BACKGROUND:One of the advantages of clear aligner treatment is molar distalization.However,tooth tilting movement and loss of anterior anchorage may occur during treatment.There are few studies on whether these problems can be improved by selecting clear aligners with different thicknesses and edges to improve the clinical treatment effect.OBJECTIVE:To analyze the control ability of clear aligners with different thickness and edges on the central incisor,lateral incisor,and second molar when pushing the maxillary second molar distally by three-dimensional finite element analysis.METHODS:Three-dimensional finite element analysis models of bilateral maxillary second molar distalization with clear aligner,maxillary dentition,periodontal ligament,and alveolar bone with different thicknesses and margins were established by Mimics,Geomagic Wrap,3-matic and SolidWorks software,respectively.There were 16 combinations of four thicknesses(0.4,0.5,0.625,and 0.75 mm)and four margins(scallop,straight,straight extension 2 mm and straight extension 4 mm).The data were imported into Ansys Workbench software for design and solution.The mean value,peak value and distribution of the periodontal ligament equivalent stress of the second molar,the equivalent stress and the maximum initial displacement of the second molar,and the control ability of each appliance on the second molar,central incisor,and lateral incisor were analyzed.RESULTS AND CONCLUSION:(1)The mean equivalent stress of periodontal ligament of the second molar,the equivalent stress of the second molar and the maximum initial displacement of the second molar increased with the extension of the appliance edge and the increase of the thickness of the appliance in the 16 groups of models.(2)When the thickness of appliances was the same,the maximum equivalent stress of the second molar in the linear appliance group was the highest,and the maximum equivalent stress of the second molar in the linear extended appliance group was greater than that in the scallop appliance group.When the edge of the appliance was the same,the periodontal ligament equivalent stress peak of the second molar increased with the increase of the thickness of the appliance.The equivalent stress distribution in the periodontal ligament of the second molar in the linear extendable appliance group was more uniform than that in the scallop appliance group and the linear appliance group.(3)When the thickness of the appliance was the same,the scallop-shaped appliance had the worst control on the second molar.When the edge of the appliance was the same,with the increase of the thickness of the appliance,the control of the second molar by the linear extender appliance was gradually stronger than that by the linear appliance.The control of the central incisor was stronger and more stable with the linear extended 2 mm appliance,while the control of the lateral incisor was stronger and more stable with the linear appliance.(4)The results showed that when using clear aligners to push molars distally,extending the edge of the appliance could improve the control of the molars and reduce the tilting movement of the teeth.The design of a straight extension margin of 2 mm for the central incisor and a straight edge for the lateral incisor can enhance the control of the anchorage incisor and reduce the labial inclination of the anterior teeth.

BACKGROUND:Nanocell vesicles possess functions such as re-epithelialization,antioxidation,anti-inflammation,and regulation of extracellular matrix remodeling.Meanwhile,apoptotic bodies have the immunomodulatory effects.Therefore,the combination of the two to form nanofusion vesicles can synergistically promote the healing of diabetic skin wounds.OBJECTIVE:To elucidate the impact of nanofusion vesicles on skin wound healing in a diabetic murine model.METHODS:(1)Material preparation and characterization:The primary bone marrow mesenchymal stem cells of C57BL/6J neonatal mice and the neutrophil apoptotic bodies of C57BL/6J mice were isolated and extracted.The nanofusion vesicles were prepared by micro-extrusion mechanism.(2)In vitro experiment:MTT assay was used to detect the proliferative effect of different concentrations of nanofusion vesicles on NIH-3T3 cells and human umbilical vein endothelial cells.Reactive oxygen species fluorescence probe was used to detect the antioxidant effect of nano-fusion vesicles on NIH-3T3 cells treated with hydrogen peroxide(H2O2).The inhibitory effect of nanofusion vesicles on RAW 264.7 macrophage inflammation induced by lipopolyside was detected by real-time quantitative RT-qPCR.