BACKGROUND:Multistimuli-responsive hydrogels have received extensive attention in the field of bone tissue engineering due to their special responsive capabilities and diverse functions.OBJECTIVE:To review the application of multistimuli-responsive hydrogels in bone damage repair,and explore their research and development ideas and future development directions.METHODS:Relevant literature was retrieved from PubMed,Web of Science,and WanFang databases.English search terms included"hydrogels,bone defect,bone repair,bone healing,bone tissue engineering,degenerative joint diseases,osteoarthritis,Cartilage."Chinese search terms were"multistimuli-responsive hydrogels,smart hydrogels,bone damage repair,bone tissue engineering."The search time limit was from database inception to August 2024.A total of 83 articles were included in the review.RESULTS AND CONCLUSION:Multistimuli-responsive hydrogels can react to various levels of physical,chemical,and biological stimuli,while exerting inherent functions such as swelling,deformation,degradation,and other special functions endowed by materials,making them highly potential in addressing clinical problems in bone damage repair.However,in practical applications,how to ensure that these materials maintain stability and durability in the complex biological environment and can be degraded in a controllable and harmless manner when needed is an urgent problem to be solved.

BACKGROUND:Arthroscopic anchor repair has become the main treatment method for rotator cuff tears at present.Among them,the insertion status of the anchor is a key factor in the success or failure of the operation.However,currently,the impact of the insertion depth of the anchor on the stress of the bone tunnel and the anchor under different bone density conditions remains unclear.OBJECTIVE:To explore the stress distribution of the bone tunnel and the anchor when the insertion depth of the anchor varies under different bone density conditions by using three-dimensional finite element analysis technology.METHODS:The CT image data of the humerus of volunteers were collected,and the models of the humerus and the anchor were constructed by using Mimics,3-Matic,and Solidworks software.In 3-Matic,holes with distances of 0,2,4,6,and 8 mm from the surface of the humerus were respectively created at the same position of the humerus and assembled with the anchor.In Mimics,values were assigned based on the CT gray value to obtain a model with normal bone mass(T value ≥-1.0).The parameters were changed to construct models with reduced bone mass(-2.5＜T value＜-1.0)and osteoporosis(T value＜-2.5).In each model,a 70 N pulling force was applied to the anchor along the direction tangent to the inner edge of the bone tunnel.The stress distribution and magnitude of the bone tunnel and the anchor when inserted at different depths under different bone density conditions were observed.RESULTS AND CONCLUSION:(1)When the insertion depth was the same,as the bone density decreased,the maximum equivalent stress of the anchor increased,while the maximum equivalent stress of the bone tunnel decreased.(2)When the bone density was the same,as the insertion depth of the anchor increased,the maximum equivalent stress of the anchor decreased.When the insertion depth was 4 mm,the stress of the bone tunnel was the smallest and the distribution was relatively uniform.The stress of the anchor was mainly distributed around the lower anchor hole and the proximal thread,and the stress of the bone tunnel was mainly at the part in contact with the proximal thread.The increase in the insertion depth would change the uniformity and pattern of the stress distribution,while the bone density had a relatively small impact on the stress distribution pattern.(3)It is concluded that the bone density of the humerus is crucial for the anchor repair of rotator cuff tears.It is recommended that clinicians measure the bone density of the greater tuberosity of the humerus before the operation.Excessive insertion depth of the anchor does not significantly increase its stability.Clinicians can conduct personalized preoperative assessments by using the finite element analysis method in combination with the actual situation of patients to achieve the best surgical results.

BACKGROUND:Multistimuli-responsive hydrogels have received extensive attention in the field of bone tissue engineering due to their special responsive capabilities and diverse functions.OBJECTIVE:To review the application of multistimuli-responsive hydrogels in bone damage repair,and explore their research and development ideas and future development directions.METHODS:Relevant literature was retrieved from PubMed,Web of Science,and WanFang databases.English search terms included"hydrogels,bone defect,bone repair,bone healing,bone tissue engineering,degenerative joint diseases,osteoarthritis,Cartilage."Chinese search terms were"multistimuli-responsive hydrogels,smart hydrogels,bone damage repair,bone tissue engineering."The search time limit was from database inception to August 2024.A total of 83 articles were included in the review.RESULTS AND CONCLUSION:Multistimuli-responsive hydrogels can react to various levels of physical,chemical,and biological stimuli,while exerting inherent functions such as swelling,deformation,degradation,and other special functions endowed by materials,making them highly potential in addressing clinical problems in bone damage repair.However,in practical applications,how to ensure that these materials maintain stability and durability in the complex biological environment and can be degraded in a controllable and harmless manner when needed is an urgent problem to be solved.

