Designing advanced hydrogels with controlled mechanical properties,drug delivery manner and multifunctional properties will be beneficial for biomedical applications.However,the further development of hydrogel is limi...Designing advanced hydrogels with controlled mechanical properties,drug delivery manner and multifunctional properties will be beneficial for biomedical applications.However,the further development of hydrogel is limited due to its poor mechanical property and structural diversity.Hydrogels combined with polymeric micelles to obtain micelle-hydrogel composites have been designed for synergistic enhancement of each original properties.Incorporation polymeric micelles into hydrogel networks can not only enhance the mechanical property of hydrogel,but also expand the functionality of hydrogel.Recent advances in polymeric micelle-hydrogel composites are herein reviewed with a focus on three typical micelle incorporation methods.In this review,we will also highlight some emerging biomedical applications in developing micelle-hydrogel composite with multiple functionalities.In addition,further development and application prospects of the micelle-hydrogels composites have also been addressed.展开更多
A series of chitosan-g-poly （acrylic acid）/vermiculite hydrogel composites were synthesized and used as adsorbents for the investigation of the effect of process parameters such as vermiculite content, pH of dye sol...A series of chitosan-g-poly （acrylic acid）/vermiculite hydrogel composites were synthesized and used as adsorbents for the investigation of the effect of process parameters such as vermiculite content, pH of dye solution, contact time, initial concentration of dye solution, temperature, ionic strength and concentration of surfactant sodium dodecyl sulfate on the removal of Methylene Blue （MB） from aqueous solution. The results showed that the adsorption capacity for dye increased with increasing pH, contact time and initial dye concentration, but decreased with increasing temperature, ionic strength and sodium dodecyl sulfate concentration in the present of the surfactant. The adsorption kinetics of MB onto the hydrogel composite followed pseudo second-order kinetics and the adsorption equilibrium data obeyed Langmuir isotherm. By introducing 10 wt.% vermiculite into chitosan-g-poly （acrylic acid） polymeric network, the obtaining hydrogel composite showed the highest adsorption capacity for MB, and then could be regarded as a potential adsorbent for cationic dye removal in a wastewater treatment process.展开更多
Polyacrylic acid(PAA)hydrogel composites with different hexagonal boron nitride(h-BN)fillers were synthesized and successfully 3D-printed while their thermal conductivity was systematically studied.With the content of...Polyacrylic acid(PAA)hydrogel composites with different hexagonal boron nitride(h-BN)fillers were synthesized and successfully 3D-printed while their thermal conductivity was systematically studied.With the content of h-BN increasing from 0.1 wt%to 0.3 wt%,the thermal conductivity of the 3D-printed composites has been improved.Moreover,through the shear force given by the 3D printer,a complete thermal conductivity path is obtained inside the hydrogel,which significantly improves the thermal conductivity of the h-BN hydrogel composites.The maximum thermal conductivity is 0.8808 W/(m·K),leading to a thermal conductive enhancement of 1000%,compared with the thermal conductivity of pure PAA hydrogels.This study shows that using h-BN fillers can effectively and significantly improve the thermal conductivity of hydrogelbased materials while its 3D-printable ability has been maintained.展开更多
Three-dimensional printing technologies exhibit tremendous potential in the advancing fields of tissue engineering and regenerative medicine due to the precise spatial control over depositing the biomaterial.Despite t...Three-dimensional printing technologies exhibit tremendous potential in the advancing fields of tissue engineering and regenerative medicine due to the precise spatial control over depositing the biomaterial.Despite their widespread utilization and numerous advantages,the development of suitable novel biomaterials for extrusion-based 3D printing of scaffolds that support cell attachment,proliferation,and vascularization remains a challenge.Multi-material composite hydrogels present incredible potential in this field.Thus,in this work,a multi-material composite hydrogel with a promising formulation of chitosan/gelatin functionalized with egg white was developed,which provides good printability and shape fidelity.In addition,a series of comparative analyses of different crosslinking agents and processes based on tripolyphosphate(TPP),genipin(GP),and glutaraldehyde(GTA)were investigated and compared to select the ideal crosslinking strategy to enhance the physicochemical and biological properties of the fabricated scaffolds.All of the results indicate that the composite hydrogel and the resulting scaffolds utilizing TPP crosslinking have great potential in tissue engineering,especially for supporting neo-vessel growth into the scaffold and promoting angiogenesis within engineered tissues.展开更多
Interfacial solar-driven evaporators have presented great potential for water purification owing to their low energy consumption and high steam generation efficiency. However, their further applications are hindered b...Interfacial solar-driven evaporators have presented great potential for water purification owing to their low energy consumption and high steam generation efficiency. However, their further applications are hindered by the high costs and complicated fabrication processes. Here, a scalable bilayer interfacial evaporator was constructed via an affordable technique, in which carbon black deposited nonwoven fabric(CB@NF) was employed as the upper photothermal layer, as well as PVA/starch hybrid hydrogel for selffloating and water transport. Under simulated one sun irradiation, CB@NF layer displayed excellent photothermal conversion performance, whose temperature could increase 30.4 ℃ within 15 min. Moreover,the introduction of starch into PVA endowed the hybrid hydrogels with considerable water-absorption capability on the premise of ensuring mechanical properties. The resultant CB@NF/PVA/starch composites achieved superior interfacial adhesion performance with interfacial toughness at about 200 J m.Combining with good evaporation performance, salt-rejection property and high purification efficiency on pollutants, this evaporation system would become a promising candidate to alleviate water shortage.展开更多
