Fabrication of Bioresorbable Barrier Membranes from Gelatin/Poly(4-Hydroxybutyrate) (P4HB).

Dental implant surgery is a procedure that replaces damaged or missing teeth with an artificial implant. During this procedure, guided bone regeneration (GBR) membranes are commonly used to inhibit the migration of epithelium and GBR at the surgical sites. Due to its biodegradability, good biocompatibility, and unique biological properties, gelatin (GT) is considered a suitable candidate for guiding periodontal tissue regeneration. However, GT-based membranes come with limitations, such as poor mechanical strength and mismatched degradation rates. To confront this challenge, a series of GT/poly(4-hydroxybutyrate) (P4HB) composite membranes are fabricated through electrospinning technology. The morphology, composition, wetting properties, mechanical properties, biocompatibility, and in vivo biodegradability of the as-prepared composite membranes are carefully characterized. The results demonstrate that all the membranes present excellent biocompatibility. Moreover, the in vivo degradation rate of the membranes can be manipulated by changing the ratio of GT and P4HB. The results indicate that the optimized GT/P4HB membranes with a high P4HB content (75%) may be suitable for periodontal tissue engineering because of their good mechanical properties and biodegradation rate compatible with tissue growth.

A Case of Severe Rhabdomyolysis, Acute Myocardial Damage and Multi-Organ Dysfunction Syndrome in a Patient with Novel Coronavirus Pneumonia.

In recent years, healthcare systems worldwide have faced the challenge of the severe COVID-19 pandemic. However, cases of severe rhabdomyolysis, acute myocardial damage, and multiple organ dysfunction syndrome (MODS) caused by COVID-19 are currently rare. This report presents a case of severe rhabdomyolysis, acute myocardial damage, and MODS caused by COVID-19. The patient was treated at The University of Hong Kong-Shenzhen Hospital. The purpose of this report is to aid clinicians in quickly identifying and treating similar cases, ultimately improving patient outcomes.

On the application of Marcus-Hush theory to small polaron chemical dynamics in oxides: its relationship to the Holstein model and the importance of lattice-orbital symmetries.

The chemical dynamics of small polaron hopping within oxides is often interpreted through two-site variations on Marcus-Hush theory, while from a physics perspective small polaron hopping is more often approached from Holstein's solid-state formalism. Here we seek to provide a chemically oriented viewpoint, focusing on small polaron hopping in oxides, concerning these two phenomenological frameworks by employing both tight-binding modelling and first-principles calculations. First, within a semiclassical approach the Marcus-Hush relations are overviewed as a two-site reduction of Holstein's model. Within the single-band regime, similarities and differences between Holstein derived small polaron hopping and the Marcus-Hush model are also discussed. In this context the emergence of adiabaticity (or, conversely, diabaticity) is also explored within each framework both analytically and by directly evolving the system wavefunction. Then, through first-principles calculations of select oxides we explore how coupled lattice and orbital symmetries can impact on hopping properties - in a manner that is quite distinct typical chemical applications of Marcus-Hush theory. These results are then related back to the Holstein model to explore the relative applicability of the two frameworks towards interpreting small polaron hopping properties, where it is emphasized that the Holstein model offers an increasingly more appealing physicochemical interpretation of hopping processes as band and/or coupling interactions increase. Overall, this work aims to strengthen the physically oriented exploration of small polarons and their physicochemical properties in the growing oxide chemistry community.

Hyperbranched Poly-L-Lysine-Based Water-Insoluble Complexes as Antibacterial Agents with Efficient Antibacterial Activity And Cytocompatibility.

Despite the advances in technology, bacterial infection associated with biomedical devices is still one of the most challenging issues in clinical practice. Incorporation of antimicrobial agents is regarded as an efficient way to combat medical device associated infectious. However, most of antimicrobial agents have high toxicity to host cells. Thus, fabrication of novel antimicrobial agents that simultaneously fulfill the requirements of antibacterial activity as well as biocompatibility is urgently needed. Herein, a series of water-insoluble antibacterial complexes based on hyperbranched poly-L-lysine (HBPL) and four different surfactants through non-covalent interactions are developed. Such kinds of surfactants have great effects on the antibacterial property of poly(ɛ-caprolactone) (PCL) films that incorporate with the HBPL-based complexes. The results reveal that the PCL films that doped with HBPL/phosphate ester surfactant complexes showed the highest bacterial killing efficiency. Moreover, the cytocompatibility of the composite films is also investigated. Hemolysis experiments indicate that all the films  had low hemolytic activities. Considering the excellent antimicrobial and cytocompatibility properties, this work believes that the optimized complexes have great potential to be used as antimicrobial agents in biomedical field.

