitro degradation behavior, biocompatibility and osteogenic ability. Pure Zn (Zn-P70) scaffolds with a porosity of 70 % were utilized for the comparison. The results showed Zn-0.8Li-0.1Mg bulks had an ultimate tensile strength of 460.78 ± 5.79 MPa, which was more than 3 times that of pure Zn ones and was the highest value ever reported for Zn alloys fabricated by L-PBF. The compressive strength (CS) and elastic modulus (E) of scaffolds decreased with increasing porosities. The CS of P70 scaffolds was 24.59 MPa, more than 2 times that of Zn-P70. The weight loss of scaffolds during in vitro immersion increased with increasing porosities. Compared with Zn-P70, a lower weight loss, better biocompatibility and improved osteogenic ability were observed for P70 scaffolds. P70 scaffolds also exhibited the best biocompatibility and osteogenic ability among all the used porosities. Influence mechanism of alloying elements and structural porosities on mechanical behaviors, in vitro biodegradation behavior, biocompatibility and osteogenic ability of scaffolds were discussed using finite element analysis and the characterization of degradation products. The results indicated that the proper design of alloying and porosity made Zn-0.8Li-0.1Mg scaffolds promising for biodegradable applications.

Immune-mediated hematological disease in dogs is associated with alterations of the fecal microbiota: a pilot study

BACKGROUND

The dog is the most popular companion animal and is a valuable large animal model for several human diseases. Canine immune-mediated hematological diseases, including immune-mediated hemolytic anemia (IMHA) and immune thrombocytopenia (ITP), share many features in common with autoimmune hematological diseases of humans. The gut microbiome has been linked to systemic illness, but few studies have evaluated its association with immune-mediated hematological disease. To address this knowledge gap, 16S rRNA gene sequencing was used to profile the fecal microbiota of dogs with spontaneous IMHA and ITP at presentation and following successful treatment. In total, 21 affected and 13 healthy control dogs were included in the study.

RESULTS

IMHA/ITP is associated with remodeling of fecal microbiota, marked by decreased relative abundance of the spirochete Treponema spp., increased relative abundance of the pathobionts Clostridium septicum and Escherichia coli, and increased overall microbial diversity. Logistic regression analysis demonstrated that Treponema spp. were associated with decreased risk of IMHA/ITP (odds ratio [OR] 0.24-0.34), while Ruminococcaceae UCG-009 and Christensenellaceae R-7 group were associated with increased risk of disease (OR = 6.84 [95% CI 2-32.74] and 8.36 [95% CI 1.85-71.88] respectively).

CONCLUSIONS

This study demonstrates an association of immune-mediated hematological diseases in dogs with fecal dysbiosis, and points to specific bacterial genera as biomarkers of disease. Microbes identified as positive or negative risk factors for IMHA/ITP represent an area for future research as potential targets for new diagnostic assays and/or therapeutic applications.

Multi-Clinical Factors Combined with an Artificial Intelligence Algorithm Diagnosis Model for HIV-Infected People with Bloodstream Infection

Purpose

Although highly active antiretroviral therapy (HA-ART) can effectively suppress the disease process in patients with acquired immunodeficiency syndrome (AIDS), opportunistic infections, mainly bloodstream infections (BSI), are still the main cause of death in people living with HIV. There is no effective diagnostic strategy for HIV-infected people with BSI. This study aimed to develop an AI diagnostic model with high sensitivity to improve the early detection of HIV-infected people with BSI.

Patients and Methods

This study retrospectively analyzed the 40 clinical factors of 498 HIV-infected people (171 with BSI positive and 327 with BSI negative) who admitted to Wenzhou Central Hospital from September 2014 to July 2021. This study used the hospital information management system to collect the clinical characteristics, laboratory and imaging examination results, and clinical diagnosis of the two groups. The diagnostic results of all patients were in line with the diagnostic criteria of the Chinese Guidelines for the Diagnosis and Treatment of AIDS (2021 Edition), and the BSI diagnosis was in line with the diagnostic criteria of sepsis and bacteremia in Practical Internal Medicine (13th Edition). On this basis, various risk prediction models were established by combining 8 artificial intelligence (AI) algorithms in the training set and validating the diagnosis performance in the testing set. The model with the best diagnostic performance was selected as the final diagnostic model.

Results

The clinical characteristics of HIV-infected people with BSI are atypical, and the pathogens in this area are mainly fungi. Ten risk factors were selected: low level of hemoglobin, CD4+T cell and platelets, high level of lactate dehydrogenase and blood urea nitrogen, splenomegaly, without ART treatment, strip shadow, nodular shadow, and shock. The combination of the ten risk factors, age, gender and the "svmRadial" model can identify the HIV-infected people with BSI from the HIV-infected people without BSI with an area under the curve of 0.916 and a sensitivity and specificity of 0.824 and 0.855, respectively.

Conclusion

The model showed excellent performance in diagnosing HIV-infected people with BSI. Internal and external validation showed that the diagnosis model had high clinical application value.

CHAF1A promotes the proliferation and growth of epithelial ovarian cancer cells by affecting the phosphorylation of JAK2/STAT3 signaling pathway

The molecular mechanism of chromatin assembly factor 1 unit A (CHAF1A) promoting the proliferation and growth of epithelial ovarian cancer (EOC) cells hasn't been reported at present. In this study, recombinant CHAF1A siRNA/overexpression plasmid (si-RNA1/pcDNA3.1-CHAF1A) was designed and constructed, and stable cell lines with knockdown or overexpression of CHAF1A were constructed. The changes of JAK2/STAT3 pathway were detected by Western blot. JAK2/STAT3 pathway was inhibited by Peficitinib, and then cell proliferation and growth ability were detected. Bioinformatics analysis suggested that CHAF1A was up-regulated in epithelial ovarian cancer. JAK2/STAT3 pathway phosphorylation was inhibited in si-RNA1 group, while it was increased in pcDNA3.1-CHAF1A group. After inhibiting JAK2/STAT3 pathway, the promoting effect of CHAF1A on epithelial ovarian cancer cell proliferation disappeared, meanwhile the inhibitory effect of CHAF1A on apoptosis enhanced. In conclusion, CHAF1A promotes the proliferation and growth of epithelial ovarian cancer cells by affecting the phosphorylation of JAK2/STAT3 signaling pathway.