Metal-organic frameworks(MOFs)have emerged as promising candidates for a wide range of applications due to their high surface area and customizable structures,however,the minimal external hydrophilicity of MOFs has li...Metal-organic frameworks(MOFs)have emerged as promising candidates for a wide range of applications due to their high surface area and customizable structures,however,the minimal external hydrophilicity of MOFs has limited their biomedical implementations.Structuring of MOFs within polymer frameworks is an approach used to create hybrid materials that retain many of the MOF characteristics(e.g.high adsorption capacity)but expand the range of mechanical and surface properties as well as form factors accessible.Using this approach,hybridizing MOFs with hydrophilic hydrogels can give rise to materials with improved hydrophilicity and biocompatibility.Here,we describe the synthesis of the first Zr-based MOF-hydrogel hybrid material(composite 3)using a green chemistry approach,in which only water was used as the solvent and relatively low temperature(50°C)was applied.Using methylene blue(MB)as a probe molecule,composite 3 exhibited greater adsorption capacity than the MOF or the hydrogel alone in aqueous solution at most tested pH values(all except pH 13).At an initial MB concentration of 0.0096 mg mL^(-1)(30.014μM)and neutral pH conditions,this new hybrid presented the highest loading of MB among similar materials(MB adsorbed=4.361±0.092 mg MB per g Zr,partition coefficient=0.172±0.004 mg g^(-1)μM^(-1))and largely retained its adsorption capacity under varied conditions(pH 1-13 and 0.2-1.0 M NaCl),rendering possible applications in drug delivery and the removal of tumor contrast agent/dye with minimal leakage due to its broad chemical stability.展开更多
Efficient recovery of uranium from radioactive wastewater significantly has far-reaching positive implications for both the recycling of uranium resources and environmental conservation.In this work,a new stable hydro...Efficient recovery of uranium from radioactive wastewater significantly has far-reaching positive implications for both the recycling of uranium resources and environmental conservation.In this work,a new stable hydrogel/MOFs composite with potential for efficient uranium capture has been developed.A double network structure was formed through the chemical covalent crosslinking of poly(acrylamide-acrylic acid) and the physical crosslinking of agar.The rapid self-crosslinking of agar not only enables the uniform dispersion of Metal-Organic Frameworks(MOFs) nanoparticles but also promotes the hydrogel to possess exceptional tensile strength and low swelling ratio,whereas the incorporation of amidoximated MOFs enhances the selectivity for uranium.The composite achieved a uranium-uptake capacity of 275.42 mg/g(298 K,C0=120 mg/L,pH=6),and it retains reproducible and stable after five cycles,while exhibiting high selectivity for uranyl,even amidst ten competing metal ions.Moreover,the uranium removal rate reached 93 % within three days in low concentration simulated nuclear wastewater.Multiple spectral analyses coupled with theoretical calculations confirmed that the mechanism of U(Ⅵ) capture involves intraparticle diffusion,along with the coordination of amidoxime,carboxyl,and amino groups.This research offers a valuable reference for the development of composite materials to treat radioactive effluent.展开更多
Rat nerve growth factor and total flavonoids from hawthorn leaf contribute to the recovery of neurological function after spinal cord injury,including traumatic,non-traumatic spinal cord injuries.However,it remains ch...Rat nerve growth factor and total flavonoids from hawthorn leaf contribute to the recovery of neurological function after spinal cord injury,including traumatic,non-traumatic spinal cord injuries.However,it remains challenging to efficiently deliver nerve growth factor and total flavonoids from hawthorn leaf to spinal cord injury sites,ensure their sustained release,and minimize further damage.In the present study,we chose a biocompatible and biodegradable gelatin as the substrate,which was crosslinked with the natural biological crosslinker genipin to form a gelatin-genipin hydrogel carrier for the slow release of nerve growth factor and total flavonoids from hawthorn leaf in spinal cord injury sites.The prepared gelatin-genipin hydrogel had good injectable properties and photothermal effects.Furthermore,when the hydrogel with 2%genipin,200 ng/mL nerve growth factor,and 320μg/mL total flavonoids from hawthorn leaf was combined with near infrared irradiation,there was a slow release of total flavonoids from hawthorn leaf and nerve growth factor,reduced oxidative stress,an improved inflammatory microenvironment,and accelerated angiogenesis and axonal regeneration via inhibition of the nuclear factor kappa-B signaling pathway,thereby promoting recovery from spinal cord injury.Collectively,our results indicate that this new hydrogel may improve the prognosis of spinal cord injury,and may represent a new strategy for treating spinal cord injury.展开更多
Flexible electronic devices with mechanical properties like the soft tissues of human organs have great potential for the next generation of wearable and implantable electronic devices.Self-healing hydrogel composites...Flexible electronic devices with mechanical properties like the soft tissues of human organs have great potential for the next generation of wearable and implantable electronic devices.Self-healing hydrogel composites typically have high tensile strength,high electrical conductivity and damage repair properties and have wide applications in flexible electronics,such as human-computer interaction,health detection and soft robots.Various self-healing hydrogel composites have been developed to produce new stretchable conductive materials with satisfactory mechanical and selfhealing properties.This paper presents the fabrication of self-healing hydrogel composites and their application in flexible electronic devices.Firstly,the repair mechanism of physically cross-linked and chemically cross-linked self-healing hydrogel composites is presented.Secondly,self-healing double network hydrogels,self-healing nanocomposite hydrogels and double crosslinked self-healing hydrogel composites and their applications in flexible sensors,energy harvesting devices,energy storage devices and optical devices are presented and discussed.Finally,the challenges and prospects of self-healing hydrogel composites in flexible electronic devices in the future are presented.展开更多
Corresponding author’s name was incorrectly written as“Dadang Guo”instead of“Dagang Guo”.The correct author name should be“Dagang Guo”.The authors would like to apologise for any inconvenience caused.
