Aesthetic Cellulose Filaments with Water-Triggered Switchable Internal Stress and Customizable Polarized Iridescence Toward Green Fashion Innovation.

Healthy, convenient, and aesthetic hair dyeing and styling are essential to fashion trends and personal-social interactions. Herein, we fabricate green, scalable, and aesthetic regenerated cellulose filaments (ACFs) with customizable iridescent colors, outstanding mechanical properties, and water-triggered moldability for convenient and fashionable artificial hairdressing. The fabrication of ACFs involves cellulose dissolution, cross-linking, wet-spinning, and nanostructured orientation. Notably, the cross-linking strategy endows the ACFs with significantly weakened internal stress, confirmed by monitoring the offset of the C-O-C group in the cellulose molecular chain with Raman imaging, which ensures a tailorable orientation of the nanostructure during wet stretching and tunable iridescent polarization colors. Interestingly, ACFs can be tailored for three-dimensional shaping through a facile water-triggered adjustable internal stress: temporary shaping with low-level internal stress in the wet state and permanent shaping with high-level internal stress in the dry state. The health, convenience, and green aesthetic filaments show great potential in personal wearables.

Fabrication of Multi-Layered Paper-Based Supercapacitor Anode by Growing Cu(OH)2 Nanorods on Oxygen Functional Groups-Rich Sponge-Like Carbon Fibers.

This work addresses the challenges in developing carbon fiber paper-based supercapacitors (SCs) with high energy density by focusing on the limited capacity of carbon fiber. To overcome this limitation, a sponge-like porous carbon fiber paper enriched with oxygen functional groups (OFGs) is prepared, and Cu(OH)2 nanorods are grown on its surface to construct the SC anode. This design results in a multi-layered carbon fiber paper-based electrode with a specific structure and enhanced capacitance. The Cu(OH)2 @PCFP anode exhibits an areal capacitance of 547.83 mF cm-2 at a current density of 1 mA cm-2 and demonstrates excellent capacitance retention of 99.8% after 10 000 cycles. Theoretical calculations further confirm that the Cu(OH)2 /OFGs-graphite heterostructure exhibits higher conductivity, facilitating faster charge transfer. A solid-state SC is successfully assembled using Ketjen Black@PCFP as the cathode and KOH/PVA as the gel electrolyte. The resulting device exhibits an energy density of 0.21 Wh cm-2 at 1.50 mW cm-2 , surpassing the performance of reported Cu(OH)2 SCs. This approach, combining materials design with an understanding of underlying mechanisms, not only expands the range of electrode materials but also provides valuable insights for the development of high-capacity energy storage devices.

Elemene Antitumor Drugs Development Based on "Molecular Compatibility Theory" and Clinical Application: A Retrospective and Prospective Outlook / 中国结合医学杂志

Elemene, derived from Curcuma wenyujin, one of the "8 famous genuine medicinal materials of Zhejiang province," exhibits remarkable antitumor activity. It has gained wide recognition in clinical practice for effectiveness on tumors. Dr. XIE Tian, introduced the innovative concept of "molecular compatibility theory" by combining Chinese medicine principles, specifically the "monarch, minister, assistant, and envoy" theory, with modern biomedical technology. This groundbreaking approach, along with a systematic analysis of Chinese medicine and modern biomedical knowledge, led to the development of elemene nanoliposome formulations. These novel formulations offer numerous advantages, including low toxicity, well-defined composition, synergistic effects on multiple targets, and excellent biocompatibility. Following the principles of the "molecular compatibility theory", further exploration of cancer treatment strategies and methods based on elemene was undertaken. This comprehensive review consolidates the current understanding of elemene's potential antitumor mechanisms, recent clinical investigations, advancements in drug delivery systems, and structural modifications. The ultimate goal of this review is to establish a solid theoretical foundation for researchers, empowering them to develop more effective antitumor drugs based on the principles of "molecular compatibility theory".

