The role and applications of extracellular vesicles in osteoporosis

Osteoporosis is a widely observed condition characterized by the systemic deterioration of bone mass and microarchitecture,which increases patient susceptibility to fragile fractures.The intricate mechanisms governing bone homeostasis are substantially impacted by extracellular vesicles(EVs),which play crucial roles in both pathological and physiological contexts.EVs derived from various sources exert distinct effects on osteoporosis.Specifically,EVs released by osteoblasts,endothelial cells,myocytes,and mesenchymal stem cells contribute to bone formation due to their unique cargo of proteins,miRNAs,and cytokines.Conversely,EVs secreted by osteoclasts and immune cells promote bone resorption and inhibit bone formation.Furthermore,the use of EVs as therapeutic modalities or biomaterials for diagnosing and managing osteoporosis is promising.Here,we review the current understanding of the impact of EVs on bone homeostasis,including the classification and biogenesis of EVs and the intricate regulatory mechanisms of EVs in osteoporosis.Furthermore,we present an overview of the latest research progress on diagnosing and treating osteoporosis by using EVs.Finally,we discuss the challenges and prospects of translational research on the use of EVs in osteoporosis.

Three-dimensional morphological and fluorescent imaging of zebrafish with a continuous-rotational light-sheet microscope

Light-sheet fluorescence microscopy(LSFM)has been widely used to image the three-dimensional(3D)structures and functions of various millimeter-size bio-specimen such as zebrafish.However,the sample adsorption and scattering cause shading of the light-sheet illumination,preventing the even 3D image of thick samples.Herein,we report a continuous-rotational light-sheet microscope(CR-LSM)that enables simultaneous 3D bright-field and fluorescence imaging.With a high-accuracy rotational stage,CR-LSM records the outline projections and the fluorescent images of the sample at multiple rotation angles.Then,3D morphology and fluorescent structure were reconstructed with a developed algorithm.Using CR-LSM,zebrafish’s whole-fish contour and blood vessel structures were obtained simultaneously.

Isolation and bioactivity screening of soy isoflavones from soybean glycolipids identifies daidzin as a promising anti-inflammatory agent

Background:Soybean has long been utilized in the realm of traditional Chinese medicine.One of its extracts,soybean glycolipids,serves as a vital by-product of soybean oil refining,but its chemical composition and pharmacological potential have yet to be fully elucidated.Methods:In this study,the chemical components were isolated,and the inhibitory effects of these isolates were explored in different zebrafish inflammatory models by survival rate,Histological examination assay and quantitative Real-time PCR assay.The cytotoxicity of daidzin in RAW264.7 cells was evaluated by cell viability assay,and the effect of daidzin on the release of inflammatory cytokines in RAW264.7 cells was detected by enzyme linked immunosorbent assay(ELISA).Western blotting,immunofluorescence assay and alpha7 nicotinic acetylcholine receptors siRNA transfection assay were used to further explore the anti-inflammatory mechanism of daidzin.Results:Four compounds(verticilloside,soya-cerebroside I,soya-cerebroside II and daidzin)were firstly isolated from the soybean glycolipids,among which verticilloside and daidzin inhibited the lipopolysaccharide,CuSO4-and tail cut-stimulated zebrafish inflammation.Noticeably,daidzin exhibited anti-inflammatory activities by increasing the survival rate,alleviating the inflammatory cells infiltration,and down-regulating the expression of pro-inflammatory cytokines and nuclear factor kappa-B,NF-kappa-B inhibitor alpha,and signal transducer and activator of transcription3 in zebrafish.Moreover,daidzin decreased the secretion of IL-6 and TNF-α,inhibited the nuclear translocations of nuclear factor kappa-B p65 and p-signal transducer and activator of transcription3 as well as the NF-kappa-B inhibitor alpha phosphorylation at Ser32 in RAW 264.7 cells.More importantly,it elevated the expression level of alpha7 nicotinic acetylcholine receptors in both zebrafish and RAW 264.7 cells,and the inhibitory effect of daidzin was attenuated after the addition of alpha7 nicotinic acetylcholine receptors siRNA.Conclusion:Our study revealed that daidzin inhibited inflammation by activating the cholinergic anti-inflammatory pathway and further inhibiting the nuclear factor kappa-B and signal transducer and activator of transcription3 signaling.At the same time,it also promotes the recycling of crude soybean glycolipids and supports the potential use of daidzin as a functional food or natural dietary anti-inflammatory agent.