BACKGROUND:Arthroscopic anchor repair has become the main treatment method for rotator cuff tears at present.Among them,the insertion status of the anchor is a key factor in the success or failure of the operation.However,currently,the impact of the insertion depth of the anchor on the stress of the bone tunnel and the anchor under different bone density conditions remains unclear.OBJECTIVE:To explore the stress distribution of the bone tunnel and the anchor when the insertion depth of the anchor varies under different bone density conditions by using three-dimensional finite element analysis technology.METHODS:The CT image data of the humerus of volunteers were collected,and the models of the humerus and the anchor were constructed by using Mimics,3-Matic,and Solidworks software.In 3-Matic,holes with distances of 0,2,4,6,and 8 mm from the surface of the humerus were respectively created at the same position of the humerus and assembled with the anchor.In Mimics,values were assigned based on the CT gray value to obtain a model with normal bone mass(T value ≥-1.0).The parameters were changed to construct models with reduced bone mass(-2.5＜T value＜-1.0)and osteoporosis(T value＜-2.5).In each model,a 70 N pulling force was applied to the anchor along the direction tangent to the inner edge of the bone tunnel.The stress distribution and magnitude of the bone tunnel and the anchor when inserted at different depths under different bone density conditions were observed.RESULTS AND CONCLUSION:(1)When the insertion depth was the same,as the bone density decreased,the maximum equivalent stress of the anchor increased,while the maximum equivalent stress of the bone tunnel decreased.(2)When the bone density was the same,as the insertion depth of the anchor increased,the maximum equivalent stress of the anchor decreased.When the insertion depth was 4 mm,the stress of the bone tunnel was the smallest and the distribution was relatively uniform.The stress of the anchor was mainly distributed around the lower anchor hole and the proximal thread,and the stress of the bone tunnel was mainly at the part in contact with the proximal thread.The increase in the insertion depth would change the uniformity and pattern of the stress distribution,while the bone density had a relatively small impact on the stress distribution pattern.(3)It is concluded that the bone density of the humerus is crucial for the anchor repair of rotator cuff tears.It is recommended that clinicians measure the bone density of the greater tuberosity of the humerus before the operation.Excessive insertion depth of the anchor does not significantly increase its stability.Clinicians can conduct personalized preoperative assessments by using the finite element analysis method in combination with the actual situation of patients to achieve the best surgical results.

The αPD-L1 antibody-based immune checkpoint blockade therapy is still limited by the poor clinical response rate as it is mainly utilized to block surface PD-L1 on tumor cells while ignoring abundant PD-L1 exosomes secreted in the environment, causing tumor immune evasion. Here, we proposed an exosome biogenesis inhibition strategy to suppress tumor exosomes secretion from the source, reducing the inhibitory effect on T cells and enhancing chemo-immunotherapy efficacy. We developed sulfafurazole homodimers (SAS) with disulfide linkages, effectively releasing the drug in response to glutathione (GSH) and inhibiting 4T1 tumor-derived exosomes secretion. Subsequently, gemcitabine (Gem) was encapsulated to induce immunogenic cell death (ICD). Consequently, Gem@SAS inhibited the secretion of tumor exosomes by more than 70%, increased proliferation and granzyme B secretion ability of T cells by more than 2 times, and showed superior efficacy in breast cancer treatment as well as lung metastasis of breast cancer.