Granular composite(GC)hydrogels have attracted considerable interest in biomedical applications due to their versatile printability and exceptional mechanical properties.However,the lack of comprehensive design guidel...Granular composite(GC)hydrogels have attracted considerable interest in biomedical applications due to their versatile printability and exceptional mechanical properties.However,the lack of comprehensive design guidelines has limited their optimal engineering,as the factors influencing their mechanical performance and printability remain largely unexamined.In this study,we developed GC hydrogels by integrating microgels with interstitial matrices of photocrosslinkable gelatin methacrylate(GelMA).We utilized confocal microscopy and nanoindentation analyses to investigate the spatial distribution and mechanical behavior of these hydrogels.Our findings indicate that the mechanical and rheological properties of GC hydrogels can be precisely tailored by adjusting the volume fraction and size of the microgels.Furthermore,hydrogen bonds were identified as significant contributors to compressive performance,although they had minimal effect on cyclic mechanical behavior.Compared to bulk GelMA hydrogels,GC hydrogels demonstrated enhanced printability and remarkable superelasticity.As a proof of concept,we illustrated their dual printability in embedded printing to create prosthetic liver models for preoperative planning.This study provides valuable insights into the design and optimization of GC hydrogels for advanced biomedical applications.展开更多
Dental pulp-dentin complex defects remain a major unresolved problem in oral medicines.Clinical therapeutic methods including root canal therapy and vital pulp therapy are both considered as conservative strategies,wh...Dental pulp-dentin complex defects remain a major unresolved problem in oral medicines.Clinical therapeutic methods including root canal therapy and vital pulp therapy are both considered as conservative strategies,which are incapable of repairing the pulpdentin complex defects.Although biomaterial-based strategies show remarkable progress in antibacterial,anti-inflammatory,and pulp regeneration,the important modulatory effects of nerves within pulp cavity have been greatly overlooked,making it challenging to achieve functional pulp-dentin complex regeneration.In this study,we propose an injectable bioceramicscontaining composite hydrogel in combination of Li-Ca-Si(LCS)bioceramics and gelatin methacrylate matrix with photocrosslinking properties.Due to the sustained release of bioactive Li,Ca and Si ions from LCS,the composite hydrogels possess multiple functions of promoting the neurogenic differentiation of Schwann cells,odontogenic differentiation of dental pulp stem cells,and neurogenesis-odontogenesis couples in vitro.In addition,the in vivo results showed that LCS-containing composite hydrogel can significantly promote the pulp-dentin complex repair.More importantly,LCS bioceramics-containing composite hydrogel can induce the growth of nerve fibers,leading to the re-innervation of pulp tissues.Taken together,the study suggests that LCS bioceramics can induce the innervation of pulp-dentin complex repair,offering a referable strategy of designing multifunctional filling materials for functional periodontal tissue regeneration.展开更多
Poly(vinyl alcohol)(PVA)/hydroxyapatite(HA)composite hydrogel specimens were prepared with 15%PVA and 1%,2%,3%,4%and 5%HA by repeated freezing-thawing.The tests of static and dynamic mechanical properties were carried...Poly(vinyl alcohol)(PVA)/hydroxyapatite(HA)composite hydrogel specimens were prepared with 15%PVA and 1%,2%,3%,4%and 5%HA by repeated freezing-thawing.The tests of static and dynamic mechanical properties were carried out todiscuss the influence of different contents of HA and freezing-thawing cycles on the mechanical properties of PVA/HA compositehydrogel.The results of static mechanical tests showed that the PVA/HA composite hydrogel with 3%HA and ninefreezing-thawing cycles had excellent stress relaxation properties,higher relaxation ratio,lower stress equilibrium value andpresented better properties of creep and recovery.The results of dynamic mechanical test showed that the PVA/HA compositehydrogel with nine freezing-thawing cycles had higher storage modulus and loss modulus,so was the PVA/HA compositehydrogel with 3%HA.展开更多
Growing health awareness triggers the public's concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome gene...Growing health awareness triggers the public's concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome general check-ups. The wearable technique provides a continuous measurement method for health monitoring by tracking a person's physiological data and analyzing it locally or remotely.During the health monitoring process,different kinds of sensors convert physiological signals into electrical or optical signals that can be recorded and transmitted, consequently playing a crucial role in wearable techniques. Wearable application scenarios usually require sensors to possess excellent flexibility and stretchability. Thus, designing flexible and stretchable sensors with reliable performance is the key to wearable technology. Smart composite hydrogels, which have tunable electrical properties, mechanical properties, biocompatibility, and multi-stimulus sensitivity, are one of the best sensitive materials for wearable health monitoring. This review summarizes the common synthetic and performance optimization strategies of smart composite hydrogels and focuses on the current application of smart composite hydrogels in the field of wearable health monitoring.展开更多
