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This work includes a novel approach for synthesis/fabrication of AuNRs of varied aspect ratios leading to investigation on the kinetics of their growth mechanism. The synthesized AuNRs were further functionalized with MWCNTs (AuNRs@MWCNTs) by one-pot synthesis. The synthesized AuNRs and AuNRs@MWCNTs were characterized by employing UV-vis spectroscopy. Red shifts in the spectra of AuNRs confirmed the formation of nanorods of higher aspect ratios. Morphology of AuNRs and functionalized AuNRs was confirmed by high-resolution scanning electron microscopy. Biological studies were carried out by fabricating efficient nonenzymatic glucose sensors for optical and electrochemical sensing via UV and cyclic voltammetry in the detection ranges of 0.7-28 mM glucose (UV) and 5.5 µM-0.33 mM (CV). An electrochemical sensing study was carried out via AuNR- and AuNRs@MWCNT-modified GCEs in a 0.1 M NaOH electrolyte solution. The modified electrodes exhibited very high sensitivity with a broad linear range. The order of sensitivity (via CV) was found to be AuNRX0@MWCNTs > AuNRD5@MWCNTs > AuNRD5 > AuNRX0.
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Red fluorescent hydrogels possessing injectable and self-healing properties have widespread potential in biomedical field. It is still a challenge to achieve a biomacromolecules based dynamic hydrogels simultaneously combining with excellent red fluorescence, good mechanical properties, and biocompatibility. Here we first explore hydrophilic inclusion complex of (R-CDs@α-CD) derived from hydrophobic red fluorescent carbon dots (R-CDs) and α-cyclodextrin (α-CD), and then achieved a red fluorescent and dynamic polysaccharide R-CDs@α-CD/CEC-l-OSA hydrogel. The nanocomposite hydrogel can be fabricated through controlled doping of red fluorescent R-CDs@α-CD into dynamic polymer networks, taking reversibly crosslinked N-carboxyethyl chitosan (CEC) and oxidized sodium alginate (OSA) as an example. The versatile red fluorescent hydrogel simultaneously combines the features of injection, biocompatibility, and augmented mechanical properties and self-healing behavior, especially in rapid self-recovery even after integration. The R-CDs@α-CD uniformly dispersed into dynamic hydrogel played the role of killing two birds with one stone, that is, endowing red emission of a hydrophilic fluorescent substance, and improving mechanical and self-healing properties as a dynamic nano-crosslinker, via forming hydrogen bonds as reversible crosslinkings. The novel red fluorescent and dynamic hydrogel based on polysaccharides is promising for using as biomaterials in biomedical field.
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Alginatos , Carbono , Quitosano , Hidrogeles , Nanocompuestos , Puntos Cuánticos , Alginatos/química , Quitosano/química , Carbono/química , Nanocompuestos/química , Hidrogeles/química , Puntos Cuánticos/química , Puntos Cuánticos/toxicidad , Colorantes Fluorescentes/química , alfa-Ciclodextrinas/química , Materiales Biocompatibles/química , Animales , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
Dynamic hydrogels with the features of injection, self-healing, and remodeling at the target site have been developed as smart multifunctional biomaterials for drug delivery. However, most self-healing injectable hydrogels are difficult to control protein release after implantation, owing to the deficiency of pH responsiveness, which reduces the bioavailability of proteins. Herein, we propose a facile strategy to endow pH responsiveness into a dynamic hydrogel with both self-healing and injectable capabilities, by crosslinking biomacromolecular backbones via dual pH sensitive dynamic covalent bond. Particularly, oxidized konjac glucomannan (OKGM) can be crosslinked with poly (aspartic hydrazide) (PAHy) and N-carboxyethyl chitosan (CEC) to form dynamic acylhydrazone bonds and imide bonds, respectively, endowing the hydrogel with pH responsiveness and dynamic behaviors. Specifically, PAHy facilitates the formation of acylhydrazone bonds, improving the mechanical properties and pH sensitivity while reducing the degradation behavior of the hydrogels under physiological conditions. Kinetics indicate that the release of bovine serum albumin follows Fick diffusion under different pH conditions. The pH responsive hydrogel with self-healing injectable capabilities has the potential to be used as a controllable and sustain release carrier for protein drugs.
