Ginsenoside Rk3 modulates gut microbiota and regulates immune response of group 3 innate lymphoid cells to against colorectal tumorigenesis

The gut microbiota plays a pivotal role in the immunomodulatory and protumorigenic microenvironment of colorectal cancer(CRC).However,the effect of ginsenoside Rk3(Rk3)on CRC and gut microbiota remains unclear.Therefore,the purpose of this study is to explore the potential effect of Rk3 on CRC from the perspective of gut microbiota and immune regulation.Our results reveal that treatment with Rk3 significantly suppresses the formation of colon tumors,repairs intestinal barrier damage,and regulates the gut microbiota imbalance caused by CRC,including enrichment of probiotics such as Akkermansia muciniphila and Barnesiella intestinihominis,and clearance of pathogenic Desulfovibrio.Subsequent metabolomics data demonstrate that Rk3 can modulate the metabolism of amino acids and bile acids,particularly by upregulating glutamine,which has the potential to regulate the immune response.Furthermore,we elucidate the regulatory effects of Rk3 on chemokines and inflammatory factors associated with group 3 innate lymphoid cells(ILC3s)and T helper 17(Th17)signaling pathways,which inhibits the hyperactivation of the Janus kinase-signal transducer and activator of transcription 3(JAK-STAT3)signaling pathway.These results indicate that Rk3 modulates gut microbiota,regulates ILC3s immune response,and inhibits the JAK-STAT3 signaling pathway to suppress the development of colon tumors.More importantly,the results of fecal microbiota transplantation suggest that the inhibitory effect of Rk3 on colon tumors and its regulation of ILC3 immune responses are mediated by the gut microbiota.In summary,these findings emphasize that Rk3 can be utilized as a regulator of the gut microbiota for the prevention and treatment of CRC.

Dietary phytochemicals: As a potential natural source for treatment of Alzheimer's Disease

Alzheimer's disease(AD)is a common neurodegenerative disease,which seriously impairs human health and life.At present,scientists have proposed more than a dozen hypotheses about the pathogenesis of AD,including the tau propagation hypothesis.However,the exact ultimate pathogenic factor of AD remains unknown.Based on the current hypotheses,some anti-AD drugs(e.g.,donepezil and Ketamine)have been developed and used in clinical treatment,which fall into two main categories,acetylcholinesterase inhibitors(AChEIs)and N-methyl-D-aspartate(NMDA)receptor antagonists,the former representative drug is donepezil,and the latter representative drug is memantine.Since these drugs have undesirable side effects,it is necessary to find safer alternatives for AD treatment.Interestingly,dietary phytochemicals have the advantages of wide source,safety,and high biological activity,which is the natural route for screening anti-AD drugs.In this study,several representatives’dietary phytochemicals with anti-AD effect,including resveratrol,lycopene,gallic acid,berberine,ginsenoside Rg1,pseudoginsenoside-F11,ginsenoside Rh2,artemisinin,and torularhodin were selected from the published data over the last 10 years and their potential molecular mechanisms and clinical applications reviewed in the treatment of AD.

Analysis of Metabolic Products by Response Surface Methodology for Production of Human-like Collagen II

Recombinant Escherichia coli BL21 is used to produce human-like collagen. The key constituents of media are optimized using response surface methodology (RSM). Before thermal induction, the highest biomass production and the lowest production of some hazardous by-products, especially acetic acid, were obtained in the media containing 0.085 mol·L-1 glucose and 0.019 mol·L-1 nitrogen (carbon-nitrogen ratio, 4.47:1). After thermal induction, when the concentrations of glucose and nitrogen in the media were 0.065 mol·L-1 and 0.017 mol·L-1 , respectively (carbon-nitrogen ratio, 3.82:1), the productivity of human-like collagen per cell was the highest while that of acetic acid was the lowest. The extended analysis showed that the production of lactic acid and propionic acid increased while that of some intermediate acids of the tricarboxylic acid cycle decreased if the dose of glucose increased.

Optimization of Fermentation Process for Human-like Collagen Production of Recombinant Escherichia coli Using Response Surface Methodology

In order to improve the production of human-like collagen III(HLC III)by fed-batch culture of recombinant Escherichia coli BL21,the Plackett-Burman and Box-Behnken design were applied to optimize the fermentation process parameters.Three variables(induction time,inoculum age and pH),which have significant effects on HLC III production,were selected from eight variables by Plackett-Burman design.With the regression coefficient analysis in the Box-Behnken design,a relationship between HLC III production and three significant factors was obtained,and the optimum levels of the three variables were as follows:induction time 3.2h,inoculum age 12.6 h and pH 6.7.The 3D response surface plots and 2D contour plots created by the Box-Behnken design showed that the interaction between induction time and pH and that between innoculum age and pH were significant.An average 9.68 g·L1HLC III production was attained in the validation experiment under optimized condition,which was 80%higher than the yield of 5.36 g·L1before optimization.