Halloysite nanotube-composited thermo-responsive hydrogel system has been successfully developed for controlled drug release by copolymerization of N-isopropylacrylamide （NIPAM） with silane-modified halloysite nanot...Halloysite nanotube-composited thermo-responsive hydrogel system has been successfully developed for controlled drug release by copolymerization of N-isopropylacrylamide （NIPAM） with silane-modified halloysite nanotubes （HNT） through thermally initiated free-radical polymerization. With methylene blue as a model drug, thermo-responsive drug release results demonstrate that the drug release from the nanotubes in the composited hy-drogel can^be well controlled by manipulating the environmental temperature. When the hydrogel network is swol- len at temperature below the lower critical solution temperature （LCST）, drug releases steadily from lumens of the embedded nanotubes, whereas the drug release stops when hydrogel shrinks at temperature above the LCST. The release of model drug from the HNT-composited hydrogel matches well with its thermo-responsive volume phasetransition, and shows characteristics of well controlled release. The design strategy and release results of the pro- posed novel HNT-composited thermo-responsive hydrogel system provide valuable guidance for designing respon- s_i_ve nanocomposites for controlled-release of active agents.展开更多
Polyvinyl alcohol hydrogels have been used in wearable devices due to their good flexibility and biocompatibility.However,due to the low thermal conductivity(κ)of pure hydrogel,its further application in high power d...Polyvinyl alcohol hydrogels have been used in wearable devices due to their good flexibility and biocompatibility.However,due to the low thermal conductivity(κ)of pure hydrogel,its further application in high power devices is limited.To solve this problem,melamine sponge(MS)was used as the skeleton to wrap boron nitride nanosheets(BNNS)through repeated layering assembly,successfully preparing a three-dimensional(3D)boron nitride network(BNNS@MS),and PVA hydrogels were formed in the pores of the network.Due to the existence of the continuous phonon conduction network,the BNNS@MS/PVA exhibited an improvedκ.When the content of BNNS is about 6 wt.%,κof the hydrogel was increased to 1.12 W m^(-1)K^(-1),about two times higher than that of pure hydrogel.The solid heat conduction network and liquid convection network cooperate to achieve good thermal management ability.Combined with its high specific heat capacity,the composites have an important application prospect in the field of wearable flexible electronic thermal management.展开更多
With the rapid development of textile industry,a large amount of dye-contaminated effluents was produced and caused serious environmental problem.To remove the dye from effluents,adsorption materials have been applied...With the rapid development of textile industry,a large amount of dye-contaminated effluents was produced and caused serious environmental problem.To remove the dye from effluents,adsorption materials have been applied because of their relatively cheap,high efficiency,and easy handling.In this study,a novel composite hydrogel bead with unique multilayer flake structure was fabricated by alginate,acrylamide and attapulgite for dye adsorption.Acrylamide was grafted polymerization onto alginate to obtain alginate-g-poly(acrylamide).Then alginate-g-poly(acrylamide)was cross-linked by Ca2+ions in present of attapulgite to form composite hydrogel bead.Scanning electron microscopy(SEM)results show that the freeze dried composite hydrogel bead has multilayer flake structure incorporating attapulgite.Fourier transform infrared spectroscopy(FTIR)and Thermo-gravimetric analysis(TGA)results indicate that acrylamide has been successfully grafted polymerization on sodium alginate.Grafting polymerization of acrylamide onto sodium alginate obviously enhances the swelling of hydrogel bead.Incorporating of attapulgite into hydrogel bead effectively enhances the adsorption capacity to methylene blue and the maximum adsorption capacity is 155.7 mg g-1.Multilayer flake structure increases the adsorption area for methylene blue,but hinders the diffusion of methylene blue into the inner of composite hydrogel bead.High pH solution is beneficial to the adsorption.Pseudo-second order model and Fraundlinch model best describe the adsorption kinetic and isotherm,respectively.These results indicate that composite hydrogel bead is a promising adsorption material for dye-contaminated water treatment.展开更多
Composites offer the option of coupling the individual benefits of their constituents to achieve unique material properties,which can be of extra value in many tissue engineering applications.Strategies combining hydr...Composites offer the option of coupling the individual benefits of their constituents to achieve unique material properties,which can be of extra value in many tissue engineering applications.Strategies combining hydrogelswith fibre-based scaffolds can create tissue constructs with enhanced biological and structural functionality.However,developing efficient and scalable approaches to manufacture such composites is challenging.Here,we use a droplet-based bioprinting system called reactive jet impingement(ReJI)to integrate a cell-laden hydrogel with a microfibrous mesh.This system uses microvalves connected to different bioink reservoirs and directed to continuously jet bioink droplets at one another in mid-air,where the droplets react and form a hydrogel that lands on a microfibrous mesh.Cell–hydrogel–fibre composites are produced by embedding human dermal fibroblasts at two different concentrations(5×10^(6) and 30×10^(6) cells/mL)in a collagen–alginate–fibrin hydrogel matrix and bioprinted onto a fibre-based substrate.Our results show that both types of cell–hydrogel–microfibre composite maintain high cell viability and promote cell–cell and cell–biomaterial interactions.The lower fibroblast density triggers cell proliferation,whereas the higher fibroblast density facilitates faster cellular organisation and infiltration into the microfibres.Additionally,the fibrous component of the composite is characterised by high swelling properties and the quick release of calcium ions.The data indicate that the created composite constructs offer an efficient way to create highly functional tissue precursors for laminar tissue engineering,particularly for wound healing and skin tissue engineering applications.展开更多
基金the Natural Science Basic Research Program of Shaanxi Province(No.2023-JC-YB-101)the Basic Science Research Program of Shaanxi Basic Sciences Institute(Chemistry,Biology)(No.22JHQ079)National Natural Science Foundation of China(No.82272150).