Fabrication of Oleophilic Polypeptide Nanoparticle from Complexing of Cross-Linked Epsilon-poly-l-lysine with Docusate Sodium for Preparation of Bactericidal Thermoplastic Polyurethanes.

Thermoplastic polyurethanes (TPUs) are extensively utilized in the biomedical field due to their exceptional mechanical properties and biocompatibility. However, the lack of antibacterial activity limits their application ranges. Nanoscopic particle-based additives with inherent antibacterial characteristics are regarded as promising strategies to prevent biomaterials-associated infection. Herein, a novel polymeric nanoparticle is prepared, which integrates chemically cross-linked epsilon-poly-l-lysine (CPL) and anionic surfactant-docusate sodium (DS). The cross-linked epsilon-poly-l-lysine/docusate sodium (CPL/DS) nanoparticle can be well dispersed in organic solvent and a polymer matrix, which is beneficial to endowing TPUs with synergistic miscibility and antibacterial properties. An antibacterial test showed that the CPL/DS nanoparticles have strong antibacterial activity against S. aureus. Moreover, the results of antibacterial experiments in vitro revealed that almost 100% of S. aureus could be killed by CPL/DS nanoparticle-embedded TPU film with a content of 0.5 wt %. In addition, all of the CPL/DS modified TPU films showed good cytocompatibility in vitro. Consequently, this kind of CPL/DS nanoplatform has great potential to serve as a safe and high-efficient bactericidal agent for endowing biomedical devices with bactericidal property.

Case report: Ultrasound-guided needle knife technique for carpal ligament release in carpal tunnel syndrome treatment.

Carpal tunnel syndrome (CTS) is a common peripheral neuropathy of the hand, mainly manifesting as sensory disturbances, motor dysfunctions, and pain in the fingers and hand. The pathogenesis of the disease is associated with fibrosis of the transverse carpal ligament in the carpal tunnel, which compresses median nerve. In our case, we demonstrate an ultrasound-guided needle knife technique to treat CTS. We guided the patient to a supine position on the examination table. The skin of the wrist area was sterilized for the procedure. After the skin was dry, we positioned sterile drapes, located the median nerve and compression, and marked the compression point. Local anesthesia was administered. An ultrasound-guided needle knife was inserted. The needle knife was advanced under ultrasound guidance. The carpal ligament was incised. A gradual release of pressure on the median nerve was observed on the ultrasound monitor. After treatment, the patient's finger sensation and motor function can significantly improve, and pain symptoms are markedly reduced, this case demonstrates that small needle-knife treatment can serve as a safe and effective minimally invasive therapeutic method.

Multifunctional Fluorinated Lubricant-Infused Poly(4-Hydroxybutyrate) (P4HB) Membranes for Full-Thickness Abdominal Wall Defect Repair.

Abdominal wall defect caused by surgical trauma, congenital rupture, or tumor resection may result in hernia formation or even death. Tension-free abdominal wall defect repair by using patches is the gold standard to solve such problems. However, adhesions following patch implantation remain one of the most challenging issues in surgical practice. The development of new kinds of barriers is key to addressing peritoneal adhesions and repairing abdominal wall defects. It is already well recognized that ideal barrier materials need to have good resistance to nonspecific protein adsorption, cell adhesion, and bacterial colonization for preventing the initial development of adhesion. Herein, electrospun poly(4-hydroxybutyrate) (P4HB) membranes infused with perfluorocarbon oil are used as physical barriers. The oil-infused P4HB membranes can greatly prevent protein attachment and reduce blood cell adhesion in vitro. It is further shown that the perfluorocarbon oil-infused P4HB membranes can reduce bacterial colonization. The in vivo study reveals that perfluoro(decahydronaphthalene)-infused P4HB membranes can significantly prevent peritoneal adhesions in the classic abdominal wall defects' model and accelerate defect repair, as evidenced by gross examination and histological evaluation. This work provides a safe fluorinated lubricant-impregnated P4HB physical barrier to inhibit the formation of postoperative peritoneal adhesions and efficiently repair soft-tissue defects.

Collaborative Enhancement of Humidity Sensing Performance by KCl-Doped CuO/SnO2 p-n Heterostructures for Monitoring Human Activities.