Strengths, weaknesses, and applications of computational axial lithography in tissue engineering

Recently,Kelly and colleagues[1],inspired by computed tomography(CT),report a“volumetric additive manufacturing”technology via a computed axial lithography(CAL)approach.A related US patent application[2]has also been filed.The cumulative light exposure solidifies the material in the target area,while the other area remains uncured,resulting in only specific points in the designed 3D objects being printed.This technology significantly improves the capability of the digital light processing(DLP)technique.Meanwhile,the lithography approach based on a similar algorithm was already proposed by Xiang Wu in a patent(application No.PCT/CN2016/080097)in 2016[3].

Development of a CLDN18.2-targeting immuno-PET probe for non-invasive imaging in gastrointestinal tumors

Claudin18.2(CLDN18.2)is a tight junction protein that is overexpressed in a variety of solid tumors such as gastrointestinal cancer and oesophageal cancer.It has been identified as a promising target and a potential biomarker to diagnose tumor,evaluate efficacy,and determine patient prognosis.TST001 is a recombinant humanized CLDN18.2 antibody that selectively binds to the extracellular loop of human Claudin18.2.In this study,we constructed a solid target radionuclide zirconium-^(89)(^(89)Zr)labled-TST001 to detect the expression of in the human stomach cancer BGC823CLDN18.2 cell lines.The[^(89)Zr]Zr-desferrioxamine(DFO)-TST001 showed high radiochemical purity(RCP,>99%)and specific activity(24.15±1.34 GBq/mmol),and was stable in 5%human serum albumin,and phosphate buffer saline(>85%RCP at 96 h).The EC_(50) values of TST001 and DFO-TST001 were as high as 0.413±0.055 and 0.361±0.058 nM(P>0.05),respectively.The radiotracer had a significantly higher average standard uptake values in CLDN18.2-positive tumors than in CLDN18.2-negative tumors(1.11±0.02 vs.0.49±0.03,P=0.0016)2 days post injection(p.i.).BGC823CLDN18.2 mice models showed high tumor/muscle ratios 96 h p.i.with[^(89)Zr]Zr-DFO-TST001 was much higher than those of the other imaging groups.Immunohistochemistry results showed that BGC823CLDN18.2 tumors were highly positive(+++)for CLDN18.2,while those in the BGC823 group did not express CLDN18.2().The results of ex vivo biodistribution studies showed that there was a higher distribution in the BGC823CLDN18.2 tumor bearing mice(2.05±0.16%ID/g)than BGC823 mice(0.69±0.02%ID/g)and blocking group(0.72±0.02%ID/g).A dosimetry estimation study showed that the effective dose of[^(89)Zr]Zr-DFO-TST001 was 0.0705 mSv/MBq,which is within the range of acceptable doses for nuclear medicine research.Taken together,these results suggest that Good Manufacturing Practices produced by this immuno-positron emission tomography probe can detect CLDN18.2-overexpressing tumors.

A hyaluronic acid granular hydrogel nerve guidance conduit promotes regeneration and functional recovery of injured sciatic nerves in rats

A hyaluronic acid granular hydrogel can promote neuronal and astrocyte colony formation and axonal extension in vitro,suggesting that the hydrogel can simulate an extracellular matrix structure to promote neural regeneration.However,in vivo experiments have not been conducted.In this study,we transplanted a hyaluronic acid granular hydrogel nerve guidance conduit to repair a 10-mm long sciatic nerve gap.The Basso,Beattie,and Bresnahan locomotor rating scale,sciatic nerve compound muscle action potential recording,Fluoro-Gold retrograde tracing,growth related protein 43/S100 immunofluorescence staining,transmission electron microscopy,gastrocnemius muscle dry/wet weight ratio,and Masson’s trichrome staining results showed that the nerve guidance conduit exhibited similar regeneration of sciatic nerve axons and myelin sheath,and recovery of the electrophysiological function and motor function as autologous nerve transplantation.The conduit results were superior to those of a bulk hydrogel or silicone tube transplant.These findings suggest that tissue-engineered nerve conduits containing hyaluronic acid granular hydrogels effectively promote the morphological and functional recovery of the injured sciatic nerve.The nerve conduits have the potential as a material for repairing peripheral nerve defects.