文摘Designing advanced hydrogels with controlled mechanical properties,drug delivery manner and multifunctional properties will be beneficial for biomedical applications.However,the further development of hydrogel is limited due to its poor mechanical property and structural diversity.Hydrogels combined with polymeric micelles to obtain micelle-hydrogel composites have been designed for synergistic enhancement of each original properties.Incorporation polymeric micelles into hydrogel networks can not only enhance the mechanical property of hydrogel,but also expand the functionality of hydrogel.Recent advances in polymeric micelle-hydrogel composites are herein reviewed with a focus on three typical micelle incorporation methods.In this review,we will also highlight some emerging biomedical applications in developing micelle-hydrogel composite with multiple functionalities.In addition,further development and application prospects of the micelle-hydrogels composites have also been addressed.
基金supported by the National Natural Science Foundation of China (No.20877077)the Project of Jiangsu Provincial Science and Technology Office (No.BE2008087)
文摘A series of chitosan-g-poly （acrylic acid）/vermiculite hydrogel composites were synthesized and used as adsorbents for the investigation of the effect of process parameters such as vermiculite content, pH of dye solution, contact time, initial concentration of dye solution, temperature, ionic strength and concentration of surfactant sodium dodecyl sulfate on the removal of Methylene Blue （MB） from aqueous solution. The results showed that the adsorption capacity for dye increased with increasing pH, contact time and initial dye concentration, but decreased with increasing temperature, ionic strength and sodium dodecyl sulfate concentration in the present of the surfactant. The adsorption kinetics of MB onto the hydrogel composite followed pseudo second-order kinetics and the adsorption equilibrium data obeyed Langmuir isotherm. By introducing 10 wt.% vermiculite into chitosan-g-poly （acrylic acid） polymeric network, the obtaining hydrogel composite showed the highest adsorption capacity for MB, and then could be regarded as a potential adsorbent for cationic dye removal in a wastewater treatment process.
基金Funed by the National Key Research and Development Program of China(No.2021YFA0715700)the Open Fund of Hubei Longzhong Laboratory。
文摘Polyacrylic acid(PAA)hydrogel composites with different hexagonal boron nitride(h-BN)fillers were synthesized and successfully 3D-printed while their thermal conductivity was systematically studied.With the content of h-BN increasing from 0.1 wt%to 0.3 wt%,the thermal conductivity of the 3D-printed composites has been improved.Moreover,through the shear force given by the 3D printer,a complete thermal conductivity path is obtained inside the hydrogel,which significantly improves the thermal conductivity of the h-BN hydrogel composites.The maximum thermal conductivity is 0.8808 W/(m·K),leading to a thermal conductive enhancement of 1000%,compared with the thermal conductivity of pure PAA hydrogels.This study shows that using h-BN fillers can effectively and significantly improve the thermal conductivity of hydrogelbased materials while its 3D-printable ability has been maintained.
基金The authors acknowledge the funding support from the National Natural Science Foundation of China(Nos.52175474 and 51775324)the China Scholarship Council(No.202006890054).
文摘Three-dimensional printing technologies exhibit tremendous potential in the advancing fields of tissue engineering and regenerative medicine due to the precise spatial control over depositing the biomaterial.Despite their widespread utilization and numerous advantages,the development of suitable novel biomaterials for extrusion-based 3D printing of scaffolds that support cell attachment,proliferation,and vascularization remains a challenge.Multi-material composite hydrogels present incredible potential in this field.Thus,in this work,a multi-material composite hydrogel with a promising formulation of chitosan/gelatin functionalized with egg white was developed,which provides good printability and shape fidelity.In addition,a series of comparative analyses of different crosslinking agents and processes based on tripolyphosphate(TPP),genipin(GP),and glutaraldehyde(GTA)were investigated and compared to select the ideal crosslinking strategy to enhance the physicochemical and biological properties of the fabricated scaffolds.All of the results indicate that the composite hydrogel and the resulting scaffolds utilizing TPP crosslinking have great potential in tissue engineering,especially for supporting neo-vessel growth into the scaffold and promoting angiogenesis within engineered tissues.
基金financially supported by the National Natural Science Foundation of China (No.51733002,51803022 and 52003042)the Fundamental Research Funds for the Central Universities (No.2232021D-05)。
文摘Interfacial solar-driven evaporators have presented great potential for water purification owing to their low energy consumption and high steam generation efficiency. However, their further applications are hindered by the high costs and complicated fabrication processes. Here, a scalable bilayer interfacial evaporator was constructed via an affordable technique, in which carbon black deposited nonwoven fabric(CB@NF) was employed as the upper photothermal layer, as well as PVA/starch hybrid hydrogel for selffloating and water transport. Under simulated one sun irradiation, CB@NF layer displayed excellent photothermal conversion performance, whose temperature could increase 30.4 ℃ within 15 min. Moreover,the introduction of starch into PVA endowed the hybrid hydrogels with considerable water-absorption capability on the premise of ensuring mechanical properties. The resultant CB@NF/PVA/starch composites achieved superior interfacial adhesion performance with interfacial toughness at about 200 J m.Combining with good evaporation performance, salt-rejection property and high purification efficiency on pollutants, this evaporation system would become a promising candidate to alleviate water shortage.