In this study, a high-performance humidity sensor based on KCl-doped CuO/SnO2 p-n heterostructures was fabricated by a ball milling-roasting method. The morphology and nanostructure of the fabricated KCl-CuO/SnO2 composite were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and nitrogen sorption analysis. The results showed that the humidity sensor had a high sensitivity of 194 kΩ/%RH, short response and recovery times of 1.0 and 1.5 s, a low hysteresis value, and good repeatability. The energy band structure and complex impedance spectrum of the KCl-CuO/SnO2 composite indicated that the excellent humidity sensing performance originated from the ionic conductivity of KCl, the formation of heterojunctions, the change in the Schottky barrier height, and the depletion of electronic depletion layers. The KCl-CuO/SnO2 sensor has great potential in respiratory monitoring, noncontact sensing of finger moisture, and environmental monitoring.

Ultra-high performance humidity sensor enabled by a self-assembled CuO/Ti3C2T X MXene.

An ultra-high performance humidity sensor based on a CuO/Ti3C2T X MXene has been investigated in this work. The moisture-sensitive material was fabricated by a self-assembly method. The morphology and nanostructure of the fabricated CuO/Ti3C2T X composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectra. The humidity sensing abilities of the CuO/Ti3C2T X sensor in the relative humidity (RH) range from 0% to 97% were studied. The results showed that the humidity sensor had a high sensitivity of 451 kΩ/% RH, short response time (0.5 s) and recovery time (1 s), a low hysteresis value, and good repeatability. The CuO/Ti3C2T X sensor exhibited remarkable properties in human respiration rate monitoring, finger non-contact sensing, and environmental detection. The moisture-sensitive mechanism of CuO/Ti3C2T X was discussed. The fabricated CuO/Ti3C2T X showed great potential in the application of moisture-sensitive materials for ultra-high-performance humidity sensors.

First-principles redox energy estimates under the condition of satisfying the general form of Koopmans' theorem: An atomistic study of aqueous iron.

In this work, we explore the relative accuracy to which a hybrid functional, in the context of density functional theory, may predict redox properties under the constraint of satisfying the general form of Koopmans' theorem. Taking aqueous iron as our model system within the framework of first-principles molecular dynamics, direct comparison between computed single-particle energies and experimental ionization data is assessed by both (1) tuning the degree of hybrid exchange, to satisfy the general form of Koopmans' theorem, and (2) ensuring the application of finite-size corrections. These finite-size corrections are benchmarked through classical molecular dynamics calculations, extended to large atomic ensembles, for which good convergence is obtained in the large supercell limit. Our first-principles findings indicate that while precise quantitative agreement with experimental ionization data cannot always be attained for solvated systems, when satisfying the general form of Koopmans' theorem via hybrid functionals, theoretically robust estimates of single-particle redox energies are most often arrived at by employing a total energy difference approach. That is, when seeking to employ a value of exact exchange that does not satisfy the general form of Koopmans' theorem, but some other physical metric, the single-particle energy estimate that would most closely align with the general form of Koopmans' theorem is obtained from a total energy difference approach. In this respect, these findings provide important guidance for the more general comparison of redox energies computed via hybrid functionals with experimental data.

[Correlation between neutrophil/lymphocyte ratio combined with low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio and severity of coronary artery disease in patients with acute coronary syndrome].