Sustained release of magnesium and zinc ions synergistically accelerates wound healing

Skin wounds are a major medical challenge that threaten human health. Functional hydrogel dressings demonstrate great potential to promote wound healing. In this study, magnesium (Mg) and zinc (Zn) are introduced into methacrylate gelatin (GelMA) hydrogel via low-temperature magnetic stirring and photocuring, and their effects on skin wounds and the underlying mechanisms are investigated. Degradation testing confirmed that the GelMA/Mg/Zn hydrogel released magnesium ions (Mg²⁺) and zinc ions (Zn²⁺) in a sustained manner. The Mg²⁺ and Zn²⁺ not only enhanced the migration of human skin fibroblasts (HSFs) and human immortalized keratinocytes (HaCats), but also promoted the transformation of HSFs into myofibroblasts and accelerated the production and remodeling of extracellular matrix. Moreover, the GelMA/Mg/Zn hydrogel enhanced the healing of full-thickness skin defects in rats via accelerated collagen deposition, angiogenesis and skin wound re-epithelialization. We also identified the mechanisms through which GelMA/Mg/Zn hydrogel promoted wound healing: the Mg²⁺ promoted Zn²⁺ entry into HSFs and increased the concentration of Zn²⁺ in HSFs, which effectively induced HSFs to differentiate into myofibroblasts by activating the STAT3 signaling pathway. The synergistic effect of Mg²⁺ and Zn²⁺ promoted wound healing. In conclusion, our study provides a promising strategy for skin wounds regeneration.

In Situ Spatial Analysis of Metabolic Heterogeneity in Single Living Tumor Spheroids Using Nanocapillary-Based Electrospray Ionization Mass Spectroscopy

Spatial metabolomic analysis of individual tumor spheroids can help investigate metabolic rearrangements in different cellular regions of a spheroid. In this work, a nanocapillary-based electrospray ionization mass spectroscopy (ESI-MS) method is established that could realize the spatial sampling of cellular components in different regions of a single living tumor spheroid and the subsequent MS analysis for a metabolic study. During the penetration of the nanocapillary into the spheroid for sampling, this "wound surface" at the outer layer of the spheroid takes only 0.1% of the whole area that maximally maintains the cellular activity inside the spheroid for the metabolic analysis. Using the ESI-MS analysis, different metabolic activities in the inner and outer (upper and lower) layers of a single spheroid are revealed, giving a full investigation of the metabolic heterogeneity inside one living tumor spheroid for the first time. In addition, the metabolic activities between the outer layer of the spheroid and two-dimensional (2D)-cultured cells show obvious differences, which suggests more frequent cell-cell and cell-extracellular environment interactions during the culture of the spheroid. This observation not only establishes a powerful tool for the in situ spatial analysis of the metabolic heterogeneity in single living tumor spheroids but also provides molecular information to elucidate the metabolic heterogeneity in this three-dimensional (3D)-cultured cell model.

The biological functions of europium-containing biomaterials: A systematic review

The biological functions of rare-earth elements (REEs) have become a focus of intense research. Recent studies have demonstrated that ion doping or alloying of some REEs can optimize the properties of traditional biomaterials. Europium (Eu), which is an REE with low toxicity and good biocompatibility, has promising applications in biomedicine. This article systematically reviews the osteogenic, angiogenic, neuritogenic, antibacterial, and anti-tumor properties of Eu-containing biomaterials, thereby paving the way for biomedical applications of Eu. Data collection for this review was completed in October 2022, and 30 relevant articles were finally included. Most articles indicated that doping of Eu ions or Eu-compound nanoparticles in biomaterials can improve their osteogenic, angiogenic, neuritogenic, antibacterial, and anti-tumor properties. The angiogenic, antibacterial, and potential neuritogenic effects of Eu(OH)₃ nanoparticles have also been demonstrated.

Systematic in vitro and in vivo study on biodegradable binary Zn-0.2 at% Rare Earth alloys (Zn-RE: Sc, Y, La-Nd, Sm-Lu)

Biomedical implants and devices for tissue engineering in clinics, mainly made of polymers and stiff metallic materials, require possibly secondary surgery or life-long medicine. Biodegradable metals for biomedical implants and devices exhibit huge potential to improve the prognosis of patients. In this work, we developed a new type of biodegradable binary zinc (Zn) alloys with 16 rare earth elements (REEs) including Sc, Y, La to Nd, and Sm to Lu, respectively. The effects of REEs on the alloy microstructure, mechanical properties, corrosion behavior and in vitro and in vivo biocompatibility of Zn were systematically investigated using pure Zn as control. All Zn-RE alloys generally exhibited improved mechanical properties, and biocompatibilities compared to pure Zn, especially the tensile strength and ductility of Zn-RE alloys were dramatically enhanced. Among the Zn-RE alloys, different REEs presented enhancement effects at varied extent. Y, Ho and Lu were the three elements displaying greatest improvements in majority of alloys properties, while Eu, Gd and Dy exhibited least improvement. Furthermore, the Zn-RE alloys were comparable with other Zn alloys and also exhibited superior properties to Mg-RE alloys. The in vivo experiment using Zn-La, Zn-Ce, and Zn-Nd alloys as tibia bone implants in rabbit demonstrated the excellent tissue biocompatibility and much more obvious osseointegration than the pure Zn control group. This work presented the significant potential of the developed Zn-RE binary alloys as novel degradable metal for biomedical implants and devices.

Antibacterial Properties of Gold Nanoparticles in the Modification of Medical Implants: A Systematic Review

The widespread occurrence of bacterial infections and their increased resistance to antibiotics has led to the development of antimicrobial coatings for multiple medical implants. Owing to their desirable properties, gold nanoparticles (AuNPs) have been developed as antibacterial agents. This systematic investigation sought to analyze the antibacterial effects of implant material surfaces modified with AuNPs. The data from 27 relevant studies were summed up. The included articles were collected from September 2011 to September 2021. According to the retrieved literature, we found that medical implants modified by AuNPs have good antibacterial effects against gram-positive and gram-negative bacteria, and the antibacterial effects would be improved by near-infrared (NIR) radiation.

NEUROD1 predicts better prognosis in pancreatic cancer revealed by a TILs-based prognostic signature

It has been well-defined that tumor-infiltrating lymphocytes (TILs) play critical roles in pancreatic cancer (PaCa) progression. This research aimed to comprehensively explore the composition of TILs in PaCa and their potential clinical significance. A total of 178 samples from the TCGA and 63 samples from the GSE57495 dataset were enrolled in our study. ImmuCellAI was applied to calculate the infiltrating abundance of 24 immune cell types in PaCa and further survival analysis revealed the prognostic values of TILs in PaCa. Moreover, the Hallmark enticement analysis of differentially expressed genes (DEGs) between low- and high-risk groups was performed as well. Immunohistochemistry staining was used to evaluate NEUROD1 expression. As result, different kinds of TILs had distinct infiltrating features. In addition, Specific TILs subsets had notable prognostic values in PaCa. We further established a 6-TILs signature to assess the prognosis of PaCa patients. Kaplan-Meier and Cox regression analyses both suggested the significant prognostic value of the signature in PaCa. Based on the prognostic signature, we screened a great deal of potential prognostic biomarkers and successfully validated NEUROD1 as a novel prognostic biomarker in PaCa. Overall, the current study illuminated the immune cells infiltrating the landscape in PaCa and identified a TILs-dependent signature and NEUROD1 for prognostic prediction in PaCa patients.

