Palladium-catalyzed regioselective carbonylation of 2-amino-2,3-diphenylpropanoate to 5/6-membered benzolactams.

Five/six-membered benzolactams are significant blocks in both organic and medicinal chemistry. Achieving 5/6-membered benzolactams from the same starting compound under varying reaction conditions presents a significant challenge. Herein, palladium-catalyzed free amine-oriented regioselective C-H activations/carbonylations mediated by hexacarbonylmolybdenum, leading to diverse sizes of benzolactams, respectively, have been developed. Six-membered dihydroisoquinolinones can be obtained selectively in acetic acid using benzoquinone as an oxidant. While unfavorable five-membered isoindolinones were formed in the presence of Cu(II) as an oxidant and dihydrooxazole ligands in 1,2-dichlorobenzene. The substituents on the phenyl ring also had a great influence on the regioselectivity of the reaction. In addition, an asymmetric version of the reaction has also been attempted preliminarily.

Self-assembling gelatin based delivery of multienzyme activity nanozyme and photosensitizer for ROS storm based cancer therapy.

Nanozymes with multienzyme activity for reactive oxygen species (ROS) generation and intracellular redox imbalance are attractive strategy for cancer therapy. However, it is severely limited by low biocompatibility and catalytic efficiency, hypoxic and high levels of GSH in the tumor microenvironment. To address these issues, a copper doping carbon nanozyme (CC) with multienzyme activity was designed and integrated with photosensitizer Ce6 and gelatin to fabricate ROS amplifier (CCC). Gelatin endowed CCC with good biocompatibility, low hemolysis, and enzyme responsive degradation. CCC with high CAT-like, POD-like, OXD-like, and GSHox-like activities can induce the intracellular ROS storm formation to eliminate the cancer cells. The OXD-like activity and PDT performance mediated 1O2 generation was markedly potentiated by the CAT-like activity of CCC via catalyzing high expression of H2O2 to generate O2. At the same time, a large amount of ·OH were produced through POD-like activity of CCC and GSH was depleted by the GSHox-like activities of CCC, resulting in a destructive ROS storm formation and cellular redox homeostasis disruption. Both in vivo and in vitro experiments showed that CCC displayed satisfactory anti-tumor activity and biocompatibility. Our work provides a novel strategy for the development of nanozyne enhanced photodynamic therapy of cancer.

Transition-Metal-Oxide-Based Nanozymes for Antitumor Applications.

Transition metal oxide (TMO)-based nanozymes have appeared as hopeful tools for antitumor applications due to their unique catalytic properties and ability to modulate the tumor microenvironment (TME). The purpose of this review is to provide an overview of the latest progress made in the field of TMO-based nanozymes, focusing on their enzymatic activities and participating metal ions. These nanozymes exhibit catalase (CAT)-, peroxidase (POD)-, superoxide dismutase (SOD)-, oxidase (OXD)-, and glutathione oxidase (GSH-OXD)-like activities, enabling them to regulate reactive oxygen species (ROS) levels and glutathione (GSH) concentrations within the TME. Widely studied transition metals in TMO-based nanozymes include Fe, Mn, Cu, Ce, and the hybrid multimetallic oxides, which are also summarized. The review highlights several innovative nanozyme designs and their multifunctional capabilities. Despite the significant progress in TMO-based nanozymes, challenges such as long-term biosafety, targeting precision, catalytic mechanisms, and theoretical supports remain to be addressed, and these are also discussed. This review contributes to the summary and understanding of the rapid development of TMO-based nanozymes, which holds great promise for advancing nanomedicine and improving cancer treatment.

Flavan-3-ol monomers intake is associated with osteoarthritis risk in Americans over 40 years of age: results from the National Health and Nutritional Examination Survey database.