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Quitosano , Hidrogeles , Mananos , Albúmina Sérica Bovina , Quitosano/química , Hidrogeles/química , Concentración de Iones de Hidrógeno , Mananos/química , Albúmina Sérica Bovina/química , Animales , Liberación de Fármacos , Preparaciones de Acción Retardada/química , Bovinos , InyeccionesRESUMEN
In this study, the copper-nickel (Cu-Ni) bimetallic electrocatalysts for electrochemical CO2 reduction reaction(CO2RR) are fabricated by taking the finely designed poly(ionic liquids) (PIL) containing abundant Salen and imidazolium chelating sites as the surficial layer, wherein Cu-Ni, PIL-Cu and PIL-Ni interaction can be readily regulated by different synthetic scheme. As a proof of concept, Cu@Salen-PIL@Ni(NO3)2 and Cu@Salen-PIL(Ni) hybrids differ significantly in the types and distribution of Ni species and Cu species at the surface, thereby delivering distinct Cu-Ni cooperation fashion for the CO2RR. Remarkably, Cu@Salen-PIL@Ni(NO3)2 provides a C2+ faradaic efficiency (FEC2+) of 80.9% with partial current density (jC 2+) of 262.9 mA cm-2 at -0.80 V (versus reversible hydrogen electrode, RHE) in 1 m KOH in a flow cell, while Cu@Salen-PIL(Ni) delivers the optimal FEC2+ of 63.8% at jC2+ of 146.7 mA cm-2 at -0.78 V. Mechanistic studies indicates that the presence of Cu-Ni interfaces in Cu@Salen-PIL@Ni(NO3)2 accounts for the preserve of high-valence Cu(I) species under CO2RR conditions. It results in a high activity of both CO2-to-CO conversion and C-C coupling while inhibition of the competitive HER.
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Growing concern regarding the impact of fossil fuels has led to demands for the development of green and renewable materials for advanced electrochemical energy storage devices. Biopolymers with unique hierarchical structures and physicochemical properties, serving as an appealing platform for the advancement of sustainable energy, have found widespread application in the gel electrolytes of supercapacitors. In this Review, we outline the structure and characteristics of various biopolymers, discuss the proposed mechanisms and assess the evaluation metrics of gel electrolytes in supercapacitor devices, and further analyze the roles of biopolymer materials in this context. The state-of-the-art electrochemical performance of biopolymer-based hydrogel electrolytes for supercapacitors and their multiple functionalities are summarized, while underscoring the current technical challenges and potential solutions. This Review is intended to offer a thorough overview of recent developments in biopolymer-based hydrogel electrolytes, highlighting research concerning green and sustainable energy storage devices and potential avenues for further development.
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Polysaccharide based self-healing and injectable hydrogels with reversible characteristics have widespread potential in protein drug delivery. However, it is a challenge to design the dynamic hydrogel for sequential release of protein drugs. Herein, we developed a novel mussel inspired sequential protein delivery dynamic polysaccharide hydrogel. The nanocomposite hydrogel can be fabricated through doping polydopamine nanoparticles (PDA NPs) into reversible covalent bond (imine bonds) crosslinked polymer networks of oxidized hyaluronic acid (OHA) and carboxymethyl chitosan (CEC), named PDA NPs@OHA-l-CEC. Besides multiple capabilities (i.e., injection, self-healing, and biodegradability), the nanocomposite hydrogel can achieve sustained and sequential protein delivery of vascular endothelial growth factor (VEGF) and bovine serum albumin (BSA). PDA NPs doped in hydrogel matrix serve dual roles, acting as secondary protein release structures and form dynamic non-covalent interactions (i.e., hydrogen bonds) with polysaccharides. Moreover, by adjusting the oxidation degree of OHA, the hydrogels with different crosslinking density could control overall protein release rate. Analysis of different release kinetic models revealed that Fickian diffusion drove rapid VEGF release, while the slower BSA release followed a Super Case II transport mechanism. The novel biocompatible system achieved sequential release of protein drugs has potentials in multi-stage synergistic drug deliver based on dynamic hydrogel.