Objectives:To investigate the clinical value of cardiac magnetic resonance imaging(CMR)feature-tracking strain analysis in risk stratification of diabetic heart failure with preserved ejection fraction(HFpEF).Methods:In this retrospective study,a total of 215 patients with diabetic HFpEF who underwent CMR at Chinese Academy of Medical Sciences Fuwai Hospital from January 2012 to December 2018 were included.Myocardial strain parameters were calculated using CMR feature-tracking technology.Patients were followed up by medical records or telephone calls.Composite endpoint event,all-cause death or heart failure hospitalization during follow-up were recorded.Patients were divided into event group and event-free group.Univariable and multivariable Cox proportional hazard regression analyses were performed to determine the risk factors for the outcomes in diabetic HFpEF.The effects of hypertension and obesity on the prognosis of diabetic HFpEF patients and whether they affect the prognostic value of CMR feature-tracking strain analysis were also analyzed.Results:During a follow-up of(7.1±1.8)years,93(43.3%)patients had endpoint events(event group),including 28 all-cause deaths and 65 heart failure hospitalization.Compared with the event-free group(n=122),patients in the event group had significantly lower left ventricular ejection fraction,higher prevalence and extent of late gadolinium enhancement,and significantly reduced global longitudinal strain(GLS),global circumferential strain,global radial strain,and global systolic longitudinal strain rate(all P<0.05).The absolute GLS value was significantly lower in event group than in event-free group,regardless of the presence of hypertension and obesity.Multivariate Cox regression analysis showed that estimated glomerular filtration rate(HR=0.983,95%CI:0.972-0.993,P=0.001),left atrial volume index(HR=1.015,95%CI:1.005-1.026,P=0.004),and GLS(HR=1.142,95%CI:1.060-1.231,P<0.001)were independent risk factors for adverse cardiovascular events in diabetic HFpEF patients.However,adjusted N-terminal pro-brain natriuretic peptide was not an independent prognostic factor.The cut-offvalue of GLS to predict outcome was-14.09%from ROC curve analysis.The Kaplan-Meier curve showed that in patients with and without hypertension and obesity,patients with the GLS>-14.09%had lower event-free survival compared to patients with GLS≤-14.09%(all P<0.05),and the ability of GLS to predict adverse outcomes was not affected by hypertension and obesity.Conclusions:GLS obtained by CMR feature-tracking strain analysis is an independent predictor of adverse outcomes in diabetic HFpEF,and its ability to predict adverse outcomes is independent of hypertension and obesity.

Objective:To investigate the mechanism by which hydrogen alleviates myocardial ischemia/reperfusion injury (IRI) through ultrasound-targeted destruction of hydrogen-loaded phospholipid microbubbles in the ischemic myocardium of rats.Methods:A total of 45 rats were randomly divided into three groups: sham operation group, IRI group (model group), and hydrogen treatment group (experimental group), with 15 rats in each group. A rat model of myocardial IRI was established. Rats in the sham group received 0.2 ml of normal saline via the tail vein, those in the model group received 0.2 ml of phospholipid microbubbles without hydrogen, and those in the treatment group received 0.2 ml of hydrogen-loaded phospholipid microbubbles. After 24 hours, cardiac function was assessed by left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS). Serum levels of cardiac troponin I (cTnI), creatine kinase-myocardial band (CK-MB), lactate dehydrogenase (LDH), and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). Expression levels of Janus knase 2(JAK2), signal transducer and activator of transcription 3(STAT3), phosphorylated JAK2(p-JAK2), and phosphorylated STAT3(p-STAT3) proteins in myocardial tissue were detected by Western blot. Myocardial infarct size was evaluated by 2,3,5-triphenyltetrazolium chloride (TTC) staining, and myocardial histopathological changes were observed by hematoxylin-eosin (HE) staining.Results:After 24 hours of reperfusion, LVEF [(54.26±2.92) % vs (45.77±27%)] and LVFS [(24.11±1.68) % vs (19.50±1.19%)] were significantly higher in the treatment group than in the model group (both P<0.001). ELISA results showed that levels of CK-MB [(13.58±2.07) μg/L vs (20.07±1.57) μg/L], LDH [(47.76±8.32) μg/L vs (74.39±10.19) μg/L], cTnI [(7.50±0.26) μg/L vs (9.05±0.34) μg/L], and IL-6 [(121.34±8.97) ng/L vs (156.99±6.46) ng/L] were significantly lower in the treatment group compared with the model group (all P<0.001). TTC staining revealed a smaller infarct size in the treatment group [(48.77±2.68)%] than in the model group [(63.53±3.10)%, P<0.001]. Western blot analysis showed that the expression levels of JAK2 and p-STAT3 proteins were significantly lower in the treatment group than in the model group ( P<0.05). HE staining showed no pathological abnormalities in major organs (heart, liver, spleen, lung, and kidney) following hydrogen microbubble treatment. Conclusions:Ultrasound-targeted destruction of hydrogen microbubbles enables local hydrogen release in the myocardium, which downregulates IL-6 and inhibits activation of the JAK/STAT signaling pathway, thereby attenuating inflammation and reducing ischemia/reperfusion injury.