pH Stimuli-Responsive, Rapidly Self-healable Coatings Enhanced the Corrosion Resistance and Osteogenic Differentiation of Mg-1Ca Osteoimplant

Mg-Ca alloys have emerged as a promising research direction for biomedical implants in the orthopedic field. However, their clinical use is deterred by their fast corrosion rate. In this work, a pH stimuli-responsive silk-halloysite (HNT)/phytic acid (PA) self-healing coating (Silk-HNT/PA) is constructed to slow down the corrosion rate of Mg-1Ca alloy and its cell viability and osteogenic differentiation ability are enhanced. The Silk-HNT/PA coating exhibits appealing active corrosion protection, by eliciting pH-triggerable self-healing effects, while simultaneously affording superior biocompatibility and osteogenic differentiation ability. Moreover, in vivo studies by histological analysis also demonstrate better osseointegration for the Silk-HNT/PA coated Mg-1Ca alloy. In summary, the Silk-HNT/PA coating in the present study has great potential in enhancing the biomedical utility of Mg alloys.

Effect of Cu and Mg addition on the mechanical and degradation properties of Zn alloy wires

In this study, Zn-xCu (-0.1 Mg) wires with a diameter of 0.3 mm were obtained by hot extrusion and cold drawing. The microstructures, mechanical properties, and degradation behaviour were investigated to evaluate their feasibility as biodegradable metals. During the drawing process of the Zn-xCu alloys, many granular CuZn5 phases were dynamically precipitated, and the grains were significantly refined, along with a significant work softening with the tensile strength decreasing and the elongation increasing (from 161 MPa to 92 MPa and 22%–103% for Zn-0.2Cu). With the increase of Cu additions, the phenomenon of work softening was more intense and there was an opposite trend in the strength changes between the as-extruded rods (increase) and as-drawn wires (decrease). With 0.1 wt.% Mg added, the stable rod-like Mg2Zn11 phase was formed in as-extruded Zn-xCu-0.1 Mg rods, which obviously improved the strength, and inhibited the dynamic precipitation of granular CuZn5 phase and work softening phenomenon in the drawing process (from 332 MPa to 313 MPa and 11%–46% for Zn-0.2Cu-0.1 Mg). In addition, due to the micro-galvanic effect induced by the precipitates, alloying accelerated the degradation of Zn alloy wires, especially Zn-1Cu-0.1 Mg, which was related to the shape, distribution, and potential of the phases.

Photocrosslinkable Col/PCL/Mg composite membrane providing spatiotemporal maintenance and positive osteogenetic effects during guided bone regeneration

Guided bone regeneration membranes have been effectively applied in oral implantology to repair bone defects. However, typical resorbable membranes composed of collagen (Col) have insufficient mechanical properties and high degradation rate, while non-resorbable membranes need secondary surgery. Herein, we designed a photocrosslinkable collagen/polycaprolactone methacryloyl/magnesium (Col/PCLMA/Mg) composite membrane that provided spatiotemporal support effect after photocrosslinking. Magnesium particles were added to the PCLMA solution and Col/PCLMA and Col/PCLMA/Mg membranes were developed; Col membranes and PCL membranes were used as controls. After photocrosslinking, an interpenetrating polymer network was observed by scanning electron microscopy (SEM) in Col/PCL and Col/PCL/Mg membranes. The elastic modulus, swelling behavior, cytotoxicity, cell attachment, and cell proliferation of the membranes were evaluated. Degradation behavior in vivo and in vitro was monitored according to mass change and by SEM. The membranes were implanted into calvarial bone defects of rats for 8 weeks. The Col/PCL and Col/PCL/Mg membranes displayed much higher elastic modulus (p < 0.05), and a lower swelling rate (p < 0.05), than Col membranes, and there were no differences in cell biocompatibility among groups (p > 0.05). The Col/PCL and Col/PCL/Mg membranes had lower degradation rates than the Col membranes, both in vivo and in vitro (p < 0.05). The Col/PCL/Mg groups showed enhanced osteogenic capability compared with the Col groups at week 8 (p < 0.05). The Col/PCL/Mg composite membrane represents a new strategy to display space maintenance and enhance osteogenic potential, which meets clinical needs.

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Photocrosslinked Col/PCL and Col/PCL/Mg membranes displayed good mechanical support to provide space for bone regeneration.

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Col/PCL and Col/PCL/Mg membranes had suitable degradation rates for the maintenance duration of bone regeneration.

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Photocrosslinked Col/PCL/Mg membranes enhanced osteogenesis and expedited the formation of high-quality bone on week 8.

Combining international survey datasets to identify indicators of stress during the COVID-19 pandemic: A machine learning approach to improve generalization

Introduction

The magnitude and exceptional opportunity to research the psychological distress of shelter in place resulted in a publication frenzy on a smorgasbord of research studies of variable scientific robustness. Confinement, fear of contagion, social isolation, financial hardship, etc. equated to stratospheric stress levels. The decline in protective factors as a function of quarantine anecdotally reflected historic rates of anxiety and depression.

Objectives

In this study, we combined 12 variegate datasets and developed an algorithm to build a model to identify key predictors of pandemic-related stress with high accuracy and generalizability.

Methods

This study reports on existing published data. We first describe the International (Adamson et al., 2020) and then the Italian dataset (Flesia et al., 2020). The time-frame (first wave of lockdown), method (survey), measurement tool (Perceived Stress Scale), and outcome measures were extremely similar to enable consolidation of datasets (see Figure1). The Flesia et al., (2020) data set was integrated into the Adamson et al., (2020) dataset as the first step towards data validation construction of the ML predictive model.

Results

We aim to demonstrate the strength of combining cross-cultural datasets, and the applicability of ML algorithms to facilitate the process and generate a predictive model that identifies and validates key predictors of pandemic-related stress and accommodates for interaction with demographic, cultural, and other mitigating factors while concurrently having high generalizability.

Conclusions

We believe our model provides clinicians, researchers, and decision-makers with evidence to investigate the moderators and mediators of stress, and introduce novel interventions to mitigate the long-term effects of the COVID-19 pandemic.

Disclosure

No significant relationships.

Evidence of altered fatty acid metabolism in dogs with naturally occurring valvular heart disease and congestive heart failure

INTRODUCTION

Myxomatous mitral valve disease (MMVD) is the most common cardiac condition in adult dogs. The disease progresses over several years and affected dogs may develop congestive heart failure (HF). Research has shown that myocardial metabolism is altered in cardiac disease, leading to a reduction in β-oxidation of fatty acids and an increased dependence upon glycolysis.

OBJECTIVES

This study aimed to evaluate whether a shift in substrate use occurs in canine patients with MMVD; a naturally occurring model of human disease.