(3)In vivo experiment:36 male C57BL/6J mice were employed to develop a murine model of diabetes mellitus.Following the successful induction of diabetes,two circular full-thickness wounds,each with a diameter of 6 mm,were created on either side of the diabetic mice's spine using a skin punch.The mice were divided into three groups by random number table method.The control group was injected with 0.1 mL of phosphate buffer solution.The nanovesicle group was injected with 0.1 mL nanovesicles(25 μg/mL).The nanofusion vesicle group was injected with 0.1 mL nanofusion(25 μg/mL)vesicles.After treatment for three consecutive days,the wound healing and histomorphological changes were observed.RESULTS AND CONCLUSION:(1)In vitro experiment:nanofusion vesicles,when administered at concentrations ranging from 0 to 100 μg/mL,exhibited no toxic effects and promoted the proliferation of NIH-3T3 and HUVEC cell lines.Notably,a concentration of 25 μg/mL nanofusion vesicle significantly enhanced the proliferation of NIH-3T3 cells.Furthermore,the survival rate of human umbilical vein endothelial cells was observed to increase in correlation with escalating concentrations of nanofusion vesicles.Nanofusion vesicles had a good antioxidant effect.In comparison to the H2O2 group,the fluorescence signal indicative of reactive oxygen species was progressively diminished in both the nanovesicle group and the nanofusion vesicle group.Furthermore,nanofusion vesicles possessed anti-inflammatory capabilities,effectively mitigating the inflammatory response in macrophages triggered by lipopolysaccharide stimulation.(2)In vivo experiment:Hematoxylin-eosin and Masson's trichrome staining revealed that in comparison to the control group,both the nanovesicle group and the nanofusion vesicle group exhibited a significant increase in granulation tissue formation and collagen fiber deposition within the wounds by day 6.Notably,the nanofusion vesicle group displayed the most pronounced effects.On day 12,the wound of nanofusion vesicle group was significantly reduced,and the healing rate was significantly faster than that of other groups(P＜0.01),and the effect of promoting wound healing was the most significant.Our findings demonstrated that nanofusion vesicles exhibited superior pro-cell proliferative,antioxidant,and anti-inflammatory properties,thereby exerting a beneficial effect on the promotion of skin wound healing in diabetic mouse models.

BACKGROUND:Choline kinase alpha is a key enzyme in phospholipid metabolism,involved in the synthesis of phosphatidylcholine,and plays an important role in maintaining cell membrane integrity and signal transduction.Research has shown that choline kinase alpha is highly expressed in various tumors and is closely related to cell proliferation,metabolic reprogramming,and tumor progression.As a potential therapeutic target,the role of choline kinase alpha in tumor metabolism and mitochondrial function still needs further exploration.OBJECTIVE:To evaluate the effects and the underlying mechanisms of choline kinase alpha on the proliferation and apoptosis of glioma U87MG and U251 cells.METHODS:Short hairpin RNA of choline kinase alpha and its empty vector control were transfected into U87MG and U251 glioma cells.Mitochondrial morphology was observed by transmission electron microscopy.Mitochondrial structure and functional protein levels were assessed by western blot assay.Reactive oxygen species levels in cells were measured using a reactive oxygen species fluorescent probe.Mitochondrial membrane potential was assessed with a JC-1 assay.Intracellular adenosine triphosphate levels were measured by chemiluminescence.Cell proliferation was evaluated using a CCK-8 assay.Apoptosis levels were analyzed by flow cytometry.The mitochondrial fission inhibitor Mdivi-1 was used to protect the mitochondrial function of the choline kinase α-silenced lentiviral cells.Finally,U87MG cells were subcutaneously injected to construct a subcutaneous tumor model in nude mice.The tumor growth in nude mice was observed before and after choline kinase alpha silencing and after the use of the mitochondrial fission inhibitor Mdivi-1.RESULTS AND CONCLUSION:(1)Compared with the empty control group,the mitochondria of U87MG and U251 cells in the choline kinase alpha silencing lentivirus group exhibited significant structural abnormalities in mitochondria,such as vacuolization and cristae disruption.The expressions of mitochondrial structure and function-related proteins TOM20,ACO2,and ATP5A were significantly decreased(P＜0.01,P＜0.001),the expression of SOD2 was significantly increased(P＜0.01,P＜0.000 1),the fluorescence intensity of reactive oxygen species was significantly increased(P＜0.01),the mitochondrial membrane potential and adenosine triphosphate level were significantly decreased(P＜0.01,P＜0.001),the cell proliferation ability was reduced(P＜0.01),and the apoptosis level was increased(P＜0.001).