The causal association between artificial sweeteners and the risk of cancer: a Mendelian randomization study.

Artificial sweeteners (ASs) have been widely added to food and beverages because of their properties of low calories and sweet taste. However, whether the consumption of ASs is causally associated with cancer risk is not clear. Here, we utilized the two-sample Mendelian randomization (MR) method to study the potential causal association. Genetic variants like single-nucleotide polymorphisms (SNPs) associated with exposure (AS consumption) were extracted from a genome-wide association study (GWAS) database including 64 949 Europeans and the influence of confounding was removed. The outcome was from 98 GWAS data and included several types of cancers like lung cancer, colorectal cancer, stomach cancer, breast cancer, and so on. The exposure-outcome SNPs were harmonized and then MR analysis was performed. The inverse-variance weighted (IVW) with random effects was used as the main analytical method accompanied by four complementary methods: MR Egger, weighted median, simple mode, and weighted mode. Sensitivity analyses consisted of heterogeneity, pleiotropy, and leave-one-out analysis. Our results demonstrated that ASs added to coffee had a positive association with high-grade and low-grade serous ovarian cancer; ASs added to tea had a positive association with oral cavity and pharyngeal cancers, but a negative association with malignant neoplasm of the bronchus and lungs. No other cancers had a genetic causal association with AS consumption. Our MR study revealed that AS consumption had no genetic causal association with major cancers. Larger MR studies or RCTs are needed to investigate small effects and support this conclusion.

Full-term pregnancy with retroperitoneal giant mucinous cyst: A case report and literature review.

RATIONALE: Retroperitoneal benign cysts during pregnancy are extremely rare and often remain asymptomatic until they attain a very large size. Diagnosis typically relies on a pathological tissue biopsy. The decision to pursue 1-step or 2-step surgical treatment should be tailored to each individual case rather than generalized. PATIENT CONCERNS: This case report presents the unique scenario of a pregnant woman with a confirmed pregnancy complicated by a large retroperitoneal cyst. The patient had a retroperitoneal cyst during her initial pregnancy, which went undetected during the first cesarean section. However, it was identified during her second pregnancy by which time it had grown to 13.0 cm × 15.0 cm × 25.0 cm, and extended from the liver margin to right ovarian pelvic infundibulopelvic ligament. Consequently, it was removed smoothly during her second cesarean section. DIAGNOSES: Postoperative pathology results indicated a massive retroperitoneal mucinous cystadenoma. INTERVENTIONS: The giant retroperitoneal cyst was smoothly excised during the second cesarean delivery for 1-step surgical treatment. OUTCOMES: Under the combined spinal and epidural anesthesia, a live female infant was delivered at 38 3/7 gestational weeks and the neonatal weight was 3200g. Under general anesthesia with endotracheal intubation, the giant retroperitoneal cyst was excised smoothly without complications. LESSONS: The findings of this case report contribute to the understanding of the diagnostic modalities, surgical approaches and postoperative considerations of giant retroperitoneal cysts associated with pregnancy.

Effects of early- and late- neuraxial analgesia on multiparous women: a retrospective monocentric study.

BACKGROUND: The mechanism underlying maternal fever and prolonged labor progression associated with neuraxial analgesia (NA) remains elusive, raising concerns among certain pregnant women regarding the application of NA during vaginal delivery. This study aimed to investigate the impact of early and late NA on maternal and neonatal outcomes in multiparous women. METHODS: This retrospective study collected data from 1119 multiparous women with singleton pregnancies, full term and live births at our labor and delivery center between August 1st, 2021 and July 31st, 2022. Based on the timing of NA initiation, participants were categorized into three groups: no-NA, early-NA and late-NA. The no-NA group comprised of 172 women who did not receive NA during vaginal delivery; the early-NA group included 603 women in which NA was initiated when cervical dilation was between 0.5 and 2.0 cm; and the late-NA group comprising 344 cases in which NA was initiated at the cervical dilation of ≥ 2 cm. Maternal and neonatal outcomes were observed, including durations of the first, second, third and total stage of labor, the rate of intrapartum cesarean delivery (CD), intrapartum fever, postpartum hemorrhage (PPH), transfer to intensive care unit (ICU), admission to the neonatal intensive care unit (NICU), meconium-stained amniotic fluid, and neonatal Apgar scores at 1 and 5 min. RESULTS: No differences were noted in the maternal age, body mass index (BMI) on admission, gestations, parity, gestational weeks at delivery and neonatal birth weight, or the rate of gestational diabetes mellitus (GDM) and hypertension disorder did not significantly differ among the three groups (p > 0.05). The no-NA group had shorter durations of first stage, second stage of labor compared to the early-NA or late-NA group (median, 215.0 min and 10.0 min vs. 300.0 min and 12.0 min vs. 280.0 min and 13.0 min) (p < 0.05), but no differences were observed between the early-NA and late-NA group (p > 0.05). There were no differences in the rate of intrapartum CD, intrapartum fever, PPH, maternal transferred to ICU, neonatal transfer to NICU, meconium-stained amniotic fluid, and postpartum stay ≥ 7d, as well as the neonatal the Apgar scores at 1 and 5 min among the three groups (p > 0.05). CONCLUSION: NA is associated with extended durations of the first, second and total stages of labor. However, the early initiation of NA in multiparous women (cervical dilation within 0.5-2.0 cm) does not increase the risk of intrapartum CD or intrapartum fever. These findings endorse the secure utilization of early NA for pain relief during labor in multiparous women.