METHODS

Client-owned dogs were longitudinally evaluated at a research clinic in London, UK and paired serum samples were selected from visits when patients were in ACVIM stage B1: asymptomatic disease without cardiomegaly, and stage C: HF. Samples were processed using ultra-performance liquid chromatography mass spectrometry and lipid profiles were compared using mixed effects models with false discovery rate adjustment. The effect of disease stage was evaluated with patient breed entered as a confounder. Features that significantly differed were screened for selection for annotation efforts using reference databases.

RESULTS

Dogs in HF had altered concentrations of lipid species belonging to several classes previously associated with cardiovascular disease. Concentrations of certain acylcarnitines, phospholipids and sphingomyelins were increased after individuals had developed HF, whilst some ceramides and lysophosphatidylcholines decreased.

CONCLUSIONS

The canine metabolome appears to change as MMVD progresses. Findings from this study suggest that in HF myocardial metabolism may be characterised by reduced β-oxidation. This proposed explanation warrants further research.

Nucleocapsid protein of SARS‐CoV‐2 is a potential target for developing new generation of vaccine

Background

Methods

Results

Conclusion

Mg/Al-LDH as a nano-adjuvant for pertussis vaccine: a evaluation compared with aluminum hydroxide adjuvant

Background. Layered double hydroxide (LDH) has been demonstrated as a highly efficient antigen platform to induce effective and durable immune response. However, whether LDH nanoparticles could act as an adjuvant for pertussis vaccines is still unknown. Here we evaluated the potential of Mg/Al-LDH as a nano-adjuvant to improve immune response against pertussis and compared it with commercial aluminum hydroxide (AH) adjuvant.Method. The Mg/Al-LDH nanoparticles were synthesized by a hydrothermal reaction. The morphology, structure and size of Mg/Al-LDH were characterized by transmission electron microscope, x-ray diffraction and MALVERN particle analysis. The ovalbumin and Pertussis toxin (PTd) was adsorbed to Mg/Al-LDH. The immune response of antigen-LDH complex was evaluated in mice, compared with commercial adjuvant alum. Hematoxylin-eosin staining was used to evaluate the inflammatory response at injection site.Results. The synthetic Mg/Al-LDH nanoparticles showed a typical hexagonal lamellar structure. The average size of synthetic nanoparticles was 102.9 nm with PDI of 0.13 and zeta potential was 44.4 mV. Mg/Al-LDH nanoparticles effectively adsorbed protein antigen and mediated antigen uptake by DC cells. Animal experiments showed that Mg/Al-LDH gave enhancement in anti-pertussis toxin (PTd) humoral immune response, which was considerable to commercial AH adjuvant. Finally, Mg/Al-LDH produced a slighter inflammatory response than AH at injection site and this injury was quickly recovered.Conclusion. Our study demonstrated the potential of Mg/Al-LDH as an effective adjuvant for pertussis vaccine, which induced comparable antibody response and had a better safety compared with commercial AH adjuvant.

3D-Printed PCL/Zn scaffolds for bone regeneration with a dose-dependent effect on osteogenesis and osteoclastogenesis

Polycaprolactone (PCL) is a polymer material suitable for being prepared into porous scaffolds used in bone tissue engineering, however, insufficient osteogenic ability and mechanical strength limit its application. Zinc (Zn) alloy with proper mechanical strength and osteogenesis is a promising biodegradable metal that have attracted much attention. Herein, we combined the advantages of PCL and Zn by fabricating PCL/Zn composite scaffolds with different Zn powder contents (1 ​wt%, 2 ​wt%, 3 ​wt%) through fused deposition modelling. The ​mechanical property, cytocompatibility and Zn ​ions release ​behavior of PCL/Zn scaffolds were analyzed ​in vitro. The osteogenesis and osteoclastogenesis properties of the scaffolds were evaluated by being implanted into Sprague-Dawley rats calvaria defect. Results showed that the PCL/Zn scaffolds exhibited improved mechanical properties and cytocompatibility compared with the pure PCL scaffolds. At 8 weeks after in vivo implantaion, the addition of Zn powder promoted new bone formation, in a dose-dependent manner. The scaffolds with 2 ​wt% Zn displayed the best osteogenic effect, while the osteogenic effect was slightly reduced in the scaffolds with 3 ​wt% Zn. In the studied Zn contents, the PCL/Zn scaffolds gradually promoted osteoclastogenesis with increasd Zn content. In the 3 ​wt% Zn group, TRAP-positive cells were observed on the newly formed bone edges around the scaffolds. These dose-dependent effects were verified in vitro using MC3T3-E1 and RAW264.7 ​cells. Finally, we revealed that Zn2+ regulated osteogenesis and osteoclastogenesis by activation of the Wnt/β-catenin and NF-κB signalling pathways, respectively.

A review on current research status of the surface modification of Zn-based biodegradable metals

Recently, zinc and its alloys have been proposed as promising candidates for biodegradable metals (BMs), owning to their preferable corrosion behavior and acceptable biocompatibility in cardiovascular, bone and gastrointestinal environments, together with Mg-based and Fe-based BMs. However, there is the desire for surface treatment for Zn-based BMs to better control their biodegradation behavior. Firstly, the implantation of some Zn-based BMs in cardiovascular environment exhibited intimal activation with mild inflammation. Secondly, for orthopedic applications, the biodegradation rates of Zn-based BMs are relatively slow, resulting in a long-term retention after fulfilling their mission. Meanwhile, excessive Zn2+ release during degradation will cause in vitro cytotoxicity and in vivo delayed osseointegration. In this review, we firstly summarized the current surface modification methods of Zn-based alloys for the industrial applications. Then we comprehensively summarized the recent progress of biomedical bulk Zn-based BMs as well as the corresponding surface modification strategies. Last but not least, the future perspectives towards the design of surface bio-functionalized coatings on Zn-based BMs for orthopedic and cardiovascular applications were also briefly proposed.

Vegetation Community Characteristics Under Different Vegetation Eco-restoration Techniques at Xiangjiaba Hydropower Station

The objective of this study is to understand the characteristics of vegetation communities under different vegetation eco-restoration models (vegetation concrete eco-restoration technique, frame beam filling soil technique, thick layer base material spraying technique, and external soil spray seeding technique). Vegetation coverage, dominant species, species composition, and species diversity of vegetation community under different vegetation eco-restoration modes were analyzed by field survey. The vegetation community of the abandoned slag slope was unstable due to the simple vegetation community structure. The species and number of the thick layer base material spraying slope were low and fail to form a healthy multilayer community structure due to invade of Leucaena leucocephala (Lam.) de Wit. Studying the allelopathy of Leucaena leucocephala (Lam.) de Wit and seeking the best species composition that can coexist with it is significant to promote the positive succession of the vegetation community. The frame beam filling soil technique, external-soil spray seeding technique, and vegetation concrete eco-restoration technique can effectively promote the succession process of the vegetation community and have well water and soil conservation capacity. These findings suggest that artificial vegetation eco-restoration measures can effectively promote vegetation eco-restoration and the positive succession of vegetation community of disturbed slopes. The research results can provide scientific advice for vegetation eco-restoration and subsequent control and management of disturbed slopes in the Xiangjiaba project, and also can be helpful to other similar projects.