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Quitosano , Factor A de Crecimiento Endotelial Vascular , Nanogeles , Factor A de Crecimiento Endotelial Vascular/química , Sistemas de Liberación de Medicamentos , Hidrogeles/química , Quitosano/química , Polisacáridos/química , Ácido Hialurónico/química , Albúmina Sérica BovinaRESUMEN
Biomacromolecules based injectable and self-healing hydrogels possessing high mechanical properties have widespread potential in biomedical field. However, dynamic features are usually inversely proportional to toughness. It is challenging to simultaneously endow these properties to the dynamic hydrogels. Here, we fabricated an injectable nanocomposite hydrogel (CS-NPs@OSA-l-Gtn) stimultaneously possessing excellent autonomous self-healing performance and high mechanical strength by doping chitosan nanoparticles (CS-NPs) into dynamic polymer networks of oxidized sodium alginate (OSA) and gelatin (Gtn) in the presence of borax. The synergistic effect of the multiple reversible interactions combining dynamic covalent bonds (i.e., imine bond and borate ester bond) and noncovalent interactions (i.e., electrostatic interaction and hydrogen bond) provide effective energy dissipation to endure high fatigue resistance and cyclic loading. The dynamic hydrogel exhibited excellent mechanical properties like maximum 2.43 MPa compressive strength, 493.91 % fracture strain, and 89.54 kJ/m3 toughness. Moreover, the integrated hydrogel after injection and self-healing could withstand 150 successive compressive cycles. Besides, the bovine serum albumin embedded in CS-NPs could be sustainably released from the nanocomposite hydrogel for 12 days. This study proposes a novel strategy to synthesize an injectable and self-healing hydrogel combined with excellent mechanical properties for designing high-strength natural carriers with sustained protein delivery.
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Alginatos , Quitosano , Alginatos/química , Nanogeles , Gelatina/química , Hidrogeles/química , Polímeros , Quitosano/químicaRESUMEN
Solar-driven interfacial evaporation materials based on nanocomposite hydrogels have emerged for seawater desalination. Nevertheless, the issue of mechanical degradation derived from the swelling behavior of hydrogel is often seriously underestimated, which strongly hinders the practical application for long-term solar vapor generation, especially in high-salinity brine. Herein, a novel CNT@Gel-nacre with enhanced capillary pumping design has been proposed and fabricated for tough and durable solar-driven evaporator through uniformly doping carbon nanotubes (CNTs) into the tough gel-nacre. Particularly, the salting out process gives rise to volume shrinkage and phase separation of polymer chains, endowing the nanocomposite hydrogel with significantly enhanced mechanical properties while simultaneously rendering more compact microchannels for water transportation, boosting the capillary pumping. Based on this unique design, the gel-nacre nanocomposite exhibits outstanding mechanical performances (13.41 MPa strength, 55.60 MJ m-3 toughness), especially mechanical durability in high salinity brine for long-term service. Furthermore, excellent water evaporation rate of 1.31 kg m-2h-1 and conversion efficiency of 93.5% in 3.5 wt% sodium chloride solution, as well as stable cycling without salt accumulation can be achieved. This work demonstrates an effective strategy for achieving solar-driven evaporator with superior mechanical properties and durability even in brine environment, showing huge potentials in long-term seawater desalination.
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The electrocatalytic reduction of CO2 to CO with high efficiency is one of the most promising approaches for CO2 conversion due to its considerable economic feasibility and broad application prospects. In this study, three Ag@COF-R (R = -H, -OCH3, -OH) hybrids were facilely fabricated by impregnating silver acetate (AgOAc) into respective covalent organic frameworks (COFs) prepared in advance. They differ significantly in the crystallinity, porosity, distribution, size, and electronic configuration of AgOAc species, which thereby influences both the activity and the selectivity of electrolytic CO2-to-CO transformation. Impressively, Ag@COF-OCH3 provided a high FECO of 93.0% with a high jCO of 213.9 mA cm-2 at -0.87 V (vs reversible hydrogen electrode, RHE) in 1 M KOH using a flow cell. In addition, it exhibited long-term durability at 100 mA cm-2 for 30 h.
