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Background and aimsWhether ultra-processed food consumption is associated with cancer prognosis remains unknown. We aimed to test whether prediagnosis ultra-processed food consumption is positively associated with all-cause and cancer-specific mortality in patients with colorectal, lung, prostate, or breast cancer.MethodsThis study included 1,100 colorectal cancer patients, 1750 lung cancer patients, 4,336 prostate cancer patients, and 2,443 breast cancer patients. Ultra-processed foods were assessed using the NOVA classification before the diagnosis of the first cancer. Multivariable Cox regression was used to calculate hazard ratio (HR) and 95% confidence interval (CI) for all-cause and cancer-specific mortality.ResultsHigh ultra-processed food consumption before cancer diagnosis was significantly associated with an increased risk of all-cause mortality in lung (HRquartile 4 vs. 1: 1.18; 95% CI: 0.98, 1.40; Ptrend = 0.021) and prostate (HRquartile 4 vs. 1: 1.18; 95% CI: 1.00, 1.39; Ptrend = 0.017) cancer patients in a nonlinear dose–response manner (all Pnonlinearity

Abstract Objective We aim to evaluate the relationship between the use of metformin and the risk of pancreatic cancer in type 2 diabetes patients. Method We systematically searched the observational studies on PubMed, Embase, Web of Science, Cochrane Library, clinicalrials.gov, and CNKI databases, extracted relevant data, combined the OR value and 95% CI using the random effect model, and conducted a sensitivity analysis, subgroup analysis, and meta-regression to evaluate the size and stability of this relationship. Result Twenty-nine studies from twenty-four articles met our inclusion criteria, including more than 2 million subjects. Overall analysis showed that compared with no use of metformin, the use of metformin could reduce the risk of pancreatic cancer in patients with type 2 diabetes (OR = 0.82, 95% CI (0.69, 0.98)). Subgroup analysis showed that compared with the use of hypoglycemic drugs, the use of metformin could reduce the risk of pancreatic cancer in patients with type 2 diabetes (OR = 0.79, 95% CI (0.66, 0.94)). However, compared with no drugs or only diet therapy, metformin users might increase the risk of pancreatic cancer (OR = 2.19, 95% CI (1.08, 4.44)). Sensitivity analysis confirmed the stability of the study, and there was no significant publication bias. Conclusion Compared with the no-use of metformin, metformin users with diabetes can reduce the risk of pancreatic cancer. More research is needed to prove it works.

Abstract The aim of this study is to explore the clinical efficacy of immediate breast reconstruction (IBR) using the latissimus dorsi muscular flap in Chinese breast cancer patients. The clinical data of 17 breast cancer patients who underwent IBR using the latissimus dorsi muscular flap between August 2013 and September 2021 at Affiliated Cancer Hospital of Nanjing Medical University were analyzed retrospectively. Harris scoring standard was used to evaluate the cosmetic effect. All the 17 cases were successfully treated. The median age was 43 years old (age range: 32–54 years old). In the clinical staging, the patients were mainly early and mid‐stage patients, with two cases in stage 0, 12 cases in stage II, and three cases in stage III. Postoperative pathology was predominantly invasive breast cancer (15/17), and two cases were carcinoma in situ. The median operation time was 300 min (range: 180–450 min) and only two patients developed complications. After 2–97 months of follow‐up, no patients had recurrence or metastasis. According to the Harris method, 9, 6, 2, and 0 cases were evaluated as “excellent”, “good”, “fair,” and “poor” respectively. The practical application of IBR using the latissimus dorsi muscular flap is a safe and feasible way to improve physical and mental health in breast cancer patients.