(2)Following Mdivi-1 treatment,the fluorescence intensity of reactive oxygen species in U87MG and U251 cells decreased(P＜0.05,P＜0.01),mitochondrial membrane potential and adenosine triphosphate levels were significantly restored(P＜0.05,P＜0.01,P＜0.001),cell proliferation ability was improved(P＜0.05,P＜0.01),and apoptosis level was decreased(P＜0.05).(3)In addition,the in vitro subcutaneous tumor formation experiment of nude mice showed that compared with the empty control group,the mass and growth rate of subcutaneous tumors formed by U87MG cells in the choline kinase alpha silencing lentivirus group were significantly reduced(P＜0.000 1).After Mdivi-1 treatment,the mass and growth rate of tumors were significantly increased(P＜0.000 1).(4)The results show that choline kinase alpha silencing affects the proliferation and apoptosis of glioma cells by inducing mitochondrial dysfunction.

BACKGROUND:Studies have shown that rheumatoid arthritis and osteoporosis are positively correlated,but the causal relationship and related mechanisms have not yet been confirmed.With the cross-fertilization of computer science and life sciences,Mendelian randomization and bioinformatics analyses based on genome-wide association study(GWAS)and transcriptome sequencing data can assess the causal relationship between two diseases,explore the related mechanisms,and mine the therapeutic targets,which will be beneficial to the precision treatment of rheumatoid arthritis combined with osteoporosis.OBJECTIVE:To explore the causal relationship between rheumatoid arthritis and osteoporosis using two-sample Mendelian randomization and to mine potential co-morbid targets and potential targeted drugs through summary-data-based Mendelian randomization and bioinformatics analyses,aiming to provide theoretical basis for mechanism exploration and precision treatment in the field of rheumatoid arthritis combined with osteoporosis.METHODS:(1)Firstly,GWAS data of rheumatoid arthritis,osteoporosis,and cis-expression quantitative trait locus(cis-eQTL)in Asian and European populations were downloaded from the GWAS Catalog,IEU Open GWAS,FinnGen,and eQTLGen databases,and were used for two-sample Mendelian randomization analysis and summary-data-based Mendelian randomization analysis.(2)Transcriptome sequencing data of rheumatoid arthritis(GSE93272 and GSE15573)were downloaded from the GEO database for bioinformatics analysis.(3)Subsequently,forward and inverse Mendelian randomization analyses between rheumatoid arthritis and osteoporosis were performed,and inverse variance weighted was used as the main metric for the analyses,and the results were corroborated with MR Egger,simple mode,weighted median and weighted mode.(4)Then,the genes closely related to rheumatoid arthritis and osteoporosis were identified based on the summary-data-based Mendelian randomization analysis,and the co-disease targets of rheumatoid arthritis and osteoporosis were mined based on cross-analysis.Meanwhile,the biological functions of the co-morbid targets were verified based on bioinformatics analysis and cellular experiments.(5)In addition,a rheumatoid arthritis risk prediction nomogram was constructed based on DYRK2,and its prediction performance was verified by receiver operating characteristic curve,correction curve and decision curve.Finally,the target potential drugs were mined based on Enrichr database and molecular docking was performed.RESULTS AND CONCLUSION:(1)Forward Mendelian randomization analysis of rheumatoid arthritis and osteoporosis showed statistically significant results except for GCST90044540 and GCST90086118,and all other results indicated a significant causal relationship and positive correlation between rheumatoid arthritis and osteoporosis.(2)Inverse Mendelian randomization analysis suggested that no significant causal relationship was seen between osteoporosis and rheumatoid arthritis.(3)Summary-data-based Mendelian randomization analysis identified a total of 412 and 344 genes positively associated with rheumatoid arthritis and osteoporosis,and 421 and 347 genes negatively associated.Based on the cross-analysis,26 co-morbid genes were subsequently obtained.Among them,DYRK2 was a potential therapeutic target,and subsequent bioinformatics analysis and cellular experiments confirmed its important role in the progression of rheumatoid arthritis and osteoporosis.