BACKGROUND:The incidence rate of chronic non-specific neck pain is high and the etiology is unknown.Myofascial pain and deep cervical flexor atrophy are the key factors.Extracorporeal shockwave therapy can improve microcirculation,relieve local pain,and delay the degenerative development of the cervical spine,while motion control training can significantly improve neck muscle strength and endurance and reduce neck pain.However,both methods have limited effectiveness when applied individually.OBJECTIVE:To explore the therapeutic efficacy of extracorporeal shock wave intervention combined with motion control training at the upper trapezius muscle on chronic non-specific neck pain.METHODS:Forty-two patients with chronic non-specific neck pain recruited from Shenyang Sport University were randomly divided into three groups:a shock wave group(n=14),in which extracorporeal shockwave intervention at the upper trapezius muscle was given for 10-15 minutes,once a week for 4 weeks;a training group(n=14),in which motion control training was given for 40-50 minutes,three times a week for 4 weeks;and a combination group(n=14),in which extracorporeal shockwave intervention at the upper trapezius muscle combined with motion control training was performed for 4 weeks.Patients were assessed for pain intensity,cervical spine function,upper trapezius muscle thickness,hemodynamic parameters,and serum interleukin 6 and tumor necrosis factor α levels before intervention,1 week and 4 weeks after intervention.RESULTS AND CONCLUSION:(1)Compared with the pre-intervention period,the visual analogue scale scores and neck disability index in the three groups were lower after 1 and 4 weeks of intervention(P＜0.05),and the visual analogue scale scores and neck disability index in the combination group were lower than those of the shock wave group and the training group(P＜0.05).(2)Compared with the pre-intervention period,the upper trapezius thickness increased in the training group and the combination group after 4 weeks of intervention(P＜0.05);the upper trapezius thickness was greater in the combination group than in the shock wave group and the training group after 4 weeks of intervention(P＜0.05).(3)The shock wave group and the combination group had an increase in the peak systolic velocity of the ascending segment of the transverse carotid artery(P＜0.05)and a decrease in the resistance index(P＜0.05)after 1 and 4 weeks of intervention,while the training group showed an increase in the peak systolic velocity of the ascending segment of the transverse carotid artery(P＜0.05)and a decrease in the resistance index(P＜0.05)after 4 weeks of intervention.The peak systolic velocity of the ascending segment of the transverse carotid artery in the combination group was higher(P＜0.05)and the resistance index was lower(P＜0.05)than those in the shockwave group and the training group after 1 and 4 weeks of intervention.(4)Compared with the pre-intervention period,the levels of interleukin 6 and tumor necrosis factor α were reduced in the shock wave and combination groups after 1 and 4 weeks of intervention(P＜0.05),and in the training group after 4 weeks of intervention(P＜0.05).After 1 and 4 weeks of intervention,the levels of interleukin 6 and tumor necrosis factor α were lower in the combination group than in the shock wave group and the training group(P＜0.05).To conclude,extracorporeal shock wave combined with motion control training for chronic non-specific neck pain significantly reduces pain and improves neck function,and the mechanism of action may be to promote the blood flow velocity at the trigger point,reduce blood flow resistance,reduce the serum levels of interleukin 6 and tumor necrosis factor α,and increase the thickness of the upper trapezius muscle.

