ROS-responsive nanoparticle delivery of ferroptosis inhibitor prodrug to facilitate mesenchymal stem cell-mediated spinal cord injury repair.

Spinal cord injury (SCI) is a traumatic condition that results in impaired motor and sensory function. Ferroptosis is one of the main causes of neural cell death and loss of neurological function in the spinal cord, and ferroptosis inhibitors are effective in reducing inflammation and repairing SCI. Although human umbilical cord mesenchymal stem cells (Huc-MSCs) can ameliorate inflammatory microenvironments and promote neural regeneration in SCI, their efficacy is greatly limited by the local microenvironment after SCI. Therefore, in this study, we constructed a drug-release nanoparticle system with synergistic Huc-MSCs and ferroptosis inhibitor, in which we anchored Huc-MSCs by a Tz-A6 peptide based on the CD44-targeting sequence, and combined with the reactive oxygen species (ROS)-responsive drug nanocarrier mPEG-b-Lys-BECI-TCO at the other end for SCI repair. Meanwhile, we also modified the classic ferroptosis inhibitor Ferrostatin-1 (Fer-1) and synthesized a new prodrug Feborastatin-1 (Feb-1). The results showed that this treatment regimen significantly inhibited the ferroptosis and inflammatory response after SCI, and promoted the recovery of neurological function in rats with SCI. This study developed a combination therapy for the treatment of SCI and also provides a new strategy for the construction of a drug-coordinated cell therapy system.

RNA-Seq Analysis Reveals the Molecular Mechanisms Regulating the Development of Different Adipose Tissues in Broiler Chicks.

In an effort to enhance growth rates, chicken breeders have undertaken intensive genetic selection. In the selection process, the primary aim is to accelerate growth, inadvertently leading to new chicken breeds having an increased capacity for rapid adipose tissue accumulation. However, little is known about the relationship between changes in gene expression and adipose tissue accumulation and deposition in chickens. Therefore, in this study, RNA-seq analysis was utilized, and transcriptome data were obtained from the abdominal fat, thoracic subcutaneous fat, and clavicular fat on day 1 (d1), day 4, day 7, day 11, and day 15 to reveal the molecular mechanisms regulating the development and deposition of different adipose tissues in broiler chicks. The results showed that the key period for adipocyte differentiation and proliferation was between d4 and d7 (abdominal fat development) and between d1 and d4 (chest subcutaneous fat and clavicular fat). In addition, candidate genes such as MYOG, S100A9, CIDEC, THRSP, CXCL13, and NMU related to adipose tissue growth and development were identified. Further, genes (HOXC9, AGT, TMEM182, ANGPTL3, CRP, and DSG2) associated with the distribution of adipose tissue were identified, and genes (MN1, ANK2, and CAP2) related to adipose tissue growth were also identified. Taken together, the results from this study provide the basis for future studies on the mechanisms regulating adipose tissue development in chickens. Further, the candidate genes identified could be used in the selection process.

Tough Hydrogels with Different Toughening Mechanisms and Applications.

Load-bearing biological tissues, such as cartilage and muscles, exhibit several crucial properties, including high elasticity, strength, and recoverability. These characteristics enable these tissues to endure significant mechanical stresses and swiftly recover after deformation, contributing to their exceptional durability and functionality. In contrast, while hydrogels are highly biocompatible and hold promise as synthetic biomaterials, their inherent network structure often limits their ability to simultaneously possess a diverse range of superior mechanical properties. As a result, the applications of hydrogels are significantly constrained. This article delves into the design mechanisms and mechanical properties of various tough hydrogels and investigates their applications in tissue engineering, flexible electronics, and other fields. The objective is to provide insights into the fabrication and application of hydrogels with combined high strength, stretchability, toughness, and fast recovery as well as their future development directions and challenges.

[Cu]/NFSI-Mediated Cascade Diels-Alder Radical Annulations Using Norbornene as H-Acceptor under Redox-Neutral Conditions.