(4)Furthermore,the constructed nomogram has excellent predictive performance.Finally,four potential DYRK2-targeting drugs(undecanoic acid,metyrapone,JNJ-38877605,and ACA)were discovered and molecular docking also demonstrated reliable targeting ability.(5)In conclusion,based on GWAS data from Asian and European populations,we successfully demonstrated that rheumatoid arthritis and osteoporosis are causally related at the genetic level,DYRK2 is a potential therapeutic target,and four small molecules are potential target drugs.

BACKGROUND:The Guilu Erxian Glue consists of Testudinis Plastrum,Cornu Cervi,Lycii Fructus,and Ginseng Radix.In earlier clinical observations,it is discovered that using Guilu Erxian Glue to treat patients with liver-kidney deficiency type knee osteoarthritis effectively alleviated knee pain,increased the range of motion,and improved walking ability.However,the exact mechanism by which oral administration of Guilu Erxian Glue can produce local therapeutic effects on the knee joint is still unclear.OBJECTIVE:To investigate the effects of Guilu Erxian Glue on gut microbiota in rats with knee osteoarthritis and to evaluate its mechanism using 16S rDNA sequencing and machine learning analysis.METHODS:Totally 18 female SD rats were randomly divided into three groups:blank group,model group,and Guilu Erxian Glue group,with 6 rats in each group.A knee osteoarthritis model was prepared using the destabilization of the medial meniscus surgical method.After successful modeling,the Guilu Erxian Glue group was given a decoction of Guilu Erxian Glue by gavage,while the blank and model groups were given an equal amount of distilled water.After 28 days of continuous intervention,high performance liquid chromatography was used to detect the active ingredients of Guilu Erxian Glue.MRI imaging was used to observe the condition of rat knee articular cartilage.Fecal samples were collected;DNA was extracted using a kit,amplified and purified by PCR,and an Illumina sequencing library was constructed.The Illumina MiSeq platform was used for high-throughput sequencing to generate raw sequence data.After obtaining the raw data,QIIME2 software was used to process the data.Linear Discriminant Analysis Effect Size analysis and random forest algorithm were used to screen for differential species in microbial data.KEGG and MetaCyc functional pathway analyses were used to explore the association between key microbial communities and experimental groups.Linear discriminant analysis effect values and random forest algorithm were used to screen for differential species.Association networks were used to analyze the interactions between microbial communities,and machine learning methods were used to analyze the composition and changes of gut microbiota.RESULTS AND CONCLUSION:(1)LC-MS component identification was conducted on the traditional Chinese medicine formula of Guilu Erxian Glue,and a total of 7 effective ingredients were identified.(2)MRI imaging showed that synovitis scope of high-density shadows in rats of the Guilu Erxian Glue group was reduced,and the degeneration of medial femoral condyle cartilage was less than that in the model group.(3)16S rDNA sequencing showed that the model group rats exhibited significant microbial imbalance,with a significant decrease in the abundance of Firmicutes and Bacteroidetes at the phylum level,while the proportion of Proteobacteria increased significantly(P＜0.05).The gut microbiota structure of rats in the Guilu Erxian Glue group was significantly improved,and the proportion of Firmicutes and Bacteroidetes increased,restoring a more diverse microbiota composition,approaching that of the blank group(P＜0.05).(4)KEGG and MetaCyc functional pathway analysis showed that the Guilu Erxian Glue group significantly activated multiple metabolic pathways,including amino acid metabolism,lipid metabolism,and biotin synthesis pathways(P＜0.05).(5)The results indicate that Guilu Erxian Glue contains seven active ingredients,and the changes in gut microbiota of knee osteoarthritis rats were analyzed using 16S rDNA sequencing.Guilu Erxian Glue can significantly improve the imbalance of gut microbiota,restore the abundance of beneficial bacteria,and have a significant impact on the composition of gut microbiota,providing scientific basis for the efficacy and mechanism of Guilu Erxian Glue.