Molecular design, synthesis strategies and recent advances of hydrogels for wound dressing applications

With the changes in the modern disease spectrum,pressure ulcers,diabetic feet,and vascular-derived diseases caused refractory wounds is increasing rapidly.The development of wound dressings has partly improved the effect of wound management.However,traditional wound dressings can only cover the wound and block bacteria,but are generally powerless to recurrent wound infection and tissue healing.There is an urgent need to develop a new type of wound dressing with comprehensive performance to achieve multiple effects such as protecting the wound site from the external environment,absorbing wound exudate,anti-inflammatory,antibacterial,and accelerating wound healing process.Hydrogel wound dressings have the aforementioned characteristics,and can keep the wound in a moist environment because of the high water content,which is an ideal choice for wound treatment.This review introduces the wound healing process and the development and performance advantages of hydrogel wound dressings.The choice of different preparation materials gives the particularities of different hydrogel wound dressings.It also systematically explains the main physical and chemical crosslinking methods for hydrogel synthesis.Besides,in-depth discussion of four typical hydrogel wound dressings including double network hydrogels,nanocomposite hydrogels,drug-loaded hydrogels and smart hydrogels fully demonstrates the feasibility of developing hydrogels as wound dressing products and their future development trends.

Optimizing the Chemical Compositions of Protective Agents for Freeze-drying Bifidobacterium longum BIOMA 5920

Freeze drying has a deleterious effect on the viability of microorganisms. In front of this difficulty, the present study adopts response surface methodology to optimize the chemical compositions of protective agents to seek for maximum viability of Bifidobacterium longum BIOMA 5920 during freeze-drying. Through the compara- tive analysis of single protectant, the complex protective agents show better effect on the Bifidobacterium viability. Human-like collagen (HLC), trehalose and glycerol are confirmed as significant factors by Box-Behnken Design. The optimized formula for these three variables is tested as follows: HLC 1.23%, trehalose 11.50% and glycerol 4.65%. Under this formula, the viability is 88.23%, 39.67% higher in comparison to the control. The viable count is 1.07×10 9 cfu·g-1 , greatly exceeding the minimum viable count requirement (10 6 cfu·g-1 ).

Efficient and Comprehensive Utilizatio℃n of Hemicellulose in the Corn Stover

Pretreatment of the corn stover powder by dilute sulphuric acid （solid-liquid ratio 1 ： 20） at 130 for 30 min was carried out with 89.09% of the hemicellulose removed. After filtration, the xylose-rich corn stover pretreatment liquid, whose fermentable sugar was from hemicellulose hydrolysis only, consisting of 81.16% xylose and 15.27% glucose, was used to cultivate genetic recombinant Escherichia coli BL21 with human-like collagen （HLC） expression enhanced by 50.00% and 63.71% xylose consumption.

High efficiency production of ginsenoside compound K by catalyzing ginsenoside Rb1 using snailase

The rare ginsenoside Compound K （C-K） is attracting more attention because of its good physiological activity and urgent need. There are many pathways to obtain ginsenoside C-K, including chemical and biological methods. Among these, the conversion of PPD-type ginsenosides by enzymatic hydrolysis is a trend due to its high efficiency and mild conditions. For effectively extracting from the other panaxadiol saponins, the conversion process for ginsenoside C-K was investigated using snailases in this study. The univariate experimental design and response surface methodology were used to determine the optimal hydrolysis conditions for the conversion of ginsenoside Rbl into ginsenoside C-K by snailases. The optimum conditions were as follows： pH 5,12, temperature 51 ℃, ratio of snailase/substrate 0.21, and reaction time 48 h. On the basis of these parameters, the addition of 1.0 mmol· L- 1 ferric ion was found to significantly improve the enzymolysis ofsnailases for the first time. With the above conditions, the maximum conversion rate reached 89.7%, suggesting that the process can obviously increase the yield of ginsenoside C-K. The bioassay tests indicated that the ginsenoside C-K showed anti-tumor activity in a series of tumor cell lines. Based on these results, we can conclude that the process of rare ginsenoside C- K production by enzymolysis with snailase is feasible, efficient, and suitable for the industrial production and application.