Dual-Cross-Linked PEI/PVA Hydrogel for pH-Responsive Drug Delivery.

Herein, a pH-responsive dual cross-linked hydrogel for controlled drug release is presented. The hydrogel was constructed with reversible borate ester bonds and crystalline poly(vinyl alcohol). By changing the environmental pH, its physicochemical characteristics, including rheological properties, mechanical properties, microstructural features, and the biocompatibility of the gels, were evaluated. The gels at tumor acidic conditions exhibited swelling and lower compressive strength and modulus than those in a physiological environment, which was attributed to the pH-responsive borate ester bonds and the protonation of amine groups on the PEI polyelectrolyte. Importantly, the drug-encapsulated biocompatible hydrogel showed sustained and increased release under an acidic environment, and it followed the Fickian diffusion mechanism. Therefore, it exemplifies that borate ester bond-based pH-responsive biomaterials have high promise in biomedical research, especially for drug delivery.

Exosomal miR-127-5p from BMSCs alleviated sepsis-related acute lung injury by inhibiting neutrophil extracellular trap formation.

Neutrophil extracellular traps (NETs) play an important role in sepsis-related acute lung injury (ALI). Bone marrow mesenchymal stem cells (BMSCs)-derived exosomes and miRNA are becoming promising agents for the treatment of ALI. The current study aimed to elucidate the mechanism by BMSCs-derived exosomes carrying miR-127-5p inhibiting to the formation of NETs in sepsis-related ALI. We successfully isolated exosomes from BMSCs and confirmed that miR-127-5p was enriched in the exosomes. ALI mice treated with BMSCs-derived exosomes histologically improved, and the release of NETs and inflammatory factors in lung tissue and peripheral blood of mice also decreased compared with LPS group, while the protective effect of exosomes was attenuated after the knockdown of miR-127-5p. Using dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay, we identified CD64 as a direct target of miR-127-5p. Meanwhile, BMSCs-derived exosomes can synergize with anti-CD64 mab in ALI mice to reduce tissue damage, inhibit the release of inflammatory factors and NETs formation. The synergistic effect of exosomes was attenuated when miR-127-5p was down-regulated. These findings suggest that exosomal miR-127-5p derived from BMSCs is a potential therapeutic agent for treatment of sepsis-induced ALI through reducing NETs formation by targeting CD64.

Cannabinoid receptor 2 alleviates sepsis-associated acute lung injury by modulating maturation of dendritic cells.

BACKGROUND: Dendritic cells (DCs) play a key role in a variety of inflammatory lung diseases, but their role in sepsis-associated acute lung injury (SA-ALI) is currently not been illuminated. Cannabinoid receptor 2 (CNR2) has been reported to regulate the DCs maturation. However, whether the CNR2 in DCs contributes to therapeutic therapy for SA-ALI remain unclear. In current study, the role of CNR2 on DCs maturation and inflammatory during SA-ALI is to explored. METHODS: First, the CNR2 level was analyzed in isolated Peripheral Blood Mononuclear Cells (PBMCs) and Bronchoalveolar Lavage Fluid (BALF) from patient with SA-ALI by qRT-PCR and flow cytometry. Subsequently, HU308, a specific agonist of CNR2, and SR144528, a specific antagonist of CNR2, were introduced to explore the function of CNR2 on DCs maturation and inflammatory during SA-ALI. Finally, CNR2 conditional knockout mice were generated to further confirm the function of DCs maturation and Inflammation during SA-ALI. RESULTS: First, we found that the expression of CNR2 on DCs was decreased in patient with SA-ALI. Besides, the result showed HU308 could decrease the maturation of DCs and the level of inflammatory cytokines, simultaneously reduce pulmonary pathological injury after LPS-induced sepsis in mice. In contrast of HU308, SR144528 exhibits opposite function of DCs maturate, inflammatory cytokines and lung pathological injury. Furthermore, comparing with SR144528 treatment, similar results were obtained in DCs specific CNR2 knockout mice after LPS treatment. CONCLUSION: CNR2 could alleviate SA-ALI by modulating maturation of DCs and inflammatory factors levels. Targeting CNR2 signaling specifically in DCs has therapeutic potential for the treatment of SA-ALI.

