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Objective@#To investigate the effects of electrochemically dealloying of Ti6Al4V abutments on human gingival fibroblasts (HGFs) and to provide experimental evidence for surface modification of implant abutments.@*Methods@#The samples were divided into an NC group (negative control, no other treatment on a smooth surface), an NM-1 group (nanomesh-1, electrochemical dealloying treatment in 1 mol/L NaOH 1 h on 2 V voltage), and an NM-2 group (nanomesh-2, electrochemical dealloying treatment in 5 mol/L NaOH 1 h on 2 V voltage). The surface morphologies of the samples and the adhesion of HGFs on the sample surfaces were observed with scanning electron microscopy (SEM). The surface hydrophilicities of the samples were measured with a contact angle measuring instrument. The proliferation of HGFs on the different samples were evaluated with CCK-8, and the expression of adhesion-related genes, including collagen Ⅰ (COL1A1), collagen Ⅲ (COL3A1), fibronectin 1 (FN1), focal adhesion kinase (FAK), vinculin (VCL), integrin α2 (ITGA2), and integrin β1 (ITGB1), on the different samples was measured with qRT-PCR. The expression of vinculin on the surfaces of HGFs was observed via confocal laser scanning microscopy (CLSM) after immunofluorescent staining. Collagen fiber secretion and syntheses of HGFs from different samples were evaluated via Sirius red staining.@*Results@#SEM revealed the formation of ordered and uniform three-dimensional mesh structures on the surfaces of the NM-1 and NM-2 groups, with grid diameters of approximately 30 nm for the NM-1 group and approximately 150 nm for the NM-2 group. Compared with that of the NC group, the water contact angles of the NM-1 group and NM-2 groups were significantly lower (P<0.000 1). Cell proliferation in the NM-1 group was significantly greater than that in the NC group (P<0.01). Moreover, there was no significant difference in the water contact angles or cell proliferation between the NM-1 group and the NM-2 group. SEM revealed that HGFs were adhered well to the surfaces of all samples, while the HGFs in the NM-1 and NM-2 groups showed more extended areas, longer morphologies, and more developed pseudopodia than did those in the NC group after 24 h. qRT-PCR revealed that the expression levels of the adhesion-related genes COL1A1, COL3A1, FN1, FAK and VCL in the NM-1 group were significantly greater than those in the NC and NM-2 groups (P<0.01). The expression of vinculin protein in the NM-1 group was the highest, and the number of focal adhesions was greatest in the NM-1 group (P<0.01). The results of Sirius red staining showed that the NM-1 group had the highest secretion and syntheses of collagen fibers (P<0.000 1).@*Conclusion@#The three-dimensional nanomechanical structure of Ti6Al4V modified by electrochemical dealloying promoted the adhesion, proliferation, collagen fiber secretion and syntheses of HGFs, and electrochemical dealloying of Ti6Al4V with a grid diameter of approximately 30 nm obviously promoted HGF formation.
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@#Objective To explore the factors affecting the stability of high concentration variable domain of heavy-chain antibody-Fc(VHH-Fc) fusion protein.Methods Three groups of forced degradation experiments,shaking,light and 40℃ high temperature were set up.Differential scanning fluorimetry,dynamic light scattering(DLS) and ultra performance liquid chromatography-mass spectrometry(UPLC-MS) were used to detect the effects of the three forced degradation conditions on the conformational stability,colloidal stability,average hydrodynamic diameter and post-translational modifications of high concentration VHH-Fc fusion protein.Results Under the light condition,the onset temperature of unfolding(T_(onset)),melting temperature(T_m) and aggregation onset temperature(T_(agg)) of high concentration VHH-Fc fusion protein decreased the most,and the oxidation ratio of Met160 and Met266 increased significantly.Under the condition of shaking,the variation of the diffusion interaction parameter(k_D) and the average hydrodynamic diameter was the largest.Conclusion Light can significantly reduce the conformational stability of high concentration VHH-Fc fusion protein and induce methionine oxidation.Shaking has the most significant effect on its colloidal stability and promotes aggregation
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A new Schiff base modified MCM-41 molecular sieve(N-MCM-41)was synthesized via post-grafting method with 2-pyridine formaldehyde for efficient removal of lead ions(Pb2+)from aqueous solution.X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Fourier transform-infrared(FT-IR)spectroscopy,thermogravimetric analysis(TGA),and X-ray photoelectron spectroscopy(XPS)were employed to characterize the structure,morphology,surface functional groups and chemical states of N-MCM-41.Moreover,the adsorption behavior of Pb2+by N-MCM-41 was systematically studied.Batch adsorption studies revealed that N-MCM-41 showed the maximal adsorption capacity of 101.3 mg/g at 45℃and pH=5.5 under the initial Pb2+ concentration of 80 mg/L after 180 min adsorption.The adsorption process conformed to the Langmuir isotherm model and the pseudo-second-order kinetics model.The adsorption of Pb2+by N-MCM-41 was a spontaneous and endothermic process.Adsorption mechanism analyses suggested that functional groups on N-MCM-41 had strong coordination ability with Pb2+to improve the adsorption capacity.The synthesized N-MCM-41 adsorbent exhibited excellent reusability in five regeneration cycles.Overall,this study showed that the N-MCM-41 had good application prospect to remove Pb2+ from aqueous solution.