An oxidative cascade [4 + 2] radical cycloaddition/dehydroaromatization reaction of aryl alkenes to access α-aryl substituted naphthalenes under redox-neutral conditions was achieved. This reaction was found to require the addition of [Cu] catalyst along with stoichiometric concentrations of NFSI as a trigger of radical series of steps. Norbornene (NBE), rather than the conventional oxidant, manifested optimal performances as a H-acceptor in this procedure. The results herein might shed encouraging insight into the transition-metal-catalyzed dehydrogenative C-H activation protocols.

Ultrafast synthesis of efficient TS-PtCoCu/CNTs composite with high feed-to-product conversion rate by Joule heating for electrocatalytic oxidation of ethanol.

Due to the challenges involved in achieving high metal load, uniform metal dispersion and nanosized metal particles simultaneously, it is difficult to develop a simple protocol for the rapid and efficient synthesis of Pt-based composites for electrocatalytic ethanol oxidation reaction (EOR). In this study, a facile ultrafast thermal shock strategy via Joule heating was applied to fabricate a series of PtCoCu ternary nanoalloys decorated carbon nanotube composites (TS-PtCoCu/CNTs), without the need for a reducing agent or surfactant. The TS-PtCoCu/CNTs with optimal Pt content (∼15 %) exhibited excellent EOR activity, with mass and specific activity of 3.58 A mgPt-1 and 5.79 mA cm-2, respectively, which are 3.8 and 13.5 times higher than those of Pt/C. Compared with the control prepared through the traditional furnace annealing, the catalyst also showed excellent activity and stability. DFT calculations revealed that the TS-PtCoCu/CNTs possesses a downshifted d-band center, weakened CO adsorption and higher OH affinity compared with monometallic Pt, all of which lead to the preferred C1 pathway for EOR. This study demonstrates an ultrafast construction of a highly efficient Pt-Co-Cu ternary catalyst for EOR. Additionally, it provides insights into the reaction mechanism based on structural characterization, electrochemical characterization, and theoretical calculations.

Electromagnetic Detection System with Magnetic Dipole Source for Near-Surface Detection.

This paper proposes a nondestructive, separate transmitter-receiver (TX-RX) electromagnetic measurement system for near-surface detection. Different from the traditional dual-coil integrated design, the proposed transient electromagnetic (TEM) system performs shallow subsurface detection using independent TX coil and movable RX coils. This configuration requires a large primary field so that the far-away secondary field is able to generate reliably induced voltages. To achieve this goal, a bipolar current-pulsed power supply (BCPPS) with a late resonant charging strategy is designed to produce a sufficiently large magnetic moment for the exciting coil with low source interference. The magnetic dipole source (MDS) with a large proportion of weight is separated from the field observation device and does not need to be dragged or transported during the detection process. This setup lowers the weight of the scanning device to 3 kg and greatly improves the measurement efficiency. The results of the laboratory test verify the effectiveness of the separate MDS and RX module system. Field experimental detection further demonstrates that the proposed system can realize highly efficient and shallow surface detection within a 200 m range of the MDS device.

Debridement-Reconstruction-Docking Management System Versus Ilizarov Technique for Lower-Extremity Osteomyelitis.