BACKGROUND:BCR/ABL gene is a specific gene of Ph chromosome-positive acute lymphoblastic leukemia,and its expression level has become a sensitive indicator for monitoring minimal residual disease before and after allogeneic hematopoietic stem cell transplantation.However,whether the expression level of BCR/ABL gene before transplantation affects the efficacy of transplantation and how to guide the early intervention of relapse with tyrosine kinase inhibitors after transplantation is still inconclusive.OBJECTIVE:To explore the relationship between BCR/ABL gene expression and recurrence in patients with Ph chromosome positive acute lymphoblastic leukemia before and after related and allogeneic hematopoietic stem cell transplantation.METHODS:Twenty-four patients with Ph chromosome positive acute lymphoblastic leukemia who achieved complete hematological remission and underwent allogeneic hematopoietic stem cell transplantation were selected at the Affiliated Hospital of North China University of Science and Technology between January 2015 and December 2022.Real time fluorescence quantitative polymerase chain reaction was used to dynamically detect the expression levels of BCR/ABL genes during treatment,representing minimal residual disease.Based on BCR/ABL gene expression,tyrosine kinase inhibitors combined with chemotherapy was administered before transplantation to select the timing of allogeneic hematopoietic stem cell transplantation.After transplantation,the disease status was evaluated to guide the use of tyrosine kinase inhibitors,and an early intervention plan for recurrence was developed.RESULTS AND CONCLUSION:Follow-up was until December 2023,with a median follow-up time of 49(12-82)months.There were 8 cases of hematological recurrence,with a median recurrence time of 14(8-39)months and a cumulative recurrence rate of 33％(8/24).Univariate analysis showed that recurrence after allogeneic hematopoietic stem cell transplantation was not significantly correlated with gender,age,extramedullary complications,time from diagnosis to transplantation,HLA typing,acute graft-versus-host disease,and chronic graft-versus-host disease(P＞0.05).There was a significant correlation between the relief treatment course and minimal residual disease levels before transplantation.The second hematology completely resolution and positive minimal residual disease before transplantation had a higher hematological recurrence rate(P＜0.05).The 3-year cumulative recurrence rate,disease-free survival rate,and overall survival rate were 27％,63％,and 74％;the 5-year cumulative recurrence rate,disease-free survival rate,and overall survival rate were 38％,57％,and 74％,respectively.It is concluded that Ph chromosome positive acute lymphoblastic leukemia patients with BCR/ABL gene positive before transplantation have a higher recurrence rate.BCR/ABL gene expression after transplantation can guide the application of tyrosine kinase inhibitors and serve as a basis for early intervention in recurrence.

BACKGROUND:Bone tissue loss caused by tumors and trauma can have an adverse effect on postoperative rehabilitation.Therefore,scaffold materials are usually implanted during treatment.However,the existing implant materials are relatively simple and lack antibacterial properties.Early implantation may lead to iatrogenic autoinfection and have an adverse effect on osteogenesis.OBJECTIVE:To construct a KR-12-a5 polypeptide-nanohydroxyapatite-small intestinal submucosa composite scaffold and evaluate its feasibility as a material for promoting bone defect repair.METHODS:The small intestinal submucosa scaffold and the small intestinal submucosa scaffold containing 25,50,and 100 mg/mL nanohydroxyapatite(referred to as nHA-SIS scaffold)were prepared by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-hydroxysuccinimide cross-linking method.The appropriate scaffold was screened for subsequent experiments by mechanical property testing.The antibacterial properties of KR-12-a5 polypeptide solution against Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum were detected.The nHA-SIS scaffolds were immersed in 250,500,and 1 000 μg/mL KR-12-a5 peptide solutions for 24 hours,and then freeze-dried to obtain peptide-loaded nanohydroxyapatite-porcine small intestinal submucosa composite scaffolds(denoted as P-nHA-SIS scaffolds).The sustained-release properties of the three groups of scaffolds were characterized.The nHA-SIS scaffolds and the three groups of P-nHA-SIS scaffolds were co-cultured with Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum for 24 hours or 48 hours.The scaffolds with strong antibacterial ability were screened by live and dead bacteria staining and scanning electron microscopy for subsequent experiments.The degradation properties and water absorption rates of the uncross-linked small intestinal submucosa scaffolds,cross-linked small intestinal submucosa scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were characterized.The extracts of cross-linked small intestinal submucosal scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were co-cultured with MC3T3-E1 cells.CCK-8 assay and live-dead cell staining were performed.The effects of the extracts of the three scaffolds on the migration of MC3T3-E1 cells were detected by Transwell chamber assay.RESULTS AND CONCLUSION:(1)The elastic modulus and compressive strength of 25,50,and 100 mg/mL nHA-SIS scaffolds were higher than those of small intestinal submucosal scaffolds(P＜0.05),among which the elastic modulus and compressive strength of 25 mg/mL nHA-SIS scaffolds were the highest,and this group of scaffolds were selected for subsequent experiments to load peptides.(2)KR-12-a5 peptide had strong antibacterial activity against common bacteria in bone defects(Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum).The three groups of P-nHA-SIS scaffolds all had sustained release properties.With the increase of peptide mass concentration,the antibacterial property of P-nHA-SIS scaffold was enhanced.Among them,the P-nHA-SIS scaffold loaded with 500 μg/mL peptide had achieved a satisfactory antibacterial effect,and this group of scaffolds would be selected in the future.(3)The degradation rate of the three groups of cross-linked scaffolds was lower than that of the uncross-linked scaffolds,and the water absorption rate was greater than that of the uncross-linked scaffolds.P-nHA-SIS scaffolds could promote the proliferation and migration of MC3T3-E1 cells without affecting the activity of MC3T3-E1 cells.(4)The results show that P-nHA-SIS scaffolds have strong antibacterial properties and the ability to promote the proliferation and migration of MC3T3-E1 cells,and are expected to be used in bone defect repair.