Recent advances in systemic and local delivery of ginsenosides using nanoparticles and nanofibers

Ginsenosides are the main pharmacologically active constituents of ginseng which have been used in East Asian countries for centuries to modulate blood pressure,metabolism and immune function.Following the technological advances in isolation,purification and mass production,their mechanisms of action are gradually elucidated,providing solid basis for clinical applications.Ginseng extracts(total ginsenosides)and ginsenoside Rg3,CK,Rd have been marketed or entered clinical trials as drugs or dietary supplements.Despite the proven safety and efficacy of some ginsenosides,their applications are hindered by inferior pharmacokinetics such as low solubility,poor membrane permeability and metabolic instability.Nanoparticle formulation of drugs and implantable drug depots are effective strategies to improve the pharmacokinetics of therapeutic agents by enhancing solubility,providing protection,facilitating intracellular transport,and enabling sustained and controlled release.This mini-review summarizes the recent advances in systemic delivery of ginsenosides using liposomes,micelles,albumin-based nanoparticles,and inorganic nanoparticles,as well as local delivery of ginsenosides by electronspun fibrous membranes and hydrogels.

Influence of L-Cysteine Concentration on Oxidation-reduction Potential and Biohydrogen Production

The effects of L-cysteine concentration on biohydrogen production by Enterobacterium Bacterium M580 were investigated in batch cultivation.The experimental results showed that L-cysteine could enhance the cell growth,hydrogen production rate and hydrogen yield when its concentration was less than 500 mg·L-1,while it had negative effects when its concentration was higher than 500 mg·L-1.The hydrogen production was the highest 1.29 mol·mol-1(H2/glucose) when 300 mg·L-1L-cysteine was added into the culture,and the yield was 9.4% higher than that in the control.The oxidation-reduction potential(ORP) ,which was influenced by L-cysteine,also affected hydrogen production.The ORP values were in the range-300 mV to-150 mV when the L-cysteine concentration was higher than 500 mg·L-1.Although the ORP in this range was favorable for hydrogen production,it was not suitable for the biomass growth.Hence,less hydrogen was produced.When the L-cysteine concentration was lower than 500 mg·L-1,the ORP was more suitable for both biomass growth and hydrogen production.In addition,at least 91%glucose was consumed when L-cysteine was added to the culture media,compared to the 97.37% consumption without L-cysteine added.

Ginsenoside Rk3 is a novel PI3K/AKT-targeting therapeutics agent that regulates autophagy and apoptosis in hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is the third leading cause of cancer death worldwide.Ginsenoside Rk3,an important and rare saponin in heat-treated ginseng,is generated from Rg1 and has a smaller molecular weight.However,the anti-HCC efficacy and mechanisms of ginsenoside Rk3 have not yet been characterized.Here,we investigated the mechanism by which ginsenoside Rk3,a tetracyclic triterpenoid rare ginsenoside,inhibits the growth of HCC.We first explored the possible potential targets of Rk3 through network pharmacology.Both in vitro(HepG2 and HCC-LM3 cells)and in vivo(primary liver cancer mice and HCC-LM3 subcutaneous tumor-bearing mice)studies revealed that Rk3 significantly inhibits the proliferation of HCC.Meanwhile,Rk3 blocked the cell cycle in HCC at the G1 phase and induced autophagy and apoptosis in HCC.Further proteomics and siRNA experiments showed that Rk3 regulates the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)pathway to inhibit HCC growth,which was validated by molecular docking and surface plasmon resonance.In conclusion,we report the discovery that ginsenoside Rk3 binds to PI3K/AKT and promotes autophagy and apoptosis in HCC.Our data strongly support the translation of ginsenoside Rk3 into novel PI3K/AKT-targeting therapeutics for HCC treatment with low toxic side effects.

Chiral inorganic nanomaterials:Harnessing chirality-dependent interactions with living entities for biomedical applications

Chirality is an intriguing and fundamental property of natural matter,which is especially crucial in supporting the processes of living systems.The selective interactions between natural chiral compounds are widespread at all levels in living entities and play a vital role in biochemical reactions.The cutting-edge advancements in synthetic chiral inorganic nanostructures have led to significant progress in their applications within biological systems.These developments have unraveled chirality-dependent interactions at the nanoscale and molecular scale,providing a better understanding of intricate process of chiral selection in biological systems and demonstrating the potential of chiral inorganic nanostructures for life science applications.Herein,we summarize recent progress in understanding the chirality origin of inorganic chiral nanoparticles and the development of wet-chemical synthesis.We also discuss the captivating interaction between chiral inorganic nanostructures and biological entities at various scales.Finally,we discuss the challenges and potential of functional chiral nanomaterials for future biomedical and bioengineering applications,offering design ideas and a forecast for their future impact.