A simple, flexible, and high-efficiency western blot analysis for age-related human induced neurons.

High-throughput western blot (WB) analysis can be used to obtain more consistent, comparable, and informative data from precious samples and materials with extremely limited availability, such as various age-related, subtype-specific human induced neurons (hiNs). In this study, p-toluenesulfonic acid (PTSA), an odorless tissue fixative, was used to inactivate horseradish peroxidase (HRP) and develop a high-throughput WB method. PTSA-treated blots demonstrated rapid and efficient HRP inactivation without detectable protein loss or epitope damage. With a brief PTSA treatment (1 min at room temperature [RT]) before every subsequent probing, 10 dopaminergic hiN proteins could be sequentially, sensitively, and specifically detected in the blot. The resulting WB data confirmed the age-associated and neuron-specific features of hiNs and revealed a significant reduction in two Parkinson's disease-associated proteins, UCHL1 and GAP43, in normal aging dopaminergic neurons. Overall, this study developed a unique and high-efficiency WB analysis method for capturing robust and useful data from limited, precious samples.

Durable and rechargeable antimicrobial cotton driven by enhanced UV stability and real-time detection of biocidal factors.

In this study, graphene oxide/N-halamine nanocomposite was synthesized through Pickering miniemulsion polymerization, which was then coated on cotton surface. The modified cotton exhibited excellent superhydrophobicity, which could effectively prevent microbial infestation and reduce the probability of hydrolysis of active chlorine, with virtually no active chlorine released in water after 72 h. Deposition of reduced graphene oxide nanosheets endowed cotton with ultraviolet-blocking properties, attributing to enhanced UV adsorption and long UV paths. Moreover, encapsulation of polymeric N-halamine resulted in improved UV stability, thus extending the life of N-halamine-based agents. After 24 h of irradiation, 85 % of original biocidal component (active chlorine content) was retained, and approximately 97 % of initial chlorine could be regenerated. Modified cotton has been proven to be an effective oxidizing material against organic pollutants and a potential antimicrobial substance. Inoculated bacteria were completely killed after 1 and 10 min of contact time, respectively. An innovative and simple scheme for determination of active chlorine content was also devised, and real-time inspection of bactericidal activity could be achieved to assure antimicrobial sustainability. Moreover, this method could be utilized to evaluate hazard classification of microbial contamination in different locations, thus broadening the application scope of N-halamine-based cotton fabrics.

A facile strategy to fabricate high-barrier, water- and oil-repellent paper with carboxymethyl cellulose/collagen fiber/modified polyvinyl alcohol.

Due to the increasingly serious environmental and human health hazards brought by traditional food packaging materials, paper-based packaging materials have become increasingly popular among consumers in recent years. Currently, the fabrication of fluorine-free degradable water- and oil-repellent paper using low-cost bio-based polymers by a simple method is a hot subject in the field of food packaging. In this work, we used carboxymethyl cellulose (CMC), collagen fiber (CF), and modified polyvinyl alcohol (MPVA) to create coatings that were impervious to water and oil. The homogeneous mixture of CMC and CF generated electrostatic adsorption to impart excellent oil repellency to the paper. PVA was chemically modified by sodium tetraborate decahydrate, and the MPVA coating imparted excellent water-repellent properties to the paper. Finally, the water- and oil-proof paper showed excellent water repellency (Cobb value: 1.12 g/m2), oil repellency (kit rating: 12/12), low air permeability (0.3 µm/Pa·s), and stronger mechanical properties (4.19 kN/m). This non-fluorinated degradable water- and oil-repellent paper with high barrier properties prepared by a convenient method is expected to be in widespread use in the food packaging field.