Identification of TNFα-mediated inflammation as potential pathological marker and therapeutic target for calcification progress of congenital bicuspid aortic valve.

BACKGROUD: Congenital bicuspid aortic valve (cBAV) develops calcification and stenotic obstruction early compared with degenerative tricuspid aortic valve (dTAV), which requires surgical intervention. Here we report a comparative study of patients with cBAV or dTAV to identify risk factors associated with the rapid development of calcified bicuspid valves. METHODS: A total of 69 aortic valves (24 dTAV and 45 cBAV) were collected at the time of surgical aortic valve replacement for comparative clinical characteristics. Ten samples were randomly selected from each group for histology, pathology, and inflammatory factors expression and comparison analyses. OM-induced calcification in porcine aortic valve interstitial cell cultures were prepared for illustrating the underlying molecular mechanisms about calcification progress of cBAV and dTAV. RESULTS: We found that cBAV patients have increased cases of aortic valve stenosis compared with dTAV patients. Histopathological examinations revealed increased collagens deposition, neovascularization and infiltrations by inflammatory cells, especially T-lymphocytes and macrophages. We identified that tumor necrosis factor α (TNFα) and its regulated inflammatory cytokines are upregulated in cBAV. Further in vitro study indicated that TNFα-NFκB and TNFα-GSK3ß pathway accelerate aortic valve interstitial cells calcification, while inhibition of TNFα significantly delays this process. CONCLUSION: The finding of intensified TNFα-mediated inflammation in the pathological cBAV advocates the inhibition of TNFα as a potential treatment for patients with cBAV by alleviating the progress of inflammation-induced valve damage and calcification.

Ergothioneine improves myocardial remodeling and heart function after acute myocardial infarction via S-glutathionylation through the NF-ĸB dependent Wnt5a-sFlt-1 pathway.

Myocardial infarction (MI) remains the leading cause of cardiovascular death worldwide. Studies have shown that soluble fms-like tyrosine kinase-1 (sFlt-1) has a harmful effect on the heart after MI. However, ergothioneine (ERG) has been shown to have protective effects in rats with preeclampsia by reducing circulating levels of sFlt-1. In this study, we aimed to investigate the mechanism by which ERG protects the heart after MI in rats. Our results indicate that treatment with 10 mg/kg ERG for 7 days can improve cardiac function as determined by echocardiography. Additionally, ERG can reduce the size of the damaged area, prevent heart remodeling, fibrosis, and reduce cardiomyocyte death after MI. To explain the mechanism behind the cardioprotective effects of ERG, we conducted several experiments. We observed a significant reduction in the expression of monocyte chemoattractant protein-1 (MCP-1), p65, and p-p65 proteins in heart tissues of ERG-treated rats compared to the control group. ELISA results also showed that ERG significantly reduced plasma levels of sFlt-1. Using Glutaredoxin-1 (GLRX) and CD31 immunofluorescence, we found that GLRX was expressed in clusters in the myocardial tissue surrounding the coronary artery, and ERG can reduce the expression of GLRX caused by MI. In vitro experiments using a human coronary artery endothelial cell (HCAEC) hypoxia model confirmed that ERG can reduce the expression of sFlt-1, GLRX, and Wnt5a. These findings suggest that ERG protects the heart from MI damage by reducing s-glutathionylation through the NF-ĸB-dependent Wnt5a-sFlt-1 pathway.

Immunosuppression by opioids: Mechanisms of action on innate and adaptive immunity.