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The human body contains a large microbial community composed of eukaryotes, archaea, bacteria, and phages. Bacteria are the most prominent members of this community, numbering in the same order of magnitude as human cells. Many commensal or pathogenic bacteria interact with their hosts through biochemical signals. Based on these bacterial properties, commensal and attenuated pathogens have been designed to deliver therapeutic molecules to target specific diseases. The engineered bacteria or bacteria-derived particles and their encapsulation, secretion, and expression of surface therapeutic molecules developed in the past five years were introduced. Their applications in anti-inflammatory, anti-tumor, thrombosis treatment, and imaging were reviewed, and the clinical translational potential of microbial drug delivery systems was discussed.
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The important role of liquid-liquid phase separation in a series of biological processes,including regulation of gene transcription and translation,stress response,autophagy and the establishment of synaptic structure,has been widely accepted.Abnormal phase separation is associated with many human diseases,including neurodevelopmental disorders and neurodegenerative diseases.Studies have shown that some proteins associated with epigenetic modifications are also subject to liquid-liquid phase separation,suggesting that epigenetic modifications regulate the development and disease of the nervous system by regulating phase separation.This review summarized the important roles of epigenetic modification and phase separation in neurodevelopment and neurodiseases,and focused on the important roles of proteins related to epigenetic modification with phase separation characteristics.Understanding the correlation between epigenetic modification and phase separation will help fully understand the underlying mechanisms of neurodevelopment and neurodiseases,and will further provide new targets and strategies for the treatment of related diseases.
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Nonalcoholic fatty liver disease(NAFLD)is a metabolic liver disease that ranges from relatively benign hepatic steatosis to nonalcoholic steatohepatitis(NASH).NASH is characterized by persistent liver damage,inflammation,and fibrosis which significantly increases the risk of end-stage liver diseases,such as liver cirrhosis and hepatocellular carcinoma.The pathogenesis of NAFLD/NASH is not yet fully understood,but its recent epigenetic advances have provided new insights into the mechanisms of this disease.This review summarized recent progress in this area which has laid a solid foundation for elucidating the pathogenesis of NAFLD and provides potential targets for early detection,diagnosis,and treatment of this disease.
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Objective To explore the regulatory role of fat mass and obesity-associated protein(FTO)and serine-threonine kinase protein kinase D2(PRKD2)in progression of diabetic kidney disease(DKD)and its regulatory mechanisms.Methods DKD model in vitro was constructed by podocytes(MPC5 cells)treated with high glucose(HG,35 mmol/L glucose)for 24 h.HG-induced MPC5 cells were transfected with FTO overexpression vector(pcDNA-FTO)and PRKD2 overexpression vector(pcDNA-PRKD2),or empty vector.The overexpression efficiency of FTO and PRKD2 were detected with RT-qPCR.MeRIP was used to detect the N6-methyladenosine(m6A)modification level of PRKD2 mRNA.The activity of Caspase-3 and the secretion of IL-6,TNF-α and monocyte chemotactic protein-1(MCP-1)were detected by ELISA.Cell apoptosis rate was analyzed by flow cytometry.The protein levels of FTO and PRKD2,as well as the key proteins in SIRT1/HIF-1α pathway,were evaluated by Western blot.Pearson analysis was used to analyze the correlation between FTO levels and PRKD2 levels.Results Compared with the control group without HG-induction,the protein expression of FTO(0.51±0.04 vs 1.00±0.03)and PRKD2(0.45±0.03 vs 1.01±0.04)was significantly down-regulated in HG-induced podocytes,and the differences were statistically significant(t=13.17,16.76,all P＜0.001).FTO protein levels were positively correlated with PRKD2 protein levels in HG-induced podocytes(r2=0.705 1,P＜0.001).Compared with the vector group,the m6A levels of PRKD2 mRNA(0.56±0.09 vs 1.01±0.13)in the pcDNA-FTO group were decreased,and the mRNA levels of PRKD2(3.16±0.14 vs 1.03±0.02)were increased,with significant differences(t=51.37,11.82,all P＜0.001).Compared with the control group(IL-6:512.76±61.85 pg/ml,TNF-α:28.17±2.83 pg/ml,MCP-1:157.31±17.69 pg/ml)and the vector group(IL-6:498.41±87.51 pg/ml,TNF-α:26.35±5.47 pg/ml,MCP-1:165.52±16.87 pg/ml),the secretion of IL-6(301.86±21.85 pg/ml),TNF-α(11.06±4.12 pg/ml)and MCP-1(81.45±9.03 pg/ml)were significantly decreased in the pcDNA-PRKD2 group,and the differences were statistically significant(F=7.51,10.47,61.97,all P＜0.01).Compared with the control group(caspase-3 activity:689.65±79.5 U/L,cell apoptosis:22.31%±2.69%)and the vector group(Caspase-3 activity:715.91±113.58 U/L,cell apoptosis:21.07%±3.28%),Caspase-3 activity(437.64±104.76 U/L)and the rate of apoptosis(8.41%±3.15%)were significantly decreased in the pcDNA-PRKD2 group,and the differences were statistically significant(F=2.35,79.13,all P＜0.01).Compared with the control group(SIRT1:1.01±0.05,HIF-1α:1.03±0.07)and the vector group(SIRT1:0.97±0.05,HIF-1α:1.02±0.03),SIRT1 protein levels(3.51±0.15)were increased and HIF-1α protein levels(0.37±0.07)were decreased in the pcDNA-PRKD2 group,and the differences were statistically significant(F=31.54,8.31,all P＜0.01).Conclusion FTO-mediated and m6A-modified PRKD2 suppresses inflammation and apoptosis in HG-induced podocytes through the SIRT1/HIF-1 pathway.