Clinical Characteristics and Inflammatory Immune Responses in COVID-19 Patients With Hypertension: A Retrospective Study

Coronavirus disease (COVID-19) patients with cardiovascular and metabolic disorders have been found to have a high risk of developing severe conditions with high mortality, further affecting the prognosis of COVID-19. However, the effect of hypertension and angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blocker (ARB) agents on the clinical characteristics and inflammatory immune responses in COVID-19 patients is still undefined. In this study, 90 COVID-19 patients were divided into hypertension and nonhypertension groups. The hypertension group was divided into well-controlled and poorly controlled subgroups based on blood pressure levels; moreover, hypertensive patients were also divided into ACEI/ARB and non-ACEI/ARB subgroups according to the administration of ACEI/ARB antihypertensive agents. The clinical characteristics of and inflammatory immune biomarker levels in the different groups of COVID-19 patients were compared, and the association between the combined effect of hypertension with ACEI/ARB antihypertensive agents and the severity of COVID-19 was examined. The results showed that the levels of aminotransferase (AST) and hs-cTnI were higher in the hypertension group compared with the nonhypertension group. The long-term use of ACEI/ARB agents in patients had statistically significantly lower AST, low-density lipoprotein cholesterol (LDL-C), and oxygen uptake and lower white cell count, neutrophil count, and levels of CD4, CD8, CRP, and PCT but without statistical significance. In addition, compared with COVID-19 patients without hypertension, hypertensive patients without the use of ACEI/ARB had a higher risk of developing severity of COVID-19 (for poorly controlled patients: OR = 3.97, 95% CI = 1.03–15.30; for well-controlled patients: OR = 6.48, 95% CI = 1.77–23.81). Hypertension could cause organ damage in COVID-19 patients, but the long-term use of ACEI/ARB agents may be beneficial to alleviate this injury.

Redox/pH-Responsive Biodegradable Thiol-Hyaluronic Acid/Chitosan Charge-Reversal Nanocarriers for Triggered Drug Release

Biodegradable nanoparticles and micelles are promising nanosystems for the targeted delivery of potent anticancer drugs. By using specialized polymers as nanocarriers, targeted drug delivery and release can be developed. We developed thiol-hyaluronic acid (HA-SH)/chitosan (CS) nanoparticles with redox/pH dual-responsiveness via electrostatic self-assembly followed by spontaneous chemical cross-linking. The nanoparticle surface charges were reversible through different HA-SH and CS mass ratios. Doxorubicin (DOX) was used as a model drug. Dual cross-linked nanoparticles with diameters of approximately 300 nm exhibited superior stability under physiological conditions compared with nanoparticles without disulfide cross-linking. DOX was loaded more efficiently into negative nanoparticles (45.7 wt%) than positive nanoparticles (14.2 wt%). Drug release from negative nanoparticles (ζ potential of approximately -20) was higher (87.8 wt%) at pH 4.5 and in the presence of 10 mM glutathione. Positive nanoparticles (ζ potential of approximately +20) showed the same trend, but the release rate was slower than that of negative nanoparticles. DOX-loaded HA-SH/CS particles were taken up by human breast cancer cells (SKBR3), and the loaded drug was released, exhibiting potential antitumor efficacy. The HA-SH/CS nanoparticles in this study were stable under physiological conditions and are promising candidates for the targeted delivery and release of anticancer drugs.

Research progress in gene editing technology

As a tool for modifying the genome, gene editing technology has developed rapidly in recent years, especially in the past two years. With the emergence of new gene editing technologies, such as transposon editing tools, numerous advancements have been made including precise editing of the genome, double base editing, and pilot editing. This report focuses on the development of gene editing tools in recent years, elaborates the progress made in classic editing tools, base editor and other new editing tools, and provides insights into challenges and opportunities.

[Molecular-related epidemic characteristics of influenza A (H3N2) viruses in Guangzhou, 2019]

Objective: To isolate the influenza A (H3N2) viruses from different sources in Guangzhou in 2019 and analyze these viruses' evolution and variation characteristics. Methods: The hemagglutinin (HA) and neuraminidase (NA) genes of H3N2 isolates from outpatient monitoring, influenza outbreaks, and inpatient severe cases in Guangzhou in 2019 were sequenced. Bioinformatics software analyzed the variations and evolution characteristics of HA and NA genes. Results: The epidemic peaks of influenza A (H3N2) viruses were made up of period Ⅰ (from January to August) and period Ⅱ (from November to December). The positive rate of influenza A (H3N2) in males was 13.46% (703/5 221), which was higher than that in females (11.50%, 510/4 435) (χ²=8.43,P=0.00). The group's positive rate of 10-20 years old was the highest (25.18%,665/2 641). The isolates from different sources were highly homologous and closely related to 3C.2a.1 branches, which could be further divided into three small groups of Group 1-3. Gene recombination was observed between different branches. The mutations of HA antigen sites gradually appeared from Group 1 to Group 3, leading to new antigen drift. Variations of HA antigenic sites mainly occurred in the region of A and B. The mutations of receptor binding sites of Group 1 and Group 3 viruses occurred in the anterior and posterior walls. There were two glycosylation sites lacked on region A of HA antigen observed in the isolates of Group 2-3. Conclusions: Genetic variations of H3N2 influenza viruses in Guangzhou included gene mutations and gene recombination. Under the pressure of the vaccine, the evolution of viruses was rapid. Therefore, the monitoring of molecular-related epidemic characteristics of the H3N2 influenza virus was necessary.

Discovery of a covalent inhibitor of heat shock protein 90 with antitumor activity that blocks the co-chaperone binding via C-terminal modification

Heat shock protein (Hsp90), a critical molecular chaperone that regulates the maturation of a large number of oncogenic client proteins, plays an essential role in the growth of neoplastic cells. Herein, DDO-6600 is identified to covalent modification of Cys598 on Hsp90 from in silico study and is verified by a series of biological assays. We demonstrated that DDO-6600 covalently bound to Cys598 on the Hsp90 C terminus and exhibited antiproliferative activities against multiple tumor cells without inhibiting ATPase activity. Further studies showed that DDO-6600 disrupted the interaction between Hsp90 and Cdc37, which induced the degradation of kinase client proteins in multiple tumor cell lines, promoted apoptosis, and inhibited cell motility. Our findings offer mechanic insights into the covalent modification of Hsp90 and provide an alternative strategy for the development of Hsp90 covalent regulators or chemical probes to explore the therapeutical potential of Hsp90.