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Accurate discrimination and classification of unknown species are the basis to predict its characteristics or applications to make correct decisions. However, for biogenic solutions that are ubiquitous in nature and our daily lives, direct determination of their similarities and disparities by their molecular compositions remains a scientific challenge. Here, we explore a standard and visualizable ontology, termed "biogenic solution map", that organizes multifarious classes of biogenic solutions into a map of hierarchical structures. To build the map, a novel 4-dimensional (4D) fingerprinting method based on data-independent acquisition data sets of untargeted metabolomics is developed, enabling accurate characterization of complex biogenic solutions. A generic parameter of metabolic correlation distance, calculated based on averaged similarities between 4D fingerprints of sample groups, is able to define "species", "genus", and "family" of each solution in the map. With the help of the "biogenic solution map", species of unknown biogenic solutions can be explicitly defined. Simultaneously, intrinsic correlations and subtle variations among biogenic solutions in the map are accurately illustrated. Moreover, it is worth mentioning that samples of the same analyte but prepared by alternative protocols may have significantly different metabolic compositions and could be classified into different "genera".
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Metabolómica , Metabolómica/métodosRESUMEN
The proper microenvironment is critical for the storage and transportation of embryonic stem cells (ESCs). To mimic a dynamic 3D microenvironment as it exists in vivo and consider "off-the-shelf" availability reaching the destination, we proposed an alternative approach that allows for facile storage and transportation of stem cells in the form of ESCs-dynamic hydrogel construct (CDHC) under ambient conditions. To form CDHC, mouse embryonic stem cells (mESCs) were in-situ encapsulated within a polysaccharide-based dynamic and self-biodegradable hydrogel. After storing CDHC in a sterile and hermetic environment for 3 days and then transferring to a sealed vessel with fresh medium for another 3 days, the large and compact colonies retained a 90% survival rate and pluripotency. Furthermore, after transporting and arriving at the destination, the encapsulated stem cell could be automatically released from the self-biodegradable hydrogel. After continuous cultivation of 15 generations of retrieved cells, automatically released from the CDHC, the mESCs underwent 3D encapsulation, storage, transportation, release, and continuous long-term subculture; resumed colony forming capacity and pluripotency were revealed by stem cell markers both in protein and mRNA levels. We believe that the dynamic and self-biodegradable hydrogel provides a simple, cost-effective, and valuable tool for storing and transporting "ready-to-use" CDHC under ambient conditions, facilitating "off-the-shelf" availability and widespread applications.
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Injectable dressings offering intrinsic antibacterial activity and antioxidation are required, because persistent bacterial infection and oxidative damage are common issues associated with chronic non-healing wounds. Herein, a versatile QCS-l-TA-l-OHA hydrogel is fabricated using ubiquitous nature derived biological macromolecules, quaternized chitosan (QCS), tannic acid (TA) and oxidant hyaluronic acid (OHA), driving by multiple dynamic interactions under physiological conditions. The hydrogel can serve as multiple functional wound dress with injectable and self-healing capabilities coupling with attractive antibacterial activity and antioxidation. The biocompatible and self-biodegradable hydrogel augments free radical scavenging capacity, antibacterial, angiogenesis, mature granulation tissue and collagen disposition, enabling fast wound healing of rat skin full-thickness incision model. This study highlights a wound dressing platform of hyaluronic acid and chitosan based injectable and self-healing hydrogel with inherent antibacterial and antioxidant bioactivities, thereby avoiding the use of antibiotics or antioxidant agents.
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Quitosano , Ratas , Animales , Quitosano/farmacología , Hidrogeles/farmacología , Antioxidantes/farmacología , Ácido Hialurónico/farmacología , Antibacterianos/farmacologíaRESUMEN
Exploring a strategy to effectively repair cerebral ischemic injury is a critical requirement for neuroregeneration. Herein, we transplanted a neural stem cell (NSC)-laden self-healing and injectable hydrogel into the brains of ischemic rats and evaluated its therapeutic effects. We observed an improvement in neurological functions in rats transplanted with the NSC-laden hydrogel. This strategy is sufficiently efficient to support neuroregeneration evidenced by NSC proliferation, differentiation, and athletic movement recovery of rats. This therapeutic effect relates to the inhibition of the astrocyte reaction and the increased expression of vascular endothelial growth factor. This work provides a novel approach to repair cerebral ischemic injury.