Rippling Colloidal Polyelectrolyte Complex for Customized Fingerprints with High Tactile Perception.

Fingerprints possess wide applications in personal identification, tactile perception, access control, and anti-counterfeiting. However, latent fingerprints are usually left on touched surfaces, leading to the leakage of personal information. Furthermore, tactile perception greatly decreases when fingerprints are covered by gloves. Customized fingerprints are developed to solve these issues, but it is a challenge to develop fingerprints with various customized patterns using traditional techniques due to their requiring special templates, materials, or instruments. Inspired by ripples on the lake, blowing air is used to generate surface waves on a colloidal polyelectrolyte complex, leading to vertical stratification and the accumulation of particles near the top of the film layer. As water rapidly evaporates, the viscosity of these particles significantly increases and the wave is solidified, forming fingerprint patterns. These customized fingerprints integrate functions of grasping objects, personal identification without leaving latent fingerprints and tactile perception enhancement, which can be applied in information security, anti-counterfeiting, tactile sensors, and biological engineering.

Hydrogel with ROS scavenging effect encapsulates BR@Zn-BTB nanoparticles for accelerating diabetic mice wound healing via multimodal therapy.

The strategies for eliminating excess reactive oxygen species (ROS) or suppressing inflammatory responses on the wound bed have proven effective for diabetic wound healing. In this work, a zinc-based nanoscale metal-organic framework (NMOF) functions as a carrier to deliver natural product berberine (BR) to form BR@Zn-BTB nanoparticles, which was, in turn, further encapsulated by hydrogel with ROS scavenging ability to yield a composite system of BR@Zn-BTB/Gel (denoted as BZ-Gel). The results show that BZ-Gel exhibited the controlled release of Zn2+ and BR in simulated physiological media to efficiently eliminated ROS and inhibited inflammation and resulted in a promising antibacterial effect. In vivo experiments further proved that BZ-Gel significantly inhibited the inflammatory response and enhanced collagen deposition, as well as to re-epithelialize the skin wound to ultimately promote wound healing in diabetic mice. Our results indicate that the ROS-responsive hydrogel coupled with BR@Zn-BTB synergistically promotes diabetic wound healing.

Water and oil-resistant paper materials based on sodium alginate/hydroxypropyl methylcellulose/polyvinyl butyral/nano-silica with biodegradable and high barrier properties.

Despite many technical challenges in the development of safe and environmentally friendly food packaging paper materials with excellent water and oil resistance using simple methods, producing paper-based functional materials using bio-based polymers is currently an important topic in the food packaging industry. In this study, novel water and oil-resistant coatings for the paper were developed through the combination of sodium alginate (SA), hydroxypropyl methylcellulose (HPMC), polyvinyl butyral (PVB), and hydrophobic silica nanoparticles (HSNPs). To impart oil-repellency to paper, SA and HPMC were first mixed uniformly and coated on the base paper, which was pre-treated with calcium chloride solution. A compact and tough coating layer was formed on paper due to the hydrogen bonding between SA and HPMC molecules, and the crosslinking between SA and Ca2+ ions in the base paper. High water resistance of the paper was achieved through the coating of PVB and HSNPs on top of the coating of SA/HPMC. The final coated paper demonstrated outstanding oil resistance (kit rating: 12/12), water resistance (Cobb value: 4.23 g/m2), low water vapor transmission rate (100 g/m2·24 h), and improved mechanical properties. This fluorine-free, and biodegradable barrier paper will find excellent applications in the food packaging industry.