BACKGROUND: Osteomyelitis causes marked disability and is one of the most challenging diseases for orthopaedists to treat because of the considerable rate of infection recurrence. In this study, we proposed and assessed the debridement-reconstruction-docking (DRD) system for the treatment of lower-extremity osteomyelitis. This procedure comprises 3 surgical stages and 2 preoperative assessments; namely, pre-debridement assessment, debridement, pre-reconstruction assessment, reconstruction, and docking-site management. We evaluated the use of the DRD system compared with the Ilizarov technique, which is defined as a 1-stage debridement, osteotomy, and bone transport. METHODS: This retrospective cohort included 289 patients who underwent either DRD or the Ilizarov technique for the treatment of lower-extremity osteomyelitis at a single institution between January 2013 and February 2021 and who met the eligibility criteria. The primary outcome was the rate of infection recurrence. Secondary outcomes included the external fixator index (EFI), refracture rate, and the Paley classification for osseous and functional results. An inverse-probability-weighted regression adjustment model was utilized to estimate the effect of the DRD system and Ilizarov technique on the treatment of lower-extremity osteomyelitis. RESULTS: A total of 131 and 158 patients underwent DRD or the Ilizarov technique, respectively. The inverse-probability-weighted regression adjustment model suggested that DRD was associated with a significant reduction in infection recurrence (risk ratio [RR], 0.26; 95% confidence interval [CI], 0.13 to 0.50; p < 0.001) and EFI (-6.9 days/cm, 95% CI; -8.3 to -5.5; p < 0.001). Patients in the DRD group had better Paley functional results than those in the Ilizarov group (ridit score, 0.55 versus 0.45; p < 0.001). There was no significant difference between the 2 groups in the rate of refracture (RR, 0.87; 95% CI, 0.42 to 1.79; p = 0.71) and Paley osseous results (ridit score, 0.51 versus 0.49; p = 0.39). CONCLUSIONS: In this balanced retrospective cohort of patients with lower-extremity osteomyelitis, the use of the DRD system was associated with a reduced rate of infection recurrence, a lower EFI, and better Paley functional results compared with the use of the Ilizarov technique. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

The discovery of the new mechanism: Celastrol improves spinal cord injury by increasing cAMP through VIP-ADCYAP1R1-GNAS pathway.

Spinal cord injury (SCI) is a debilitating condition that results in significant impairment of motor function and sensation. Despite the ongoing efforts to develop effective treatments, there are currently very limited options available for patients with SCI. Celastrol, a natural anti-inflammatory compound extracted from Tripterygium wilfordii, has been shown to exhibit anti-inflammatory and anti-apoptotic properties. In this study, we aimed to explore the therapeutic potential of celastrol for SCI and elucidate the underlying molecular mechanisms involved. We found that local tissue often experiences a significant decrease in cAMP content and occurrs apoptosis after SCI. However, the treatment of celastrol could promote the production of cAMP by up-regulating the VIP-ADCYAP1R1-GNAS pathway. This could effectively inhibit the phosphorylation of JNK and prevent apoptosis, ultimately improving the exercise ability after SCI. Together, our results reveal celastrol may be a promising therapeutic agent for the treatment of SCI.

Blocking Nonspecific Interactions Using Y-Shape Poly(ethylene glycol).

Nonspecific interactions play a significant role in physiological activities, surface chemical modification, and artificial adhesives. However, nonspecificity sometimes causes sticky problems, including surface fouling, decreased target specificity, and artifacts in single-molecule measurements. Adjusting the liquid pH, using protein-blocking additives, adding nonionic surfactants, or increasing the salt concentration are common methods to minimize nonspecific binding to achieve high-quality data. Here, we report that grafting heteromorphic polyethylene glycol (Y-shape PEG) with two inert terminates could noticeably decrease nonspecific binding. As a proof-of-concept, we performed single-molecule force spectroscopy and fluorescence staining imaging experiments to verify the feasibility of Y-shape PEG in blocking nonspecific interactions. Our results indicate that Y-shape PEG could serve as a prominent and efficient candidate to minimize nonspecificity for scientific and biomedical applications.

A prospective study on the differential association of sarcopenia and frailty with health outcomes in cirrhotic patients.

BACKGROUND: To investigate the joint impact of sarcopenia and frailty on mortality and the development of decompensation in cirrhosis. METHODS: Sarcopenia was assessed using the skeletal muscle mass index (SMI) by computed tomography, whereas frailty was measured using the Fried Frailty Phenotype (FFP). Cox proportional hazard regression and competing risks analysis were used to evaluate their association with adverse outcomes. RESULTS: The prevalence of sarcopenia and frailty was 29.6% and 37.2%, respectively. Sarcopenia and frailty separately increased more than two times higher risk of all-cause mortality after adjustment for age, gender, Child-Turcotte-Pugh, and comorbidities. Co-occurrence of sarcopenia and frailty was associated with a higher incremental risk of mortality in patients with cirrhosis (HR = 4.16, 95% CI: 1.64-10.58, P = 0.003), but these two conditions didn't have significant interaction. Frailty, but not sarcopenia, was significantly associated with an increased cumulative incidence of liver-related mortality and decompensation after adjusting covariates. Subgroup analysis revealed that frailty shortened the liver-related survival of cirrhosis patients with male or higher liver severity based on MELD. CONCLUSIONS: Co-occurrence of sarcopenia and frailty increased the risk of death in cirrhosis, but these two conditions didn't have a significant interaction association. Frailty, but not sarcopenia, was associated with more adverse outcomes in cirrhotic patients.