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Acute kidney injury(AKI)is a global public health problem with high morbidity,high mortality and costly treatment cost.The pathogenesis of AKI is very complex,and the treatment strategies for AKI are lim-ited,then it is very matter to explore the pathophysiological mechanism and potential therapeutic targets of acute kidney injury.N6-methyladenosine(m6A)is the most abundant and extremely conservative epigenetic modification in eukaryotic,which is a dynamic and reversible process involving in splicing,nuclear export,translation,stabil-ity,and higher structure of RNA,and regulated by three regulatory factors:methyltransferase,demethylase and methylated reading protein.Current studies have found that m6A plays an important regulatory role in AKI and can be a potential therapeutic target for AKI.In this review,we provide a brief description of m6A and summarize the impact of m6A on AKI and possible future study directions for this research.
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BACKGROUND:Epigenetics,as an important regulation mode of gene expression network,has been proved to play an important role in the occurrence and development of aortic aneurysm mediated by vascular smooth muscle cell remodeling. OBJECTIVE:To review the epigenetic regulation mechanism underlying vascular smooth muscle cell remodeling during the occurrence and progression of aortic aneurysm. METHODS:Related articles published from 1970 to 2022 were retrieved from PubMed,Web of Science and CNKI databases.The keywords were"Aortic aneurysm,Vascular smooth muscle,Smooth muscle cells,Epigenetic,DNA methylation,Histone modification,Non coding RNA"in English and Chinese.Ultimately,we included 71 articles for review. RESULTS AND CONCLUSION:Epigenetic modification can influence the occurrence and progression of aortic aneurysm by targeting vascular smooth muscle cell remodeling and extracellular matrix degradation.Targeted epigenetic modification can play a key role in aortic aneurysm treatment,delaying the disease and improving the prognosis.Epigenetic related enzymes,such as DNA methylesterases and histone-modifying enzymes,can influence the progression of aortic aneurysm by regulating vascular smooth muscle cell remodeling,including cell proliferation,migration and apoptosis,and can be used as targets for drug therapy.The research of epigenetic modification on aortic aneurysm is still in the basic research stage and some epigenetic modification mechanisms have not yet been explored.With the development of medical research,targeted epigenetic modification is expected to achieve new breakthroughs in the treatment of aortic aneurysm and clinical transformation.
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BACKGROUND:Medium-and large-diameter polytetrafluoroethylene artificial blood vessels have been widely used in clinical practice.However,most of the products were imported from other countries.Small-diameter porous polytetrafluoroethylene vessels are easy to form thrombosis and intimal hyperplasia,resulting in an extremely low long-term patency rate,which is difficult to fulfill clinical requirements. OBJECTIVE:To review and summarize the research progress of polytetrafluoroethylene in the field of artificial blood vessels,which can provide a reference for the functional modification of small-diameter polytetrafluoroethylene artificial blood vessels and the improvement of their long-term patency rate. METHODS:The relevant articles published from October 2022 to March 2023 in CNKI,Web of Science,Wiley Online Library,SpringerLink,Science Direct and IOP Science databases were searched by the first author.The search terms in Chinese were"porous polytetrafluoroethylene,vascular graft,electrospinning,medical application,functional modification".The search terms in English were"ePTFE,porous polytetrafluoroethylene,vascular graft,electrospinning,medical application,functional modification".All the articles about the preparation and modification of polytetrafluoroethylene artificial blood vessels were retrieved. RESULTS AND CONCLUSION:The preparation and functional modification of porous polytetrafluoroethylene artificial blood vessels were still research hotspots and difficult problems.From the research progress in and outside China in recent years,the preparation of porous polytetrafluoroethylene artificial blood vessels mainly adopted the rapid thermal stretching method,but the preparation of polytetrafluoroethylene artificial blood vessels by electrospinning was a promising new method.By analyzing and summarizing different functional modification methods,it was found that the long-term patency rate of porous polytetrafluoroethylene artificial blood vessels had been improved.However,the functional modification of small-diameter polytetrafluoroethylene artificial blood vessels still needed further exploration and optimization.