Hair growth-promotion effects and antioxidant activity of the banana flower extract HappyAngel^(■):double-blind, placebo-controlled trial

Banana flowers contain various bioactive components, including several antioxidants with anti-inflammatory effects. However, it is unclear whether they can reduce and prevent hair loss. This study examines the effect of banana flower extracts on preventing hair loss and strengthening hair roots. The banana flower extract(HappyAngel^(■))was used to treat human hair follicle dermal papilla cells(HFDPCs)and the expression of reactive oxygen species(ROS), dihydrotestosterone(DHT), and hair-related genes(SRD5A1, SRD5A2, AR, and KROX20)were monitored. Fifty subjects were divided into a placebo group and a banana flower group. The experimental group consumed banana flower extract daily for twelve weeks and then underwent hair testing, hair-related genes analysis, collection of hair loss, and questionnaires. The results showed that the banana flower extract significantly increased hair cell growth and decreased the expression of ROS, DHT, and hair follicle growth inhibition-related SRD5A1, SRD5A2, and AR genes, and significantly increased the expression of hair growth-related KROX20 gene in HFDPCs. Consuming banana flower extract for twelve weeks increased the hair root diameter and reduced hair loss and scalp redness compared to the placebo group. Thus, banana flower extract(HappyAngel^(■))can stimulate hair growth and inhibit the activation of hair loss genes.

BME Frontiers: A Platform for Engineering the Future of Biomedicine

With immense enthusiasm, we introduce Biomedical Engineering (BME) Frontiers, the third addition to the family ofScience Partner Journals. The launch of BME Frontiers follows a year of intense preparation. As an open-access, peerreviewed academic journal, BME Frontiers covers basicresearch in relevant fields, as well as preclinical and clinicalinvestigations. The content will include innovative fundamental and translational concepts, mechanisms, materials,devices, systems, processes, and methods. BME Frontiers willalso serve as a platform for catalyzing forward-looking discussions about the field and will include perspectives ontraining and educating the future BME workforce.

Investigations of moiréartifacts induced by flux fluctuations in x-ray dark-field imaging

X-ray dark-field imaging using a grating interferometer has shown potential benefits for a variety of applications in recent years.X-ray dark-field image is commonly retrieved by using discrete Fourier transform from the acquired phasestepping data.The retrieval process assumes a constant phase step size and a constant flux for each stepped grating position.However,stepping errors and flux fluctuations inevitably occur due to external vibrations and/or thermal drift during data acquisition.Previous studies have shown that those influences introduce errors in the acquired phase-stepping data,which cause obvious moiréartifacts in the retrieved refraction image.This work investigates moiréartifacts in x-ray dark-field imaging as a result of flux fluctuations.For the retrieved mean intensity,amplitude,visibility and dark-field images,the dependence of moiréartifacts on flux fluctuation factors is theoretically derived respectively by using a first-order Taylor series expansion.Results of synchrotron radiation experiments verify the validity of the derived analytical formulas.The spatial frequency characteristics of moiréartifacts are analyzed and compared to those induced by phase-stepping errors.It illustrates that moiréartifacts can be estimated by a weighted mean of flux fluctuation factors,with the weighting factors dependent on the moiréphase and different greatly for each retrieved image.Furthermore,moiréartifacts can even be affected by object’s features not displayed in the particular contrast.These results can be used to interpret images correctly,identify sources of moiréartifacts,and develop dedicated algorithms to remove moiréartifacts in the retrieved multi-contrast images.