Opioids are excellent analgesics for the clinical treatment of various types of acute and chronic pain, particularly cancer-related pain. Nevertheless, it is well known that opioids have some nasty side effects, including immunosuppression, which is commonly overlooked. As a result, the incidence of opportunistic bacterial and viral infections increases in patients with long-term opioid use. Nowadays, there are no effective medications to alleviate opioid-induced immunosuppression. Understanding the underlying molecular mechanism of opioids in immunosuppression can enable researchers to devise effective therapeutic interventions. This review comprehensively summarized the exogenous opioids-induced immunosuppressive effects and their underlying mechanisms, the regulatory roles of endogenous opioids on the immune system, the potential link between opioid immunosuppressive effect and the function of the central nervous system (CNS), and the future perspectives in this field.

Modification of the resting-state network involved at different stages of neuropathic pain.

Neuropathic pain (NeuP) is shown to be associated with abnormal changes in several specific brain regions. However, the large-scale interactivity of neuronal networks underlying the sensory and emotional abnormalities during NeuP remains unexplored. The present study aimed to explore the alterations in the relevant functional resting-state networks (RSNs) and their intra-networks at the different stages of NeuP based on resting-state functional magnetic resonance imaging (rs-fMRI). A NeuP rat model was established by chronic constriction injury (CCI). Three RSNs were identified to be associated with the NeuP, including the default mode network (DMN), sensorimotor network (SMN), and interoceptive network (IN). The functional connectivity (FC) of the left caudate putamen (CPu) within the DMN and the right piriform cortex within the IN were significantly reduced at the early stage of NeuP, when the maximum allodynia was apparent early, which reflected the suppressed function of the DMN and IN. At 4 weeks post-CCI, when negative emotions were present, the FC of the right insular cortex in the SMN and left visual cortex in the IN were significantly elevated, representing the increased excitability of both SMN and IN. Our study revealed the characteristic functional organization at the network level induced by NeuP and emphasized the role of SMN, DMN, and IN in the pathological mechanisms of NeuP.

Brain Functional Alteration at Different Stages of Neuropathic Pain With Allodynia and Emotional Disorders.

Neuropathic pain (NeuP), a challenging medical condition, has been suggested by neuroimaging studies to be associated with abnormalities of neural activities in some brain regions. However, aberrancies in brain functional alterations underlying the sensory-discriminative abnormalities and negative emotions in the setting of NeuP remain unexplored. Here, we aimed to investigate the functional alterations in neural activity relevant to pain as well as pain-related depressive-like and anxiety-like behaviors in NeuP by combining amplitude of low frequency fluctuation (ALFF) and degree centrality (DC) analyses methods based on resting-state functional magnetic resonance imaging (rs-fMRI). A rat model of NeuP was established via chronic constriction injury (CCI) of the sciatic nerve. Results revealed that the robust mechanical allodynia occurred early and persisted throughout the entire observational period. Depressive and anxiety-like behaviors did not appear until 4 weeks after injury. When the maximum allodynia was apparent early, CCI rats exhibited decreased ALFF and DC values in the left somatosensory and nucleus accumbens shell (ACbSh), respectively, as compared with sham rats. Both values were significantly positively correlated with mechanical withdrawal thresholds (MWT). At 4 weeks post-CCI, negative emotional states were apparent and CCI rats were noted to exhibit increased ALFF values in the left somatosensory and medial prefrontal cortex (mPFC) as well as increased DC values in the right motor cortex, as compared with sham rats. At 4 weeks post-CCI, ALFF values in the left somatosensory cortex and DC values in the right motor cortex were noted to negatively correlate with MWT and exhibition of anxiety-like behavior on an open-field test (OFT); values were found to positively correlate with the exhibition of depressive-like behavior on forced swimming test (FST). The mPFC ALFF values were found to negatively correlate with the exhibition of anxiety-like behavior on OFT and positively correlate with the exhibition of depressive-like behavior on FST. Our findings detail characteristic alterations of neural activity patterns induced by chronic NeuP and underscore the important role of the left somatosensory cortex, as well as its related networks, in the mediation of subsequent emotional dysregulation due to NeuP.

[Therapeutic effect of Fanzhen Jieci needling on discogenic sciatica: a randomized controlled trial].

