This work aimed at analyzing the petroleum adsorption capacity and the compressive strength of cellulose cryogels produced with the addition of 4 and 8%(w/w)sodium hydroxide(NaOH).Cryogels were produced from a 1.5%(m/...This work aimed at analyzing the petroleum adsorption capacity and the compressive strength of cellulose cryogels produced with the addition of 4 and 8%(w/w)sodium hydroxide(NaOH).Cryogels were produced from a 1.5%(m/m)suspension of cellulose microfibers,which originated from Pinus elliotti,in distilled water.The addition of NaOH increased the compression strength of cryogel by 30% when compared to cryogel without the reagent.Due to the 50% decrease in volume,the cryogel FLNB-8h(8%NaOH)has its petroleum adsorption capacity decreased in average by 58%,whereas the FLNB-4(4%NaOH)cryogel had it only by 14%.The cellulose suspension which provided the best results for the properties of the cryogels tested had a 4%concentration of NaOH.展开更多
Cryogels are gel matrices that have interconnected macropores and are formed in freezing-thawing systems. These interconnected macropores give elasticity to cryogels. Transdermal controlled-release systems can be used...Cryogels are gel matrices that have interconnected macropores and are formed in freezing-thawing systems. These interconnected macropores give elasticity to cryogels. Transdermal controlled-release systems can be used to deliver drugs with short biological half-life and can maintain plasma levels of very potent drugs within a narrow therapeutic range for prolonged periods. In this study, cryogels have been used in a different area--transdermal controlled-release system, to obtain controlled drug release medium. For this purpose, naproxen sodium has been selected as a model drug. Naproxen, a propionic acid derivative, is a NSAID （nonsteroidal anti-inflammatory drug）. For controlled releasing of naproxen sodium, cryogels that have naproxen sodium in macropores have been prepared in sheet form for local application. Acrylamide based cryogel bands have been synthesized by flee radical cryogelation process. These cryogel bands have different pore size and includes naproxen sodium in their pores. This cryogel material has been characterized by swelling tests and SEM. Then, releasing ofnaproxen sodium from cryogels has been investigated at two different pH values, 7.4 and 5.5. According to experimental data, it has seen that these cryogel matrices that including naproxen sodium in macropores could be used in controlled drug releasing systems as bandages or other transdermal controlled releasing agents at room temperature展开更多
Effective therapies are urgently needed to stabilize patients with marginally compressible junctional hemorrhage long enough to get them to the hospital alive.Herein,we report injectable and rapidly expandable cryogel...Effective therapies are urgently needed to stabilize patients with marginally compressible junctional hemorrhage long enough to get them to the hospital alive.Herein,we report injectable and rapidly expandable cryogels consisting of polyacrylamide and thrombin(AT cryogels)created by cryo-polymerization for the efficient management of lethal junctional hemorrhage in swine.The produced cryogels have small pore sizes and highly interconnected porous architecture with robust mechanical strength.The cryogels exhibit rapid shape memory properties and prove to be resilient against fatigue.These cryogels also show high water/blood absorption capacity,fast blood clotting effect,and enhanced adhesion of red blood cells and platelets in vitro.Further,in vivo,hemostatic efficacy tests in a lethal swine junctional hemorrhage model suggest that treatment with AT cryogels,especially AT-2 cryogels,achieves the least blood loss and the highest survival rate(100%)compared to currently employed products such as XStat®and combat gauze.The high hemostatic performance of the cryogels may be attributed to highly interconnected porous architecture with small pore size and the use of thrombin as a pro-coagulant agent.Collectively,injectable and rapidly expandable thrombin-decorated polyacrylamide-based cryogels show significant promise as hemostatic material,offering effective management of marginally compressible junctional hemorrhages in prehospital settings.展开更多