BACKGROUND:Autologous bone,allogeneic bone or artificial bone has been used to promote bone defect repair in the clinic,but the rate of non-healing is still high.The key is to ignore the importance of periosteum in the bone healing process.In the early stage of the project,the project team constructed an electrospinning membrane loaded with vascular endothelial growth factor to highly simulate the intramembranous osteogenesis of natural periosteum at the bone defect site,which promoted bone regeneration to a certain extent.However,the injured area often faces the dilemma of severe inflammatory response mediated by macrophages and lack of seed cells,resulting in the risk of inactivation or diffusion of delivered biological factors.Therefore,it is necessary to further optimize and coordinate the immune regulation and angiogenesis functions of biomimetic periosteum to promote bone repair.OBJECTIVE:To investigate the physicochemical properties of stem cell-engineered bionic periosteum and its role in regulating the inflammatory microenvironment to promote bone repair.METHODS:By combining L-polylactic acid-based microsol electrospinning,type Ⅰ collagen self-assembly and gel stem cell transplantation technology,a bionic periosteum(M@C-B)was constructed,in which the core layer loaded with vascular endothelial growth factor and the shell layer delivered bone marrow mesenchymal stem cells to regulate the immune microenvironment of bone defects.The physicochemical properties of the periosteum were characterized by scanning electron microscopy,transmission electron microscopy,and Fourier transform infrared spectroscopy.A co-culture system was established between the bionic periosteum and macrophages,bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to explore immune regulation and in vitro osteogenic and angiogenic abilities.Finally,the osteogenic properties of the stem cell engineered bionic periosteum were further verified in a rat femoral condyle defect model.RESULTS AND CONCLUSION:(1)Transmission electron microscopy results showed that the micro-sol electrospinning(MS)formed a distinct core-shell structure.Scanning electron microscopy indicated that after the assembly of the collagen-l artificial periosteum(M@C)on the surface of the vascular endothelial growth factor-loaded micro-sol,a distinct"spider web-like"fibrous structure was deposited.Infrared spectroscopy further confirmed the successful self-assembly of collagen-l.Release experiments demonstrated that the M@C group mitigated the burst release phenomenon compared to the MS group,maintaining internal vascular endothelial growth factor activity and sustained release.(2)Live/dead cell staining and CCK-8 assay showed that bone marrow mesenchymal stem cells proliferated well and survived on three types of artificial periosteum:MS,purely aligned poly(L-lactic acid)(PLLA)surface self-assembled collagen-l artificial periosteum(PLLA@C),and vascular endothelial growth factor-loaded micro-sol fiber surface self-assembled collagen-l-bone marrow mesenchymal stem cells artificial periosteum(M@C-B).Among them,the M@C-B group had the highest number of live cells and the fastest proliferation rate.(3)Alkaline phosphatase staining,alizarin red staining,and osteopontin immunofluorescence staining showed that the PLLA@C and M@C-B groups significantly promoted osteogenic differentiation of bone marrow mesenchymal stem cells.Angiogenesis experiments demonstrated that the vascular endothelial growth factor-loaded groups(MS and M@C-B)had longer blood vessel lengths and more reticular vascular-like structures with more cross-linked nodes,with the M@C-B group being the most prominent.(4)Immunofluorescence and flow cytometry showed that artificial periosteum in the M@C-B group significantly inhibited the pro-inflammatory macrophage phenotype and promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype.(5)In vivo studies further confirmed that the M@C-B group showed superior bone mineral density,trabecular thickness,relative bone volume,and trabecular spacing compared to other groups.(6)These results indicate that bone marrow mesenchymal stem cell-engineered artificial periosteum,through the rapid regulation of the bone defect immune microenvironment by the collagen-l-bone marrow mesenchymal stem cells outer phase and the sustained release of vascular endothelial growth factor by the micro-sol electrospinning core-shell structure of the inner phase,synergistically promotes bone healing.