Analysis of Cryptosporidium spp. from clinical samples by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry

AIM

To purify Cryptosporidium spp. oocysts from clinical stool samples and evaluate using an up-to-date mass spectrometry protocol producing high-quality reference spectra.

METHODS AND RESULTS

A refined purification protocol was developed for oocysts from stools, involving salt flotation and potassium bromide density centrifugation. Purified oocysts were prepared for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) by formic acid extraction, and the extracts analysed using the Bruker MALDI Biotyper system. Individual spectral markers were identified by their specific mass peaks. Cryptosporidium parvum oocysts (Iowa strain) propagated in vivo, and C.  parvum (n = 2) and Cryptosporidium hominis (n = 1) oocysts from clinical stool samples produced distinct spectra that were considered specific to Cryptosporidium spp. with no evidence of contamination.

CONCLUSIONS

The production of distinct spectra demonstrated the utility of the purification method for oocysts from clinical stool samples and provided reference spectra.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of MALDI-TOF MS and other mass spectrometry techniques has been limited previously to C.  parvum oocysts propagated in vivo. Appropriate purification of oocysts can achieve sufficient biomass, enabling analysis by MALDI-TOF MS and potentially other mass spectrometry platforms, facilitating peptide and protein discovery and identification of biomarkers from a much wider range of Cryptosporidium spp. from natural infections.

Hydrogen selenide, a vital metabolite of sodium selenite, uncouples the sulfilimine bond and promotes the reversal of liver fibrosis

Sodium selenite has alleviating effects on liver fibrosis; however, its therapeutic molecular mechanism remains unclear. Herein, hydrogen selenide, a major metabolite of Na₂SeO₃, was tested to uncouple the sulfilimine bond in collagen IV, the biomarker of liver fibrosis. A mouse model of liver fibrosis was constructed via a CCl₄-induced method, followed by the administration of 0.2 mg kg^-1 Na₂SeO₃ via gavage three times per week for 4 weeks. Changes in H₂Se, NADPH, and H₂O₂ levels were monitored in real time by using NIR-H₂Se, DCI-MQ-NADPH, and H₂O₂ probes in vivo, respectively. H₂Se continuously accumulated in the liver throughout the Na₂SeO₃ treatment period, but the levels of NADPH and H₂O₂ decreased. The expression of collagen IV was analyzed through Western blot and liquid chromatography-mass spectrometry. Results confirmed that the sulfilimine bond of collagen IV in the fibrotic mouse livers could be broken by H₂Se with the Na₂SeO₃ treatment. Therefore, the therapeutic effect of Na₂SeO₃ on liver fibrosis could be mainly attributed to H₂Se that uncoupled the sulfilimine bond to induce collagen IV degradation. This study provided a reasonable explanation for the molecular mechanism of the in vivo function of Na₂SeO₃ and the prevention of liver fibrosis by administering inorganic selenium.

miR-29a in Exosomes from Bone Marrow Mesenchymal Stem Cells Inhibit Fibrosis during Endometrial Repair of Intrauterine Adhesion

Background and Objectives

Bone marrow mesenchymal stem cells (BMSCs) is an ideal source of stem cells in the treatment of intrauterine adhesion. Exosomes are a type of membrane vesicle and the diameter is 30∼100 nm. Exosomes can take their contents into the target cells, releasing and exerting their functions. In this study, we intend to study the role of human BMSC-derived exosomes (BMSC-Exo) in promoting endometrial damage repair in the treatment of IUA.

Methods

We used the magnetic bead affinity method to extract BMSC-Exo and analyzed its biological character. Then we co-cultured the BMSCs-Exo with endometrial cells to detect its effect. We injected BMSCs-Exo into the IUA mouse model. We over-expressed miR-29a in BMSCs-Exo by transient transfection, then used RT-PCR to analyze the expression of the related genes.

Results

BMSCs-Exo expressed exosome-specific proteins CD9, CD63, and CD81. BMSCs-Exo could bring the contents into the target cells. BMSCs-Exo can promote endometrial repair in vitro or in vivo. BMSCs-Exo overexpressing miR-29a can reduce αSMA, Collagen I, SMAD2, and SMAD3.

Conclusions

In this study, we successfully isolated BMSCs-Exo and proved its character and biological activity. BMSCs-Exo can promote cell proliferation and cell migration in vitro and can repair damaged endometrium in the IUA model. The presence of miR-29a in BMSCs-Exo may be an important factor in its resistance to fibrosis during endometrial repair of IUA. This study provides new ideas for the treatment of patients with IUA and has important clinical research significance.

pH-responsive silk fibroin-based CuO/Ag micro/nano coating endows polyetheretherketone with synergistic antibacterial ability, osteogenesis, and angiogenesis

Polyetheretherketone has been widely used for bone defect repair, whereas failures may happen due to implant loosening and infection. Thus, PEEK implant with multi-function (osteogenesis, angiogenesis, and bacteria-killing) is essential to solve this problem. Herein, copper oxide microspheres (µCuO) decorated with silver nanoparticles (nAg) were constructed on porous PEEK surface via silk fibroin. In vitro studies highlighted the pH controlled release ability of this coating. It liberated a high dose of Cu²⁺ and Ag⁺ at low pH environment (pH 5.0), leading to 99.99% killing of planktonic bacteria and complete eradication of sessile bacteria, avoiding biofilm formation. Under physiological environment (pH 7.4), a lower amount of leaked metal ions induced promoted ALP production, collagen secretion, and calcium deposition, as well as NO production, which indicated potentiated osteogenesis and angiogenesis. In vivo results displayed the highest new bone volume around, and the appearance of new bone inside porous structure of, PEEK implant with this coating in rabbit tibia, signified the abilities of this coating to promote bone regeneration and osseointegration. Our study established solid support for implants with this coating to be a successful bone defect repair solution. STATEMENT OF SIGNIFICANCE: In this study, CuO/Ag micro/nano particles were incorporated into the porous surface of PEEK through polydopamine and silk fibroin layers. The design of this coating conferred pH-controlled release behavior to Cu²⁺ and Ag⁺. High dose of metal ions were released at pH 5.0, which presented synergistic antibacterial ability and killed 99.99% of planktonic bacteria. Low concentration of metal ions were controlled by this coating at physiological environment, which potentiated osteodifferentiation of Ad-MSC in vitro and led to complete integration of implant with bone tissue in vivo.