Subinhibitory Levels of Fluoroquinolones Result in Enrichment of the Membrane Proteome of Staphylococcus aureus

Staphylococcus aureus is a common marine foodborne pathogen.In this study,antibiotics ciprofloxacin and enrofloxacin were used to induce drug-resistance in S.aureus.The differentially expressed proteins(DEPs)were analyzed and compared with those in the bacteria cultured without antibiotics.The primary proteomic alterations were in the levels of cell membrane components and proteins related to lysine and folic acid biosynthesis,which were all significantly up-regulated.The minimal inhibitory concentrations(MIC)for both test drugs were elevated to 10μg m L^(-1)following serial passaging.These results indicated that,for both ciprofloxacin and enrofloxacin,drug-resistance were developed even in the subinhibitory levels and the primary response was a major alteration in the cell membrane proteome.These changes were similar to those observed in S.aureus cultured with super-MIC levels of these antibiotics.The current study provides a theoretical basis for in-depth study of the related changes of marine foodborne pathogens in subinhibitory concentrations that are commonly found in situ.

Development of a portable reflectance confocal microscope and its application in the noninvasive in vivo evaluation of mesenchymal stem cell-promoted cutaneous wound healing

The process of wound healing is routinely evaluated by histological evaluation in the clinic,which may cause scarring and secondary injury.Reflectance confocal microscopy(RCM)represents a noninvasive,real-time imaging technique that allows in vivo evaluation of the skin.Traditional RCM was wide-probe-based,which limited its application on uneven and covered skin.In this study,we report the development of a portable reflectance confocal microscope(PRCM)in which all components were assembled in a handheld shell.Although the size and weight of the PRCM were reduced based on the use of a microelectromechanical system,the resolution was kept at 0.91μm,and the field of view of the system was 343μm×532μm.When used in vivo,the PRCM was able to visualize cellular and nuclear morphology for both mouse and human skin.PRCM evaluations were then performed on wounds after topically applied mesenchymal stem cells(MSCs)or saline treatment.The PRCM allowed visualization of the formation of collagen bundles,re-epithelization from the wound edge to the wound bed,and hair follicle regeneration,which were consistent with histological evaluations.Therefore,we offer new insights into monitoring the effects of topically applied MSCs on the process of wound healing by using PRCM.This study illustrates that the newly developed PRCM represents a promising device for real-time,noninvasive monitoring of the dynamic process of wound healing,which demonstrates its potential to diagnose,monitor,or predict disease in clinical wound therapy.

Identification of injury type using somatosensory and motor evoked potentials in a rat spinal cord injury model

The spinal cord is at risk of injury during spinal surgery.If intraoperative spinal co rd injury is identified early,irreve rsible impairment or loss of neurological function can be prevented.Different types of spinal cord injury result in damage to diffe rent spinal cord regions,which may cause diffe rent somatosensory and motor evoked potential signal res ponses.In this study,we examined electrophysiological and histopathological changes between contusion,distra ction,and dislocation spinal cord injuries in a rat model.We found that contusion led to the most severe dorsal white matter injury and caused considerable attenuation of both somatosensory and motor evoked potentials.Dislocation resulted in loss of myelinated axons in the lateral region of the injured spinal cord along the rostrocaudal axis.The amplitude of attenuation in motor evoked potential responses caused by dislocation was greater than that caused by contusion.After distraction injury,extracellular spaces were slightly but not significantly enlarged;somatosensory evoked potential res ponses slightly decreased and motor evoked potential responses were lost.Correlation analysis showed that histological and electrophysiological findings we re significantly correlated and related to injury type.Intraope rative monitoring of both somatosensory and motor evoked potentials has the potential to identify iatrogenic spinal cord injury type during surgery.

High-throughput sorting of two-color fluorescent-labeled zebrafish embryos

The zebrafish embryos were widely employed in genetics,development and drug discovery studies as miniatured animal models.Sorting of two-color fluorescent embryos is often required in large-scale experiments but it is challenging to manually sort with high efficiency.Here,we reported a high-throughput sorting system for two-color fluorescent zebraflsh embryos.The embryos can be automatically loaded from a sample pool and sorted based on the average fluorescent intensity.The two-color fluorescent signals were split into two lines and detected by an area array camera.The system achieves the sorting of 100 embryos in less than 10 min with an accuracy of greater than 95%.