Hypoxia is a major factor shaping the immune landscape,and several cancer models have been developed to emulate hypoxic tumors.However,to date,they still have several limitations,such as the lack of reproducibility,in...Hypoxia is a major factor shaping the immune landscape,and several cancer models have been developed to emulate hypoxic tumors.However,to date,they still have several limitations,such as the lack of reproducibility,inadequate biophysical cues,limited immune cell infiltration,and poor oxygen(O_(2))control,leading to non-pathophysiological tumor responses.Therefore,it is essential to develop better cancer models that mimic key features of the tumor extracellular matrix and recreate tumor-associated hypoxia while allowing cell infiltration and cancer-immune cell interactions.Herein,hypoxia-inducing cryogels(HICs)have been engineered using hyaluronic acid(HA)to fabricate three-dimensional microtissues and model a hypoxic tumor microenvironment.Specifically,tumor cell-laden HICs have been designed to deplete O_(2) locally and induce long-standing hypoxia.HICs promoted changes in hypoxia-responsive gene expression and phenotype,a metabolic adaptation to anaerobic glycolysis,and chemotherapy resistance.Additionally,HIC-supported tumor models induced dendritic cell(DC)inhibition,revealing a phenotypic change in the plasmacytoid DC(pDC)subset and an impaired conventional DC(cDC)response in hypoxia.Lastly,our HIC-based melanoma model induced CD8^(+)T cell inhibition,a condition associated with the downregulation of pro-inflammatory cytokine secretion,increased expression of immunomodulatory factors,and decreased degranulation and cytotoxic capacity of T cells.Overall,these data suggest that HICs can be used as a tool to model solid-like tumor microenvironments and has great potential to deepen our understanding of cancer-immune cell relationship in low O_(2) conditions and may pave the way for developing more effective therapies.展开更多
The study presents the experimental results of measurements of the relaxation time of cryogels formed from various colloid-dispersed systems based on a poly(vinyl alcohol) aqueous solution.It is shown that the value o...The study presents the experimental results of measurements of the relaxation time of cryogels formed from various colloid-dispersed systems based on a poly(vinyl alcohol) aqueous solution.It is shown that the value of relaxation time,which characterizes the relationship between the viscosity and elasticity of real bodies,describes the rheological properties of materials more objectively than the traditional assessment of their physical and mechanical characteristics only by the elasticity modulus of the samples.展开更多
A poor biocompatibility and bioactivity of invasive materials remains major problems for biomaterialbased therapy. In this study, we introduced gelatin scaffolds carrying both bone morphogenetic protein-2(BMP-2) biomi...A poor biocompatibility and bioactivity of invasive materials remains major problems for biomaterialbased therapy. In this study, we introduced gelatin scaffolds carrying both bone morphogenetic protein-2(BMP-2) biomimetic peptide and vascular endothelial growth factor-165(VEGF) that achieved controlled release, cell attachment, proliferation and differentiation. To promote osteogenesis with VEGF, we designed the BMP-2 biomimetic peptide that comprised BMP-2 core sequence oligopeptide(SSVPT), phosphoserine, and synthetic cell adhesion factor(RGDS). In vitro cell experiments, the scaffold was conducive to the adhesion and proliferation of rat bone marrow mesenchymal stem cells(r BMSCs). The micro-CT3 D reconstruction of the rat cranial bone defect model showed that bone regeneration patterns occurred from one side edge towards the center area implanted with the prepared cryogel, and tissue section staining analysis demonstrated that the scaffold with double-growth factor can synergistically accelerate bone regeneration. These findings suggested that the obtained gelatin cryogel could serve as a cell-responsive platform for biomaterial-based nonbearing bone repair.展开更多
Incautious discharge of organic dyes such as methyl orange(MO)has produced serious pollution to the environment,calling for the efficient techniques to remove them with retaining the green world.The photo-catalytic de...Incautious discharge of organic dyes such as methyl orange(MO)has produced serious pollution to the environment,calling for the efficient techniques to remove them with retaining the green world.The photo-catalytic degradation of organic dyes is promising among the developed techniques.Thus,a strategy based on transpiration-prompted photocatalytic degradation of dye pollutant under sunlight is put forward.Aniline(ANI)is graft-polymerized onto poly(acrylamide-co-N-4-aminophenylacrylamide)(PAAm)cryogel embedded with gold nanoparticles(AuNPs,diameter:4-10 nm).The obtained cryogels integrated with AuNPs and PANI inside PAAm matrix(AuNP@PAAm-g-PANI)have been structurally explored based on the chemical composition and the phase/porous morphology.SEM and TEM observation shows that PANI and AuNPs are uniformly distributed in PAAm matrix.Since the macro-porosity of cryogel,hydrophilicity of PAAm and photo-thermal activity of PANI,PAAm-g-PANI cryogels without AuNPs can have a photo-thermal evaporation rate of water at 1.63 kg·m^(-2)·h^(-1).As a comparison,Au NP@PAAm-g-PANI cryogels with AuNPs exhibit higher one at 2.20 kg·m^(-2)·h^(-1),suggesting the promotion of AuNPs to photo-thermal evaporation.Meanwhile,PANI appreciatively assists AuNPs to display higher catalytic ability for the oxidative degradation of MO.Therefore,the removal of MO from water is obviously prompted by the water transpiration under sunlight with AuNP@PAAm-g-PANI cryogels,whose rate constant can reach to 0.320 h^(-1),being three folds of that for the sole absorption of MO.This transpiration-prompted photocatalytic degradation provides a fascinating route to eliminate organic pollutants and obtain pure water from wastewater simultaneously with sustainable sunlight energy.展开更多