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BACKGROUND:In recent years,metal-organic frameworks have been widely used in the biomedical field because of their unique properties,and metal-organic frameworks can be applied to implant surface modification for improving their biological properties and the surgery's success rate. OBJECTIVE:To introduce metal-organic frameworks commonly used in implant surface modification and the preparation and action mechanism of surgical implants modified by metal-organic frameworks. METHODS:The articles concerning metal-organic frameworks used in implant surface modification published from 2010 to 2023 were searched on PubMed,Web of Science and CNKI.Finally,64 articles were included for review. RESULTS AND CONCLUSION:(1)Metal-organic frameworks have the properties of high porosity,large specific surface area,and diverse spatial structure.As bioactive material,metal-organic frameworks have attracted much attention in tissue engineering and regenerative medicine.(2)The metal-organic frameworks commonly used in the field of implant surface modification include three types.Zeolitic imidazolate frameworks are commonly used as carriers,carrying various drugs and biomolecules.The MIL series are suitable for drug carriers and nanoenzymes.Bio-metal-organic frameworks have many applications because of their diverse structure and are characterized by excellent biosafety.(3)The preparation of implant materials modified by metal-organic frameworks can be mainly divided into two types:one is to incorporate metal-organic frameworks into pretreated implants;the other is to synthesize metal-organic frameworks in situ on pretreated implants.(4)Metal-organic frameworks on the implant surface could release their components,load drugs,catalyze active reactions,or combine with other materials,giving implants antibacterial and anti-inflammatory characteristics and promoting osseointegration.The preparation method of metal-organic framework coatings needs further improvement,and the metabolism and distribution of metal-organic framework coatings should be deeply explored,and its clinical application should be actively promoted.
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BACKGROUND:Micro-arc oxidation can effectively add bioactive elements to the metal surface and improve the anti-bacterial and anti-inflammatory properties of biomedical metal materials,so this technology has become one of the hotspots of biomedical materials. OBJECTIVE:To summarize the anti-bacterial and anti-inflammatory properties of surface coatings prepared by the combination of micro-arc oxidation and other surface modification technologies. METHODS:Articles from January 1996 to December 2022 were searched on CNKI,WanFang and PubMed databases using Chinese and English search terms"micro-arc oxidation,antibacterial properties,anti-inflammatory properties,metal implants".After preliminary screening according to inclusion and exclusion criteria,89 articles were retained and summarized. RESULTS AND CONCLUSION:The ceramic layer prepared by micro-arc oxidation can improve the anti-bacterial and anti-inflammatory properties of titanium,magnesium and other alloys.Combination with other surface modification technologies can effectively solve the effect of pores on the surface properties of the alloy,and further improve the biological properties of the oxide film.It has a wide application prospect in orthopedics and dentistry.At present,most studies are limited to metal coatings,and most of them focus on metal elements with good antibacterial properties such as silver and copper,while only a few studies mention non-metallic coatings such as graphene oxide,hydroxyapatite and chitosan.In the future,extensive studies can be conducted on inorganic coatings and polymer coatings,and more combinations of different bioactive elements can also be adopted to improve antibacterial properties.Currently,studies on the inflammation of implant coatings prepared by micro-arc oxidation are mostly limited to the immune system and focused on macrophages,while studies on neutrophils and platelets are scarce.In the future,a variety of advanced technologies should be combined to explore the specific effects of micro-arc oxidation coating on other immune cells and inflammatory cells.