BACKGROUND:Titanium elastic intramedullary nailing for the treatment of significantly displaced midshaft clavicle fractures has the characteristics of minimally invasive and elastic fixation.The displacement of the fracture is closely related to the later function.However,there are few studies on the three-dimensional displacement analysis of the fracture ends before surgery and after intramedullary fixation such as titanium elastic intramedullary nailing.OBJECTIVE:To explore the three-dimensional displacement of fracture ends after midshaft clavicle fracture and fixation with titanium elastic intramedullary nails,and to analyze the risk factors.METHODS:A total of 91 patients with midshaft clavicle fracture(fracture end shortening ≥15 mm)admitted to Wendeng Orthopedic Hospital of Shandong Province from April 2019 to April 2024 were selected,including 57 males and 34 females,aged(51.73±10.21)years old.All patients received closed reduction and internal fixation with titanium elastic intramedullary nail.CT scans of the affected clavicle were performed before and on the first day after surgery.The CT data were imported into Mimics software for modeling.The length of the clavicle,lateral displacement of the fracture end,and rotation of the distal end of the fracture along the X,Y,and Z axes were measured and recorded before and after surgery.Pearson correlation coefficient was used for correlation analysis of various parameters,and generalized linear regression was used to evaluate risk factors.RESULTS AND CONCLUSION:(1)Preoperatively,the variable that increased the risk of lateral displacement was the number of comminuted bone fragments,the variable that increased the risk of shortening displacement was male patients,and the variable that increased the risk of Z-axis rotation was the left limb.Shortening displacement was significantly positively correlated with lateral displacement(r=0.715,P＜0.001);shortening displacement was significantly positively correlated with X-axis rotation displacement and Y-axis rotation displacement(r=0.265,P=0.028;r=0.303,P=0.011);lateral displacement was significantly positively correlated with Y-axis rotation and Z-axis rotation(r=0.258,P=0.032;r=0.250,P=0.038);X-axis rotation was significantly positively correlated with Y-axis rotation(r=0.382,P=0.001),and Z-axis rotation was significantly positively correlated with Y-axis rotation(r=0.280,P=0.020).(2)Postoperatively:The number of scapula fractures and comminuted bone fragments were variables that increased the risk of postoperative shortening and lateral displacement:Preoperative X-,Y-,and Z-axis rotation displacements were risk variables that increased postoperative X-,Y-,and Z-axis rotation displacements,respectively.Postoperative lateral displacement was significantly positively correlated with postoperative shortening and displacement(r=0.584,P=0.000),and postoperative lateral displacement was also significantly positively correlated with postoperative Y axis rotation and Z axis rotation(r=0.360,P=0.002;r=0.250,P=0.038).Postoperative Y axis rotation was significantly positively correlated with postoperative Z axis rotation(r=0.248,P=0.040).(3)The results showed that the three-dimensional displacement of the clavicle end before and after surgery was affected by many factors,especially the number of comminuted bone fragments,scapula fractures,gender,and original rotation displacement.At the same time,there were complex correlations between various displacements,especially the correlation between shortening displacement and lateral displacement was the strongest.