Background:Most traditional wound dressings only partially meet the needs of wound healing because of their single function.Patients usually suffer from the increasing cost of treatment and pain resulting from the fre...Background:Most traditional wound dressings only partially meet the needs of wound healing because of their single function.Patients usually suffer from the increasing cost of treatment and pain resulting from the frequent changing of wound dressings.Herein,we have developed a mutifunctional cryogel to promote bacterial infected wound healing based on a biocompatible polysaccharide.Methods:The multifunctional cryogel is made up of a compositive scaffold of chitosan(CS),gelatin(Gel)and tannic acid(TA)and in situ formed silver nanoparticles(Ag NPs).A liver bleeding rat model was used to evaluate the dynamic hemostasis performance of the various cryogels.In order to evaluate the antibacterial properties of the prepared cryogels,gram-positive bacterium Staphylococcus aureus(S.aureus)and gram-negative bacterium Escherichia coli(E.coli)were cultured with the cryogels for 12 h.Meanwhile,S.aureus was introduced to cause bacterial infection in vivo.After treatment for 2 days,the exudates from wound sites were dipped for bacterial colony culture.Subsequently,the anti-inflammatory effect of the various cryogels was evaluated by western blotting and enzyme-linked immunosorbent assay.Finally,full-thickness skin defect models on the back of SD rats were established to assess the wound healing performances of the cryogels.Results:Due to its porous structure,the multifunctional cryogel showed fast liver hemostasis.The introduced Ag NPs endowed the cryogel with an antibacterial efficiency of>99.9%against both S.aureus and E.coli.Benefited from the polyphenol groups of TA,the cryogel could inhibit nuclear factor-κB nuclear translocation and down-regulate inflammatory cytokines for an anti-inflammatory effect.Meanwhile,excessive reactive oxygen species could also be scavenged effectively.Despite the presence of Ag NPs,the cryogel did not show cytotoxicity and hemolysis.Moreover,in vivo experiments demonstrated that the biocompatible cryogel displayed effective bacterial disinfection and accelerated wound healing.Conclusions:The multifunctional cryogel,with fast hemostasis,antibacterial and anti-inflammation properties and the ability to promote cell proliferation could be widely applied as a wound dressing for bacterial infected wound healing.展开更多
An effective cation-exchange chromatographic method for lysozyme isolation from chicken egg white is presented, using supermacroporous cryogel grafted with sulfo functional groups. The chromatographic processes were c...An effective cation-exchange chromatographic method for lysozyme isolation from chicken egg white is presented, using supermacroporous cryogel grafted with sulfo functional groups. The chromatographic processes were carried out by one-step and sequential elution, respectively. Sodium phosphate buffer （pH 7.8） containing different concentrations of NaC1 is used as elution agent. The corresponding breakthrough characteristics and elution behaviors in the cryogel bed were investigated and analyzed. Purity of lysozyme in the elution effluent was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. The maximum purity of the obtained lysozyme was about 96%, and the cryogel is demonstrated as a potential separation medium for purification of high-purit lysozyme from chicken egg white.展开更多