JTE-013 mediates RhoA/ROCKl/Drpl signaling axis regulating mitochondrial damage and apoptosis to alleviate allergic rhinitis / 中国药理学通报

Aim To investigate the protective effect and mechanism of JTE-013 on allergic rhinitis (AR) by regulating mitochondrial injury and apoptosis through RhoA/ROCKl/Drpl pathway. Methods AR model was established by ovalbumin (OVA) in mice. Nasal tissue sections were then stained with HE, TUNEL and DHE. Western blot assay. In vitro, human nasal epithelial cells (HNEpCs) were stimulated with human recombinant interleukin-13 (IL-13), and the effects of JTE-013 and Y27632-related protein expression were detected by Western blot. Immunofluorescence was used to observe the effects of JTE-013 and Y 27632 on total ROS, mitochondrial membrane potential and mitochondrial ROS generation, Drpl translocation and Cyt-c expression in cells. Results JTE-013 reduced the frequency of nose rubbing and sneezing, reduced nasal mucosal thickening and decreased eosinophil infiltration in AR mice. TUNEL and DHE staining results suggested that JTE-013 could inhibit apoptosis and reduce ROS expression in mouse nasal epithelial cells. Western blot showed that both JTE-013 and Y 27632 could significantly reduce RhoA, ROCK1, Drpl and p-Drpl(616), inhibit the expression of apoptotic proteins Bax, cleaved-caspase-3, Cyt-c, cleavedcaspase-9 and up-regulate the expression of p-Drpl (637) and Bcl-2. Immunofluorescence showed that inhibitors of JTE-013 or ROCK1 almost blocked IL-13mediated increase in ROS and mtROS production, inhibited decrease in mitochondrial membrane potential, and blocked Cyt-c expression and Drpl translocation in nasal mucosal epithelial cells. Conclusion JTE-013 can regulate the morphology and function of mitochondria by inhibiting RhoA/ROCKl/Drpl signaling axis, thereby alleviating nasal epithelial cell inflammation in mice with allergic rhinitis.

Effects of zhongfeng cutong moxibustion on motor function and corticospinal tract in the patients with motor dysfunction during the recovery period of cerebral infarction / 中国针灸

OBJECTIVES@#To observe the effects of zhongfeng cutong moxibustion (moxibustion therapy for unblocking and treating stroke) on the motor function and the structure of corticospinal tract (CST) in the patients with motor dysfunction during the recovery period of cerebral infarction, and to explore the central mechanism of this moxibustion therapy for improving the motor function.@*METHODS@#Fifty patients with motor dysfunction during the recovery period of cerebral infarction were randomly divided into an observation group (25 cases, 1 case dropped out) and a control group (25 cases, 1 case dropped out). The patients in both groups underwent the conventional basic treatment. In the control group, acupuncture was applied to Baihui (GV 20) and Shuigou (GV 26), as well as Chize (LU 5), Neiguan (PC 6), Weizhong (BL 40) and Sanyinjiao (SP 6) etc. on the affected side. Besides the intervention of the control group, in the observation group, zhongfeng cutong moxibustion therapy was combined at Baihui (GV 20), Shenque (CV 8) and bilateral Zusanli (ST 36). Both acupuncture and moxibustion therapies were delivered once daily, 5 times a week, for 2 weeks. The scores of Fugl-Meyer assessment scale (FMA) and National Institutes of Health stroke scale (NIHSS) were compared between the two groups before and after treatment. The diffusion tensor imaging technique was used to observe the fractional anisotropy (FA) of CST at the bilateral whole segment, the cerebral cortex, the posterior limb of the internal capsule and the cerebral peduncle before and after treatment in the two groups.@*RESULTS@#The scores of the upper and the lower limbs of FMA, as well as the total FMA score swere increased after treatment when compared with those before treatment in the two groups (P<0.05), the upper limb FMA score and the total FMA score in the observation group were higher than those in the control group (P<0.05), and NIHSS scores of the two groups were dropped compared with those before treatment (P<0.01). FA of CST at the bilateral sides of the posterior limb of the internal capsule and the whole segment on the focal side was improved in comparison with that before treatment in the observation group (P<0.05), and FA of CST at the healthy side of the whole segment was higher than that before treatment in the control group (P<0.05).@*CONCLUSIONS@#Zhongfeng cutong moxibustion improves motor function and reduces neurological deficits in the patients with motor dysfunction during the recovery period of cerebral infarction, which may be related to enhancing the remodeling of white matter fiber bundles in the corticospinal tract on the focal side of the whole segment and the bilateral posterior limb of the internal capsule.