Broken-gap type-III band alignment in monolayer halide perovskite/antiperovskite oxide van der Waals heterojunctions.

The integration of halide perovskites with other functional materials provides a new platform for applications beyond photovoltaics, which has been realized in experiments. Here, through first-principles methods, we explore the possibility of constructing halide perovskite/antiperovskite oxide van der Waals heterostructures (vdWHs) for the first time with monolayers Rb2CdCl4 and Ba4OSb2 as representative compounds. Our calculation results reveal that the Rb2CdCl4/Ba4OSb2 vdWHs have negative binding energies and their most stable stacking possesses a rare type-III band alignment with a broken gap, which is highly promising for tunnel field-effect transistor (TFET) applications. Moreover, their electronic features can be further tuned by applying strain or an external electric field. Specifically, compressive strain can enlarge the tunneling window, while tensile strain can realize a type-III to type-II band alignment transformation. Therefore, our work provides fundamental insights into the electronic properties of Rb2CdCl4/Ba4OSb2 vdWHs and paves the way for the design and fabrication of future halide perovskite/antiperovskite-based TFETs.

One-pot synthesis of ultrafine trimetallic PtPdCu alloy nanoparticles decorated on carbon nanotubes for bifunctional catalysis of ethanol oxidation and oxygen reduction.

Bifunctional catalysts for ethanol oxidation reaction (EOR) and oxygen reduction reaction (ORR) with high noble-metal utilization are highly beneficial to direct ethanol fuel cells (DEFCs). This study developed a ternary bifunctional catalyst composed of ultrafine PtPdCu alloy nanoparticles and carbon nanotubes (CNTs) support through a facile surfactant-free solvothermal route. The carboxyl terminal groups on CNTs ensure the confined growth of PtPdCu alloys (∼5 nm) and suppress Ostwald ripening of metallic active sites during electrochemical cycling. Consequently, PtPdCu/CNTs exhibits high mass activity (1.95 A mg-1) and specific activity (4.08 mA cm-2) toward EOR, which are 7.8 and 8.9 times higher, respectively, than those of commercial Pt/C. Furthermore, PtPdCu/CNTs displays superior stability toward EOR compared with its bimetallic counterparts (PtPd/CNTs and PtCu/CNTs). In addition, PtPdCu/CNTs exhibits the highest half-wave potential of 0.888 V among all electrocatalysts, indicating high ORR activity. Density functional theory calculations reveal that Pd and Cu mediate the electronic structure of Pt, leading to enhanced catalytic activity of PtPdCu/CNTs. The excellent catalytic property of PtPdCu/CNTs can also be attributed to the bifunctional effects of Pd/Cu and the interaction between metal and the carbon support. The proposed material is a contribution to the family of efficient ternary-alloy electrocatalysts for fuel cells.

Diagnosis of Sarcopenia Using the L3 Skeletal Muscle Index Estimated From the L1 Skeletal Muscle Index on MR Images in Patients With Cirrhosis.