OBJECTIVE: To investigate the correlation between neutrophil/lymphocyte ratio (NLR) combined with low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio (LDL-C/HDL-C) and severity of coronary lesions in patients with acute coronary syndrome (ACS). METHODS: Patients who were diagnosed with ACS due to chest pain and received emergency coronary angiography in the First Affiliated Hospital of University of Science and Technology of China and the Affiliated Hospital of Anhui Medical University from January 2017 to June 2020 were enrolled in the final analysis. The data of gender, age, body mass index (BMI), past history, emergency blood routine indicators [neutrophil (NEU), lymphocyte (LYM), monocyte (MON), eosinophil (EOS), basophil (BAS), red blood cell (RBC), mean corpuscular volume (MCV), blood red cell distribution width (RDW), mean platelet volume (MPV), platelet volume distribution width (PDW)], blood lipid index [triglyceride (TG), total cholesterol (TC), HDL-C, LDL-C, very low-density lipoprotein cholesterol (VLDL-C)], and coronary angiography were collected. The results of coronary angiography were evaluated by the Gensini score. According to the Gensini score, the patients were divided into the control group (Gensini score = 0, 55 cases) and the study group (Gensini score > 0, 889 cases), and then the patients in the study group were divided into the low-Gensini-score group (Gensini score < 66, 419 cases) and the high-Gensini-score group (Gensini score ≥ 66, 470 cases). The differences in the general baseline data of the four groups were compared, and the correlation between the statistically significant data and the Gensini score was linearly analyzed, and then the combined diagnostic factors (NLR combined with LDL-C/HDL-C ratio) were obtained by Logistic regression analysis. The receiver operator characteristic curve (ROC curve) was used to evaluate the predictive value of NLR combined with LDL-C/HDL-C ratio in predicting the severity of coronary artery lesions in patients with ACS. Finally, multivariate linear regression analysis was used to establish the predictive model between NLR combined with LDL-C/HDL-C ratio and Gensini score. RESULTS: A total of 944 patients were finally included. The differences in gender, age, BMI, hypertension, diabetes, smoking history, NEU, LYM, MON, EOS, RDW, TC, HDL-C, LDL-C, NLR, LDL-C/HDL-C ratio between the control group and the study group were statistically significant. The differences in BMI, hypertension, diabetes, smoking history, NEU, LYM, MON, EOS, TG, TC, HDL-C, LDL-C, NLR and LDL-C/HDL-C ratio between the low-Gensini-score group and the high-Gensini-score group were statistically significant. Linear regression analysis showed that compared with other indicators, the correlation between NLR, LDL-C/HDL-C ratio and Gensini score was stronger in the study group (r values were 0.634 and 0.663, respectively, both P < 0.05). Binary Logistic regression analysis of the indicators related to Gensini score showed that NEU, LYM, HDL-C and LDL-C were independent risk factors for coronary stenosis in patients with ACS [odds ratio (OR) were 0.189, 10.309, 13.993, 0.251, 95% confidence intervals (95%CI) were 0.114-0.313, 4.679-22.714, 3.402-57.559, 0.121-0.519, respectively, all P < 0.05]. ROC curve analysis showed that NLR combined with LDL-C/HDL-C ratio had higher predictive value in predicting the severity of coronary lesions in ACS patients [area under the ROC curve (AUC) was 0.952, 95%CI was 0.93-0.969], when the cutoff value was -3.152, the sensitivity was 98.20%, and the specificity was 81.60%. According to the results of multivariate linear regression analysis, the prediction model between NLR, LDL-C/HDL-C ratio and Gensini score was established, and the formula was Gensini score = -7.772+15.675×LDL-C/HDL-C ratio+8.288×NLR (R2 = 0.862). CONCLUSIONS: There is a significant correlation between emergency NLR combined with LDL-C/HDL-C ratio and Gensini score in patients with ACS at admission, which has a certain predictive value for the severity of coronary artery stenosis in patients with ACS, and can be used as a predictor for evaluating the severity of coronary artery disease.

Bioactive Poly(4-hydroxybutyrate)/Poly(ethylene glycol) Fibrous Dressings Incorporated with Zinc Oxide Nanoparticles for Efficient Antibacterial Therapy and Rapid Clotting.

Antibacterial and hemostatic properties are of great importance to wound dressing in treating trauma. Poly(4-hydroxybutyrate) (P4HB), an U.S. Food and Drug Administration (FDA)-approved bioabsorbable polyester, is used as dermal substitutes to prevent sever wound contraction and improve wound healing. However, P4HB fibrous mats are not efficient in halting bleeding and preventing bacterial associated infection. Here the authors prepare a new kind of wound dressing by incorporating poly(ethylene glycol) (PEG) and zinc oxide (ZnO) nanoparticles into the P4HB matrix by using electrospinning method. The in vitro results reveal that the P4HB/PEG/ZnO dressings can synergistically help blood clotting, prevent bacteria adhesion, and kill bacteria efficiently. It's found that the bactericidal activity of the bioactive P4HB/PEG/ZnO dressings is related to the release of Zn2+ ions rather than reactive oxygen species (ROS) under dark condition. The in vivo antibacterial evaluation indicates that the bioactive P4HB/PEG/ZnO dressings can successfully prevent wound infections in Sprague-Dawley (SD) rats' skin defect model. The in vivo hemostatic experiments evaluated in the rabbit ear injury model further confirm that the bioactive P4HB/PEG/ZnO dressings have excellent hemostatic performance. Hence, this study demonstrates that the bioactive P4HB/PEG/ZnO dressings with hemostatic and bactericidal properties have great potential in possible clinical applications.