Background and AimsAbnormal expression of E3 ubiquitin ligase plays an important role in the development and progression of hepatocellular carcinoma (HCC), although the mechanism has remained elusive. This study aimed to investigate the biological function and potential mechanism of FBXO43 in HCC.MethodsFBXO43 expression in tissues and cells were detected by quantitative real-time PCR (qRT−PCR), Western blot, and immunohistochemistry (IHC). The Kaplan-Meier method and Cox regression analysis were used to explore the correlation between the expression level of FBXO43 and the clinical survival. MTT assay, EdU incorporation, colony formation, Transwell, and wound healing assays were performed to evaluate the function of FBXO43 in cell proliferation and migration in vitro. The interaction between FBXO43 and cyclin D1 (CCND1) was assessed by co-immunoprecipitation (Co-IP) assay and in vivo ubiquitination assay.ResultsWe found that FBXO43 was upregulated in HCC patient tissues and positively associated with poor clinicopathological features. Meanwhile, HCC patients with high expression of FBXO43 had shorter overall survival (OS) and disease-free survival (DFS). Furthermore, knockdown of FBXO43 inhibited HCC cell proliferation, migration and epithelial-mesenchymal transition (EMT) in HCC cells. Mechanistically, FBXO43 interacted with CCND1 and promoted its stability by polyubiquitination, leading to HCC cell proliferation, migration and EMT. Functional rescue experiments demonstrated that knockdown of CCND1 blocks FBXO43-mediated cell proliferation and metastasis.ConclusionsFBXO43, as an independent prognostic biomarker, promotes HCC cell proliferation, metastasis and EMT by stability of CCND1, which provides a new potential strategy for HCC treatment by targeting FBXO43-CCND1 axis.

As a protective mechanism regulating excessive inflammation, endotoxin tolerance plays a vital role in regulating endotoxin shock. Kupffer cells are players in mediating endotoxin tolerance. Nonetheless, the regulatory mechanism regulating endotoxin tolerance is barely known. A nonclassical IKK kinase called TRAF-associated NF-κB activator (TANK)-binding kinase 1 (TBK1) can regulate inflammation. Here, we found that TBK1 is required for endotoxin tolerance in Kupffer cells. TBK1 plays a dominant role in regulating endotoxin tolerance by negatively regulating the induction of p100 processing. Deltex E3 ubiquitin ligase 4 (DTX4), a negative regulator of TBK1, can promote TBK1 K48-mediated ubiquitination and indirectly regulate endotoxin tolerance in Kupffer cells. We demonstrate that the c-Myb transcription factor could negatively regulate DTX4. Overexpression of c-Myb can be used to reduce the ubiquitination of TBK1 by reducing DTX4 transcription and to boost the anti-inflammatory effect of endotoxin tolerance. Thus, this study reveals a novel theory of TBK1-mediated endotoxin tolerance in Kupffer cells.

Background and aimsWhether fried food consumption is associated with the risk of pancreatic cancer remains elusive. We aimed to examine this association in a US population.MethodsA population-based cohort of 101,729 US adults was identified. Fried food consumption was assessed with a validated food frequency questionnaire. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. Explanatory analyses were conducted to identify main contributor(s) to the observed association.ResultsDuring an average follow-up of 8.86 years (900871.2 person-years), 402 pancreatic cancer cases occurred. High consumption of total fried foods (deep-fried plus pan-fried foods; HRquartile4 vs. 1 0.71, 95% CI 0.51–0.99, Ptrend = 0.047) and deep-fried foods (HRquartile 4 vs. 1 0.64, 95% CI 0.47–0.88, Ptrend = 0.011), but not pan-fried foods (HRquartile 4 vs. 1 0.98, 95% CI 0.73–1.32; Ptrend = 0.815), was found to be associated with a reduced risk of pancreatic cancer in a non-linear dose–response manner, which was not modified by predefined stratification factors and persisted in sensitivity analyses. In explanatory analyses, only chip consumption was found to be inversely associated with the risk of pancreatic cancer; consistently, the initial significant associations between total fried food and deep-fried food consumption and the risk of pancreatic cancer changed to be non-significant after omitting or further adjusting for chip consumption.ConclusionConsumption of deep-fried foods, but not pan-fried foods, is inversely associated with the risk of pancreatic cancer in this US population. The role of deep-fried foods in reducing the risk of pancreatic cancer appears to be mainly attributable to chips. More studies are needed to confirm our findings in other populations and settings.