BACKGROUND:Acupuncture at Xinshu(BL 15)can significantly improve cardiac function and protect myocardial cells in acute myocardial ischemia,but the effect and mechanism of thread embedding treatment at Xinshu(BL 15)on cardiac function in acute myocardial ischemia are yet unclear.Nuclear factor κB activation often appears as an intranuclear translocation of the P65 isoform,and activation of the nuclear factor κB signaling pathway is marked by elevated P65 levels.OBJECTIVE:To explore the effects of thread embedding pretreatment at Xinshu(BL 15)on cardiac function and the expression levels of interleukin-10,tumor necrosis factor-α,P65 genes and proteins in rats with acute myocardial ischemia.METHODS:Thirty-two male Sprague-Dawley rats were randomly divided into a blank group,a model group,a Xinshu(BL 15)acupoint group,and a non-meridian/non-acupoint group using a random number table method,with eight rats in each group.Rat models of acute myocardial ischemia were established in the latter three groups.The Xinshu(BL 15)acupoint group had thread embedding at Xinshu(BL 15)for 14 days,followed by subcutaneous injection of isoproterenol hydrochloride into the back to establish an acute myocardial ischemia rat model.The non-meridian/non-acupoint group had local thread embedding for 14 days,and the rest procedures were the same as above.In the model group,Xinshu(BL 15)was only marked,and the rest procedures were the same as above.In the blank group,Xinshu(BL 15)was only marked,and then an equal amount of physiological saline was injected subcutaneously into the back.After 24 hours of modeling,electrocardiogram and cardiac ultrasound were performed.Abdominal aorta blood was extracted for detection of serum creatine kinase and creatine kinase isoenzyme levels using enzyme-linked immunosorbent assay.Subsequently,the rats were euthanized and samples were collected.Hematoxylin-eosin and TUNEL staining were used to observe the pathological changes of myocardial tissue and the apoptosis of myocardial cells.Real-time fluorescence quantitative PCR(RT-qPCR)and western blot were used to detect the mRNA and protein expression of tumor necrosis factor-α,interleukin-10,and P65 in myocardial tissue respectively.RESULTS AND CONCLUSION:(1)Electrocardiogram:Compared with the blank group,the model group,non-meridian/non-acupoint group,and Xinshu(BL 15)acupoint group had significantly elevated ST segment in lead Ⅱ of the electrocardiogram.(2)Cardiac ultrasound:Compared with the model group,the Left ventricular end-systolic dimension in the Xinshu(BL 15)acupoint group were significantly reduced(P＜0.05),while left ventricular ejection fraction and left ventricular fractional shortening rate were significantly increased(P＜0.05).(4)Serum creatine kinase and creatine kinase isoenzyme:Compared with the model group,the Xinshu(BL 15)acupoint group showed a significant decrease in serum creatine kinase and creatine kinase isoenzyme levels(P＜0.05).(4)Hematoxylin-eosin staining:Compared with the model group,the arrangement of myocardial fibers in the Xinshu(BL 15)acupoint group was basically neat,with less edema and a small amount of inflammatory cell infiltration.(5)TUNEL staining:Compared with the model group,the fluorescence intensity of myocardial cell apoptosis in the Xinshu(BL 15)acupoint group was significantly reduced,and its apoptosis rate was significantly reduced(P＜0.05).(6)RT-qPCR and western blot:Compared with the model group,the myocardial tissue interleukin-10 level in the Xinshu(BL 15)acupoint group was significantly increased(P＜0.05),while tumor necrosis factor-α and P65 levels were significantly decreased(P＜0.05).These findings indicate that thread embedding pretreatment at Xinshu(BL 15)can improve cardiac function in rats with acute myocardial ischemia,and its mechanism of action may be related to the inhibition of the activation of the nuclear factor-κB signaling pathway.