ZHANG Jian-bin's clinical experience in treatment of depressive disorder based on the theory of governor vessel / 中国针灸

Depressive disorder is manifested as emotional and physical abnormality. Theoretically, the governor vessel is distributed along the spine, related to the brain and communicated with five zang and six fu organs. It is the key meridian for understanding the various symptoms of depressive disorder. Depressive disorder is caused by dysfunction, stagnation or emptiness of the governor vessel, resulting in malnutrition of the brain. In clinical diagnosis and treatment, based on the theory of the governor vessel, the etiology and pathogenesis are analyzed in the patients with depressive disorder. In order to achieve harmonizing mutually the mental and physical conditions, acupuncture is delivered to adjust the spirit and physical state, moving cupping is to regulate the governor vessel, tuina manipulation is to promote meridians and collaterals and physical exercise is to coordinate the body and the spirit.

Baicalin inhibits PDK1 to mediate glucose metabolism reprogramming and intervene rheumatoid arthritis synovial inflammation / 药学学报

This study started from the effect of baicalin (BC), the main active component of the labiaceae plant Scutellaria baicalensis, on collagen-induced arthritis (CIA) in rats, to explore the mechanism of glucose metabolism reprogramming in fibroblast like synoviocytes (FLSs), a key effector cell of synovial inflammation in rheumatoid arthritis (RA). First of all, CIA rats and tumor necrosis factor-α (TNF-α)-induced RASFs in vitro and in vivo models were established, the arthritis index (AI) score and histopathological changes of CIA rats after BC administration were observed, and the levels of inflammatory factors in serum and cell supernatant were quantified by ELISA, immunocytochemistry and Western blot were used to detect the expression of G-protein-coupled receptor 81 (GPR81) and pyruvate dehydrogenase kinase 1 (PDK1) proteins. In addition, the kit was used to measure the levels of key products and enzyme activities in glucose metabolism reprogramming. The results showed that BC (50, 100 and 200 mg·kg-1) could alleviate the symptoms of arthritis in CIA rats in a dose-dependent manner, inhibit synovial hyperplasia, alleviate the infiltration of inflammatory cells, down-regulate the levels of pro-inflammatory factors TNF-α and interleukin (IL)-1β, and up-regulate the levels of anti-inflammatory factor IL-10 in CIA rats. At the same time, the secretion levels of lactate, pyruvate, acetyl-CoA, citrate and the activity of lactate dehydrogenase B (LDH-B) were decreased, and the expressions of GRP81 and PDK1 were down-regulated, suggesting that BC mediated the reprogramming process of glucose metabolism. However, when GPR81 inhibitor 3-OBA inhibited lactate uptake, the activity of LDH-B was significantly increased, suggesting that BC inhibited the expression of PDK1, a key enzyme in the reprogramming metabolism from glycolysis to oxidative phosphorylation. All animal experiments in this study were conducted in accordance with the ethical standards of the Laboratory Animal Care Center of Anhui University of Chinese Medicine (approval number: AHUCM-rats-2021049). These studies revealed that baicalin mediated metabolic reprogramming of RASFs from glycolysis to oxidative phosphorylation by inhibiting PDK1 protein expression, and alleviated joint inflammation in CIA rats.