基金NSF funded Partnership for Research and Education in Materials(PREM)at CSULA(DMR 1523588)American Chemical Society Petroleum Research Fund(57951-UNI10)+2 种基金REU program at the Pennsylvania State University(DMR1460920,DMR 1420620,and DMR1523588)NSF-CREST program(HRD 1547723 and Amendment 003)National Institute of General Medical Sciences of the National Institute of Health under Award Number GM08228。
文摘Metal-organic frameworks(MOFs)have emerged as promising candidates for a wide range of applications due to their high surface area and customizable structures,however,the minimal external hydrophilicity of MOFs has limited their biomedical implementations.Structuring of MOFs within polymer frameworks is an approach used to create hybrid materials that retain many of the MOF characteristics(e.g.high adsorption capacity)but expand the range of mechanical and surface properties as well as form factors accessible.Using this approach,hybridizing MOFs with hydrophilic hydrogels can give rise to materials with improved hydrophilicity and biocompatibility.Here,we describe the synthesis of the first Zr-based MOF-hydrogel hybrid material(composite 3)using a green chemistry approach,in which only water was used as the solvent and relatively low temperature(50°C)was applied.Using methylene blue(MB)as a probe molecule,composite 3 exhibited greater adsorption capacity than the MOF or the hydrogel alone in aqueous solution at most tested pH values(all except pH 13).At an initial MB concentration of 0.0096 mg mL^(-1)(30.014μM)and neutral pH conditions,this new hybrid presented the highest loading of MB among similar materials(MB adsorbed=4.361±0.092 mg MB per g Zr,partition coefficient=0.172±0.004 mg g^(-1)μM^(-1))and largely retained its adsorption capacity under varied conditions(pH 1-13 and 0.2-1.0 M NaCl),rendering possible applications in drug delivery and the removal of tumor contrast agent/dye with minimal leakage due to its broad chemical stability.
基金supported by the National Natural Science Foundation of China(No.22376091)the Natural Science Foundation of Hunan Province(No.2023JJ40530)the Scientific Research Fund of Hunan Provincial Education Department(No.23B0778).
文摘Efficient recovery of uranium from radioactive wastewater significantly has far-reaching positive implications for both the recycling of uranium resources and environmental conservation.In this work,a new stable hydrogel/MOFs composite with potential for efficient uranium capture has been developed.A double network structure was formed through the chemical covalent crosslinking of poly(acrylamide-acrylic acid) and the physical crosslinking of agar.The rapid self-crosslinking of agar not only enables the uniform dispersion of Metal-Organic Frameworks(MOFs) nanoparticles but also promotes the hydrogel to possess exceptional tensile strength and low swelling ratio,whereas the incorporation of amidoximated MOFs enhances the selectivity for uranium.The composite achieved a uranium-uptake capacity of 275.42 mg/g(298 K,C0=120 mg/L,pH=6),and it retains reproducible and stable after five cycles,while exhibiting high selectivity for uranyl,even amidst ten competing metal ions.Moreover,the uranium removal rate reached 93 % within three days in low concentration simulated nuclear wastewater.Multiple spectral analyses coupled with theoretical calculations confirmed that the mechanism of U(Ⅵ) capture involves intraparticle diffusion,along with the coordination of amidoxime,carboxyl,and amino groups.This research offers a valuable reference for the development of composite materials to treat radioactive effluent.
基金Guangxi Science and Technology Base and Talent Special Project,No.GuiKeAD24010037(to SZ)Guangxi Health Commission Self-Funded Research Project,No.Z-A20241029(to YL).
文摘Rat nerve growth factor and total flavonoids from hawthorn leaf contribute to the recovery of neurological function after spinal cord injury,including traumatic,non-traumatic spinal cord injuries.However,it remains challenging to efficiently deliver nerve growth factor and total flavonoids from hawthorn leaf to spinal cord injury sites,ensure their sustained release,and minimize further damage.In the present study,we chose a biocompatible and biodegradable gelatin as the substrate,which was crosslinked with the natural biological crosslinker genipin to form a gelatin-genipin hydrogel carrier for the slow release of nerve growth factor and total flavonoids from hawthorn leaf in spinal cord injury sites.The prepared gelatin-genipin hydrogel had good injectable properties and photothermal effects.Furthermore,when the hydrogel with 2%genipin,200 ng/mL nerve growth factor,and 320μg/mL total flavonoids from hawthorn leaf was combined with near infrared irradiation,there was a slow release of total flavonoids from hawthorn leaf and nerve growth factor,reduced oxidative stress,an improved inflammatory microenvironment,and accelerated angiogenesis and axonal regeneration via inhibition of the nuclear factor kappa-B signaling pathway,thereby promoting recovery from spinal cord injury.Collectively,our results indicate that this new hydrogel may improve the prognosis of spinal cord injury,and may represent a new strategy for treating spinal cord injury.
基金supported by the Linyi University 2023 High-level Talents(PhD)Research Start-up Fund(Natural Sciences)(Nos.Z6124014 and Z6124015)the College Students’Innovation and Entrepreneurship Training Program(No.X202310452291)+1 种基金the Key Research and Development Project for the Highlevel Technological Talent of Lvlang City(Nos.2023GXYF09 and 2022RC15)Scientific Research Start-up Funds of Lyuliang University.
文摘Flexible electronic devices with mechanical properties like the soft tissues of human organs have great potential for the next generation of wearable and implantable electronic devices.Self-healing hydrogel composites typically have high tensile strength,high electrical conductivity and damage repair properties and have wide applications in flexible electronics,such as human-computer interaction,health detection and soft robots.Various self-healing hydrogel composites have been developed to produce new stretchable conductive materials with satisfactory mechanical and selfhealing properties.This paper presents the fabrication of self-healing hydrogel composites and their application in flexible electronic devices.Firstly,the repair mechanism of physically cross-linked and chemically cross-linked self-healing hydrogel composites is presented.Secondly,self-healing double network hydrogels,self-healing nanocomposite hydrogels and double crosslinked self-healing hydrogel composites and their applications in flexible sensors,energy harvesting devices,energy storage devices and optical devices are presented and discussed.Finally,the challenges and prospects of self-healing hydrogel composites in flexible electronic devices in the future are presented.