BackgroundThe study was conducted to explore whether high-intensity focused ultrasound (HIFU) can improve the effect of transcatheter arterial chemoembolization (TACE) in intermediate and advanced hepatocellular carcinoma (HCC).MethodsPubMed, Embase, Cochrane Library, Web of Science, Wanfang Data, CQVIP, China National Knowledge Infrastructure (CNKI), and Chinese Biomedical (CBM) databases were searched for randomized controlled trials (RCTs) comparing the effect of TACE in combination with HIFU group (group A) to TACE alone group (group B) in treating intermediate and advanced HCC. The primary outcomes were overall survival (OS) rate and tumor response rate. The odds ratio (OR) and 95% confidence interval (CI) for each study were calculated and then pooled with fixed effects model or random effects model. Sensitivity analyses and subgroup analyses were conducted. A publication bias was also evaluated.ResultsAfter literature selection, eleven RCTs involving 803 patients were included in this meta-analysis. This meta-analysis revealed that group A was associated with an increased 6-month OS rate (OR = 0.20), 12-month OS rate (OR = 0.23), 24-month OS rate (OR = 0.32), and overall response rate (WHO criterion, OR = 0.22; RECIST criterion, OR = 0.30). Furthermore, subgroup analyses showed no bias in the result. Given the limited number of studies that reported major complications, no additional meta-analysis of complication was conducted. Despite no special treatment, any complication following HIFU treatment was found to subside within 3-7 days.ConclusionTACE in combination with HIFU is associated with increased OS and tumor response in intermediate and advanced HCC. Current evidence supports the use of HIFU after TACE treatment in intermediate and advanced HCC.

Abstract Background The activation of tumour-associated macrophages (TAMs) contributes to the progression of hepatocellular carcinoma (HCC). SIRT4 acts as a tumour suppressor of tumour growth by regulating cell metabolism, inflammation, and anti-tumourigenesis. However, the involvement of SIRT4 in the activation of TAMs is unknown. Based on previous findings, the expression of SIRT4 in distinct groups of TAMs as well as the effect of SIRT4 silencing on macrophage polarization was investigated. Methods The expression of SIRT4 in HCC tissues and peritumour tissues was tested by qRT-PCR, western blotting and histological analysis. A Kaplan-Meier survival curve was generated based on the expression of SIRT4 in the HCC samples. Next, immunofluorescence staining was used to evaluate distinct groups of TAMs in human HCC samples, and the expression of SIRT4 in M1 and M2 TAMs was examined by flow cytometry. A homograft mouse model was used to assess the effect of SIRT4 silencing in TAMs on the development of HCC cells. Results SIRT4 was significantly downregulated in HCC tumour tissues, and the expression of SIRT4 in peritumour tissues was positively associated with survival in patients. We further found that downregulation of SIRT4 was associated with increased macrophage infiltration and a high ratio of M2/M1 macrophages in HCC peritumour tissues. Using gene interference, we found that SIRT4 silencing in TAMs significantly modulated the alternative activation of macrophages and promoted in vitro and in vivo HCC cell growth. Mechanistically, we revealed that HCM restricted the expression of SIRT4 in macrophages and promoted alternative activation of macrophages via the FAO-PPARδ-STAT3 axis. Furthermore, we also revealed that elevated MCP-1 expression induced by SIRT4 downregulation was responsible for increased TAM infiltration in peritumour tissues. Conclusions Overall, our results demonstrate that downregulation of SIRT4 in TAMs modulates the alternative activation of macrophages and promotes HCC development via the FAO-PPARδ-STAT3 axis. These results could provide a new therapeutic target for the treatment of HCC.