BRCA1 Is a Novel Prognostic Indicator and Associates with Immune Cell Infiltration in Hepatocellular Carcinoma

The breast cancer gene 1 (BRCA1) is a tumor suppressor, and mutations or epigenetic inactivation will increase the risk of breast cancer oncogenesis. The current research aimed to explore the relationship between BRCA1 expression, prognosis, and tumor immunity in hepatocellular carcinoma (HCC). In this study, BRCA1 expression was analyzed via multiple online databases and its association with clinical characteristics, prognosis and genetic alterations was identified using the original The Cancer Genome Atlas-liver hepatocellular carcinoma cohorts. DNA methylation sites and their prognostic values were analyzed using MethSurv. The correlations between BRCA1 and immune infiltration were investigated via Tumor Immune Estimation Resource. As results, BRCA1 was significantly upregulated in tumor tissues in multiple HCC cohorts. Besides, high BRCA1 expression was correlated with race, advanced T stage, clinical stage, poor tumor grade, MSI status, and worse prognosis. Notably, BRCA1 expression was positively correlated with infiltration levels of B cells, CD4+ T cells, CD8+ T cells, neutrophils, macrophages, and dendritic cells. The current findings imply that BRCA1 is associated with prognosis and immune infiltration, laying foundations for in-depth research on the role of BRCA1 in HCC.

Comparative transcriptomic analysis reveals mechanisms of divergence in osmotic regulation of the turbot Scophthalmus maximus

The turbot Scophthalmus maximus has evolved extensive physiological ability to adapt to multiple environmental salinities. The morphological changes of the kidney indicated the adaptability difference and similarity of turbot to salinity stress. Identify transcriptome-wide differences between low-salinity seawater (LSW, salinity 5)- and high-salinity seawater (HSW, salinity 50)-acclimated kidneys of turbot to decipher the osmotic regulation mechanism. We identified 688 differentially expressed genes (DEGs) in the LSW-acclimated kidneys and 2441 DEGs in the HSW-acclimated kidneys of turbot compared with seawater-acclimated kidneys, respectively. We investigated three patterns of gene regulation to salinity stress that involved in ion channels and transporters, functions of calcium regulation, organic osmolytes, energy demand, cell cycle regulation, and cell protection. Additionally, protein-protein interaction (PPI) analysis of DEGs suggested the presence of a frequent functional interaction pattern and that crucial genes in the PPI network are involved in hyper-osmotic regulation. Based on the analysis of comparative transcriptome data and related literature reports, we conclude that the mechanisms responsible for osmotic regulation and its divergence in turbot are related to various genes that are involved in canonical physiological functions. These findings provide insight into the divergence in osmoregulation of turbot and valuable information about osmoregulation mechanisms that will benefit other studies in this field.

Systematic summarization of the expression profiles and prognostic roles of the dishevelled gene family in hepatocellular carcinoma

Background

Dishevelled (DVL) family members are crucial to Wnt‐induced signaling transduction, and their expression is highly correlated with the progression of multiple malignant cancers. However, the expression profiles and exact prognostic values of DVLs in hepatocellular carcinoma (HCC) have not been explored until now.

Methods

The expression of DVL isoforms was assessed using the Oncomine, HCCDB and UALCAN databases. The prognostic roles of DVLs were further evaluated using the GEPIA database. The relationship between the expression of DVLs and immune infiltration of HCC was investigated using the Timer and ImmuCellAI tools. Furthermore, protein–protein interaction (PPI) networks were built and enrichment analyses were conducted.

Results

We found that the expression levels of DVL2 (OMIM accession number: 602151) and DVL3 (OMIM accession number: 601368) were upregulated in HCC tissues as revealed by the Oncomine and HCCDB databases. Additionally, the expression of DVLs tended to be associated with advanced clinical features in the UALCAN database. Prognostic analysis revealed that the expression levels of DVL1 (OMIM accession number: 601365) and DVL3 were remarkably associated with a poor prognosis in HCC patients. The results also revealed that the DVL expression level was correlated with the infiltration levels of multiple immune cells. By constructing the PPI network and enrichment analyses, the DVL1‐3 gene was identified to interact with 20 key genes and participate in several pathways.

Conclusion

In summary, DVL2 and DVL3 are highly expressed in HCC, and DVL1 and DVL3 are related to a poor prognosis, which might be used as candidate targets for targeted therapy and reliable prognostic biomarkers in HCC.

Cloning and molecular characterization of PRL and PRLR from turbot (Scophthalmus maximus) and their expressions in response to short-term and long-term low salt stress

The pituitary hormone prolactin (PRL) regulates salt and water homeostasis by altering ion retention and water uptake through peripheral osmoregulatory organs. To understand the role of PRL and its receptor (PRLR) in hypoosmoregulation of turbot (Scophthalmus maximus), we characterized the PRL and PRLR gene and analyzed the tissue distribution of the two genes and their gene transcriptional patterns in the main expressed tissues under long-term and short-term low salt stress. The PRL cDNA is 1486 bp in length, incorporating an ORF of 636 bp with a putative primary structure of 211 residues. And the PRLR cDNA is 2849 bp in length, incorporating an ORF of 1944 bp with a putative primary structure of 647 residues. The deduced amino acid sequences of these two genes shared highly conserved structures with those from other teleosts. Quantitative real-time PCR results showed that PRL transcripts were strongly expressed in the pituitary and very weakly in brain, but were hardly expressed in other tissues. PRLR transcripts were most abundant in the kidney, to a lesser extent in the gill, intestine, brain, and spleen, and at low levels in the pituitary and other tissues examined. The expression of PRL in the pituitary increased after short-term or long-term low salt stress, and the highest expression level appeared 12 h after stress (P < 0.05). And there is no significant difference between both low salt group (5 ppt and 10 ppt) at each sampling point. The variation of PRLR expression in gill under short-term low salt stress is similar to that of PRL gene in pituitary, with highest value in 12 h (P < 0.05). However, the expression under long-term low salt stress was significantly higher than control group even than 12 h group under 5 ppt (P < 0.05). The expression of PRLR in the kidney increased first and then decreased after low salt stress, and the highest value also appeared in 12 h after stress and there was no significant difference between the salinity groups. After long-term low salt stress, the expression level also increased significantly (P < 0.05), but it was flat with 24 h, which was lower than 12 h. The variation of PRLR expression in the intestine was basically consistent with that in the kidney. The difference was that the expression level of 24 h after stress in the 5 ppt group was significantly higher than that of the 10 ppt group (P < 0.05). After a comprehensive analysis of the expression levels of the two genes, it can be found that the expression level increased and peaked at 12 h after short-term low salt stress, indicating that this time point is the key point for the regulation of turbot in response to low salt stress. This also provides very important information for studying the osmotic regulation of turbot. In addition, our results also showed that the expression of PRLR was stable in the kidney and intestine after long-term low salt stress, while the expression in the gill was much higher than short-term stress. It suggested that PRL and its receptors mainly exert osmotic regulation function in the gill under long-term low salt stress. At the same time, such a result also brings a hint for the low salt selection of turbot, focusing on the regulation of ion transport in the gill.