Objectives: Osteoarthritis (OA) stands as the prevailing progressive musculoskeletal disease, serving as the primary cause of chronic pain and activity limitations among adults over 40. Flavan-3-ols, common polyphenolic compounds, are believed to harbor anti-inflammatory and anti-aging properties. This study explores the relationship between flavan-3-ol intake and osteoarthritis risk in individuals over the age of 40 in the US. Methods: This study included 7452 participants over the age of 40 from three cycles (2007-2008, 2009-2010, and 2017-2018) of the National Health and Nutrition Examination Survey. Information on OA history was obtained via home surveys. Information on flavan-3-ol monomers intake was obtained using a survey from the Food and Nutrient Database for Dietary Studies. We used a logistic regression model and restricted cubic spline to analyze the relationships between flavan-3-ol monomers and OA. Stratified analyses were also conducted in this study. Results: There were 1056 participants with OA and 6396 without OA. Compared to the first tertile (T1) group, the adjusted odds ratio with a 95% confidence interval (CI) of logistic regression model 2 for the flavan-3-ol T2 group was 1.296 (0.979-1.715) (p = 0.068), the OR for (-)-epigallocatechin was 1.292 (1.025-1.629) (p = 0.032), and the OR for (-)-epicatechin 3-gallate was 1.348 (1.013, 1.793) (p = 0.042). A dose-response curve indicated a non-linear association (p for non-linearity <0.05) between OA and total flavan-3-ol monomers (nadir point: 483.29 mg, 95% CI: 0.61-0.90). No interaction effects were found in the subgroup analysis. Conclusions: In individuals over 40 in the US, the average daily dietary intake of flavan-3-ol monomers manifests a J-shaped relationship with OA risk.

Copper peroxide loaded gelatin/oxide dextran hydrogel with temperature and pH responsiveness for antibacterial and wound healing activity.

Bacterial infection and tissue hypoxia always prevent wound healing, so multifunctional platforms with antimicrobial and oxygen-supplying functions were developed. However, they face many difficulties such as complex preparation and low oxygen release. To address this challenge, a copper peroxide loaded gelatin/oxide dextran hydrogel (CGO) was prepared. Surprisingly, CGO hydrogel as a wound dressing not only had good biocompatibility, injectivity, and mechanical properties, but also exhibited mild photothermal properties, temperature responsiveness, and pH responsiveness. After being applied to wounds infected with bacteria, CGO hydrogel released copper peroxide under near-infrared laser irradiation, which produced copper ions and hydrogen peroxide, combined with PTT to kill bacteria. After the bacteria were cleared from the wound and the pH of the wound was changed to be acidic, CGO hydrogel released copper peroxide via pH response. Copper ions and oxygen produced from copper peroxide accelerated wound healing by promoting angiogenesis. The multi-responsive and multi-mode treatment platform provided a potential strategy for treating bacteria-infected wounds.

Triglyceride to high-density lipoprotein cholesterol ratio associated with long-term adverse clinical outcomes in patients deferred revascularization following fractional flow reserve.

BACKGROUND: Guidelines on coronary intermediate lesions strongly recommend deferred revascularization after detecting a normal fractional flow reserve (FFR). Researches about triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) on cardiovascular diseases has also been well conducted. However, the association of TG/HDL-C and long-term adverse clinical outcomes remains unknown for patients deferred revascularization following FFR. METHODS: This study retrospectively included 374 coronary artery disease (CAD) patients with non-significant coronary lesions diagnosed by coronary angiography (CAG) and FFR. The main outcome measure was the combination of major adverse cardiovascular and cerebrovascular events (MACCEs). All patients were categorized into three subgroups in terms of TG/HDL-C tertiles (T1 < 0.96, 0.96 ≤ T2 < 1.58, T3 ≥ 1.58). Three different Cox regression models were utilized to reveal the association between TG/HDL-C and prevalence of MACCEs. RESULTS: 47 MACCEs were recorded throughout a median monitoring period of 6.6 years. The Kaplan-Meier survival curves showed a higher MACCEs rate occurred in the higher TG/HDL-C group (5.6% vs. 12.9% vs. 19.4%, log-rank P < 0.01). After adjustment, patients in T3 suffered a 2.6-fold risk compared to the T1 group (T3 vs. T1: HR 2.55, 95% CI 1.05-6.21, P = 0.038; T2 vs. T1: HR 1.71, 95% CI 0.65-4.49, P = 0.075; P for trend = 0.001). The restricted cubic spline (RCS) analysis demonstrated that the HR for MACCEs rose as TG/HDL-C increased. Both the receiver operating characteristic (ROC) and time-dependent ROC proved the excellent predictive ability of TG/HDL-C. CONCLUSION: The study illustrates that TG/HDL-C correlates with the risk of MACCEs in CAD patients deferred revascularization following FFR. TG/HDL-C could serve as a dependable predictor of cardiovascular events over the long term in this population.