Slippery 3-dimensional porous bioabsorbable membranes with anti-adhesion and bactericidal properties as substitute for vaseline gauze.

Vaseline gauze is a common type of wound dressing that consist of absorbent gauze impregnated with white petrolatum. It has excellent anti-adhesive property which can reduce trauma during dressing changes. However, this kind of wound dressing doesn't have bacterial killing property. Thus, a new kind of wound dressing that has anti-adhesive and bactericidal properties is needed urgently. Creating slippery liquid-impregnated porous surfaces (SLIPS) that insensitive to the structure of porous solid are generally viewed as a new anti-adhesion strategy. To expand the potential utility of SLIPS as substitute for vaseline gauze, dual-functional slippery membranes with anti-adhesion and bactericidal properties by using triclosan, vegetable oils and polylactic acid (PLA) were prepared. It's demonstrated that the triclosan-loaded/vegetable oils-infused PLA membranes (T/V-PM) has good cytocompatibility in vitro. Notably, the T/V-PM can gradually release biocide molecule into surrounding aqueous media. Moreover, the T/V-PM can kill planktonic bacterial cells without loss of their antifouling property. The in vivo study revealed that the T/V-PM can prevent the secondary injuries during wound dressing changes. This simple and low-cost strategy can be applied to inhibit blood and bacterial adhesion, and prevent tissue adhesion at the wound site. It's confirmed that the T/V-PM have great potential as substitute for vaseline gauze.

Dual Interface Protection for High Performance and Excellent Long-Term Stability of Organic Solar Cells.

Stability is still the main barrier to the commercial application of organic solar cells (OSCs), although the maximal power conversion efficiency (PCE) value has exceeded 19%. The encapsulation technique is an effective and vital way to guarantee the long-term stabilities of OSCs, but it can only avoid the penetration of water and oxygen from the environment. Herein, we introduced a structure that provides dual interface protection by using commercially available and chemically stable polyvinylidene fluoride (PVDF) as the cathode interface protection layer working as the cathode interlayer (CIL) and poly(styrene-comethyl-methacrylate) (PS-r-PMMA) as the anode interface protection layer between the poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) and the active layer. With this structure, both the migration of impurities caused by degradation of the interfacial layer and the infiltration of oxygen and water in the air can be prevented. PVDF can effectively provide optimal electron transfer by improving the surface potential of active layers and lowering the work function of the Al electrode. PS-r-PMMA can improve the hydrophobicity of PEDOT:PSS and induce optimized phase separation, facilitating charge transfer. After storage in an air environment with a humidity of approximately 60% for 3600 h, the device based on the PM6:IT-4F blend film with dual interface protection showed a decrease in its PCE value from 13.43 to 10.90%, retaining 81.2% of its original PCE value, in contrast to the sharp decrease in the PCE value from 13.66 to 0.74% of the device without dual interface protection. The dual interface protection design could also be useful in the high-performance PM6:Y6 system, which shows a champion PCE of 15.39% and shows potential for the effective fabrication of stable OSCs in the future.

Bioabsorbable poly(4-hydroxybutyrate) (P4HB) fibrous membranes as a potential dermal substitute.

Dermal substitutes are indispensable for repairing large full-thickness skin defects. Only a few biomaterials for dermal substitution have been put into clinical practice. Therefore, novel artificial dermal substitutes that can meet clinical requirements are in urgent need. Biodegradable poly(4-hydroxybutyrate) (P4HB), which has been approved by the U.S. FDA, can be considered as a possible alternative biomaterial to construct dermal substitutes. In this work, three-dimensional P4HB fibrous membranes were constructed by an electrospinning technique. These P4HB fibrous membranes showed excellent air-permeability, and better water uptake capacity compared to P4HB strip and polycaprolactone (PCL) fibrous membrane controls. The in vitro hemocompatibility and cytotoxicity of P4HB fibrous membranes were investigated. In vivo Sprague-Dawley (SD) rat model studies revealed that P4HB fibrous membranes can be used as artificial dermis to improve wound healing for full-thickness skin defects.

Injectable Cell- and Growth Factor-Free Poly(4-hydroxybutyrate) (P4HB) Microspheres with Open Porous Structures and Great Efficiency of Promoting Bone Regeneration.