A novel degradable injectable HLC-HPA hydrogel with antiinflammatory activity for biomedical materials:Preparation,characterization,in vivo and in vitro evaluation

In situ injectable hydrogels,which have great potential in tissue engineering,are characterized by simple preparation,minimal invasiveness and adaptation to complex shapes.However,injectable hydrogels have higher requirements for biocompatibility and safety due to their use in vivo implantation.Therefore,in this study,a human-like collagen(HLC)-based in situ gel-forming injectable HLC-HPA hydrogel was synthesized by combining the amino group of HLC with the carboxyl group of HPA activated using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride(EDC)and N-hydroxysuccinimide(NHS),followed by crosslinking by horseradish peroxidase(HRP)and H_2O_2,and used as scaffold material for tissue engineering.The hydrogel stiffness,gel time and biodegradation rate could be easily and independently adjusted by varying the H_2O_2 and HRP concentrations.Scanning electron microscope(SEM)clarified the homogeneous porous and interconnected internal structures of the hydrogel.In vitro cell viability and in vivo degradation experiments confirmed that the HLC-HPA hydrogel had good biodegradability and excellent biocompatibility.Interestingly,in cultured macrophages,the HLC-HPA hydrogel showed anti-inflammatory activity by reducing the amount of the pro-inflammatory cytokines tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)and increasing the secretion of the anti-inflammatory cytokine interleukin-10(IL-10)induced by lipopolysaccharide(LPS).Meanwhile,in animal experiments,HLC-HPA hydrogels exhibit excellent biocompatibility and have properties of hemostasis and reduction of inflammatory response.Therefore,the HLC-HPA hydrogel prepared in this study has great potential for development for use in the biomedical field.

Rapid synthesis of oxygen-defected molybdenum oxides quantum dots as efficient nanozymes for healing diabetic ulcers

The continuous inflammatory response in diabetic skin wounds leads to excessive production of reactive oxygen species,which cause a vicious circle of long-term inflammation.In the therapeutic research of metal nanoenzymes for healing diabetic ulcers,it still faces the challenges in poor nanoenzymes activity and low-efficient therapeutic efficiency.Herein,ultrasmall oxygen-deficient MoO_(3−X)quantum dots were fabricated and employed as nanoenzymes for healing fiabetic ulcers.After PEGylation,PEGylated MoO_(3−X)quantum dots(MoO_(3−X)/PEG)with oxygen vacancies exhibits excellent photothermal,peroxidase/catalase-like activities.In addition,these MoO_(3−X)/PEG showed superior properties in scavenging H_(2)O_(2)and effectively inhibiting the scavenging of reactive oxygen species.More importantly,such an oxygen-defected MoO_(3−X)/PEG had obvious antibacterial and skin repairing effects on alleviating hypoxia and excessive oxidative stress even in a mouse model of diabetic ulcers,inhibiting proinflammatory cytokines and significantly accelerating the healing of infected wounds,which shows great application potential for promoting wound healing.This work highlights that the developed oxygen defected molybdenum oxide compounds capable of peroxidaselike and catalase-like activities show great application potential for healing diabetes wound.

Antibacterial hydrogel with pH-responsive microcarriers of slow-release VEGF for bacterial infected wounds repair

Bacterial infection causes wound inflammation and makes angiogenesis difficult.It is urgent to develop effectively antibacterial and pro-vascularizing dressings for wound healing.The hydrogel is developed with pH-responsive drug-releasing microcarriers which were loaded with vascular endothelial growth factor(VEGF)that promotes angiogenesis and actively respond to wound pH for control and prolong VEGF release.The surfaces of the microcarriers were coated with polydopamine which can reduce the silver nanoparticles(AgNPs)in situ,and dynamically crosslink with the polyacrylamide,which forms a stable slow-release system with different release behavior for the VEGF and AgNPs.The hydrogel inhib-ited bacterial formation and accelerated wound healing.With the hydrogel dressing,83.3%±4.29%of the wound heals at day 7,which is 40.9%±8.5%higher than the non-treatment group in defect infected model.The antibacterial properties of hydrogel down-regulate early inflammation-related cytokines,and the release of VEGF in the middle and late phases of wound healing in response to pH changes pro-motes angiogenesis and up-regulate the expression of angiogenesis-associated cytokine.The sequential release of antibacterial agents and pro-vascularizing agents in response to the change in wound microen-vironmental cues facilitate temporally controlled therapy that suites the need of different wound healing phases.Collectively,the hydrogel loaded with multifunctional microcarriers that enable controlled release of AgNPs and VEGF is an effective system for treating infected wounds.