文摘Corresponding author’s name was incorrectly written as“Dadang Guo”instead of“Dagang Guo”.The correct author name should be“Dagang Guo”.The authors would like to apologise for any inconvenience caused.
基金support from the National Natural Science Foundation of China(Nos.U21A20394 and 52305314)the Beijing Natural Science Foundation(Nos.7252285 and L246001)the National Key Research and Development Program of China(No.2023YFB4605800)。
文摘Granular composite(GC)hydrogels have attracted considerable interest in biomedical applications due to their versatile printability and exceptional mechanical properties.However,the lack of comprehensive design guidelines has limited their optimal engineering,as the factors influencing their mechanical performance and printability remain largely unexamined.In this study,we developed GC hydrogels by integrating microgels with interstitial matrices of photocrosslinkable gelatin methacrylate(GelMA).We utilized confocal microscopy and nanoindentation analyses to investigate the spatial distribution and mechanical behavior of these hydrogels.Our findings indicate that the mechanical and rheological properties of GC hydrogels can be precisely tailored by adjusting the volume fraction and size of the microgels.Furthermore,hydrogen bonds were identified as significant contributors to compressive performance,although they had minimal effect on cyclic mechanical behavior.Compared to bulk GelMA hydrogels,GC hydrogels demonstrated enhanced printability and remarkable superelasticity.As a proof of concept,we illustrated their dual printability in embedded printing to create prosthetic liver models for preoperative planning.This study provides valuable insights into the design and optimization of GC hydrogels for advanced biomedical applications.
基金funded by the National Key R&D Program of China(2022YFC2405904)the National Natural Science Foundation of China(52272284,32225028)+1 种基金Joint Research Unit Plan of the Chinese Academy of Sciences(121631ZYLH20240014)the Science and Technology Commission of Shanghai Municipality(24520750100)。
文摘Dental pulp-dentin complex defects remain a major unresolved problem in oral medicines.Clinical therapeutic methods including root canal therapy and vital pulp therapy are both considered as conservative strategies,which are incapable of repairing the pulpdentin complex defects.Although biomaterial-based strategies show remarkable progress in antibacterial,anti-inflammatory,and pulp regeneration,the important modulatory effects of nerves within pulp cavity have been greatly overlooked,making it challenging to achieve functional pulp-dentin complex regeneration.In this study,we propose an injectable bioceramicscontaining composite hydrogel in combination of Li-Ca-Si(LCS)bioceramics and gelatin methacrylate matrix with photocrosslinking properties.Due to the sustained release of bioactive Li,Ca and Si ions from LCS,the composite hydrogels possess multiple functions of promoting the neurogenic differentiation of Schwann cells,odontogenic differentiation of dental pulp stem cells,and neurogenesis-odontogenesis couples in vitro.In addition,the in vivo results showed that LCS-containing composite hydrogel can significantly promote the pulp-dentin complex repair.More importantly,LCS bioceramics-containing composite hydrogel can induce the growth of nerve fibers,leading to the re-innervation of pulp tissues.Taken together,the study suggests that LCS bioceramics can induce the innervation of pulp-dentin complex repair,offering a referable strategy of designing multifunctional filling materials for functional periodontal tissue regeneration.
基金supported by National Natural Science Foundation of China(Grant No.50875252)Program for New Century Excellent TaIents in University(Grant No.NCET-06-0479)Natural Science Foundation of Jiangsu Proyince(Grant No.BK2008005)
文摘Poly(vinyl alcohol)(PVA)/hydroxyapatite(HA)composite hydrogel specimens were prepared with 15%PVA and 1%,2%,3%,4%and 5%HA by repeated freezing-thawing.The tests of static and dynamic mechanical properties were carried out todiscuss the influence of different contents of HA and freezing-thawing cycles on the mechanical properties of PVA/HA compositehydrogel.The results of static mechanical tests showed that the PVA/HA composite hydrogel with 3%HA and ninefreezing-thawing cycles had excellent stress relaxation properties,higher relaxation ratio,lower stress equilibrium value andpresented better properties of creep and recovery.The results of dynamic mechanical test showed that the PVA/HA compositehydrogel with nine freezing-thawing cycles had higher storage modulus and loss modulus,so was the PVA/HA compositehydrogel with 3%HA.
基金financial support from the National Natural Science Foundation of China (No. 61801525)the Guangdong Basic and Applied Basic Research Foundation (Nos. 2020A1515010693, 2021A1515110269)+1 种基金the Fundamental Research Funds for the Central Universities, Sun Yatsen University (No. 22lgqb17)the Independent Fund of the State Key Laboratory of Optoelectronic Materials and Technologies (Sun Yat-sen University) under grant No. OEMT-2022-ZRC-05。
文摘Growing health awareness triggers the public's concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome general check-ups. The wearable technique provides a continuous measurement method for health monitoring by tracking a person's physiological data and analyzing it locally or remotely.During the health monitoring process,different kinds of sensors convert physiological signals into electrical or optical signals that can be recorded and transmitted, consequently playing a crucial role in wearable techniques. Wearable application scenarios usually require sensors to possess excellent flexibility and stretchability. Thus, designing flexible and stretchable sensors with reliable performance is the key to wearable technology. Smart composite hydrogels, which have tunable electrical properties, mechanical properties, biocompatibility, and multi-stimulus sensitivity, are one of the best sensitive materials for wearable health monitoring. This review summarizes the common synthetic and performance optimization strategies of smart composite hydrogels and focuses on the current application of smart composite hydrogels in the field of wearable health monitoring.