BACKGROUND:Radiotherapy significantly improves survival rates in patients with various malignant tumors.However,with prolonged post-treatment survival,many patients face the risk of radiation-related cardiac toxicity.This is especially true after chest radiotherapy,where the risk of radiation-induced heart disease significantly increases,becoming one of the most severe complications affecting prognosis survival.OBJECTIVE:To identify diagnostic markers of endothelial cellular senescence in radiation-induced heart disease through systematic transcriptomic analysis.METHODS:Firstly,genes associated with cellular senescence were screened from the CellAge database and intersected with the transcriptomic training dataset of a mouse model of radiation-induced heart disease to identify differentially expressed senescence-related genes.Secondly,weighted gene co-expression network analysis and machine learning were used to identify key hub genes that play critical roles in radiation-induced heart disease.The expression of these genes was validated using a dataset of radiation-induced endothelial injury.Additionally,the quanTlseq method was employed to assess the immune infiltration status related to radiation-induced heart disease.The expression levels of key genes and their association with survival in esophageal squamous cell carcinoma patients receiving chest radiotherapy were explored through the analysis of The Cancer Genome Atlas database.RESULTS AND CONCLUSION:(1)Systematic transcriptomic analysis identified CCND1 as the core gene of endothelial cellular senescence in radiation-induced heart disease,and this finding was validated in the mouse model of radiation-induced heart disease.(2)The diagnostic model constructed from these data indicated that CCND1 had high specificity and sensitivity for diagnosing radiation-induced heart disease.(3)Immune infiltration analysis revealed significant immune response dysregulation in the mouse model of radiation-induced heart disease,and CCND1 was closely related to various immune cells.(4)Kaplan-Meier survival analysis showed that CCND1 was associated with poorer disease-specific survival in esophageal squamous cell carcinoma patients receiving chest radiotherapy.This study systematically uncovers,for the first time,the pivotal role of CCND1 in endothelial cell senescence associated with radiation-induced heart disease.CCND1,a gene integral to cell cycle regulation,can induce cellular senescence when abnormally expressed.Furthermore,the findings highlight its potential as an early diagnostic marker.

BACKGROUND:β-Caryophyllene has a variety of pharmacological activities such as antioxidant,anti-inflammatory and anti-apoptotic,which may have a better therapeutic effect on osteoarthritis.OBJECTIVE:To investigate the effect and mechanism of β-caryophyllene on mouse osteoarthritis.METHODS:Forty C57BL/6J mice were randomly divided into sham group,model group,low-dose β-caryophyllene group and high-dose β-caryophyllene group,with 10 mice in each group.Hulth method was used to construct an osteoarthritis model in the latter three groups.Four weeks after modeling,70 and 140 mg/kg/d β-caryophyllene was intragastrically given in the low-and high-dose β-caryophyllene groups,respectively,and normal saline was given by gavage in the sham group and the model group,once a day,for 4 weeks.After administration,knee joint morphological changes were observed by hematoxylin-eosin staining,serum levels of inflammatory factors(tumor necrosis factor-α,interleukin-1β,interleukin-6,and interleukin-10)were detected by ELISA,and oxidative stress indexes(glutathione peroxidase,superoxide dismutase,and malondialdehyde)were detected by chemiluminescence.The expression levels of key proteins in the Sonic hedgehog(Shh)/glioma associated oncogene homolog 1(Gli1)signaling pathway were detected by immunohistochemistry and western blot.RESULTS AND CONCLUSION:(1)Compared with the sham group,a large number of inflammatory cells infiltrated in the knee joint of mice in the model group,cartilage tissue was seriously damaged,serum levels of tumor necrosis factor-α,interleukin-1β,interleukin-6,interleukin-10 and malondialdehyde were significantly increased(P＜0.01),the activities of glutathione peroxidase and superoxide dismutase were significantly decreased(P＜0.01),and the relative expression levels of Shh and Gli1 in the knee joint were significantly increased(P＜0.01).(2)Compared with the model group,in the low-and high-dose β-caryophyllene groups,inflammatory cell infiltration in the mouse knee joint was decreased,cartilage tissue injury was alleviated,serum levels of tumor necrosis factor-α,interleukin-1 β,interleukin-6 and malondialdehyde were significantly decreased(P＜0.05),the activities of glutathione peroxidase and superoxide dismutase were significantly increased(P＜0.01),and the expression levels of Shh and Gli1 in the knee joint were significantly decreased(P＜0.01).The above-mentioned improvements were more significant in the high-dose β-caryophyllene group than the low-dose β-caryophyllene group.To conclude,β-caryophyllene can improve osteoarthritis,and its mechanism may be related to reducing inflammation and oxidative stress damage by regulating the Shh/Gli1 signaling pathway.