BACKGROUND: Cirrhotic patients with sarcopenia have poor prognoses and higher mortality. The third lumbar vertebra (L3) skeletal muscle index (SMI) is widely used to assess sarcopenia. However, L3 is generally outside the scanning volume on standard liver MRI. PURPOSE: To investigate SMIs change between slices in cirrhotic patients and the relationships between SMI at the 12th thoracic vertebra (T12), the first lumbar vertebra (L1) and the second lumbar vertebra (L2) levels and L3-SMI and assess the accuracy of the estimated L3-SMIs in diagnosing sarcopenia. STUDY TYPE: Prospective. SUBJECTS: A total of 155 cirrhotic patients (109 with sarcopenia, 67 male; 46 without sarcopenia, 18 male). FIELD STRENGTH/SEQUENCE: A 3.0 T, 3D dual-echo T1-weighted gradient echo sequence (T1WI). ASSESSMENT: Two observers analyzed T12 to L3 skeletal muscle area (SMA) in each patient based on T1W water images and calculated the SMI (SMA/height2 ). Reference standard was L3-SMI. STATISTICAL TESTS: Intraclass correlation coefficient (ICC), Pearson correlation coefficients (r), and Bland-Altman plots. Models relating L3-SMI to the SMI at T12, L1, and L2 levels were constructed using 10-fold cross-validation. Accuracy, sensitivity, and specificity were calculated for the estimated L3-SMIs for diagnosing sarcopenia. P < 0.05 was considered statistically significant. RESULTS: Intraobserver and interobserver ICCs were 0.998-0.999. The L3-SMA/L3-SMI were correlated with the T12 to L2 SMA/SMI (r = 0.852-0.977). T12-L2 models had mean-adjusted R2 values of 0.75-0.95. The estimated L3-SMI from T12 to L2 levels to diagnose sarcopenia had good accuracy (81.4%-95.3%), sensitivity (88.1%-97.0%), and specificity (71.4%-92.9%). The recommended L1-SMI threshold of 43.24 cm2 /m2 in males and 33.73 cm2 /m2 in females. DATA CONCLUSION: The estimated L3-SMI from T12, L1 and L2 levels had good diagnostic accuracy in assessing sarcopenia in cirrhotic patients. Although L2 was best associated with L3-SMI, L2 is generally not included in standard liver MRI. L3-SMI estimate from L1 may therefore be most clinically applicable. EVIDENCE LEVEL: 1. TECHNICAL EFFICACY: Stage 2.

Study on molecular biological mechanism of Chinese herbal medicines for the treatment of gastric precancerous lesions based on data mining and network pharmacology.

OBJECTIVE: To explore the molecular biological mechanisms of Chinese herbal medicines for the treatment of gastric precancerous lesions by data mining and network pharmacology. METHODS: The keywords "gastric precancerous lesions""gastric precancerous disease""gastric mucosal intraepithelial neoplasia""gastric mucosal heterogeneous hyperplasia""gastric precancerous state""chronic gastritis, atrophic""combined Chinese and Western medicine""Chinese medicine therapy""efficacy evaluation" "randomized controlled trial"were searched in China Journal Full-text Database, Wanfang Data, VIP database, PubMed and Embase from 2001 to 2021. The information was extracted from the literature which met the inclusion and exclusion criteria, and the database was constructed to identify the high-frequency herbal medicines. The top six Chinese herbal medicines were analyzed by the network pharmacology methods, including the acquisition of herbs compounds and gastric precancerous lesions targets using Pharmacology Database and Analysis Platform and GeneCards databases, construction of protein-protein interaction network, and screening of core targets, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of core targets through Metascape platform, etc., to elucidate their active components, targets and pathways. RESULTS: A total of 482 compound prescriptions with 603 herbal medicines were included, and the top 6 herbal medicines with higher application frequency were Ume plum (63.35%), Curcuma longa (58.54%), Paeonia lactiflora (54.06%), Salvia miltiorrhiza (49.92%), Rhizoma alba (46.43%), and Astragalus membranaceus (45.44%). The results of the network pharmacological analysis showed that the active ingredients were 4 types from Ume plum, 3 from Curcuma longa, 9 from Paeonia lactiflora, 13 from Salvia miltiorrhiza, 7 from Astragalus alba, and 9 from Astragalus; 77 predicted targets were in Ume plum, 11 in Curcuma longa, 33 in Paeonia lactiflora, 58 in Salvia miltiorrhiza, 65 in Astragalus alba and 89 in Astragalus; and 98 crossover genes were obtained after these targets were compared with the disease genes, among which HSP90AA1, AKT1, TP53, STAT3, MAPK1 and TNF had higher relevance to the treatment of gastric precancerous lesions. The results of the GO enrichment analysis showed that the active ingredients of high frequency Chinese medicine mostly acted through biological processes such as response to inorganic substance, response to hormone, gland development, positive regulation of cell migration, positive regulation of cell motility, etc. The targets include cellular components such as vesicle lumen, secretory granule lumen, cytoplasmic vesicle lumen, transcription regulator complex, and with molecular functions such as kinase binding, protein kinase binding and DNA-binding transcription factor binding. The results of the KEGG pathway enrichment analysis showed that Paeonia lactiflora, Ulmus lucidus, Salvia miltiorrhiza and Astragalus mainly act through the cancer pathway and PI3K-AKT pathway; Curcuma longa and Rhizoma alba mainly act through the cancer pathway and proteoglycans in cancer, and all six herbs were involved in the cancer pathway and five herbs are involved in the PI3K-AKT pathway. CONCLUSION: In this study, we obtained the top 6 high-frequency Chinese herbal medicines in the treatment of gastric precancerous lesions by data mining method, and revealed that their mechanisms are involved in cell proliferation, differentiation, immunity, inflammation and other processes mainly through cancer pathway, PI3K-AKT signaling pathway, proteoglycans in cancer.