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BACKGROUND:The study of the physical properties of scaffolds has always been a hot topic in the field of tissue engineering research.However,for vascular stimulating scaffolds,in addition to meeting the basic performance of the scaffold,other methods are also needed to promote the regeneration of blood vessels within the scaffold,in order to achieve the ultimate goal of repairing bone tissue. OBJECTIVE:A visualization analysis was carried out on the literature published in and outside China on scaffold stimulation for bone tissue engineering,to explore the research hotspots and research status in this field,and to provide a reference for subsequent studies. METHODS:Using the CNKI database and Web of Science core database as retrieval databases,the relevant literature on vascular scaffolds for bone tissue engineering was retrieved.The literature that did not conform to the research object was removed.The obtained data were imported into CiteSpace 6.1.R2 software.Visualization analysis was performed on authors,national institutions,and keywords in the research field. RESULTS AND CONCLUSION:(1)China,the United States,and Germany were the top three countries with the most articles on scaffold stimulation for bone tissue engineering.(2)The top 3 institutions in the CNKI database were Southern Medical University,Huazhong University of Science and Technology,and Donghua University.In the core database of Web of Science,Shanghai Jiao Tong University,Sichuan University and Chinese Academy of Sciences ranked the top 3 in terms of the number of institutional publications.(3)The top 3 keywords in the CNKI database were"tissue engineering,vascularization,angiogenesis".The top 3 keywords in the Web of Science core database were"mesenchymal stem cell,scaffold,vascularization".(4)Through the analysis of co-citation and highly cited references,the main concerns were as follows:vascularization strategies:scaffold design,angiogenic factor delivery,in vitro co-culture,and in vivo pre-vascularization.Technology:3D printing,electrospinning,vascular transplantation,vascular fusion.Mechanisms:immune regulation and macrophages,drug/growth factor delivery,the relationship between endothelial cells and osteoblasts,the paracrine relationship between bone cells and endothelial cells,signaling molecular pathways,angiogenesis,and anti-angiogenesis molecules.(5)The researches concerning vascular stimulating scaffolds in bone tissue engineering in and outside China attach great importance to the application of stem cells and 3D printing technology.Current research focuses on biological 3D printing technology,scaffold modification methods,and the development and application of intelligent biomaterials based on bone repair mechanisms.
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BACKGROUND:Mesenchymal stem cells have great potential in the treatment of ischemia-reperfusion injury of skin flaps.However,their defects and the decline of their role in the treatment of ischemia-reperfusion injury of skin flaps restrict their wide application. OBJECTIVE:To review the strategies for improving the treatment of ischemia-reperfusion injury of skin flaps with mesenchymal stem cells,and provide a reference for its further theoretical research and clinical application. METHODS:Relevant documents included in CNKI,WanFang and PubMed were searched.The Chinese and English search terms were"mesenchymal stem cell,ischemia-reperfusion adjustment of skin flap,mesenchymal stem cells,stem cells,skin flap,ischemia-reperfusion injury,pretreatment,gene modification,biomaterial packaging,joint application".The relevant documents since 2007 were retrieved,and the documents with little relationship between the research content and the article theme,poor quality and outdated content were eliminated through reading the article,and finally 75 documents were included for summary. RESULTS AND CONCLUSION:(1)Mesenchymal stem cells can inhibit inflammatory reactions,resist oxidative stress and induce angiogenesis,which has great potential in the treatment of skin flap ischemia-reperfusion injury.(2)Although mesenchymal stem cells have shown great potential in the treatment of skin flap ischemia-reperfusion injury,their shortcomings in treatment have limited their widespread clinical application.Through pre-treatment(cytokines,hypoxia,drugs,and other pre-treatment mesenchymal stem cells),gene-modified mesenchymal stem cells,biomaterial encapsulation of mesenchymal stem cells,as well as the combined use of mesenchymal stem cells and other drugs or therapeutic methods,can not only overcome the shortcomings of mesenchymal stem cells in treatment,but also improve their therapeutic effectiveness in skin flap ischemia-reperfusion injury.(3)Therefore,further improving the effectiveness of mesenchymal stem cells in treating skin flap ischemia-reperfusion injury and exploring its therapeutic potential are of great significance for the research of mesenchymal stem cells and the treatment of skin flap ischemia-reperfusion injury.
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BACKGROUND:The appearance of the crescent sign in femoral head necrosis is a"turning point"in the progression of the disease,and repairing and stabilizing the bone-cartilage interface is particularly important in preventing further progression and collapse of the femoral head.Tissue engineering offers potential advantages in the simultaneous repair and integration of the bone-cartilage interface. OBJECTIVE:To review potentially suitable techniques addressing the subchondral separation in femoral head necrosis. METHODS:Relevant articles from January 1970 to April 2023 were searched in PubMed,Web of Science,and China National Knowledge Infrastructure(CNKI)using English search terms"femoral head necrosis,avascular necrosis of femoral head,osteonecrosis of femoral head"and Chinese search terms"femoral head necrosis,subchondral bone,cartilage,integration of cartilage and subchondral bone".A total of 114 articles were included for review and analysis. RESULTS AND CONCLUSION:(1)Structural defects,ischemic and hypoxic environment,inflammatory factors,and stress concentration may cause subchondral separation in osteonecrosis of the femoral head.Subchondral bone collapse and failure of hip-preserving surgery may be associated.Integration of tissue engineering scaffolds with the bone-cartilage interface is one potential approach for treating subchondral separation in osteonecrosis of the femoral head.(2)Current literature suggests that multiphase scaffolds,gradient scaffolds,and composite materials have shown improvements in promoting cell adhesion,proliferation,and deposition of bone and cartilage matrix.These advancements aid in the integration of scaffolds with the bone-cartilage interface and have implications for the treatment of subchondral separation in osteonecrosis of the femoral head.(3)Surface modifications of scaffolds can enhance interface integration efficiency,but they have their advantages and disadvantages.Scaffolds providing different environments can induce differentiation of mesenchymal stem cells and facilitate integration between different interfaces.(4)Future scaffolds for subchondral separation in osteonecrosis of the femoral head are expected to be composite materials with gradient and differentiated biomimetic structures.Surface modifications and stem cell loading can promote integration between the bone-cartilage interface and scaffolds for therapeutic purposes,but further experimental verification is still needed.Challenges include synchronizing scaffold degradation rate with repair progress and ensuring stability between different interfaces.