OBJECTIVE:Elevated blood pressure increases the risk of cardiovascular diseases.Isometric exercise training has been shown to significantly reduce resting blood pressure,but the factors influencing its effectiveness remain unclear,and specific application guidelines are yet to be established.This study aims to evaluate the impact of isometric exercise training on resting blood pressure through meta-analysis,explore its moderating factors,and provide evidence-based recommendations based on its dose-response relationship.METHODS:Following the PRISMA guidelines,a systematic search was conducted in PubMed,Embase,Cochrane Library,Scopus,and Web of Science databases using keywords"Isometric exercise training,""Systolic blood pressure,"and"Diastolic blood pressure,"covering literature up to September 2024.Randomized controlled trials involving isometric exercise training and resting blood pressure were included.Three independent researchers performed literature screening and data extraction,assessing bias risk and quality grades using the Risk of Bias 2.0 tool and GRADE framework.Main effect pooling,publication bias assessment,subgroup,and regression analysis were conducted using R software(version 4.3.4).RESULTS:A total of 28 articles(comprising 32 randomized controlled trials)involving 977 participants were included.(1)Meta-analysis results indicated that isometric exercise training significantly reduced resting systolic blood pressure(MD=-8.01,95％CI=-9.22 to-6.80,P＜0.01,I2=18.20％,low evidence grade)and diastolic blood pressure(MD=-3.46,95％CI=-4.64 to-2.28,P＜0.01,I2=0％,moderate evidence grade)compared to no exercise.(2)Subgroup analysis results revealed significant influences of gender,health status,exercise modality,frequency,intensity,duration,sets per session,rest duration,and baseline blood pressure on the main effects for both systolic(P＜0.01)and diastolic blood pressure(P＜0.05).(3)Regression analysis results did not show any significant influencing factors,but body mass index(β=-4.11,P=0.091)showed a significant negative trend on the main effect for systolic blood pressure.(4)No significant publication bias was observed in the meta-analysis results(P＞0.05).CONCLUSION:(1)Isometric exercise training significantly lowers systolic(low evidence grade)and diastolic(moderate evidence grade)blood pressure with clinically meaningful thresholds.(2)Participant characteristics(gender,health status,baseline blood pressure,and body mass index)and isometric exercise training protocols(modality,frequency,intensity,duration,cycle,sets per session,and rest duration)influence its antihypertensive effects.(3)The article recommends the optimal blood pressure management prescription:three sessions per week,with four sets per session,each set lasting 2 minutes with a 2-minute rest,at an intensity of 95％HRpeak using isometric wall squat exercises;the intervention period can be adjusted around a 6-week node.Future high-quality research is urgently needed to further validate and support these conclusions.