Anisodine hydrobromide alleviates oxidative stress caused by hypoxia/reoxygenation in human cerebral microvascular endothelial cells predominantly via inhibition of muscarinic acetylcholine receptor 4

Background:Anisodine hydrobromide(AT3),an anti-cholinergic agent,could be delivered to the brain across the blood-brain barrier and has been used clinically for the treatment of cerebral ischemia/reperfusion injury.Endothelial dysfunction can be caused by hypoxia/reoxygenation(H/R)via oxidative stress and metabolic alterations.The present study investigated whether AT3 regulates the production of nitric oxide(NO)and reactive oxygen species(ROS),and the HIF-1αpathway via regulation of muscarinic acetylcholine receptors(mAChRs)in brain microvascular endothelial cells after H/R exposure.Methods:Under H/R conditions,hCMEC/D3 cerebral microvascular endothelial cells were treated with AT3.Specific inhibitors of M2-and M4-mAChRs were used to explore the mechanism by which AT3 influences oxidative stress in endothelial cells.Then,mAChRs expression was detected by western blotting and NO production was detected by Greiss reaction.The intracellular ROS level was measured using DCFH-DA probes.The expression of hypoxia-inducible transcription factor 1α(HIF-1α)was also detected.Results:While H/R induced the expression of M2-and M4-mAChRs,AT3 suppressed the H/R-upregulated M2-and M4-mAChRs.H/R also induced the production of NO,ROS,and apoptosis.AT3 and M4-mAChR inhibitors inhibited the H/R-induced production of NO and ROS and apoptosis.HIF-1αwas induced by H/R,but was suppressed by AT3.Conclusion:Thus,the in vitro evidence shows that AT3 protects against H/R injury in cerebral microvascular endothelial cells via inhibition of HIF-1α,NO and ROS,predominantly through the downregulation of M4-mAChR.The findings offer novel understandings regarding AT3-mediated attenuation of endothelial cell apoptosis and cerebral ischemia/reperfusion injury.

Analysis of refraction and scattering image artefacts in x-ray analyzer-based imaging

X-ray analyzer-based imaging(ABI) is a powerful phase-sensitive technique that can provide a wide dynamic range of density and extract useful physical properties of the sample. It derives contrast from x-ray absorption, refraction, and scattering properties of the investigated sample. However, x-ray ABI setups can be susceptible to external vibrations, and mechanical imprecisions of system components, e.g., the precision of motor, which are unavoidable in practical experiments. Those factors will provoke deviations of analyzer angular positions and hence errors in the acquired image data.Consequently, those errors will introduce artefacts in the retrieved refraction and scattering images. These artefacts are disadvantageous for further image interpretation and tomographic reconstruction. For this purpose, this work aims to analyze image artefacts resulting from deviations of analyzer angular positions. Analytical expressions of the refraction and scattering image artefacts are derived theoretically and validated by synchrotron radiation experiments. The results show that for the refraction image, the artefact is independent of the sample’s absorption and scattering signals. By contrast, artefact of the scattering image is dependent on both the sample’s refraction and scattering signals, but not on absorption signal.Furthermore, the effect of deviations of analyzer angular positions on the accuracy of the retrieved images is investigated,which can be of use for optimization of data acquisition. This work offers the possibility to develop advanced multi-contrast image retrieval algorithms that suppress artefacts in the retrieved refraction and scattering images in x-ray analyzer-based imaging.