基金Supported by the National ]qatural Science Foundation of China （20906064）, the National Basic Research Program of China （2009CB623407）, the Program for Changjiang Scholars and Innovative Research Team in University （IRTl163）, and the Foundation for the Author of National Excellent Doctoral Dissertation of China （201163）.
文摘Halloysite nanotube-composited thermo-responsive hydrogel system has been successfully developed for controlled drug release by copolymerization of N-isopropylacrylamide （NIPAM） with silane-modified halloysite nanotubes （HNT） through thermally initiated free-radical polymerization. With methylene blue as a model drug, thermo-responsive drug release results demonstrate that the drug release from the nanotubes in the composited hy-drogel can^be well controlled by manipulating the environmental temperature. When the hydrogel network is swol- len at temperature below the lower critical solution temperature （LCST）, drug releases steadily from lumens of the embedded nanotubes, whereas the drug release stops when hydrogel shrinks at temperature above the LCST. The release of model drug from the HNT-composited hydrogel matches well with its thermo-responsive volume phasetransition, and shows characteristics of well controlled release. The design strategy and release results of the pro- posed novel HNT-composited thermo-responsive hydrogel system provide valuable guidance for designing respon- s_i_ve nanocomposites for controlled-release of active agents.
基金the National Natural Science Foundation of China(Nos.52173078,52130303,and 51803151)the Young Elite Scientists Sponsorship Program by CAST(No.2019QNRC001)。
文摘Polyvinyl alcohol hydrogels have been used in wearable devices due to their good flexibility and biocompatibility.However,due to the low thermal conductivity(κ)of pure hydrogel,its further application in high power devices is limited.To solve this problem,melamine sponge(MS)was used as the skeleton to wrap boron nitride nanosheets(BNNS)through repeated layering assembly,successfully preparing a three-dimensional(3D)boron nitride network(BNNS@MS),and PVA hydrogels were formed in the pores of the network.Due to the existence of the continuous phonon conduction network,the BNNS@MS/PVA exhibited an improvedκ.When the content of BNNS is about 6 wt.%,κof the hydrogel was increased to 1.12 W m^(-1)K^(-1),about two times higher than that of pure hydrogel.The solid heat conduction network and liquid convection network cooperate to achieve good thermal management ability.Combined with its high specific heat capacity,the composites have an important application prospect in the field of wearable flexible electronic thermal management.
基金for Doctors of Jinling Institute of Technology(Grant No.jit-b-201415)the Natural Science Foundation for Colleges and Universities of Jiangsu Province(Grant No.12KJD150006)for the financial support of this research.
文摘With the rapid development of textile industry,a large amount of dye-contaminated effluents was produced and caused serious environmental problem.To remove the dye from effluents,adsorption materials have been applied because of their relatively cheap,high efficiency,and easy handling.In this study,a novel composite hydrogel bead with unique multilayer flake structure was fabricated by alginate,acrylamide and attapulgite for dye adsorption.Acrylamide was grafted polymerization onto alginate to obtain alginate-g-poly(acrylamide).Then alginate-g-poly(acrylamide)was cross-linked by Ca2+ions in present of attapulgite to form composite hydrogel bead.Scanning electron microscopy(SEM)results show that the freeze dried composite hydrogel bead has multilayer flake structure incorporating attapulgite.Fourier transform infrared spectroscopy(FTIR)and Thermo-gravimetric analysis(TGA)results indicate that acrylamide has been successfully grafted polymerization on sodium alginate.Grafting polymerization of acrylamide onto sodium alginate obviously enhances the swelling of hydrogel bead.Incorporating of attapulgite into hydrogel bead effectively enhances the adsorption capacity to methylene blue and the maximum adsorption capacity is 155.7 mg g-1.Multilayer flake structure increases the adsorption area for methylene blue,but hinders the diffusion of methylene blue into the inner of composite hydrogel bead.High pH solution is beneficial to the adsorption.Pseudo-second order model and Fraundlinch model best describe the adsorption kinetic and isotherm,respectively.These results indicate that composite hydrogel bead is a promising adsorption material for dye-contaminated water treatment.
基金funded by the EPSRC Centre for Doctoral Training in Additive Manufacturing and 3D Printing (EP/L01534X/1)DePuy International Limited
文摘Composites offer the option of coupling the individual benefits of their constituents to achieve unique material properties,which can be of extra value in many tissue engineering applications.Strategies combining hydrogelswith fibre-based scaffolds can create tissue constructs with enhanced biological and structural functionality.However,developing efficient and scalable approaches to manufacture such composites is challenging.Here,we use a droplet-based bioprinting system called reactive jet impingement(ReJI)to integrate a cell-laden hydrogel with a microfibrous mesh.This system uses microvalves connected to different bioink reservoirs and directed to continuously jet bioink droplets at one another in mid-air,where the droplets react and form a hydrogel that lands on a microfibrous mesh.Cell–hydrogel–fibre composites are produced by embedding human dermal fibroblasts at two different concentrations(5×10^(6) and 30×10^(6) cells/mL)in a collagen–alginate–fibrin hydrogel matrix and bioprinted onto a fibre-based substrate.Our results show that both types of cell–hydrogel–microfibre composite maintain high cell viability and promote cell–cell and cell–biomaterial interactions.The lower fibroblast density triggers cell proliferation,whereas the higher fibroblast density facilitates faster cellular organisation and infiltration into the microfibres.Additionally,the fibrous component of the composite is characterised by high swelling properties and the quick release of calcium ions.The data indicate that the created composite constructs offer an efficient way to create highly functional tissue precursors for laminar tissue engineering,particularly for wound healing and skin tissue engineering applications.