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Materiales Biocompatibles/farmacología , Isquemia Encefálica/tratamiento farmacológico , Hidrogeles/farmacología , Células-Madre Neurales/efectos de los fármacos , Neurogénesis/efectos de los fármacos , Polisacáridos/farmacología , Animales , Materiales Biocompatibles/química , Isquemia Encefálica/patología , Hidrogeles/química , Masculino , Ensayo de Materiales , Células-Madre Neurales/patología , Tamaño de la Partícula , Polisacáridos/química , Ratas , Ratas Sprague-Dawley , Recuperación de la FunciónRESUMEN
[This corrects the article DOI: 10.3389/fchem.2020.00102.].
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Tough gel with extreme temperature tolerance is a class of soft materials having potential applications in the specific fields that require excellent integrated properties under subzero temperature. Herein, physically crosslinked Europium (Eu)-alginate/polyvinyl alcohol (PVA) organohydrogels that do not freeze at far below 0°C, while retention of high stress and stretchability is demonstrated. These organohydrogels are synthesized through displacement of water swollen in polymer networks of hydrogel to cryoprotectants (e.g., ethylene glycol, glycerol, and d-sorbitol). The organohydrogels swollen water-cryoprotectant binary systems can be recovered to their original shapes when be bent, folded and even twisted after being cooled down to a temperature as low as -20 and -45°C, due to lower vapor pressure and ice-inhibition of cryoprotectants. The physical organohydrogels exhibit the maximum stress (5.62 ± 0.41 MPa) and strain (7.63 ± 0.02), which is about 10 and 2 times of their original hydrogel, due to the synergistic effect of multiple hydrogen bonds, coordination bonds and dense polymer networks. Based on these features, such physically crosslinked organohydrogels with extreme toughness and wide temperature tolerance is a promising soft material expanding the applications of gels in more specific and harsh conditions.
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The reliable and accurate quantification of ammonia in electrochemical and photochemical experiments has been a technical challenge owing to the extremely low concentration of generated ammonia, interference from trace amounts of cations and organic compounds, and ammonia contamination from various sources. As a result, overestimation and significant errors may happen in many research works. Herein, accuracy and precision of ion chromatography (IC) are evaluated at different pH; excellent performance with a low detection limit (<2â µg L-1 ) under acidic and neutral conditions is found, whereas the linearity is unsatisfactory in the low NH4 + concentration range (0-100â µg L-1 ) under alkaline conditions. High concentrations of Li+ and Na+ are difficult to separate from NH4 + in conventional IC, but this can be solved by employing a high-exchange-capacity column or gradient elution. The interference effects of 14 common transition metal cations and 6 common organic compounds on the quantification of ammonium with low-level concentration (500â µg L-1 ) using IC are systematically investigated, and the results demonstrate good robustness. The overestimation caused by ammonia contamination from reagent water, surroundings, and even the analytical grade of inorganic and organic reagents are confirmed and the results indicate the necessity to prepare and test fresh electrolyte solutions before each experiment, owing to the high sensitivity of acidic and neutral solutions to ammonia contamination from the surroundings. The ammonization of a Nafion membrane during experiments and the underestimation in quantification are also discussed. Finally, a reliable level of synthesized ammonia is identified and some recommendations are presented to improve the reliability and accuracy of ammonia quantification.