Application and progress of techno-economic analysis and life cycle assessment in biomanufacturing of fuels and chemicals

To reduce the dependency on petroleum-based products and emission of greenhouse gas,renewable biofuels and chemicals play an important role to meet the unmatched energy demands of the rapidly growing population.However,most biofuel and chemical products do not reach the commercialization stage,mainly hindered by incomparable economics to petroproducts.Techno-economic assessment(TEA)is a useful tool to estimate eco-nomic performance,and identify bottlenecks for the development of biofuel and chemical production technology,meanwhile,life cycle assessment(LCA)is applied to assess sustainability by reducing the environmental impact of biofuel and chemical production.This present review covers TEA and LCA research progress in the manufacturing of biofuels and biochemical,and discusses the impacts of TEA and LCA results on the development and optimi-zation of biofuel and chemical production.In addition,challenges associated with TEA and LCA of biofuel and biochemical production were briefly overviewed,and potential approaches that may overcome such challenges were discussed enabling viable and sustainable biomanufacturing of fuels and chemicals.Future integrated TEA and LCA studies could significantly promote the economic and sustainable development of the biomanufacturing process.

Bovine Serum Albumin-Conjugated Ferrimagnetic Iron Oxide Nanoparticles to Enhance the Biocompatibility and Magnetic Hyperthermia Performance

Magnetic hyperthermia is a fast emerging, non-invasive cancer treatment method which is used synergistically with the existing cancer therapeutics. We have attempted to address the current challenges in clinical magnetic hyperthermia-improved biocompatibility and enhanced heating characteristics, through a single combinatorial approach. Both superparamagnetic iron oxide nanoparticles(SPIONs) of size 10 nm and ferrimagnetic iron oxide nanoparticles(FIONs) of size 30 nm were synthesized by thermal decomposition method for comparison studies. Two different surface modifying agents, viz, Cetyl Trimethyl Ammonium Bromide and 3-Aminopropyltrimethoxysilane, were used to conjugate Bovine Serum Albumin(BSA) over the iron oxide nanoparticles via two different methods—surface charge adsorption and covalent amide bonding, respectively. The preliminary haemolysis and cell viability experiments show that BSA conjugation mitigates the haemolytic effect of the iron oxide nanoparticles on erythrocytes and is non-cytotoxic to the healthy Baby Hamster Kidney cells. It was observed from the results that due to better colloidal stability, the SAR value of the BSA-iron oxide nanoparticles is higher than the iron oxide nanoparticles without BSA, irrespective of the size of the iron oxide nanoparticles and method of conjugation. The BSA-FIONs seem to show improved biocompatibility, as the haemolytic index is less than 2 % and cell viability is up to 120 %, when normalized with the control. The SAR value of BSAFIONs is 2300 Wg^(-1) when compared to 1700 Wg^(-1) of FIONs without BSA conjugation. Thus, we report here that BSA conjugation over FIONs(with a high saturation magnetization of 87 emug^(-1)) provide a single combinatorial approach to improve the biocompatibility and enhance the SAR value for magnetic hyperthermia, thus addressing both the current challenges of the same.

Thiol-ene conjugation of a VEGF peptide to electrospun scaffolds for potential applications in angiogenesis