BACKGROUND:Hydrogen peroxide-based bleach is widely used in clinical tooth whitening treatment,but its mechanism of action has not been uniformly determined so far.OBJECTIVE:To examine the effects of two bleaching agents,neutral 10％carbamide peroxide and neutral 40％hydrogen peroxide,on teeth and explore the mechanism of teeth whitening.METHODS:Forty-five discarded teeth extracted for orthodontic treatment were collected,and the dentin sections were made and polished.After removing the smear layer,they were randomly divided into three groups.The control group(n=15)was placed in deionized water;the carbamide peroxide group(n=15)was placed in a neutral 10％carbamide peroxide solution,and the hydrogen peroxide group(n=15)was placed in a neutral 40％hydrogen peroxide solution.The treatment was continued for 6 hours every day for 1 week.The Raman absolute intensity and Raman relative intensity of the three groups of samples were detected by Raman spectrometer every day,and the fluorescence background intensity(the difference between the Raman absolute intensity and the Raman relative intensity)was calculated.The change trend of the amide peak of the three groups of samples every day was recorded by infrared spectrometer.RESULTS AND CONCLUSION:(1)The relative Raman intensity of the three groups did not change significantly during the 1-7 days of treatment.The fluorescence background intensity of the control group did not change significantly during the 1-7 days of treatment.The fluorescence background intensity of the carbamide peroxide group showed a downward trend during the 1-7 days of treatment.The fluorescence background intensity of the hydrogen peroxide group decreased significantly during the 1-4 days of treatment and did not change significantly thereafter.(2)The peak areas of amide Ⅰ and amide Ⅲ did not change significantly during the 1-7 days of treatment in the control group.The peak areas of amide Ⅰ and amide Ⅲ showed a downward trend during the 1-7 days of treatment in the carbamide peroxide group and the hydrogen peroxide group,and the downward trend was more obvious in the hydrogen peroxide group.(3)The results show that the change in the laser-induced fluorescence background intensity of dentin Raman spectroscopy may be derived from the non-collagen components in dentin,and under the action of whitening agents,it may have a certain adverse effect on tooth tissue.

BACKGROUND:Pure titanium and titanium alloy implants are widely used in the field of implant restoration due to their excellent biocompatibility and elastic modulus.However,the biological inertness of the surface of titanium-based implants leads to poor integration with surrounding bone tissues,and surface modification is required to improve the bone integration ability of titanium-based implants.OBJECTIVE:To fabricate hydroxyapatite/graphene oxide/interleukin-4 composite coatings on pure titanium substrates,and to investigate their physicochemical properties and biocompatibility of the coating materials.METHODS:Hydroxyapatite/graphene oxide/interleukin-4 composite coatings were prepared on pure titanium substrates by electrochemical deposition and freeze-drying.Titanium sheets loaded with interleukin-4 and titanium sheets loaded with hydroxyapatite/graphene oxide coatings were prepared at the same time,and the physicochemical properties of pure titanium sheets and the above three titanium sheets were characterized.MC3T3-E1 cells were inoculated on the surfaces of pure titanium sheets and the above three titanium sheets,respectively.Cell proliferation was detected by CCK-8 assay and DAPI staining.Cell activity was detected by Calcein-AM/PI staining.Cell morphology and adhesion were observed by scanning electron microscopy.RESULTS AND CONCLUSION:(1)Scanning electron microscopy,energy-dispersive X-ray spectroscopy,X-ray photoelectron spectroscopy,X-ray diffraction,and Raman spectroscopy confirmed the successful fabrication of the hydroxyapatite/graphene oxide/interleukin-4 composite coating on the titanium surface.The water contact angle of hydroxyapatite/graphene oxide/interleukin-4 group was larger than that of pure titanium group and hydroxyapatite/graphene oxide group,and smaller than that of interleukin-4 group.(2)CCK-8 assay and DAPI staining results showed that hydroxyapatite/graphene oxide/interleukin-4 coating could promote the proliferation of MC3T3-E1 cells.Calcein-AM/PI staining results showed that MC3T3-E1 cells in hydroxyapatite/graphene oxide/interleukin-4 coating group had higher activity and fewer dead cells.Scanning electron microscopy showed that MC3T3-E1 cells adhered to the surfaces of the four groups of materials with good cell morphology.Compared with the pure titanium group,the MC3T3-E1 cells in the interleukin-4 group extended more pseudopodia,the cell-cell connections were closer,and the adhesion area was larger;compared with the hydroxyapatite/graphene oxide group,the MC3T3-E1 cells in the hydroxyapatite/graphene oxide/interleukin-4 group extended more pseudopodia,the cell-cell connections were closer,and the adhesion area was larger.(3)These findings indicate that the hydroxyapatite/graphene oxide/interleukin-4 composite coating possesses favorable physicochemical and biological properties.