Agreement and correlation of abdominal skeletal muscle area measured by CT and MR imaging in cirrhotic patients.

BACKGROUND: CT-based abdominal skeletal muscle area (SMA) serves as a standard for assessing muscle mass in patients with cirrhosis. Few studies have used MR imaging to measure SMA in cirrhotic patients. The purpose of this study was to investigate the agreement and correlation of the SMA measured by MRI and CT in cirrhotic patients. METHODS: CT and MR images from 38 cirrhotic patients were analyzed using the Slice-O-Matic V5.0 software. One observer independently measured SMA at the mid-third lumbar vertebral (L3) level on CT and MR images. The intraclass correlation coefficient (ICC), Pearson correlation coefficient, and Bland-Altman plot were used to evaluate the agreement and correlation between CT and MRI SMA and their relationship with the sarcopenia severity and Child-Pugh grades. RESULTS: CT and MRI had a high intraobserver agreement, with ICCs ranging from 0.991 to 0.996. CT and MRI measurements were closely correlated (r = 0.991-0.998, all for P < 0.01), and the bias of the measurements was 0.68-3.02%. Among all MR images, T1w water images had the strongest correlation (r = 0.998, P < 0.01) and the minimum bias of 0.68%. The measurements of mid-L3 SMA on CT and T1w water images remained highly consistent in cirrhotic patients with different severities of sarcopenia and Child-Pugh grades. CONCLUSIONS: MRI and CT showed high agreement and correlation for measuring mid-L3 SMA in cirrhotic patients. In addition to CT, MR images can also be used to assess muscle mass in cirrhotic patients, regardless of the severity of sarcopenia and Child-Pugh grades.

The multifaceted roles of peptides in "always-on" near-infrared fluorescent probes for tumor imaging.

Tumor-targeted near-infrared (NIR) fluorescence imaging by using NIR fluorescent probes has attracted extensive attentions in the field of tumor imaging and is becoming an attractive strategy for early cancer diagnosis and surgical guidance for the past few decades. Especially, due to the high affinity and low toxicity, the peptide-based NIR fluorescent probes play an important role in the field of tumor-targeted imaging and therapy. Extensive attempts have been made to develop a set of nontoxic and efficacious "always-on" peptide-based NIR fluorescent probes. In this review, we give a comprehensive analysis of the "always-on" peptide-based NIR fluorescent probes for tumor-targeting for the past 5 years, highlighting the design strategy, chemical synthesis, therapeutical applications, spectroscopic and pharmacological characterization, as well as the multifaceted roles of peptides. A comprehensive understanding of the tumor-targeted, "always-on" peptide-based NIR fluorescent probes will increase our knowledge of cancer diagnosis and benefit clinical cancer therapeutics.