Supermacroporous composite cryogels embedded with SiO2 nanoparticles were prepared by radical cryogenic copolymerization of the reactive monomer mixture of acrylamide（AAm） and N,N-methylene-bis-acrylamide（MBAAm） c...Supermacroporous composite cryogels embedded with SiO2 nanoparticles were prepared by radical cryogenic copolymerization of the reactive monomer mixture of acrylamide（AAm） and N,N-methylene-bis-acrylamide（MBAAm） containing SiO2 nanoparticles（mass ratios of nanoparticles to the monomer AAm from 0.01 to 0.08） under the freezing-temperature variation condition in glass columns.The properties of these composite cryogels were measured.The height equivalent to theoretical plate（HETP） of the cryogel beds at different liquid flow rates was determined by residence time distribution（RTD） using tracer pulse-response method.The composite cryogel matrix embedded with the mass fraction of SiO2 nanoparticles of 0.02 presented the best properties and was employed in the following graft polymerization.Chromatographic process of lysozyme in the composite cryogel grafted with 2-acrylamido-2-methyl-1-propanesulfonic acid（AMPSA） was carried out to evaluate the protein breakthrough and elution characteristics.The chromatography can be carried out at relatively high superficial velocity,i.e.,15 cm·min-1,indicating the satisfactory mechanical strength due to the embedded nanoparticles.展开更多
Following myocardial infarction(MI),cardiac tissue undergoes irreversible cellular alterations,with cardiomy-ocytes being replaced by fibrotic tissue.In order to improve tissue regeneration,a previously characterized ...Following myocardial infarction(MI),cardiac tissue undergoes irreversible cellular alterations,with cardiomy-ocytes being replaced by fibrotic tissue.In order to improve tissue regeneration,a previously characterized chitosan-based cryogel,which was designed by our group,was used.The treatment regimen involved the sequen-tial delivery of the cryogel loaded with specific cytokines and growth factors,followed by a separate injection of pre-differentiated cells.Initially,the cryogel loaded with interleukin-10 and transforming growth factor-βwas injected into infarcted tissue immediately after MI induction,targeting the acute inflammatory response.On day four post-MI,a second injection was administered,this time utilizing cryogel loaded with vascular endothelial growth factor and fibroblast growth factor-2,aimed at promoting tissue regeneration and angiogenesis.Subse-quently,on day six post-MI,the experimental group received cardiomyocyte-like cells,smooth muscle cells,and endothelial cells.The purpose of these cells,in synergy with cytokines and growth factors,was to repopulate the lost cellular populations,thereby enhancing myocardial repair.The treatment improved myocardial tissue regeneration,increased cardiac output,ejection fraction,and reduced fibrotic regions.Thus,the chitosan-based cryogel,enriched with anti-inflammatory and proangiogenic factors and supplemented with pre-differentiated cells,offers a promising platform for controlled release of therapeutics,promoting substantial tissue repair and regeneration following MI.展开更多
Macroporous hydrogels are water-swollen polymer networks with porous structures beyond the mesh size.They provide high specific surface areas and hieratical mass transfer channels which are desired for emerging applic...Macroporous hydrogels are water-swollen polymer networks with porous structures beyond the mesh size.They provide high specific surface areas and hieratical mass transfer channels which are desired for emerging applications including cell culturing,bio-separation,and drug delivery.A variety of approaches have been developed to fabricate macroporous hydrogels,including gas foaming,porogen templating,phase separation,3D printing,etc.Alternatively,ice templating utilizes the crystallization of water as the porogenation mechanism which doesn't need the leaching of porogens.展开更多
The dense networks of conventional hydrogel hinder the efficient cell penetration and thus tissue regeneration.In this study,a macroporous cryogel with excellent mechanical properties was designed and fabricated throu...The dense networks of conventional hydrogel hinder the efficient cell penetration and thus tissue regeneration.In this study,a macroporous cryogel with excellent mechanical properties was designed and fabricated through cryogelation and crosslinking of methacrylated gelatin(Gel-MA)and gelatin grafted with 2-ureido-4[1H]-6-methyl-pyrimidinone(Gel-UPY).The successful modification of the two functional units on the side chain of gelatin was confirmed by ^(1)H-NMR and infrared spectroscopy.The macroporous structure of cryogel was verified by scanning electron microscopy and confocal microscopy.The compressive modulus of cryogel(110 kPa)was 2 magnitudes higher than that of the conventional hydrogel of the same chemical compositions(8 kPa).Both the hydrogel and cryogel exhibited excellent stress-recovery ability.The cryogel could well maintain the viability of chondrocytes and facilitated their migration into the scaffold interior.After being implanted into osteochondral defects in rabbits for 12 w,the Gel-MA/Gel-UPY cryogel better facilitated the regeneration of upper cartilage and subchondral bone compared to the conventional hydrogel.展开更多