A high level of uric acid is associated with long-term adverse cardiovascular outcomes in patients who received fractional flow reserve with coronary intermediate stenosis.

BACKGROUND AND AIMS: The role of fractional flow reserve (FFR) in coronary intermediate lesions is widely recommended by guidelines. The effect of uric acid (UA) on cardiovascular events is also well known. However, the relationship between UA and long-term cardiovascular outcomes in patients who received FFR with intermediate lesions remains unknown. METHODS AND RESULTS: We retrospectively included 428 patients who underwent both coronary angiography (CAG) and FFR. Participants were stratified into two groups based on the median UA. The primary endpoint was the composite of major adverse cardiovascular and cerebrovascular events (MACCEs), including repeat revascularization, nonfatal stroke, nonfatal myocardial infarction, and all-cause death. A Cox proportional hazards model was utilized to analyze the association between UA and the prevalence of MACCEs. During a median follow-up of 5.8 years, a higher MACCEs rate occurred in the high UA group compared to the low UA group (16.8% vs. 5.1%, p log-rank<0.01). Elevated UA was independently linked to a higher incidence of MACCEs, whether UA was treated as a categorical or continuous variable (hazard ratio [HR] 2.76, 95% confidence interval [CI] 1.27-6.03 or HR 1.01, 95% CI 1.01-1.02). The restricted cubic spline (RCS) analysis illustrated that the HR for MACCEs increased with increasing UA. CONCLUSION: The present study demonstrates that UA is associated with MACCEs risk and suggests that UA is a reliable predictor of long-term cardiovascular events in coronary intermediate stenosis patients.

Identification of Reduced mTOR T1262 Phosphorylation as a Novel Mechanism and Therapeutic Target of Apoptosis in Senescent Cardiomyocytes: Aging and Cardiomyocyte Apoptosis.

The mechanisms through which aging increases heart injury remain partially understood. Protein phosphorylation plays a critical regulatory role in cell survival and death. Using an unbiased phosphoproteomics approach, we aimed to identify the proteins whose phosphorylation could be causatively related to aging-related cardiomyocyte apoptosis and elucidate the underlying mechanisms. Comparative phosphoproteomics was conducted on cardiac tissues obtained from young (8 weeks) and aged (24 months) mice. Our findings revealed that the Mammalian Target of Rapamycin phosphorylation at T1262 (mTORT1262) was reduced in the aging heart. Immunohistochemical and Western blot analyses confirmed these findings in aging myocardia and D-galactose-induced senescent AC16 cardiomyocytes. In hypoxia/reoxygenation cardiomyocytes, mTORT1262 phosphorylation deficiency (mTORT1262A, lentivirus-mediated transfection) inhibited AKT1, suppressed NF-κB, activated FOXO1/3a signaling, and ultimately exacerbated apoptosis. Conversely, mTORT1262 pseudophosphorylation (mTORT1262E) exhibited opposite effects. Through bioinformatics and CO-IP, purinergic receptor P2X4 (P2X4R) was found to be the possible receptor responsible for mTORT1262 phosphorylation. Knockdown of P2X4R increased apoptosis, whereas its overexpression decreased it. In senescent cardiomyocytes, P2X4R expression and mTORT1262 and AKT1S473 phosphorylation were reduced, NF-κB signaling was suppressed, and FOXO1/3a signaling was activated. We demonstrated that P2X4R downregulation and the subsequent reduction of mTORT1262 phosphorylation is a novel mechanism contributing to cardiomyocyte apoptosis in aging hearts. The P2X4R-mTOR-AKT1 signaling pathway represents a potential therapeutic target against accelerated cardiac injury in aging.