A pure zinc membrane with degradability and osteogenesis promotion for guided bone regeneration: In vitro and in vivo studies

Selection of an appropriate membrane material for guided bone regeneration (GBR) is still ongoing among resorbable and nonresorbable membranes with different characteristics. The major problem with nonresorbable membranes is the inevitable secondary surgery, while resorbable polymer membranes have limitations in providing sufficient mechanical support during the bone repair period due to premature loss of mechanical strength. Pure magnesium foil has been evaluated to explore its feasibility as a resorbable GBR membrane. It exhibited better mechanical properties, whereas poor formability and fast degradation rate were noted. In light of this, pure zinc membrane was developed as a pilot research in this paper. We designed three types of pure zinc membranes: pure Zn without pores, pure Zn with 300 µm diameter and 1000 µm diameter pores, and pure titanium without pores as a control. The mechanical property, in vitro immersion tests, and MC3T3-E1 cell viability assays were tested. Moreover, in vivo behaviors of three type zinc membranes were evaluated by using a rat calvarial critical-sized bone defect model. The experimental results indicated that pure Zn membrane with 300 µm pores showed the most favorable osteogenic capability, comparable to that of titanium membrane without pores. Therefore, considering appropriate degradation rate, adequate mechanical maintenance, and profitable osteogenic capacity, metallic pure zinc is believed to be a promising candidate for barrier membranes in GBR therapy for bone regeneration, and its mechanical property can be enhanced with further alloying. STATEMENT OF SIGNIFICANCE: Metallic element zinc plays a pivotal role in the growth and mineralization of bone tissues. As a pilot research, three type of guided bone regeneration (GBR) membranes were developed in the present work: pure Zn without pores, pure Zn with 300 µm-diameter and 1000 µm-diameter pores respectively. The mechanical property, in vitro immersion tests and MC3T3-E1 cell viability assays were tested, with pure titanium without pores as a control, thereafter the in vivo performance were evaluated by using a rat calvarial critical-sized bone defect model. It indicated that pure Zn membrane with 300 µm pores showed the most favorable osteogenic capability, comparable to that of titanium membrane control, and is believed to be a promising material candidate as barrier membrane in GBR therapy for bone regeneration.

LAMA2 regulates the fate commitment of mesenchymal stem cells via hedgehog signaling

BACKGROUND

Bone defects are a common clinical condition that has gained an increasing amount of attention in recent years. Causes of bone defect include tumors, inflammation, and fractures. Bone tissue engineering is a novel treatment of bone defect, and human mesenchymal stem cells (hMSCs) are the ideal seed cells for bone tissue engineering due to their multi-lineage differentiation potential and immunogenicity. The laminin α2 (LAMA2) gene encodes the α2 subunit of laminins. Mutations in this gene have been reported to cause muscular dystrophy, but thus far no studies have elucidated the role of LAMA2 in the fate choices of MSCs. Here, we aimed to investigate the critical role of LAMA2 in the osteogenesis and adipogenesis of mesenchymal stem cells (MSCs).

METHODS

We investigated LAMA2 function in osteogenic and adipogenic differentiation of MSCs in vitro and in vivo through loss- and gain-of-function experiments. In addition, molecular mechanism was clarified by Western blot and siRNA.

RESULTS

Our results demonstrated that LAMA2 was a critical regulator for fate commitment of MSCs. Both in vitro and in vivo studies indicate that LAMA2 inhibits osteogenesis and promotes adipogenesis. Mechanistically, we found that LAMA2 regulated osteogenesis and adipogenesis of MSCs by modulating the hedgehog signaling pathway.

CONCLUSIONS

The present work confirms that LAMA2 is a new molecular target for MSC-based bone regeneration.

Controllable biodegradation and enhanced osseointegration of ZrO2-nanofilm coated Zn-Li alloy: In vitro and in vivo studies

Zinc and its alloys have emerged as a new research direction of biodegradable metals (BMs) due to the significant physiological functions of Zn²⁺ ions in human body. However, low inhibitory concentration threshold value to cause cytotoxicity by Zn²⁺ ions during in vitro study and delayed osseointegration in vivo are two key flaws for the bulk Zn-based BMs. To combat these issues, we constructed a barrier layer of ZrO₂ nanofilm on the surface of Zn-0.1(wt.%) Li alloy via atomic layer deposition (ALD). A decreased release of Zn²⁺ ions accompanied with accelerated release of Li⁺ ions was observed on account of galvanic coupling between the coating compositions and Zn-0.1Li alloy substrate. Cytocompatibility assay reflected that ZrO₂ nanofilm coated Zn-0.1Li alloy exhibited improved cell adhesion and viability. Histological analysis also demonstrated better in vivo osseointegration for the ZrO₂ nanofilm coated Zn-0.1Li alloy. Hence, the present study elucidated that the ALD of ZrO₂ nanofilm on Zn-based BMs can effectively promote osseointegration and control their biodegradation behavior. STATEMENT OF SIGNIFICANCE: Zn-Li binary alloy was reported recently to be the promising biodegradable metals with ultimate tensile strength over 500 MPa, yet the low inhibitory concentration threshold value to cause cytotoxicity by Zn²⁺ ions is the obstacle needed to be overcome. As a pilot study, a systematic investigation on the ZrO₂ nanofilm coated Zn-Li alloy, prepared by atomic layer deposition (ALD) technique, was conducted in the present study, which involved in the formation process, in vitro and in vivo degradation behavior as well as biocompatibility evaluation. We found a controllable corrosion rate and better in vivo osseointegration can be achieved by ZrO₂ nanofilm coating on Zn-Li alloy, which provides new insight into the surface modification on biodegradable Zn alloys for usage within bone.

Drug target discovery by magnetic nanoparticles coupled mass spectrometry

Drug target discovery is the basis of drug screening. It elucidates the cause of disease and the mechanism of drug action, which is the essential of drug innovation. Target discovery performed in biological systems is complicated as proteins are in low abundance and endogenous compounds may interfere with drug binding. Therefore, methods to track drug-target interactions in biological matrices are urgently required. In this work, a Fe₃O₄ nanoparticle-based approach was developed for drug-target screening in biofluids. A known ligand-protein complex was selected as a principle-to-proof example to validate the feasibility. After incubation in cell lysates, ligand-modified Fe₃O₄ nanoparticles bound to the target protein and formed complexes that were separated from the lysates by a magnet for further analysis. The large surface-to-volume ratio of the nanoparticles provides more active sites for the modification of chemical drugs. It enhances the opportunity for ligand-protein interactions, which is beneficial for capturing target proteins, especially for those with low abundance. Additionally, a one-step magnetic separation simplifies the pre-processing of ligand-protein complexes, so it effectively reduces the endogenous interference. Therefore, the present nanoparticle-based approach has the potential to be used for drug target screening in biological systems.

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Fe₃O₄ NPs were made hydrophilic to adequately disperse in the cell lysate and fully contact with target proteins.

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The magnetic property of the NPs allowed one-step isolation while maintaining ligand-protein non-covalent bindings.

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It enabled the capture of low abundant targets in biological matrices while eliminated the endogenous interference.