Vascular endothelial growth factor(VEGF)plays a vital role in promoting attachment and proliferation of endothelial cells,and induces angiogenesis.In recent years,much research has been conducted on the functionalization of tissue engineering scaffolds with VEGF or a VEGF-mimetic peptide to promote angiogenesis.However,most chemical reactions are nonspecific and require organic solvents,which can compromise control over functionalization and alter peptide/protein activity.An attractive alternative is the fabrication of functionalizable electrospun fibers,which can overcome these hurdles.In this study,we used thiol-ene chemistry for the conjugation of a VEGF-mimetic peptide to the surface of poly(ε-caprolactone)(PCL)fibrous scaffolds with varying amounts of a functional PCL-diacrylate(PCL-DA)polymer.30%PCL-DA was selected due to homogeneous fiber morphology.A VEGF-mimetic peptide was then immobilized on PCL-DA fibrous scaffolds by a light-initiated thiol-ene reaction.7-Mercapto-4-methylcoumarin,RGD-FITC peptide and VEGF-TAMRA mimetic peptide were used to validate the thiol-ene reaction on the fibrous scaffolds.Tensile strength and elastic modulus of the 30%PCL-DA fibrous scaffolds were significantly increased after the reaction.Conjugation of the 30%PCL-DA fibrous scaffolds with the VEGF peptide increased the surface water wettability of the scaffolds.Patterned structures could be obtained after using a photomask on the fibrous film.Moreover,in vitro studies indicated that scaffolds functionalized with the VEGF-mimetic peptide were able to induce phosphorylation of the VEGF receptor and enhanced HUVECs survival,proliferation and adhesion.A chick chorioallantoic membrane(CAM)assay further indicated that the VEGF peptide functionalized scaffolds were able to promote angiogenesis in vivo.These results show that scaffold functionalization can be controlled via a simple polymer mixing approach,and that the functionalized VEGF peptide-scaffolds have potential for vascular tissue regeneration.

Construction of multifunctional hydrogel based on the tannic acid-metal coating decorated MoS2 dual nanozyme for bacteria-infected wound healing

Bacterial infection,tissue hypoxia and inflammatory response can hinder the infected wound repair process.To mitigate the above issues,tannic acid-chelated Fe-decorated molybdenum disulfide nanosheets(MoS2@TA/Fe NSs)with dual enzyme activities were developed and anchored to a multifunctional hydrogel.The hydrogel exhibited excellent antibacterial ability owing to the combined effects of photothermal therapy(PTT),glutathione(GSH)loss,and the peroxidase(POD)-like activity(catalyse H2O_(2)into⋅OH under acid condition)of MoS2@TA/Fe NSs.Benefitting from the catalase(CAT)-like activity,the hydrogel could decompose H2O_(2)into O_(2)at neutral pH to relieve hypoxia and supply adequate O_(2).POD-like activity was mainly attributed to MoS2 NSs,while CAT-like activity was primarily due to TA/Fe complex.Moreover,MoS2@TA/Fe NSs endowed the hydrogel with outstanding anti-oxidant ability to scavenge redundant reactive oxygen species(ROS)and reactive nitrogen species(RNS)under neutral environment to maintain the balance of antioxidant systems and prevent inflammation.In addition,the hydrogel could inhibit the release of inflammatory factors for the anti-inflammatory property of TA.TA retained partial phenolic hydroxyl groups,which cross-linked the nanosheets to the network structure of the hydrogel and promoted the adhesion of hydrogels.Due to the dynamic boron ester bonds between polyvinyl alcohol(PVA),dextran(Dex),MoS2@TA/Fe,and borax,the hydrogel demonstrated fast self-healing and rapid shape adaptability.This shape-adaptable adhesive hydrogel could fill the whole wound and closely contact the wound,ensuring that it achieved its functions with maximum efficiency.The MoS2@TA/Fe nanozyme-anchored multifunctional hydrogel showed high potential for bacteria-infected wound healing.

A temperature responsive adhesive hydrogel for fabrication of flexible electronic sensors

Flexible electronics are playing an increasingly important role in human health monitoring and healthcare diagnosis.Strong adhesion on human tissue would be ideal for reducing interface resistance and motion artifacts,but arising problems such as skin irritation,rubefaction,and pain upon device removal have hampered their utility.Here,inspired by the temperature reversibility of hydrogen bonding,a skin-friendly conductive hydrogel with multiple-hydrogen bonds was designed by using biocompatible poly(vinyl alcohol)(PVA),phytic acid(PA),and gelatin(Gel).The obtained PVA/PA/Gel(PPG)hydrogel with temperature-triggered tunable mechanic could reliably adhere to skin and detect electrophysiological signals under a hot compress while be readily removed under a cool compress.Furthermore,the additional advantages of transparency,breathability,and antimicrobial activity of the PPG hydrogel ensure its long-time wearable value on the skin.It is both environmentally friendly and cost saving for the waste PPG hydrogel during production can be recycled based on their reversible physical bonding.The PPG hydrogel sensor is expected to have good application prospects to record electrophysiological signals in human health monitoring.