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BACKGROUND:Titanium and its alloys are widely used in orthopedic implants due to their excellent biocompatibility,corrosion resistance,and mechanical properties.However,it has biological inertia itself,cannot provide a good growth environment for osteoblasts,and it is difficult to form good osseointegration. OBJECTIVE:To construct a composite hydrogel material of gelatin methacryloyl and polyacrylamide on the surface of titanium alloy scaffold,and analyze its osteogenic ability in vitro. METHODS:Gelatin methacryloyl was mixed with acrylamide.Crosslinking agent and catalyst were added to synthesize gelatin methacryloyl and acrylamide(Gelma-PAAM)composite hydrogel.The titanium alloy scaffold modified by affinity silane was mixed with the Gelma hydrogel and Gelma-PAAM composite hydrogel to complete the loading(recorded as Ti-Gelma and Ti-Gelma-PAAM,respectively).The swelling ratio and degradation rate of the two hydrogels on the surface of the scaffold were compared.The bonding state between hydrogels and titanium alloy was observed by scanning electron microscope.Rat bone marrow mesenchymal stem cells were inoculated into Ti,Ti-Gelma and Ti-Gelma-PAAM scaffolds,separately.Cell proliferation,adhesion,and osteogenic differentiation were detected. RESULTS AND CONCLUSION:(1)Compared with Gelma hydrogel,Gelma-PAAM hydrogel had higher swelling rate and lower degradation rate.(2)Scanning electron microscope showed that the surface of the two kinds of hydrogels was honeycomb structure.After being combined with porous titanium alloy scaffold,the film was wrapped on the surface of scaffold and filled with pores.Among them,the Gelma-PAAM composite hydrogel coated the scaffold more fully.(3)CCK-8 assay and live/dead fluorescence staining showed that bone marrow mesenchymal stem cells proliferated well after coculture with Ti-Gelma and Ti-Gelma-PAAM scaffolds and maintained high activity.After osteogenic induction culture,alkaline phosphatase activity,calcium deposition,and osteogenic gene expression of cells of titanium alloy scaffold group were the lowest,and alkaline phosphatase activity,calcium deposition,and osteogenic gene expression of cells of Ti-Gelma-PAAM scaffold group were the highest.(4)Phalloidin cytoskeletal staining exhibited that the cells of pure titanium alloy scaffold group and Ti-Gelma scaffold group were sparse and insufficiently extended,while the cells of Ti-Gelatin-PAAM group had the most adequate stretching and the densest filamentous actin.(5)The results show that Gelma-PAAM hydrogel has good biocompatibility and osteogenic ability,and is more suitable for osteogenic modification on the surface of titanium alloy than Gelma hydrogel.
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BACKGROUND:As a bone replacement and filling material,calcium phosphate stone bone cement has good biocompatibility,bone conductivity,and other advantages,especially its better biodegradability compared to other calcium phosphate bone cements.It has important application value in bone repair.However,due to its limitations such as insufficient mechanical properties,fast solidification reaction,and poor injection performance,it is currently only suitable for the repair of non weight-bearing bone. OBJECTIVE:To explore the modification of brushite cements with bioactive ions(metal and non metal ions)to expand its application range. METHODS:The author used PubMed,ScienceDirect,CNKI,and WanFang to search the literature published between 2018 and 2023 with the search terms"metal ion,iron,copper,strontium,magnesium,zinc,non-metal ion,modification,bone,brushite cements"in Chinese and"metal ion,iron,Fe,copper,Cu,strontium,Sr,magnesium,Mg,zinc,Zn,non-metal ion,modification,bone,brushite cements"in English.After reading titles and abstracts,the articles were initially screened,and irrelevant and duplicate articles were excluded.Finally,64 articles were included for review. RESULTS AND CONCLUSION:(1)Bioactive ions affect the hydration process of calcium phosphate bone cement.Different ions are substituted by ions and incorporated into the crystal structure of calcium phosphate bone cement,changing the crystal morphology of the cement and causing changes in physical and chemical properties such as setting time,injectability,and compressive strength.(2)Ionic modified calcium phosphate bone cement produces different ion release effects due to different crystal structures.Different types of ions have properties such as promoting angiogenesis/osteogenesis,antibacterial,anti-tumor,etc.In addition,calcium phosphate bone cement has good biodegradability,which has great advantages for the performance of various ions.