Liver ischemia-reperfusion injury (IRI) represents a risk factor for early graft dysfunction and an obstacle to expanding donor pool in orthotopic liver transplantation (OLT). Kupffer cells (KCs) are the largest antigen-presenting cell (APC) group and the primary modulators of inflammation in liver tissues. The vital role of Notch1/Jagged1 pathway in mouse OLT model has been reported, however, its potential therapeutic mechanism is unknown. Here, we made use of short hairpin RNA-Jagged1 and AAV-Jagged1 to explore the effects of Notch1/Jagged1 pathway in OLT. In vitro, blockade of Notch1/Jagged1 pathway downregulated the expression of Hairy and enhancer of split-1 (Hes1) gene, which in turn increased the proinflammatory effects of KCs. Moreover, the anti-inflammatory effects of Notch1/Jagged1 pathway were induced by inhibiting Hes1/gene of phosphate and tension/protein kinase B/Toll-like receptor 4/nuclear factor kappa B (Hes1/PTEN/AKT/TLR4/NF-κB) axis in KCs. In vivo, we used a well-established mouse model of OLT to mimic clinical transplantation. Mice were stochastically divided into 6 groups: Sham group (n = 15); Normal saline (NS) group (n = 15); Adeno-associated virus–green fluorescent protein (AAV-GFP) group (n = 15); AAV-Jagged1 group (n = 15); Clodronate liposome (CL) group (n = 15); CL+AAV-Jagged1 group (n = 15) . After OLT the liver damage in AAV-Jagged1 group were significantly accentuated compared to the AAV-GFP group. While blockade of Jagged1 aftet clearence of KCs by CL would not lead to further liver injuries. Taken together, our study demonstrated that blockade of Notch1/Jagged1 pathway aggravates inflammation induced by lipopolysaccharide (LPS) via Hes1/PTEN/AKT/TLR4/NF-κB in KCs, and the blockade of Notch1/Jagged1 pathway in donor liver increased neutrophil/macrophage infiltration and hepatocellular apoptosis, which suggested the function of Notch1/Jagged1 pathway in mouse OLT and highlighted the protective function of Notch1/Jagged1 pathway in liver transplantation.

Objective: The α-ketoglutarate (αKG), a metabolite of glutaminolysis, is reported to orchestrate macrophages activation. This study aims to clarify whether the αKG / glutaminolysis metabolism can suppress Kupffer cells (KCs) activation during liver transplantation and attenuate hepatic ischemia-reperfusion injury (IRI). Methods: Donor livers were perfused with DM-αKG (a cell-permeable analog of αKG) or BPTES (an inhibitor of glutaminase 1) via portal vein during cold preservation, and controls were perfused with UW solution. Then, a rat model of liver transplantation was performed. Serum levels of alanine transaminase (ALT), total bilirubin (TBIL) and inflammatory cytokines, as well as histology, were analyzed after 24 h. KCs were isolated from grafts. RT-PCR and immunofluorescence were used to evaluate polarization-specific marker genes. Western bolt was employed to assess the expression of phosphorylation of glycogen synthase kinase 3β (p-GSK3β) and suppressor of cytokine signaling 1 (SOCS1). EMSA was utilized to quantify the NF-κB transcriptional activity. Results: Compared with controls, DM-αKG perfusion decreased ALT and TBIL levels, alleviated liver damage, and reduced apoptosis, while BPTES group showed higher ALT and TBIL levels, severe damage and more apoptosis. Furthermore, DM-αKG perfusion suppressed NF-κB activity, up-regulated the expression of p-GSK3β and SOCS1 in KCs, and shifted the M1/M2 balance toward an anti-inflammatory profile. Besides, DM-αKG suppressed serum pro-inflammatory cytokines secretion and increased IL-10. Conclusions: αKG produced by glutaminolysis protects liver graft from IRI by regulating the inflammatory response and modifying the polarization of KCs.