Delivering injectable microspheres in a minimally invasive way to repair complexly shaped tissue defects renders them attractive for clinical use. Especially, open porous microspheres that provide sufficient internal space for cell proliferation and nutrient diffusions can efficiently aid to completing reconstructions of tissue defects. In this work, chemically synthesized and biodegradable poly(4-hydroxybutyrate) (P4HB), which is the U.S. FDA-approved polyhydroxyalkanoate (PHA), was employed for fabricating open porous microspheres using a double-emulsion solvent evaporation method. The influences of fabrication parameters were discussed. It was found that the P4HB-based cell-free and growth factor-free open porous microspheres can enhance osteoblast differentiation of adipose-derived stem cells in vitro and accelerate rat calvarial bone-defect healing in vivo. These results demonstrated that the injectable open porous P4HB microspheres present a remarkable potential in bone tissue regeneration.

Ergodic and Nonergodic Dynamics of Oxygen Vacancy Migration at the Nanoscale in Inorganic Perovskites.

Perovskites are widely utilized either as a primary component or as a substrate in which the dynamics of charged oxygen vacancy defects play an important role. Current knowledge regarding the dynamics of vacancy mobility in perovskites is solely based upon volume- and/or time-averaged measurements. This impedes our understanding of the basic physical principles governing defect migration in inorganic materials. Here, we measure the ergodic and nonergodic dynamics of vacancy migration at the relevant spatial and temporal scales using time-resolved atomic force microscopy techniques. Our findings demonstrate that the time constant associated with oxygen vacancy migration is a local property and can change drastically on short length and time scales, such that nonergodic states lead to a dramatic increase in the migration barrier. This correlated spatial and temporal variation in oxygen vacancy dynamics can extend hundreds of nanometers across the surface in inorganic perovskites.

Electrical Stressing Induced Monolayer Vacancy Island Growth on TiSe2.

To ensure practical applications of atomically thin transition metal dichalcogenides, it is essential to characterize their structural stability under external stimuli such as electric fields and currents. Using vacancy monolayer islands on TiSe2 surfaces as a model system, we have observed nonlinear area evolution and growth from triangular to hexagonal driven by scanning tunneling microscopy (STM) subjected electrical stressing. The observed growth dynamics represent a 2D departure from the linear area growth law expected for bulk vacancy clustering. Our simulations of monolayer island evolution using phase-field modeling and first-principles calculations are in good agreement with our experimental observations, and point toward preferential edge atom dissociation under STM scanning driving the observed nonlinear area growth. We further quantified a parabolic growth rate dependence with respect to the tunneling current magnitude. The results could be potentially important for device reliability in systems containing ultrathin transition metal dichalcogenides and related 2D materials subject to electrical stressing.

pH-Responsive Peptide Supramolecular Hydrogels with Antibacterial Activity.

Smart hydrogels have received increasing attention for many applications. Here, we synthesized a class of cationic peptide amphiphiles that can self-assemble into hydrogels by ring-opening polymerization (ROP) and post-modification strategy. The incorporation of cationic lysine residues suppresses the formation of fibril-like structure and further the gelation ability of the samples. Sodium alginate (SA) is used to enhance the rheology performance of the hydrogels. The hydrogels exhibit pH-dependent self-assembly and the gelation behavior that enables them to be ideal smart hydrogel systems for biomedical applications. Furthermore, the as-prepared hybrid peptide hydrogels show antibacterial activity.

A hierarchical polymer brush coating with dual-function antibacterial capability.

Bacterial infections are problematic in many healthcare-associated devices. Antibacterial surfaces integrating the strength of bacteria repellent and bactericidal functions exhibit an encouraging efficacy in tackling this problem. Herein, a hierarchical dual-function antibacterial polymer brush coating that integrates an antifouling bottom layer with a bactericidal top layer is facilely constructed via living photograft polymerization. Excellent resistance to bacterial attachment is correlated with the antifouling components, and good bactericidal activity is afforded by the bactericidal components, and therefore the hierarchical coating shows an excellent long-term antibacterial capability. In addition, due to the presence of the hydrophilic background layer, the hierarchical surface has the greatly improved biocompatibility, as shown by the suppression of platelet adhesion and activation, the inhibition of erythrocyte adhesion and damage, and low toxicity against mammalian cells. The hierarchical polymer brush system provides the basis for the development of long-term antibacterial and biocompatible surfaces.