(3)The physicochemical properties of calcium phosphate bone cement modified with different ions are as follows:iron,copper,strontium,magnesium,zinc,silver,and cobalt can prolong the setting time.Strontium,and magnesium can improve injection performance.Copper,strontium,magnesium,silver and silicon can enhance compressive strength.The ions that can simultaneously improve the three physical and chemical properties of calcium phosphate bone cement include strontium and magnesium.Good physical and chemical properties are a prerequisite for clinical application,so improving the setting time,injectability,compressive strength,and other properties of calcium phosphate bone cement with ions is of great significance for the research and application of bone cement.(4)The biological properties of calcium phosphate bone cement modified with different ions are as follows:copper,strontium,magnesium,zinc,cobalt,lithium,selenium,and silicon have promoting angiogenesis/osteogenic effects.Iron,copper,magnesium,zinc,and silver have antibacterial properties.Magnesium ions have anti-inflammatory properties.Copper and selenium have anti-tumor properties.(5)In summary,magnesium ions can improve the setting time,injectability,and compressive strength of calcium phosphate bone cement,while also promoting neovascularization/osteogenesis,antibacterial properties,and have good application prospects for the treatment of bone defects with concurrent infections.In addition,copper also has anti-tumor properties,so copper ions have great potential in the treatment of bone defects caused by infections and tumors.However,relevant research is still in the basic research stage,and the effects of different ion doping concentrations and synthesis conditions on the physicochemical properties of calcium phosphate bone cement need to be further explored.At the same time,the impact of biological properties also needs to be studied and observed for a longer period of time.
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BACKGROUND:There is less report about mitigating sustained bone grinding injuries during craniotomy based on a model of traumatic brain injury established using the modified Feeney's free-fall method. OBJECTIVE:To modify a modified traumatic brain injury model by altering the opening of the skull window. METHODS:Thirty-six Sprague-Dawley rats were equally randomized into sham group,model group and modified model group.The modified procedure of opening the bone window was used in the modified model group.Six to eight small holes of 0.3-0.5 mm in diameter were punched at the edge of the impact area and the drill was immediately withdrawn without touching the cortex.In the modified model group,the skull window was opened by using the modified method,while the skull window in the model group was opened using the conventional method.The modified model group and model group were established using the Feeney's free-fall method.In the sham group,only the skull window was opened without impact.The modified neurological severity scoring was performed at 1 day after modeling.T2 weighted imaging was performed and T2 values were measured at 1 and 7 days after modeling.Hematoxylin-eosin staining of the brain section was made for histopathological observation at 7 days after modeling.The level of blood viscosity,interleukin-6,interleukin-1β,and tumor necrosis factor-α were determined at 7 days after modeling. RESULTS AND CONCLUSION:Compared with the sham group,the modified neurological severity scores in the model group and modified model group were significantly increased at 1 day after modeling(P＜0.000 1).Meanwhile,the modified neurological severity scores in the modified model group were lower than those in the model group(P＜0.000 1).Compared with the sham group,the T2 values were significantly increased in the model group and modified model group at 1 and 7 days after modeling(P＜0.05),while the T2 values in the modified model group were lower than those in the model group(P＜0.05).Compared with the sham group,the level of blood viscosity,interleukin-6,interleukin-1β and tumor necrosis factor-α were increased in the model group and modified model group at 7 days after modeling(P＜0.05),while the level of interleukin-6 in the modified model group was lower than that in the model group(P＜0.05).To conclude,establishing a modified traumatic brain injury model based on the Feeney's free-fall method provides better controls of injury factors during cranial opening.