Objective To explore the protective effects of pretreatment with the Mongolian medicine Jiruhen Gurigumu-7(JG-7)and Guangzao Sanwei Tang(GZ-3)on myocardial ischemia-reperfusion injury(MIRI)in mice.Methods 60 male C57BL/6J mice were randomly divided into sham operation(Sham)group,model(Model)group,compound danshen drip pill(CDDP)positive control group,JG-7 group,GZ-3 group,and 12 mice in each group to establish the MIRI model,and the H9C2 cells were randomly divided into Control(normoxic)group,H/R(hypoxia 6 h reoxygenation 14 h)group,H/R+JG-7 group,H/R+GZ-3 group.The mice in each group were tested for cardiac function indexes after 30 min of ischemia,24 h and 7 d of reperfusion,TTC staining to detect infarct area after 24 h of MIRI,HE staining to detect myocardial tissue structure and cellular morphology after 24 h of MIRI,TUNEL apoptosis kit to detect apoptosis of myocardial cells after 24 h of MIRI,Masson staining to detect myocardial fibrosis after 7 d of MIRI.Blood was taken from the abdominal aorta,serum was separated,and the indexes after oxidative stress of MIRI were detected in each group of mice,and the survival rate of H9C2 cells after H/R was detected in each group by CCK-8 method.Results The results of TTC showed that JG-7 and GZ-3 reduced the infarct area after 24 h of MIRI in mice.ELISA and kit assays proved that JG-7 and GZ-3 reduced creatine phosphokinase isoenzyme(Creatinekinase-MB,CK-MB),Lactic dehydrogenase(LDH),malondialdehyde(MDA)levels,and increased superoxide dismutase(SOD)levels.HE staining showed that JG-7 and GZ-3 improved myocardial pathology after MIRI 24 h.The results of TUNEL apoptosis assay showed that JG-7 and GZ-3 improved apoptosis in myocardial tissues 24 h after MIRI.Masson staining results showed that JG-7 and GZ-3 could reduce the area of myocardial tissue fibrosis after MIRI 7 d.CCK-8 assay results showed that JG-7 and GZ-3 could improve the cell survival rate after H/R in H9C2 cells.Conclusion Pre-treatment with Mongolian medicine Jiruhen Gurigumu-7 and Guangzao Sanwei Tang can reduce the damage caused after ischemia-reperfusion(I/R),decrease the area of myocardial infarction and fibrosis after I/R in mice,and protect the heart.

The incidence of cardiovascular diseases(CVD)has been increasing year by year,with atherosclerosis(As)being the leading cause in terms of both incidnce and mortality for CVD in China.Traditional theories suggest that the pathogenesis of atherosclerotic CVD is associated with endothelial dysfunction and inflammatory responses caused by the accumulation of oxidized low density lipoprotein(ox-LDL).However,recent studies have demonstrated that perivascular adipose tissue(PVAT)can positively influence the occurrence and development of CVD through the vascular adventitia pathway.This article reviews the connection between PVAT and CVD,effective pathways for promoting CVD improve-ment,and the regulatory role of AMP-activated protein kinase(AMPK)on PVAT,aiming to explore effective intervention targets for CVD.

As a novel form of cell death, ferroptosis is mainly regulated by the accumulation of soluble iron ions in the cytoplasm and the production of lipid peroxides and is closely associated with several diseases, including acute kidney injury, ischemic reperfusion injury, neurodegenerative diseases, and cancer. The term "immunosuppression" refers to various factors that can directly harm immune cells' structure and function and affect the synthesis, release, and biological activity of immune molecules, leading to the insufficient response of the immune system to antigen production, failure to successfully resist the invasion of foreign pathogens, and even organ damage and metabolic disorders. An immunosuppressive phase commonly occurs in the progression of many ferroptosis-related diseases, and ferroptosis can directly inhibit immune cell function. However, the relationship between ferroptosis and immunosuppression has not yet been published due to their complicated interactions in various diseases. Therefore, this review deeply discusses the contribution of ferroptosis to immunosuppression in specific cases. In addition to offering new therapeutic targets for ferroptosis-related diseases, the findings will help clarify the issues on how ferroptosis contributes to immunosuppression.
Ferroptosis/immunology* ; Humans ; Immune Tolerance/immunology* ; Animals ; Immunosuppression Therapy ; Iron/metabolism* ; Neoplasms/immunology*