Abstract Background MicroRNAs (miRNAs) posttranscriptionally regulate gene expression and thereby contribute to the modulation of numerous complex and disease-relevant cellular processes, including cell proliferation, cell motility, apoptosis and stress response. miRNA-31-5p is encoded on a genomic fragile site, 9p21.3, which is reportedly lost in many hepatocellular carcinoma (HCC) tumors. Based on previous findings, we hypothesized that miR-31-5p alters chemosensitivity and that miR-31-5p mimics may influence sensitivity to chemotherapeutics in HCC as well as in a variety of other cancers. Methods MiR-31-5p and PARP1 in HCC tissues were tested by RT-PCR and histological analysis, respectively. Next, clonogenic assay and western blot were used to detect miR-31-5p and PARP1 to modulate sensitivity to OXA-based chemotherapy. The distribution of OXA in the nuclear and intracellular was detected by ICP-MS. Coimmunoprecipitation was used to characterize the protein-protein interaction between PARP1 and ABCB9. A xenograft nude mouse model was used to examine the in vivo effects of miR-31-5p. Results Reintroduction of miR-31-5p into miR-31-5p-null Hep3B cells significantly enhanced clonogenic resistance to oxaliplatin. Although miR-31-5p re-expression increased chemoresistance, it paradoxically increased the relative intracellular accumulation of oxaliplatin. This effect was coupled with a significantly decreased intranuclear concentration of oxaliplatin by ICP-MS. miR-31-5p prevents the nuclear location of PARP1 detected by immunofluorescence, histological analysis and Western blotting analysis. We subsequently identified an indirect miR-31-5p-mediated upregulation of ABCB9, which is a transporter associated with drug accumulation in lysosomes, along with an increased uptake of oxaliplatin to lysosomes; these phenomena were associated with a downregulation of PARP1, a bipotential transcriptional regulator with multiple miR-31-5p binding sites. However, the indirect overexpression of ABCB9 promoted cellular chemosensitivity, suggesting that miR-31-5p promotes chemoresistance largely via an ABCB9-independent mechanism. Conclusions Overall, our data suggest that the loss of miR-31-5p from HCC tumors promotes chemosensitivity, and this knowledge may be prognostically beneficial in the context of therapeutic sensitivity.

Liver transplantation has been deemed the best choice for end-stage liver disease patients but immune rejection after surgery is still a serious problem. Patients have to take immunosuppressive drugs for a long time after liver transplantation, and this often leads to many side effects. Mesenchymal stem cells (MSCs) gradually became of interest to researchers because of their powerful immunomodulatory effects. In the past, a large number of in vitro and in vivo studies have demonstrated the great potential of MSCs for participation in posttransplant immunomodulation. In addition, MSCs also have properties that may potentially benefit patients undergoing liver transplantation. This article aims to provide an overview of the current understanding of the immunomodulation achieved by the application of MSCs in liver transplantation, to discuss the problems that may be encountered when using MSCs in clinical practice, and to describe some of the underlying capabilities of MSCs in liver transplantation. Cell–cell contact, soluble molecules, and exosomes have been suggested to be critical approaches to MSCs’ immunoregulation in vitro; however, the exact mechanism, especially in vivo, is still unclear. In recent years, the clinical safety of MSCs has been proven by a series of clinical trials. The obstacles to the clinical application of MSCs are decreasing, but large sample clinical trials involving MSCs are still needed to further study their clinical effects.