Association of D-dimer to albumin ratio with adverse cardiovascular outcomes in ischaemic heart failure patients with diabetes mellitus: a retrospective cohort study.

OBJECTIVE: To determine the association of D-dimer to albumin ratio (DAR) with major adverse cardiovascular events (MACE) after percutaneous coronary intervention (PCI) in ischaemic heart failure patients with diabetes mellitus. DESIGN: A retrospective observational cohort study. SETTING: Single centre in Beijing, China, conducted at one of the largest cardiology centres in China. PARTICIPANTS: From June 2017 to June 2019, 3707 patients with heart failure and concomitant multiple vessel disease undergoing elective PCI were screened. A total 1021 of patients were enrolled after exclusion and the follow-up period was up to 36 months. PRIMARY AND SECONDARY OUTCOME MEASURES: The MACE was the primary measured outcome. The secondary outcomes were all-cause mortality, non-fatal myocardial infarction and any revascularisation. METHODS: These participants were grouped according to DAR tertiles. The cumulative incidence functions, Cox regression, restricted cubic spline and receiver operating characteristic curves were used to determine the association between DAR and outcomes. The subgroup analysis was also performed. RESULTS: After follow-up, MACE occurred in 404 (39.6%) participants. The cumulative hazards curve manifested significant differences in MACE, all-cause mortality and any revascularisation (log-rank test: all p<0.001). In adjusted models, DAR was an independent risk factor of MACE (tertile 2: HR 1.82, 95% CI 1.37 to 2.42; tertile 3: HR 1.74, 95% CI 1.28 to 2.36) and all-cause mortality (tertile 2: HR 2.04, 95% CI 1.35 to 3.11; tertile 3: HR 1.89, 95% CI 1.20 to 2.98). The optimal cut-off of DAR was 1.2. In the stratified analysis, sex, age, hypertension, hypercholesterolaemia, total revascularisation and any interfered vessel did not affect the independent predictive ability. CONCLUSION: Higher DAR was independently associated with MACE and all-cause mortality after PCI in ischaemic heart failure patients with diabetes mellitus.

Mild hyperthermia-assisted chitosan hydrogel with photothermal antibacterial property and CAT-like activity for infected wound healing.

Infected wounds pose a serious threat to public health and pose a significant challenge and financial burden worldwide. The treatment of infected wounds is now an urgent problem to be solved. Herein, mild hyperthermia-assisted hydrogels composed of carboxymethyl chitosan (CMCs), oxidized dextran (Odex), epigallocatechin gallate (EGCG) and PtNPs@PVP (CAT-like nanoenzymes) were proposed for the repair of infected wounds. The incorporation of PtNPs@PVP nanoenzymes give the hydrogels excellent photothermal property and CAT-like activity. When the temperature is maintained at 42-45 °C under 808 nm near infrared (NIR) exposure, the CMCs/Odex/EGCG/Nanoenzymes (COEN2) hydrogel demonstrated highly enhanced antibacterial ability (95.9 % in vivo), hydrogen peroxide (H2O2) scavenging ratio (85.1 % in vitro) and oxygen supply (20.7 mg/L in vitro). Furthermore, this mild-heat stimulation also promoted angiogenesis in the damaged skin area. Overall, this multifunctional hydrogel with antibacterial, antioxidant, oxygen supply, hemostasis, and angiogenesis capabilities has shown great promise in the repair of infected wounds. This study establishes the paradigm of enhanced infected wound healing by mild hyperthermia-assisted H2O2 scavenging, oxygen supplemental, and photothermal antibacterial hydrogels.

Research status of elderly-care robots and safe human-robot interaction methods.