Design of Evolutionary Algorithm Based Energy Efficient Clustering Approach for Vehicular Adhoc Networks

In a vehicular ad hoc network(VANET),a massive quantity of data needs to be transmitted on a large scale in shorter time durations.At the same time,vehicles exhibit high velocity,leading to more vehicle disconnections.Both of these characteristics result in unreliable data communication in VANET.A vehicle clustering algorithm clusters the vehicles in groups employed in VANET to enhance network scalability and connection reliability.Clustering is considered one of the possible solutions for attaining effectual interaction in VANETs.But one such difficulty was reducing the cluster number under increasing transmitting nodes.This article introduces an Evolutionary Hide Objects Game Optimization based Distance Aware Clustering(EHOGO-DAC)Scheme for VANET.The major intention of the EHOGO-DAC technique is to portion the VANET into distinct sets of clusters by grouping vehicles.In addition,the DHOGO-EAC technique is mainly based on the HOGO algorithm,which is stimulated by old games,and the searching agent tries to identify hidden objects in a given space.The DHOGO-EAC technique derives a fitness function for the clustering process,including the total number of clusters and Euclidean distance.The experimental assessment of the DHOGO-EAC technique was carried out under distinct aspects.The comparison outcome stated the enhanced outcomes of the DHOGO-EAC technique compared to recent approaches.

Efficient Simultaneous Detection of Metabolites Based on Electroenzymatic Assembly Strategy

Objective and Impact Statement:We describe an electroenzymatic mediator(EM)sensor based on an electroenzymatic assembly peak separation strategy,which can efficiently realize the simultaneous detection of 3 typical cardiovascular disease(CVD)metabolites in 5μl of plasma under one test.This work has substantial implications toward improving the efficiency of chronic CVD assessment.Introduction:Monitoring CVD of metabolites is strongly associated with disease risk.Independent and time-consuming detection in hospitals is unfavorable for chronic CVD management.Methods:The EM was flexibly designed by the cross-linking of electron mediators and enzymes,and 3 EM layers with different characteristics were assembled on one electrode.Electrons were transferred under tunable potential;3 metabolites were quantitatively detected by 3 peak currents that correlated with metabolite concentrations.Results:In this study,the EM sensor showed high sensitivity for the simultaneous detection of 3 metabolites with a lower limit of 0.01 mM.The linear correlation between the sensor and clinical was greater than 0.980 for 242 patients,and the consistency of risk assessment was 94.6%.Conclusion:Metabolites could be expanded by the EM,and the sensor could be a promising candidate as a home healthcare tool for CVD risk assessment.

A digital microfluidic single-cell manipulation systemoptimized by extending-depth-of-field device

Microfuidic systems have been widely utilized in high-throughput biology analysis,but thedificulties in iquid manipulation and cell cultivation limit its application.This work has developed a new digital microfluidic(DMF)system for on-demand droplet control.By adopting anextending-depth-of-field(EDoF)phase modulator to the optical system,the entire depth of themicrofluidic channel can be covered in one image without any refocusing process,ensuring that 95%of the particles in the droplet are captured within three shots together with shaking pro-cesses.With this system,suspension droplets are generated and droplets containing only oneyeast cll can be recognized,then each single cell is cultured in the array of the chip.Byobservingtheir growth in cell numbers and the green fluorescence protein(GFP)production via fluorescence imaging,the single cell with the highest production can be identified.The results haveproved the heterogeneity of yeast cells,and showed that the combined system can be applied forrapid single-cell sorting,cultivation,and analysis.

Unified deep learning model for predicting fundus fluorescein angiography image from fundus structure image

The prediction of fundus fluorescein angiography(FFA)images from fundus structural images is a cutting-edge research topic in ophthalmological image processing.Prediction comprises estimating FFA from fundus camera imaging,single-phase FFA from scanning laser ophthalmoscopy(SLO),and three-phase FFA also from SLO.Although many deep learning models are available,a single model can only perform one or two of these prediction tasks.To accomplish three prediction tasks using a unified method,we propose a unified deep learning model for predicting FFA images from fundus structure images using a supervised generative adversarial network.The three prediction tasks are processed as follows:data preparation,network training under FFA supervision,and FFA image prediction from fundus structure images on a test set.By comparing the FFA images predicted by our model,pix2pix,and CycleGAN,we demonstrate the remarkable progress achieved by our proposal.The high performance of our model is validated in terms of the peak signal-to-noise ratio,structural similarity index,and mean squared error.