Background/Aims: Few studies have been designed to directly investigate the exact mechanisms underlying the different phenotypes between cirrhotic and non-cirrhotic hepatocellular carcinoma (HCC). This study aimed to illuminate the incidence and developmental mechanisms for both types of HCC through differentially expressed microRNAs (miRNAs) using bioinformatic analysis. Methods: The miRNA-seq data and clinical data of patients (from The Cancer Genome Atlas (TCGA) database) were utilized to determine differentially expressed miRNAs between cirrhotic and non-cirrhotic HCC. Afterwards, the function of the selected miRNAs was predicted with online tools. Furthermore, the miRNA expression and clinical significance were validated by external datasets and our experiment. Results: The present study included 135 non-cirrhotic and 80 cirrhotic patients to find differentially expressed miRNAs. Among them, four miRNAs (mir-1296, mir-23c, mir-149, and mir-95) were finally selected for further validation and analysis. Correlation analysis found that two miRNAs are greatly associated with the non-cirrhotic HCC patients’ clinical traits, such as the T, M, and N tumor stages. However, only mir-23c was associated with the cirrhotic HCC patients’ tumor T and N stages. Furthermore, survival analysis revealed that increased mir-149 in non-cirrhotic HCC, patients’ age and the existence of vessels in the tumor in cirrhotic HCC were independent risk factors for the patients’ postoperative overall survival. Functional and interaction analyses also supported the notion that these miRNAs function through some pathways that influence the behavior of the HCC. These results are strongly supported by analysis of extra datasets and our experiment. Conclusions: The cirrhotic and non-cirrhotic HCC types involve differentially expressed miRNAs, which are correlated with distinctive pathological traits. To some extent, non-cirrhotic HCC seems more dependent on miRNA network regulation, but additional studies are needed to confirm this conclusion.

Abstract In this study, we aimed to compare and validate the prognostic abilities of preoperative systemic immune cells in hepatocellular carcinoma (HCC) after curative hepatectomy. We developed two nomograms to predict the postoperative recurrence‐free survival (RFS) and overall survival (OS) after comparisons of the systemic immune cell prognostic scores. The two nomograms were constructed based on 305 patients who underwent curative hepatectomy for HCC. The predictive accuracy and discriminative ability of the nomograms were compared with six commonly used staging systems for HCC. The results were validated using bootstrap resampling and an internal validation cohort of 142 patients and an external validation cohort of 169 patients. Necroinflammatory activity in peritumoral liver tissues in the primary cohort was evaluated by hematoxylin and eosin (H&E) staining. Neutrophil, monocyte, and lymphocyte ratio (NMLR) had a higher area under the receiver operating characteristic curves (AUROC) value at both RFS (AUC = 0.603) and OS (AUC = 0.726) compared to that of other systemic immune cell prognostic scores. The independent predictors of RFS or OS, including α‐fetoprotein (AFP), tumor size, tumor number, microvascular invasion, and NMLR, were incorporated into the two nomograms. In the primary cohort, the C‐indexes of the RFS and OS nomograms were 0.705 and 0.797, respectively. The ROC analyses showed that the two nomograms had larger AUC values (0.664 for RFS and 0.821 for OS) than those of the American Joint Commission on Cancer seventh edition, Barcelona Clinic Liver Cancer, Cancer of the Liver Italian Program, Japan Integrated Staging Score, Okuda stage, and the Vauthey's system. These results were verified by internal and external validations. The nomogram‐predicted probability of RFS was associated with peritumoral necroinflammatory activity scores (r = 0.304, P

Abstract Methodology for accurate quantification of intra-hepatic cccDNA has long been a technical challenge, yet it is highly desired in the clinic. Here, we developed a sensitive method for quantification of intrahepatic cccDNA in liver biopsies from patients, which allowed to predict patient’s response to interferon therapy at baseline. Twenty-five patients with HBeAg+ CHB were recruited and liver biopsies were obtained at baseline and 1-year after interferon treatment, respectively. Both intrahepatic cccDNA and HBV DNA were absolutely quantified by a droplet digital PCR amplification system. Patients were categorized as either responder or non-responder group based on their HBeAg status 1-year after interferon therapy. Levels of both intrahepatic HBV DNA and HBV cccDNA were significantly reduced after interferon treatment among the responders, but not the non-responders, in comparison with their levels at baseline. Baseline values of intrahepatic HBV DNA over cccDNA significantly correlated with patient’s response to PEG-IFN therapy (P = 0.000). In addition, HBeAg seroconversion also correlates with a significant reduction in intrahepatic pgRNA production among the responders after interferon therapy (P = 0.030). In conclusion, our results suggest that baseline value of intrahepatic HBV DNA over cccDNA may be a preferable indicator for selecting appropriate patients for IFN-based therapy in the clinic.