Faced with the increasingly severe global aging population with fewer children, the research, development, and application of elderly-care robots are expected to provide some technical means to solve the problems of elderly care, disability and semi-disability nursing, and rehabilitation. Elderly-care robots involve biomechanics, computer science, automatic control, ethics, and other fields of knowledge, which is one of the most challenging and most concerned research fields of robotics. Unlike other robots, elderly-care robots work for the frail elderly. There is information exchange and energy exchange between people and robots, and the safe human-robot interaction methods are the research core and key technology. The states of the art of elderly-care robots and their various nursing modes and safe interaction methods are introduced and discussed in this paper. To conclude, considering the disparity between current elderly care robots and their anticipated objectives, we offer a comprehensive overview of the critical technologies and research trends that impact and enhance the feasibility and acceptance of elderly care robots. These areas encompass the collaborative assistance of diverse assistive robots, the establishment of a novel smart home care model for elderly individuals using sensor networks, the optimization of robot design for improved flexibility, and the enhancement of robot acceptability.

Monocyte to high-density lipoprotein cholesterol ratio predicts poor outcomes in ischaemic heart failure patients combined with diabetes: a retrospective study.

BACKGROUND: The prevalence of ischaemic heart failure (HF) continues to increase. Diabetes mellitus (DM) concomitant with ischaemic HF increases the risk of major adverse cardiovascular events (MACEs). As a promising predictor for cardiovascular diseases, the predictive value of the monocyte to high-density lipoprotein cholesterol ratio (MHR) for MACE in the ischaemic HF with DM cohort has never been investigated before. OBJECTIVE: We aimed to investigate the MHR as a predictor for MACE in ischaemic HF patients with DM who underwent percutaneous coronary intervention (PCI). METHODS: This observational study enrolled 1049 patients with ischaemic HF and DM undergoing PCI from June 2017 to June 2019. The baseline data were collected. MACEs, including all-cause mortality, nonfatal myocardial infarction, and any revascularization, were recorded within the 36-month follow-up. The characteristics and incidence of MACE were analysed in four groups stratified by the quartiles of MHR. The hazard ratio for MACE was analysed with Cox regression models. The incidence of MACE in the four groups was evaluated by Kaplan‒Meier survival analysis. Restricted cubic spline analysis was performed to determine the nonlinear correlation between the MHR and MACE. RESULTS: After the 36-month follow-up, 407 patients (38.8%) experienced MACEs. The incidence of MACE was significantly higher among patients in the upper MHR quartile than among those in the lower MHR quartiles (23.4% vs. 36.0% vs. 41.4% and 54.6%; P < 0.001, respectively), which was consistent with the Kaplan‒Meier survival analyses (P < 0.0001). A multivariate Cox regression model showed that the MHR was an independent risk factor for MACE after variables were adjusted (adjusted HR: 2.11; 95% CI 1.47-3.03; P < 0.001). Its predictive effects on MACE showed no interaction with hypercholesterolemia (P > 0.05). CONCLUSION: The MHR was a significant and independent predictor of MACEs in ischaemic HF patients with DM undergoing PCI.

PMN-incorporated multifunctional chitosan hydrogel for postoperative synergistic photothermal melanoma therapy and skin regeneration.

Melanoma excision surgery is usually accompanied by neoplasm residual, tissue defect, and bacterial infection, resulting in high tumor recurrence and chronic wound. Nanocomposite hydrogels can satisfy the twin requirements of avoiding tumor recurrence and skin wound healing following skin melanoma surgery due to their photothermal anti-tumor and anti-bacterial activities. In this study, carboxymethyl chitosan, oxidized fucoidan and polyphenol-metal nanoparticle (PMN) of tannic acid capped gold nanoparticles were used to fabricate multifunctional nanocomposite hydrogels through Schiff base reaction. The prepared hydrogel demonstrated outstanding photothermal effect, and the controlled high temperature will rapidly kill melanoma cells as well as bacteria within 10 min. Good injectability, self-healing and adhesion combined with high reactive oxygen species (ROS) scavenging capacity, hemostasis and biocompatibility made this hydrogel platform perfect for the postoperative treatment of melanoma and promoting wound healing. With the assistance of NIR irradiance, hydrogel can inhibit tumor tissue proliferation and promote tumor cell apoptosis, thereby helping to prevent melanoma recurrence after surgical removal of tumors. Simultaneously, the irradiance heat and polyphenol component kill bacteria on the wound surface, eliminate ROS, inhibit inflammatory responses, and promote angiogenesis, collagen deposition, and skin regeneration, all of which help to speed up wound healing.