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BACKGROUND:Previous studies have successfully constructed erythropoietin-overexpressed umbilical cord mesenchymal stem cells.It was found that the apoptosis of ischemic and hypoxic human neuroblastoma cell line(SH-SY5Y)was significantly reduced by erythropoietin-overexpressed umbilical cord mesenchymal stem cells. OBJECTIVE:To explore the possible neuroprotective mechanisms of erythropoietin-overexpressed umbilical cord mesenchymal stem cells against ischemic-hypoxic SH-SY5Y and their associated epigenetic mechanisms. METHODS:Oxygen-glucose deprivation was applied to ischemia-hypoxia-induced SH-SY5Y cell injury,and multifactorial assays were applied to detect the expression levels of inflammatory factors in the cells before and after hypoxia and co-culture,respectively,with mesenchymal stem cells,as well as lentiviral-transfected null-loaded plasmids of the negative control mesenchymal stem cells and erythropoietin-overexpressed umbilical cord mesenchymal stem cells.The expression levels of supernatant inflammatory factors were detected by multifactor assay after co-culture.Proteomics was used to detect the differentially expressed proteins of negative control mesenchymal stem cells and erythropoietin-overexpressed umbilical cord mesenchymal stem cells.Cleavage under targets and tagmentation sequencing was applied to detect genomic H3K4me2 modification,and joint analysis was conducted with RNA-sequencing.Lentiviral vector infection was applied to construct the stable knockdown of REST in SH-SY5Y cells.qRT-PCR and western blot assay were performed to detect the expression level of REST.The apoptosis was detected by flow cytometry after co-culture of oxygen-glucose deprivation treatment with erythropoietin-overexpressed umbilical cord mesenchymal stem cells.The expression difference of H3K36me3 group proteins was detected by western blot assay,and transcriptome sequencing was performed to analyze the differentially expressed genes. RESULTS AND CONCLUSION:(1)Compared with the control group,monocyte chemotactic protein 1,interleukin-6,interleukin-18,and interleukin-1 beta,interferon α2,and interleukin-23 levels significantly increased in the cerebrospinal fluid supernatant of patients with ischemic-hypoxic encephalopathy(P<0.01).(2)After co-culturing SH-SY5Y cells with erythropoietin-overexpressed umbilical cord mesenchymal stem cells under ischemia and hypoxia,the expression levels of monocyte chemotactic protein 1 and interleukin-6 were significantly reduced.(3)Analysis of protein network interactions revealed significant downregulation of monocyte chemotactic protein 1,interleukin-6 related regulatory proteins CXCL1 and BGN.(4)Transcriptome sequencing analysis found that pro-inflammatory genes were down-regulated,and functional enrichment of histone modifications,and the expression of transcription factors REST and TET3 significantly up-regulated in the erythropoietin-overexpressed umbilical cord mesenchymal stem cell group compared with the negative control mesenchymal stem cell group.(5)Combined analysis of transcriptome sequencing and cleavage under targets and tagmentation revealed changes in epigenetic levels as well as significant activation of the promoter regions of transcription factors REST and TET3.(6)Stable knockdown REST in SH-SY5Y cells was successfully constructed;the transcript levels of REST mRNA and protein expression were both decreased.(7)After the REST knockdown SH-SY5Y cells were co-cultured with erythropoietin-overexpressed umbilical cord mesenchymal stem cells,apoptosis was significantly increased and H3K36me3 expression was significantly decreased.Transcriptome sequencing results showed that the expression of inflammation-related genes Aldh1l2 and Cth,as well as apoptosis-suppressor genes Mapk8ip1 and Sod2 was reduced at mRNA transcription level(P<0.01).(8)It is concluded that erythropoietin-overexpressed umbilical cord mesenchymal stem cells activated the expression of REST and TET3 by altering the kurtosis of H3K4me2 and upregulated the modification level of H3K36me3,which in turn regulated the expression of inflammation-related genes Aldh1l2 and Cth,as well as apoptosis-suppressor genes Mapk8ip1 and Sod2,and facilitated neuronal survival.
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Objective To observe the effect of Shoutai Pills on endometrial decidualization of mice with recurrent spontaneous abortion(RSA);To explore its possible mechanism in the treatment of RSA based on histone modification.Methods Totally 40 female CBA/J mice were divided into normal group,model group,Shoutai Pills low-dosage group(7.5 g/kg),Shoutai Pills high-dosage group(15 g/kg)and dydrogesterone group(3 mg/kg).The normal group were co housed with BALB/C male mice,while the other groups were co housed with DBA/2 male mice to establish an RSA mouse model.After modeling,the administration groups were given corresponding medication solution by gavage,while the normal group and model group were given equal volume of pure water by gavage for 10 consecutive days.The embryo condition was observed and the embryo loss rate was calculated,ELISA was used to detect serum prolactin(PRL)content,HE staining was used to observe the morphological changes of decidual tissue,RT-PCR was used to detect PRL mRNA expression in decidual tissue,Western blot was used to detect the protein expressions of H4ac,H3K27ac,H3K27me3.Results Compared with the normal group,the model group mice showed a significant increase in embryo loss rate,a significant decrease in serum PRL content,disordered arrangement of decidual cells,and extensive bleeding and necrosis;the expression of PRL mRNA and protein in decidual tissue significantly decreased,the protein expressions of H4ac and H3K27ac significantly decreased,while the expression of H3K27me3 protein significantly increased,with statistical significance(P<0.05).Compared with the model group,the embryo loss rate of Shoutai Pills low-and high-dosage groups and the dexamethasone group significantly decreased,the serum PRL content significantly increased,tightly arranged decidual cells,reduced necrosis,and intact glands;the expression of PRL mRNA and protein in decidual tissue of mice in Shoutai Pills high-dosage group and the dexamethasone group significantly increased,the protein expressions of H4ac and H3K27ac significantly increased,the expression of H3K27me3 protein significantly decreased,with statistical significance(P<0.05).Conclusion Shoutai Pills can promote endometrial decidualization in RSA mice,which is related to the changes of histone modification in endometrial stromal cells.