The authors are retracting this article [1] because it overlaps significantly with a previously published article by Moody et al. [2] without proper citation. All authors agree with this retraction.

BACKGROUND: Addiction and major depression are mental health problems associated with stressful events in life with high relapse and reoccurrence even after treatment. Many laboratories were not able to detect the presence of cannabinoid CB2 receptors (CB2-Rs) in healthy brains, but there has been demonstration of CB2-R expression in rat microglial cells and other brain associated cells during inflammation. Therefore, neuronal expression of CB2-Rs had been ambiguous and controversial and its role in depression and substance abuse is unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study we tested the hypothesis that genetic variants of CB2 gene might be associated with depression in a human population and that alteration in CB2 gene expression may be involved in the effects of abused substances including opiates, cocaine and ethanol in rodents. Here we demonstrate that a high incidence of (Q63R) but not (H316Y) polymorphism in the CB2 gene was found in Japanese depressed subjects. CB2-Rs and their gene transcripts are expressed in the brains of naïve mice and are modulated following exposure to stressors and administration of abused drugs. Mice that developed alcohol preference had reduced CB2 gene expression and chronic treatment with JWH015 a putative CB2-R agonist, enhanced alcohol consumption in stressed but not in control mice. The direct intracerebroventricular microinjection of CB2 anti-sense oligonucleotide into the mouse brain reduced mouse aversions in the plus-maze test, indicating the functional presence of CB2-Rs in the brain that modifies behavior. We report for the using electron microscopy the sub cellular localization of CB2-Rs that are mainly on post-synaptic elements in rodent brain. CONCLUSIONS/SIGNIFICANCE: Our data demonstrate the functional expression of CB2-Rs in brain that may provide novel targets for the effects of cannabinoids in depression and substance abuse disorders beyond neuro-immunocannabinoid activity.

In this work, we have found that a prenotched double-network (DN) hydrogel, when subjected to tensile loading in a pure-shear geometry, exhibits intriguing stick--slip crack dynamics. These dynamics synchronize with the oscillation of the damage (yielding) zone at the crack tip. Through manipulation of the loading rate and the predamage level of the brittle network in DN gels, we have clarified that this phenomenon stems from the significant amount of energy dissipation required to form the damage zone at the crack tip, as well as a kinetic contrast between the rapid crack extension through the yielding zone (slip process) and the slow formation of a new yielding zone controlled by the external loading rate (stick process). [ABSTRACT FROM AUTHOR]

Morphogenesis is one of the most marvelous natural phenomena. The morphological characteristics of biological organs develop through growth, which is often triggered by mechanical force. In this study, we propose a bioinspired strategy for hydrogel morphogenesis through force-controlled chemical reaction and growth under isothermal conditions. We adopted a double network (DN) hydrogel with sacrificial bonds. Applying mechanical force to the gel caused deformation and sacrificial bond rupture. By supplying monomers to the gel, the radicals generated by the bond rupture triggered the formation of a new network inside the deformed gel. This new network conferred plasticity to the elastic gel, allowing it to maintain its deformed shape, along with increased volume and strength. We demonstrated that sheet-shaped DN hydrogels rapidly adopted various three-dimensional shapes at ambient temperature when subjected to forces such as drawing and blowing. This mechanism enables morphogenesis of elastic hydrogels and will promote the application of these materials in biomedical fields and soft machines. [ABSTRACT FROM AUTHOR]