Alloying-Induced Synthesis of Amorphous PdZnS Hollow Spheres as Enhanced Oxygen Reduction Catalysts.

Amorphous alloys have multiple advantages in electrocatalysis, yet the isotropic nature makes their syntheses a great obstacle in application. In this work, it is shown that the Zn2+ can interfere with the crystallization of Pd-base structures to form amorphous alloy materials. By simply adjusting the Zn2+ content, unique PdZnS amorphous hollow spheres (AHS) with various compositions and degrees of crystallinity can be obtained through a facile one-pot wet chemical method. Owing to both the amorphous nature and hollow morphologies, the PdZnS AHSs possess appealing activities and stabilities as oxygen reduction catalysts. Typically, the Pd20 ZnS10 AHSs exhibit the highest half-wave potential (E1/2 ) of 0.940 V (vs reversible hydrogen electrode), and such E1/2 only negatively shifts 25 mV after 60 000 cycles.

Application of Flow Cytometry in the Diagnosis of Bovine Epidemic Disease.

As science and technology continue to advance, the use of flow cytometry is becoming more widespread. It can provide important information about cells in the body by detecting and analysing them, thereby providing a reliable basis for disease diagnosis. In the diagnosis of bovine epidemic diseases, flow cytometry can be used to detect bovine viral diarrhoea, bovine leukaemia, bovine brucellosis, bovine tuberculosis, and other diseases. This paper describes the structure of a flow cytometer (liquid flow system, optical detection system, data storage and analysis system) and its working principles for rapid quantitative analysis and sorting of single cells or biological particles. Additionally, the research progress of flow cytometry in the diagnosis of bovine epidemic diseases was reviewed in order to provide a reference for future research and application of flow cytometry in the diagnosis of bovine epidemic diseases.

[Horizontal Variation Characteristics of Alpine Grassland Soil Function and Vertical Changes Along Soil Genetic Horizons in the Three-River Headwaters Region].

The Three-River Headwaters region is a hotspot for studying the response of soil function to climate change. To study the horizontal variation characteristics of alpine grassland soil function and vertical changes along soil genetic horizons, soil functional indicators (including respiration, nitrogen conversion rate, and enzymatic activity) of different genetic horizons in alpine grassland soil profiles and their correlations with environmental factors were analyzed. The results showed that there were no significant differences in soil functional characteristics between alpine meadows and steppes, and topsoil had higher respiration rates, nitrogen conversion rates, and enzymatic activities than those of subsoil. Total nitrogen was a key driver of soil functional characteristics in different genetic horizons, explaining 18.3%, 21.4%, and 27.5% of the horizontal variation in functional characteristics, respectively. Climate and vegetation factors mainly affected soil function indirectly by changing soil physicochemical properties in topsoil, but atmospheric nitrogen deposition still affected soil function in subsoil. These results indicate the significant nitrogen limitation of alpine grassland soil in the Three-River Headwaters region, and the findings provide a new insight into the maintenance of soil functional diversity and the response to climate change in the context of global climate change.

[Coupling Relationship Between Soil Functions and Environmental Factors Along an Altitudinal Gradient: A Case Study of the Meili Mountain].

Soil respiration and extracellular enzyme activity are important components of the material cycle of mountain ecosystems and play key roles in maintaining ecosystem functions. To explore the coupling relationship between soil functions and environmental factors, the soil functional indicators, environmental factors, and effects of altitude on the soil function of 36 soil samples from 12 altitudes of the Meili Mountain were analyzed. The results showed that there were significant differences in soil respirations and enzyme activities among altitudes of Meili Mountain, and high-altitude areas had higher soil functions. Soil functions increased with altitudinal difference. PCA analysis showed that the first three axes explained 56.7%, 17.4%, and 8.7% of the variance in soil functional elevation change, respectively, indicating that the functional changes related to carbon and phosphorus were higher than those related to nitrogen. There were significant correlations between environmental factors and soil functional indicators; soil function indicators had stronger correlations with soil physicochemical properties than with climatic factors. Altitude mainly affected soil function indirectly by affecting soil physicochemical properties and climatic factors. These results have great scientific significance for improving the understanding of the material cycle and ecological function of the Meili Mountain ecosystem and provide an important reference for in-depth study of the altitude distribution pattern and evolution characteristics of the soil function of the mountain ecosystem.