OBJECTIVE: To compare the therapeutic effect between Fanzhen Jieci (warming acupuncture plus fast needling) combined with conventional acupuncture and simple conventional acupuncture on discogenic sciatica. METHODS: A total of 76 patients with discogenic sciatica were randomized into a Fanzhen Jieci group and a conventional acupuncture group, 38 cases in each one. Conventional acupuncture was applied at Shenshu (BL 23), Dachangshu (BL 25), L1-L5 Jiaji (EX-B 2) and Huantiao (GB 30) on the affected side, etc. in the conventional acupuncture group. On the basis of the treatment in the conventional acupuncture group, Fanzhen Jieci was applied at L1-L5 Jiaji (EX-B 2) and Huantiao (GB 30) on the affected side in the Fanzhen Jieci group, i.e. warming acupuncture was applied at L1-L5 Jiaji (EX-B 2), and fast needling was applied at Huantiao (GB 30) on the affected side for a depth of 40-60 mm, so as to introduce a sensation of electric shock transmitting to lower limb, and then the needle was immediately withdrawn. The treatment was given once every other day, 3 times a week for 3 weeks in both groups. The visual analogue scale (VAS) score of leg and low back pain, the Oswestry disability index (ODI) score and the 36-item short form health survey (SF-36) score before and after treatment were compared between the two groups. RESULTS: Compared before treatment, the VAS scores of leg and low back pain and the ODI scores after treatment were decreased in both groups (P<0.001), the changes of the VAS scores of leg and low back pain in the Fanzhen Jieci group were larger than those in the conventional acupuncture group (P<0.05). After treatment, except for the role emotional and health transition scores, the various scores of SF-36 were increased compared before treatment in the Fanzhen Jieci group (P<0.01); except for the role physical, role emotional and health transition scores, the various scores of SF-36 were increased compared before treatment in the conventional acupuncture group (P<0.01). After treatment, the physical functioning, role physical, bodily pain, mental health and general health scores of SF-36 in the Fanzhen Jieci group were higher than those in the conventional acupuncture group (P<0.05). CONCLUSION: Fanzhen Jieci combined with conventional acupuncture can effectively relieve the pain and improve the mental state in patients with discogenic sciatica, its therapeutic effect is superior to simple conventional acupuncture.

A network pharmacology approach to predict potential targets and mechanisms of "Ramulus Cinnamomi (cassiae) - Paeonia lactiflora" herb pair in the treatment of chronic pain with comorbid anxiety and depression.

BACKGROUND: Traditional Chinese medicine (TCM) prescriptions have multiple bioactive properties. "Gui Zhi-Shao Yao" herb pair is widely used to treat chronic pain (CP), as well as anxiety and depression. However, its related targets and underlying mechanisms have not been deciphered. METHODS: In this study, the network pharmacology method was used to explore the bioactive components and targets of "Gui Zhi-Shao Yao" herb pair and further elucidate its potential biological mechanisms of action in the treatment of CP with comorbid anxiety disorder (AD) and mental depression (MD). RESULTS: Following a series of analyses, we identified 15 active compounds, hitting 130 potential targets. After the intersections the targets of this herb pair and CP, AD and MD - sorted by the value of degree - nine targets were identified as the vital ones: Akt1, IL6, TNF, PTGS2, JUN, CASP3, MAPK8, PPARγ and NOS3. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis results demonstrated 11 pathways, such as AGE-RAGE signalling pathway, IL-17 signalling pathway, TNF signalling pathway, which primarily participate in the pathological processes. CONCLUSIONS: This study preliminarily predicted and verified the pharmacological and molecular mechanisms of "Gui Zhi-Shao Yao" herb pair for treating CP with comorbid AD and MD from a holistic perspective. In vivo and in vitro experiments will be required to further investigate the mechanisms.KEY MESSAGEA network pharmacology approach was applied to identify key targets and molecular mechanisms.Nine targets were regarded as the vital targets for chronic pain with comorbid anxiety and depression.Predicted 11 pathways were the potential therapy targets and pharmacological mechanism of "Gui Zhi-Shao Yao" herb pair.

Knowledge Mapping Analysis of International Research on Acupuncture for Low Back Pain Using Bibliometrics.