BACKGROUND:Cell-free therapy is a research hotspot in the field of medical cosmetic anti-aging.It is still unknown for paracellular secretion of human umbilical cord mesenchymal stem cell-derived small extracellular vesicles loaded with the antiaging drug α-ketoglutaric acid to delay skin aging.OBJECTIVE:To investigate the effect of the anti-aging agent α-ketoglutarate engineered human umbilical cord mesenchymal stem cell-derived small extracellular vesicles in a D-galactose-induced model of dermal fibroblast senescence.METHODS:(1)Biological characteristics of primary human umbilical cord mesenchymal stem cells were identified by osteogenic-lipogenic differentiation staining and flow cytometry.(2)The small extracellular vesicles derived from human umbilical cord mesenchymal stem cell were obtained by using differential-ultracentrifugation.α-Ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles were constructed by electroporation,and biologically characterized by transmission electron microscopy and nanoparticle tracking analyzer,while the encapsulation rate was assessed using high-performance liquid chromatography.(3)The effect of α-ketoglutarate on the proliferative capacity of dermal fibroblasts was assessed by CCK-8 and Edu cell proliferation assay kits.(4)The effect of α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles on delaying the senescence of dermal fibroblasts was evaluated by reactive oxygen species detection kit,western blot assay,and cellular immunofluorescence.RESULTS AND CONCLUSION:(1)The obtained human umbilical cord mesenchymal stem cell and human umbilical cord mesenchymal stem cell-small extracellular vesicles were biologically compatible.(2)There was no toxic effect on dermal fibroblasts when α-ketoglutarate was used in the concentration range of 0.5-8 mmol/L.(3)D-gal induced senescence in dermal fibroblasts,while α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles treatment reduced the level of oxidative stress,DNA damage,and collagen loss,which was further verified that α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles could effectively slow down the skin aging process.