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Epididymitis can be caused by infectious and noninfectious etiological factors. While microbial infections are responsible for infectious epididymitis, the etiological factors contributing to noninfectious epididymitis remain to be defined. The present study demonstrated that damaged male germ cells (DMGCs) induce epididymitis in mice. Intraperitoneal injection of the alkylating agent busulfan damaged murine male germ cells. Epididymitis was observed in mice 4 weeks after the injection of busulfan and was characterized by massive macrophage infiltration. Epididymitis was coincident with an accumulation of DMGCs in the epididymis. In contrast, busulfan injection into mice lacking male germ cells did not induce epididymitis. DMGCs induced innate immune responses in epididymal epithelial cells (EECs), thereby upregulating the pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1ß (IL-1ß), as well as the chemokines such as monocyte chemotactic protein-1 (MCP-1), monocyte chemotactic protein-5 (MCP-5), and chemokine ligand-10 (CXCL10). These results suggest that male germ cell damage may induce noninfectious epididymitis through the induction of innate immune responses in EECs. These findings provide novel insights into the mechanisms underlying noninfectious epididymitis, which might aid in the diagnosis and treatment of the disease.
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Citocinas/metabolismo , Epididimitis/inmunología , Epididimitis/patología , Células Germinativas/inmunología , Células Germinativas/metabolismo , Animales , Busulfano , Movimiento Celular , Quimiocina CCL2/metabolismo , Quimiocina CXCL10/metabolismo , Células Germinativas/patología , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas Quimioatrayentes de Monocitos/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Fabricating a strain sensor that can detect large deformation over a curved object with a high sensitivity is crucial in wearable electronics, human/machine interfaces, and soft robotics. Herein, an ionogel nanocomposite is presented for this purpose. Tuning the composition of the ionogel nanocomposites allows the attainment of the best features, such as excellent self-healing (>95% healing efficiency), strong adhesion (347.3 N m-1 ), high stretchability (2000%), and more than ten times change in resistance under stretching. Furthermore, the ionogel nanocomposite-based sensor exhibits good reliability and excellent durability after 500 cycles, as well as a large gauge factor of 20 when it is stretched under a strain of 800-1400%. Moreover, the nanocomposite can self-heal under arduous conditions, such as a temperature as low as -20 °C and a temperature as high as 60 °C. All these merits are achieved mainly due to the integration of dynamic metal coordination bonds inside a loosely cross-linked network of ionogel nanocomposite doped with Fe3 O4 nanoparticles.
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Design and synthesis of environmentally friendly adsorbents with high adsorption capacities are urgently needed to control pollution of water resources. In this work, a calcium ion-induced approach was used to synthesize sodium alginate fibroid hydrogel (AFH). The as-prepared AFH has certain mechanical strength, and the mechanical strength is enhanced especially after the adsorption of heavy metal ions, which is very convenient for the recovery. AFH exhibited excellent adsorption performances for Cu2+, Cd2+, and Pb2+ ions and displayed very high saturated adsorption capacities (Qe) of 315.92 mg·g-1 (Cu2+), 232.35 mg·g-1 (Cd2+), and 465.22 mg·g-1 (Pb2+) with optimized pH values (3.0-4.0) and temperature (303 K). The study of isotherms and kinetics indicated that adsorption processes of heavy metal ions fitted well with the pseudo-second-order kinetics model and the Langmuir model. Pb2+ was found to have the strongest competitiveness among the three heavy metal ions. Thus, AFH has great application prospects in the field of heavy metal ions removing from wastewater.
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Exploring photoluminescent silk fibers, possessing biocompatibility as well as stable and durable fluorescent properties, is a requirement for the development of novel photoluminescent biomaterials. Herein, we fabricate photoluminescent silk fibers, TPCA@SF, via modifying an organic fluorescent molecule (5-oxo-3,5-dihydro-2H-thiazolo [3,2-a] pyridine-7-carboxylic acid, TPCA) onto silk fibers, along with using quaternary ammonium salt didodecyldimethylammonium bromide (DDAB) as a color-fixing agent. The hydrogen bonds and electrostatic association among silk fibers, TPCA and DDAB, ensure the stable modification. The facile and green fabrication process is achieved in water under mild conditions without using any toxic substances. The TPCA@SF manifests the combining features of high quantum yield, fluorescence water-fastness, antiphotobleaching, good mechanical property, and biocompatibility. The strategy holds great potential for exploring various biocompatible photoluminescent substances with stability and durability.