Estimation of COVID-19 incidence in Shanghai under optimized epidemic prevention and control strategies / 中华流行病学杂志

Objective: To quantitatively estimate the incidence of COVID-19 in different backgrounds, including vaccination coverage, non-pharmacological interventions (NPIs) measures, home quarantine willingness and international arrivals, and the demands of healthcare resource in Shanghai in the context of optimized epidemic prevention and control strategies. Methods: Based on the natural history of 2019-nCoV, local vaccination coverage and NPI performance, an age-structured Susceptible-Exposed-Infections-Removed (SEIR) epidemic dynamic model was established for the estimation of the incidence of COVID-19 and demand of hospital beds in Shanghai by using the data on December 1, 2022 as the basis. Results: Based on current vaccination coverage, it is estimated that 180 184 COVID-19 cases would need treatment in hospitals in Shanghai within 100 days. When the booster vaccination coverage reaches an ideal level, the number of the cases needing hospitalization would decrease by 73.20%. School closure or school closure plus workplace closure could reduce the peak demand of regular beds by 24.04% or 37.73%, respectively, compared with the situation without NPI. Increased willingness of home quarantine could reduce the number of daily new cases and delay incidence peak of COVID-19. The number of international arrivals has little impact on the development of the epidemic. Conclusions: According to the epidemiological characteristics of COVID-19 and the actual situation of vaccination in Shanghai, the incidence of COVID-19 and health resource demand might be reduced by increasing vaccination coverage and early implementation of NPI.

Intracranial tumors mimicking benign paroxysmal positional vertigo: A case series.

Background: A few intracranial lesions may present only with positional vertigo which are very easy to misdiagnose as benign paroxysmal positional vertigo (BPPV); the clinicians should pay more attention to this disease. Objectives: To analyze the clinical characteristics of 6 patients with intracranial tumors who only presented with positional vertigo to avoid misdiagnosing the disease. Material and methods: Six patients with intracranial tumors who only presented with positional vertigo treated in our clinic between May 2015 to May 2019 were reviewed, and the clinical symptoms, features of nystagmus, imaging presentation, and final diagnosis of the patients were evaluated. Results: All patients presented with positional vertigo and positional nystagmus induced by the changes in head position or posture, including one case with downbeating nystagmus in a positional test, two cases with left-beating nystagmus, one case with apogeotropic nystagmus in a roll test, one case with right-beating nystagmus, and one case with left-beating and upbeating nystagmus. Brain MRI showed the regions of the tumors were in the vermis of the cerebellum, the fourth ventricle, the lateral ventricle, and the cerebellar hemisphere.

Coacervation-Based Method for Constructing a Multifunctional Strain-Stiffening Crystalline Polyvinylamine Hydrogel.

Strain-stiffening hydrogels are essential in the development of ionic skin, as human skin possesses a strain-stiffening property for self-protection. Semicrystalline polymers such as poly(vinyl alcohol) (PVA) have been widely investigated to fabricate strain-stiffening hydrogels via freeze-thaw cycling or chemical cross-linking but with limited adjustable properties. Compared with PVA, polyvinylamine (PVAm) has a higher reactive activity, making it easier to achieve multifunctionalities including strain-stiffening in a PVAm hydrogel. However, the amine moieties in the backbone tend to be ionized and form strong ionic hydrogen bonds with water, resulting in difficulties in forming crystalline hydrogels by conventional methods. Herein, a one-pot method to induce crystallinity and achieve multifunctional hydrogel is devised via coacervation of PVAm. Different from a published coacervation method to fabricate hydrogels with various properties via noncovalent interactions between different chemicals, coacervation occurs between PVAm to form aggregated and loose PVAm in our devised system. Such a strategy lowers the amine-water binding energy in the polymer-dense phase to achieve crystallinity and subsequently the strain-stiffening property; meanwhile, self-healability, self-adhesion, and ionic conductivity can be realized in the polymer-loose phase. The obtained hydrogel integrates stretchability (∼1300% elongation), toughness (227 kPa), the strain-stiffening property (∼10 times increase), self-adhesion (90 J m-2), self-healability (∼80% healing efficiency in toughness), and ionic conductivity (0.22 mS m-1). This convenient strategy will open a new horizon to design multifunctional skin-mimic materials.