BACKGROUND:Clinical studies suggest that both bone quality and excessive crown-to-implant ratio are factors that affect the success rate of implant surgery,but there is no consensus on how large the crown-to-implant ratio under each bone quality will affect the prognosis of implant repair.OBJECTIVE:To analyze the stress and strain of bone tissue around implant restorations with different crown-to-implant ratios under different bone types after stress loading using three-dimensional finite element method.Combined with the Frost bone mechanics regulation system theory,the physiological limits of bone strain were observed for each bone type within a certain range of crown to implant ratios.METHODS:Cone beam CT data were selected from a patient to establish solid bone block models with four different bone types(class Ⅰ bone:cortical bone thickness 3 mm+dense cancellous bone,class Ⅱ bone:cortical bone thickness 2 mm+relatively dense cancellous bone,class Ⅲ bone:cortical bone thickness 1 mm+relatively low-density cancellous bone,class Ⅳ bone:cortical bone thickness 1 mm+low-density cancellous bone).Implant restorations with five different crown-to-implant ratios(1,1.5,2,2.5,and 3)were created on each bone block model,for a total of 20 models.Vertical and oblique forces were applied to the dental crown to observe the von Mises stress values,strains,and displacement of the cortical and cancellous bones,as well as the degree of implant displacement.RESULTS AND CONCLUSION:(1)In the class Ⅰ bone model,when the crown-to-implant ratio reached 3 under oblique loading,the cortical bone strain exceeded the physiological limit.In the class Ⅱ bone model,under oblique loading,when the crown-to-implant ratio reached 2.5,the cortical bone strain exceeded the physiological limit.In the class Ⅲ bone model,under oblique loading,cortical bone exceeded the physiological limit when the crown-to-implant ratio reached 2.5,while cancellous bone reached the critical physiological limit at 1.In the class Ⅳ bone model,under oblique loading,when the crown-to-implant ratio reached 1.5,2,2.5,and 3,the cortical bone strain exceeded the physiological limit.In the class Ⅳ bone model,all five crown-to-implant ratios of cancellous bone exceeded physiological limits.(2)Under vertical load,the cancellous bone strain exceeded the physiological limit when the crown-root ratio reached 1,2,2.5,and 3 in the class Ⅲ bone model,and when the cancellous bone strain of the five crown-root ratios in the class Ⅳ bone model exceeded the physiological limit.(3)Under oblique or vertical load,the implant displacement of the 20 groups of models did not exceed 100 μm.(4)From the perspective of biomechanics,when patients with insufficient bone height choose implant restoration,the crown-root ratio that class Ⅰ bone can tolerate is up to 2.5 times,the crown-root ratio that class Ⅱ bone can tolerate is up to 2 times,and the crown-root ratio that class Ⅲ and class Ⅳ bones can tolerate is up to 1 times due to excessive strain of cancellous bone;but the crown-root ratio that cortical bone in class Ⅲ bone can tolerate is up to 2 times.Whether class Ⅲ bone can tolerate implant restoration with a high crown-root ratio and whether cancellous bone can tolerate higher strains needs further study.

BACKGROUND:The long-term patency rate of synthetic blood vessels remains a significant challenge that requires urgent attention.Enhancing the anticoagulant performance of small-caliber artificial blood vessels is crucial in ensuring their long-term efficacy.OBJECTIVE:To investigate the anticoagulation activity of polycaprolactone/low molecular weight fucoidan nanofibers with shell core structure and determine the effect on the activity of human umbilical vein endothelial cells.METHODS:Polycaprolactone nanofiber membranes and polycaprolactone/low molecular weight fucoidan nanofiber membranes with polycaprolactone as shell layer and low molecular weight fucoidan as core layer were prepared by emulsion electrospinning method(the mass ratio of low molecular weight fucoidan to polycaprolactone was 10％,25％,40％,and 55％,respectively).The morphology and structure of the fibers were characterized by scanning electron microscopy,fluorescence microscopy,and infrared spectroscopy.The mechanical strength of the fiber membranes was detected by tensile test.The loading rate and sustained release rate of low molecular weight fucoidan in the nanofibers were detected by 1,9-dimethylmethylene blue dye.The anticoagulant properties of the fiber membranes were verified by hemolysis test,dynamic coagulation test,plasma recalcification test,and platelet adhesion test.The five fiber membranes were co-cultured with human umbilical vein endothelial cells.The cell proliferation was detected by CCK-8 assay and the cell morphology was observed by fluorescence microscopy.RESULTS AND CONCLUSION:(1)Scanning electron microscope showed that the surface of polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane was smooth,the fiber diameter was uniform,and there was no obvious beaded structure.With the increase of low molecular weight brown algae polysaccharide content in the fiber membrane,the diameter of the fiber membrane increased and the maximum tensile stress decreased,but it still met the mechanical properties requirements of small-caliber artificial blood vessels.Fluorescence images and infrared spectra confirmed that low molecular weight brown algae polysaccharide was successfully loaded into polycaprolactone nanofiber membrane,and the low molecular weight brown algae polysaccharide loaded in each group of fiber membranes was released suddenly within 12 hours and released at a relatively low rate after 48 hours.(2)Compared with polycaprolactone nanofiber membrane,polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane had better anticoagulant activity,among which the group with a mass ratio of low molecular weight brown algae polysaccharide to polycaprolactone of 25％had the best anticoagulant effect.All five fiber membranes supported the growth and proliferation of human umbilical vein endothelial cells without affecting cell morphology and had no obvious cytotoxicity.(3)The results show that the polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane has good anticoagulant function,blood compatibility,and cell compatibility.