Collagen hydrogel with multiple antimicrobial mechanisms as anti-bacterial wound dressing.

Wound infection by multidrug-resistant bacteria seriously threatens human life. Chronic wounds, with necrosis, persistent inflammation, and covered by hypoxic tissue, seriously hinder anti-infection treatments. Herein, we have developed a multifunctional hydrogel dressing with antibacterial activity in the hypoxia environment to promote wound healing. The hydrogel comprises Cypate-conjugated antimicrobial peptides (AMP-Cypates), liposome-encapsulated perfluorodecalin, and recombinant type III collagen. AMP-Cypates exhibited outstanding antibacterial activity, jointly achieved through antimicrobial peptide (AMP) activity, photothermal therapy (PTT), and photodynamic therapy (PDT). The perfluorodecalin liposomes act as the oxygen carrier to mitigate wound hypoxia condition and enhance the efficacy of PDT. The recombinant type III collagen in the hydrogel further promoted the healing of the wounds together with the eradication of bacterial infection. Taken together, the hydrogel dressing provides a platform for integrating multiple antimicrobial mechanisms for the rapid removal of bacterial infection and the healing of chronic wounds.

Nanocomposite multifunctional hyaluronic acid hydrogel with photothermal antibacterial and antioxidant properties for infected wound healing.

Bacterial infection and subsequent reactive oxygen species (ROS) damage are major factors that delay wound healing in infected skin. Recently, photothermal therapy (PTT), as a new antibacterial method, has shown great advantages in the treatment of infected skin wound. Antibacterial and antioxidant hydrogels can reduce bacterial colonization and infection, scavenge ROS, relieve inflammation, and accelerate wound healing. In this study, an enzyme-crosslinked hyaluronic acid-tyramine (HT) hydrogel loaded with antioxidant and photothermal silver nanoparticles (AgNPs), named HTA, was developed as functional wound dressing to promote the infected skin wound healing. Natural antioxidant tannic acids (TA) were used as both reducing and stabilizing agents to facilely synthesize the silver nanoparticles capped with TA (AgNPs@TA). The incorporation of AgNPs@TA significantly enhanced the antioxidant, antibacterial, photothermal antibacterial, adhesive, and hemostatic abilities of the resulted HTA hydrogel. Besides, HTA hydrogel has rapid gelation, well injection and biocompatibility. In vivo results on the Staphylococcus aureus and Escherichia coli co-infected mouse skin wound model showed that HTA0.4 (containing 0.4 mg/mL AgNPs@TA) hydrogel combined with near infrared ray radiation highly alleviated inflammation, promoted angiogenesis, and accelerated the healing process. Therefore, this nanocomposite hydrogel wound dressing with antibacterial and antioxidant capabilities has great application potential in the treatment of infected skin wounds.

Multi-targeted fluorescent probes for detection of Zn(II) and Cu(II) ions based on ESIPT mechanism.

With the rapid development of industry, it is pretty critical to detect the heavy metals. Recently, the 2-(2-hydroxyphenyl) benzothiazole derivatives with different numbers of rotatable phenyl m (m = 1,2,3) fluorescent probes HLm were synthesized. However, the theoretical analysis of the mechanism was still missing. In this work, we have systematically researched the mechanisms of excited state intramolecular proton transfer (ESIPT) and the detection of Cu(II), Zn(II) ions for the hydrogen-bond system HLm though quantum chemistry methods. By bond parameters and the minimum energy pathways analyses, the proton of this system was probed directly transfer without barrier. Bond parameters, real space function at bond critical point, the frontier molecular orbital, electron spectra and orbital interaction diagram were carried to elucidate response to Cu(II), Zn(II) ions. In addition, comparing the Gibbs free energy variation of the complexation reaction between fluorescent probes and ions, it can be proved that the number of rotatable benzene rings affects the response ability of the probe to target ions.