This study demonstrates the preparation and characterization of a novel ion imprinted cryogel which exhibits high affinity and selectivity towards Ce（Ⅲ） ions in aqueous solutions and bastnasite ore samples.2-Hydrox...This study demonstrates the preparation and characterization of a novel ion imprinted cryogel which exhibits high affinity and selectivity towards Ce（Ⅲ） ions in aqueous solutions and bastnasite ore samples.2-Hydroxyethyl methacrylate（HEMA） and N-methacryloylamido antipyrine（MAAP） were used as functional monomers for the preparation of Ce（Ⅲ） imprinted cryogel. The effects of various factors such as initial Ce（Ⅲ） concentration, flow rate, pH, interaction time and ionic strength on the Ce（Ⅲ） binding to the prepared ion imprinted cryogels were also studied. The binding equilibrium for Ce（Ⅲ） is obtained in30 min at the flow rate of 0.5 mL/min. The maximum binding capacity of the prepared ion imprinted cryogel towards Ce（Ⅲ） is obtained as 36.58 mg/g at optimum conditions. The selectivity of the prepared ion imprinted cryogel towards Ce（Ⅲ） in the presence of other possible interfering lanthanide ions such as La（Ⅲ） and Nd（Ⅲ） were also performed. The obtained results showed that the prepared ion imprinted cryogel exhibits high selectivity and sensitivity towards Ce（Ⅲ） ions. The limit of detection（LOD） was found as 50 μg/L.展开更多
Cryogel dressings with good absorption ability and photothermal antibacterial properties for preventing wound infections and treating infected wounds have attracted widespread attention.In this work,a series of cryoge...Cryogel dressings with good absorption ability and photothermal antibacterial properties for preventing wound infections and treating infected wounds have attracted widespread attention.In this work,a series of cryogels with macroporous structure,antioxidant and photothermal properties were prepared based on adipic dihydrazide modified hyaluronic acid(HA-ADH),and dopamine(DA).The antioxidant properties,hemostatic properties,near infrared(NIR)assisted photothermal antibacterial ability provided by polydopamine,recyclable compression mechanical properties,and cytocompatibility were tested.The results demonstrated that the HA-ADH/DA cryogels have stable mechanical properties,great antibacterial properties against E.coli(EC)and methicillin-resistant S.aureus(MRSA).The high swelling ratio due to the high water retention of HA equipped the cryogels with the capability of absorbing exuded blood and excessive tissue fluid in the infected full-thickness skin defect model of mouse.The cryogels demonstrated good cytocompatibility and antioxidant performance through cell tests and 1,1-diphenyl-2-methylbenzohydrazino(DPPH)scavenging efficiency test.The cryogels showed enhanced blood-clotting index(BCI)and better hemostatic ability in the mouse liver trauma model and the rat deep noncompressible liver defect model compared with gauze and gelatin sponge.Furthermore,compared with commercial TegadermTMdressing in vivo,the HA-ADH/DA cryogels could greatly promote infected skin wound healing in a full-thickness infected skin defect wound model.In summary,the macroporous HAADH/DA cryogels with good antioxidant,high swelling ratio,photothermal antibacterial property,and biocompatibility are a promising hemostatic material and wound healing dressing.展开更多
Severe blood loss due to traumatic injuries remains one of the leading causes of death in emergency settings.Chitosan continues to be the candidate material for hemostatic applications due to its inherent hemostatic p...Severe blood loss due to traumatic injuries remains one of the leading causes of death in emergency settings.Chitosan continues to be the candidate material for hemostatic applications due to its inherent hemostatic properties.However,available chitosan-based dressings have been reported to have an acidic odor at the wound site due to the incorporation of acid based solvents for their fabrication and deformation under compression owing to low mechanical strength limiting its usability.In the present study semi-IPN cryogel was fabricated via Schiff's base cross-linking between the polyaldehyde groups of oxidized dextran and thiolated chitosan in presence of locust bean gum(LBG)known for its hydrophilicity.Polymerization at12C yielded macroporous semi-IPN cryogels with an average pore size of 124.57±20.31 mm and 85.46%porosity.The hydrophobicity index of LBG reinforced semi-IPN cryogel was reduced 2.42 times whereas the swelling ratio was increased by 156.08%compare to control cryogel.The increased hydrophilicity and swelling ratio inflated the compressive modulus from 28.1 kPa to 33.85 for LBG reinforced semi-IPN cryogel.The structural stability and constant degradation medium pH were also recorded over a period of 12 weeks.The cryogels demonstrated lower adsorption affinity towards BSA.The cytotoxicity assays(direct,indirect)with 3T3-L1 fibroblast cells confirmed the cytocompatibility of the cryogels.The hemolysis assay showed<5%hemolysis confirming blood compatibility of the fabricated cryogel,while whole blood clotting and platelet adhesion assays confirmed the hemostatic potential of semi-IPN cryogel.展开更多