BACKGROUND:In previous studies,glass materials were infiltrated into 5Y-PSZ ultra-translucent zirconia by a double sintering method to prepare 5Y-PSZ-YGI graded glass infiltrated ultra-translucent zirconia materials that can maintain high transparency and high flexural strength.OBJECTIVE:To evaluate the in vitro biocompatibility of 5Y-PSZ-YGI graded glass infiltrated ultra-translucent zirconia materials.METHODS:(1)Glass materials were infiltrated into 5Y-PSZ ultra-translucent zirconia by double sintering to prepare 5Y-PSZ-YGI graded glass infiltrated ultra-translucent zirconia.5Y-PSZ-YGI graded glass infiltrated ultra-translucent zirconia(or 5Y-PSZ ultra-translucent zirconia,3Y-TZP transparent zirconia)was placed in DMEM culture medium containing 10％fetal bovine serum for 12,24 and 72 hours,and the surface area ratio of culture medium to sample was 3 mL/cm2,and the 12-,24-and 72-hour material extracts were obtained.(2)After culturing mouse fibroblast L929 for 24 hours,the original culture medium was discarded and divided into 7 groups for culture:the control group was replaced with DMEM culture medium containing 10％fetal bovine serum by volume,and the other 6 groups were replaced with 24-hour extract of 3Y-TZP transparent zirconia,24-hour extract of 5Y-PSZ ultra-translucent zirconia,24-hour extract of 5Y-PSZ-YGI graded glass infiltrated ultra-translucent zirconia,72-hour extract of 3Y-TZP transparent zirconia,72-hour extract of 5Y-PSZ ultra-translucent zirconia,and 72-hour extract of 5Y-PSZ-YGI graded glass infiltrated ultra-translucent zirconia.After 1,3,and 5 days of culture,cell growth was observed under a microscope,and the cell proliferation rate was obtained by CCK-8 assay to determine cytotoxicity.(3)Human anticoagulated blood was mixed with 5Y-PSZ-YGI graded glass infiltrated ultra-translucent zirconia,5Y-PSZ ultra-translucent zirconia,and 3Y-TZP transparent zirconia,and the hemolysis rate was detected after 0.5 hours.Human anticoagulated blood was mixed with 12-hour extract of 3Y-TZP transparent zirconia,12-hour extract of 5Y-PSZ ultra-translucent zirconia,and 12-hour extract of 5Y-PSZ-YGI graded glass infiltrated ultra-translucent zirconia,and the hemolysis rate was detected after 0.5 hours.RESULTS AND CONCLUSION:(1)Under the microscope,it could be seen that the number of cells in each group increased with the extension of culture time,and the cell morphology of each experimental group was basically the same as that of the control group.The cytotoxicity grade of the 24-hour extract of 3Y-TZP transparent zirconia group on the first day of culture was grade 0,and the cytotoxicity grade of the other experimental groups at each time period was grade 1.(2)Neither the material nor the material extract caused obvious hemolytic reaction,and the hemolytic rate was less than 5％.(3)The results showed that 5Y-PSZ-YGI graded glass infiltrated ultra-translucent zirconia had no significant effect on the growth and proliferation of mouse fibroblasts L929,and did not cause hemolytic reaction with human blood,and had good in vitro biocompatibility.