Engineering Bio-Adhesives Based on Protein-Polysaccharide Phase Separation.

Glue-type bio-adhesives are in high demand for many applications, including hemostasis, wound closure, and integration of bioelectronic devices, due to their injectable ability and in situ adhesion. However, most glue-type bio-adhesives cannot be used for short-term tissue adhesion due to their weak instant cohesion. Here, we show a novel glue-type bio-adhesive based on the phase separation of proteins and polysaccharides by functionalizing polysaccharides with dopa. The bio-adhesive exhibits increased adhesion performance and enhanced phase separation behaviors. Because of the cohesion from phase separation and adhesion from dopa, the bio-adhesive shows excellent instant and long-term adhesion performance for both organic and inorganic substrates. The long-term adhesion strength of the bio-glue on wet tissues reached 1.48 MPa (shear strength), while the interfacial toughness reached ~880 J m-2. Due to the unique phase separation behaviors, the bio-glue can even work normally in aqueous environments. At last, the feasibility of this glue-type bio-adhesive in the adhesion of various visceral tissues in vitro was demonstrated to have excellent biocompatibility. Given the convenience of application, biocompatibility, and robust bio-adhesion, we anticipate the bio-glue may find broad biomedical and clinical applications.

Stretchable and self-healable hydrogel artificial skin.

Hydrogels have emerged as promising materials for the construction of skin-like mechanical sensors. The common design of hydrogel-based artificial skin requires a dielectric sandwiched between two hydrogel layers for capacitive sensing. However, such a planar configuration limits the sensitivity, stretchability and self-healing properties. Here, we report the design of single-layer composite hydrogels with bulk capacitive junctions as mechanical sensors. We engineer dielectric peptide-coated graphene (PCG) to serve as homogenously dispersed electric double layers in hydrogels. Any mechanical motions that alter the microscopic distributions of PCG in the hydrogels can significantly change the overall capacitance. We use peptide self-assembly to render strong yet dynamic interfacial interactions between the hydrogel network and graphene. The resulting hydrogels can be stretched up to 77 times their original length and self-heal in a few minutes. The devices can effectively sense strain and pressure in both air and aqueous environments, providing tremendous opportunities for next-generation iontronics.

Hydrogel Development for Rotator Cuff Repair.

Rotator cuff tears (RCTs) are common in shoulder disease and disability. Despite significant advances in surgical repair techniques, 20-70% of patients still have postoperative rotator cuff dysfunction. These functional defects may be related to retear or rotator cuff quality deterioration due to tendon retraction and scar tissue at the repair site. As an effective delivery system, hydrogel scaffolds may improve the healing of RCTs and be a useful treatment for irreparable rotator cuff injuries. Although many studies have tested this hypothesis, most are limited to laboratory animal experiments. This review summarizes differences in hydrogel scaffold construction, active ingredients, and application methods in recent research. Efforts to determine the indications of hydrogel scaffolds (with different constructions and cargos) for various types of RCTs, as well as the effectiveness and reliability of application methods and devices, are also discussed.

Chiral Supramolecular Hydrogel Loaded with Dimethyloxalyglycine to Accelerate Chronic Diabetic Wound Healing by Promoting Cell Proliferation and Angiogenesis.

Chronic refractory wounds are one of the most serious complications of diabetes, and the effects of common treatments are limited. Chiral hydrogel combined with dimethyloxalyglycine (DMOG) as a dressing is a promising strategy for the treatment of chronic wounds. In this research, we have developed a DMOG-loaded supramolecular chiral amino-acid-derivative hydrogel for wound dressings for full-thickness skin regeneration of chronic wounds. The properties of the materials, the ability of sustained release drugs, and the ability to promote angiogenesis were tested in vitro, and the regeneration rate and repair ability of full-thickness skin were tested in vivo. The chiral hydrogel had the ability to release drugs slowly. It can effectively promote cell migration and angiogenesis in vitro, and promote full-thickness skin regeneration and angiogenesis in vivo. This work offers a new approach for repairing chronic wounds completely through a supramolecular chiral hydrogel loaded with DMOG.