OBJECTIVE: Acupuncture has made recommendations to relieve low back pain (LBP) in a few guidelines. However, few articles focused on the papers published before, which may reflect the trend of study, main researchers, reciprocal collaboration, and other information in this field. In this study, we utilize the bibliometric analysis methods to objectively analyze the current trend and research hotspots about this field, aiming to provide a foundation and reference for future study. METHODS: The Web of Science database was searched for publications related to acupuncture therapy for treating low back pain between 1985 and 2021. VOSviewer and CiteSpace were used to analyze the annual publication, authors and co-cited authors and their countries (regions) and institutions, journals and co-cited journals, co-cited references, co-occurrence keywords, burst keywords, and the relevant centrality. RESULTS: A total of 1279 papers were retrieved from the database, and the trend of annual publications maintained growth. Article was the most document type (867). The USA (451) and the Kyung Hee University (49) were the most productive country (region) and institution, respectively, while the USA (0.37) and University of Maryland (0.13) had the highest centrality. MacPherson, Hugh and Sherman, Karen J. published the most papers in this field (32), and Ernst, Edzard became the most influential author (474 co-citations). Journal of Alternative and Complementary Medicine was the most productive journal (79), whereas SPINE was the most influential one (3111 co-citations). Haake's (2007) article had the most co-citation count (186), while Furlan's (2005) article had the highest centrality (0.23). The three frontier topics were pain management, disease, and protocol. CONCLUSION: The present study investigated publications on acupuncture for treating low back pain using bibliometric analysis methods, which may help researchers explore the potential directions for the future.

Low-intensity pulsed ultrasound prevents angiotensin II-induced aortic smooth muscle cell phenotypic switch via hampering miR-17-5p and enhancing PPAR-γ.

Vascular events can trigger a pathological phenotypic switch in vascular smooth muscle cells (VSMCs), decreasing and disrupting the plasticity and diversity of vascular networks. The development of novel therapeutic approaches is necessary to prevent these changes. We aimed to investigate the effects and associated mechanisms of low-intensity pulsed ultrasound (LIPUS) irradiation on the angiotensin II (AngII)-induced phenotypic switch in VSMCs. In vivo, AngII was infused subcutaneously for 4 weeks to stimulate vascular remodeling in mice, and LIPUS irradiation was applied for 20 min every 2 days for 4 weeks. In vitro, cultured rat aortic VSMCs (RAVSMCs) were pretreated once with LIPUS irradiation for 20 min before 48-h AngII stimulation. Our results showed that LIPUS irradiation prevents AngII-induced vascular remodeling of the whole wall artery without discriminating between adventitia and media in vivo and RAVSMC phenotypic switching in vitro. LIPUS irradiation downregulated miR-17-5p expression and upregulated peroxisome proliferator-activated receptor gamma (PPAR-γ) expression. The PPAR-γ activator rosiglitazone could mimic the favorable effects of LIPUS irradiation on AngII-treated RAVSMCs. In contrast, GW9662 could impede the LIPUS-mediated downregulation of RAVSMC proliferation and inflammation under AngII stimulation conditions in vivo and in vitro. Also, the miR-17-5p agomir has the same effects as GW9662 in vitro. Besides, the inhibitory effects of GW9662 against the anti-remodeling effects of LIPUS irradiation in AngII-induced RAVSMCs could be blocked by pretreatment with the miR-17-5p antagomir. Overall, LIPUS irradiation prevents AngII-induced RAVSMCs phenotypic switching through hampering miR-17-5p and enhancing PPAR-γ, suggesting a new approach for the treatment of vascular disorders.

"Fan-zhen Jie-ci" acupuncture therapy for treatment of discogenic sciatica: protocol for a single-blind, randomized controlled clinical trial.

BACKGROUND: Curative medical treatment for patients with discogenic sciatica is limited. Acupuncture is an important non-pharmacological therapy reported to have positive therapeutic effects on discogenic sciatica. According to traditional Chinese acupuncture theory, discogenic sciatica is a channel tendon disease which can be treated by a special "Fan-zhen Jie-ci (FZJC)" method. Our recent preliminary clinical evidence indicated that the FZJC method had a positive treatment effect on the disease. This study will further evaluate the efficacy and safety of FZJC on patients with discogenic sciatica. METHODS: A single-blind randomized controlled clinical trial will be conducted, assigning 76 participants with discogenic sciatica to a randomly assigned FZJC group or a control group. Acupuncture treatment combined with the FZJC method will be applied in the FZJC group while routine acupuncture treatment only will be applied in the control group. Treatments will be administered three times a week for a total of 3 consecutive weeks. The primary outcome of this trial is change in the visual analogue scale of leg pain (VAS-LP), and the secondary outcomes are changes in the visual analogue scale of back pain (VAS-BP), the Brief Pain Inventory (BPI), the Oswestry Disability Index (ODI), the 36-Item Short Form Health Survey (SF-36), and serum concentrations of mitochondrial DNA (mtDNA) and high sensitivity C reactive protein (hsCRP). DISCUSSION: The results of this study will provide insight into the efficacy and safety of FZJC acupuncture as a treatment for discogenic sciatica. TRIAL REGISTRAION: The trial has been registered at the Chinese Clinical Trial Registry (ChiCTR1900026272) and the Acupuncture-Moxibustion Clinical Trial Registry (AMCTR-IOR-19000275).

Tough thermoplastic hydrogels with re-processability and recyclability for strain sensors.

Tough hydrogels with the ability to be repeatedly processed into various shapes as thermoplastics are highly desired in advanced medical devices and tissue engineering. Here, we have developed a kind of versatile supramolecular hydrogel with a network cross-linked by double hydrogen bonds from poly(N-acryloyl glycinamide) (PNAGA). The resulting PNAGA-30 hydrogels (30 wt% solid content) are tough, re-processable, and recyclable similar to thermoplastics. The hydrogels in the form of fragments can be easily re-processed into various shapes including sheet, filament, cylinder and other complex shapes by using simple stamping and injection methods. The mechanical properties of the re-programed hydrogels are comparable to the properties of the original hydrogels. The re-processability and robust mechanical properties of the PNAGA hydrogels are promising for practical applications in soft materials, tissue engineering and wearable devices. Furthermore, the PNAGA-30&LiCl ionic hydrogels can be fabricated by simply compositing LiCl into thermoplastic hydrogels. The PNAGA-30&LiCl hydrogels can function as multifunctional strain sensors to monitor large human movements and tiny vibrations, thereby showing great application potential in robotics, biomedical prosthetics, personal healthcare monitoring and so on.

Tubular Silk Fibroin/Gelatin-Tyramine Hydrogel with Controllable Layer Structure and Its Potential Application for Tissue Engineering.

In recent years, biomimetic tubular scaffolds have been widely used to repair various human tissue defects, due to their hollow structure similar to the native tissues such as blood vessel, trachea, ureter, and bone marrow cavity. However, there are still many challenges in manufacturing a tubular hydrogel scaffold with suitable mechanical properties, specific microstructure, and good biocompatibility. In this study, we exploited an enzymatic cross-linking method using horseradish peroxidase (HRP) as an enzyme and hydrogen peroxide (H2O2) as a substrate, and combining with gelatin's thermal sensitivity to produce an enzymatically cross-linked silk fibroin/gelatin-tyramine (E-SF/GT) tubular hydrogel. Through further treatment with methanol, we fabricated an EM-SF/GT tubular hydrogel with fine-wall architecture that consists of two different layers (inner and outer, dense and porous). Mechanical measurement showed that the compressive moduli values were up to 4.82 MPa and the tensile moduli values were up to 4.79 kPa under the static loading conditions. Also, degradation test showed that the hydrogel's degradation time was prolonged. Finally, the bioactivity was tested by seeding mouse bone marrow mesenchymal stem cells (mBMSCs) in the lumen of a small-diameter (2 mm) EM-SF/GT tubular hydrogel. Cell morphology and immunofluorescence test indicated that mBMSCs differentiated into endothelial cells and lined the inner surface of the tubular hydrogel under induction. This work provided a feasible strategy for developing tubular hydrogels, which could be potentially used as scaffolds for hollow multilayer tissue engineering, such as blood vessels.

Engineered macroporous hydrogel scaffolds via pickering emulsions stabilized by MgO nanoparticles promote bone regeneration.

Hydrogels are appealing biomaterials for regenerative medicine since biomimetic modifications of their polymeric network can provide unique physical properties and emulate the native extracellular matrix (ECM). Meanwhile, therapeutic metal ions, such as magnesium ions (Mg2+), not only regulate cellular behaviours but also stimulate local bone formation and healing. However, the absence of a meaningful macroporous structure and the uncompromising mechanical strength are still challenges. Herein, we designed a macroporous composite hydrogel based on mild and fast thiol-ene click reactions. The Pickering emulsion method was adopted to form a macroporous structure and introduce MgO nanoparticles (NPs). The results show that the composite hydrogel possesses good mechanical strength and an evenly distributed macroporous structure. MgO NPs stabilized at the oil/water interface not only function as effective emulsion stabilizers, but also enhance the mechanical properties of hydrogels and mediate the sustained release of Mg2+. In vitro cell experiments demonstrated that the composite hydrogel displays good biocompatibility. More importantly, the release of Mg2+ ions from hydrogels can effectively promote the osteogenic differentiation of BMSCs. Furthermore, an in vivo study showed that macroporous hydrogels can provide a good extracellular matrix microenvironment for in situ osteogenesis and accelerate bone tissue regeneration.