Currently,it is a challenge to develop hemostatic materials with high water absorption capacity and anti-fatigue properties for quickly preventing massive hemorrhage from arteries and visceral organs.A series of polya...Currently,it is a challenge to develop hemostatic materials with high water absorption capacity and anti-fatigue properties for quickly preventing massive hemorrhage from arteries and visceral organs.A series of polyacrylic acid/chitosan(PAA/CS)cryogels were prepared by a cryostructurization technique to improve mechanical performance and hemostatic efficiency of chitosan(CS).In this system,the chemically cross-linked PAA network was used as a framework to improve water absorption behaviors and mechanical strength.The CS network was co-blended by hydrogen bonding and electrostatic interactions,both of which synergistically promoted hemostasis.These cryogels had high porosity(>94%),rapid water absorption rate(<3 s),high blood absorption capacity(>2000%),outstanding mechanical strength,and fatigue resistance.Moreover,the results of cytotoxicity and hemolysis demonstrated that the cryogels had good biocompatibility.Notably,the PAA/CS cryogels exhibited superior whole blood coagulation ability and red blood cell and platelet adhesion ability compared to those of commercial hemostatic dressing(gauze,gelatin sponges,and CS sponges).Based on these results,mouse femoral artery hemorrhage models and liver hemorrhage models were prepared to investigate the hemostatic ability of the prepared PAA/CS cryogels.Results suggested that the hemostatic ability of PAA5/CS cryogels was superior to that of commercial hemostatic materials.Therefore,the PAA/CS cryogels showed potential application in preventing massive hemorrhage from arteries and visceral organs.展开更多
Three-dimensional macroporous scaffolds are commonly used in bone tissue engineering applications since they provide sufficient space for cell migration and proliferation, facilitating bone ingrowth and implant vascul...Three-dimensional macroporous scaffolds are commonly used in bone tissue engineering applications since they provide sufficient space for cell migration and proliferation, facilitating bone ingrowth and implant vascularisation. The aim of this work was to combine two simple methods, freeze-drying and gas-foaming, in order to fabricate highly macroporous bone scaffolds made of chitosan/agarose matrix reinforced with nanohydroxyapatite. The secondary goal of this research was to comprehensively assess biomedical potential of developed biomaterials. In this work, it was demonstrated that simultaneous application of freeze-drying and gas-foaming technique allows to obtain hybrid(as proven by ATR-FTIR)macroporous bone scaffolds(pore diameter > 50 um) characterized by high open(70%) and interconnected porosity. Novel scaffolds were non-toxic, favoured osteoblasts adhesion and growth and induced apatite formation on their surfaces, indicating their high bioactivity that is essential for good implant osseointegration. Biomaterials were also prone to enzymatic degradation, degradation in acidified microenvironment(e.g. osteoclast-mediated), and slow degradation under physiological p H of 7.4.Moreover, the scaffolds revealed microstructure(70% open porosity, SSA approx. 30 m2/g, high share of macropores with diameter in the range 100-410 um) and compressive strength(1–1.4 MPa) comparable to cancellous bone, indicating that they are promising implants for cancellous bone regeneration.展开更多
Dextran-hyaluronate （Dex-HA） based supermacroporous cryogel scaffolds for soft tissue engineering were prepared by free radical cryo-copolymerization of aqueous solutions containing the dextran methacrylate （Dex-MA...Dextran-hyaluronate （Dex-HA） based supermacroporous cryogel scaffolds for soft tissue engineering were prepared by free radical cryo-copolymerization of aqueous solutions containing the dextran methacrylate （Dex-MA） and hyaluronate methacrylate （HA-MA） at various macromonomer concentrations under the freezing condition. It was observed that the suitable total concen- tration of macromonomers for the preparation of Dex-HA cryogel scaffold with satisfied properties was 5% （w/w） at the HA-MA concentration of 1% （w/v）, which was then used to produce the test scaffold. The obtained cryogel scaffold with 5% （w/w） macromonomer solution had high water permeability （5.1 × 10 ^-2m2） and high porosity （92.4%）. The pore diameter examined by scanning electron microscopy （SEM） was in a broad range of 50-135 um with the mean pore diameter of 91 um. Furthermore, the cryogel scaffold also had good elastic nature with the elastic modulus of 17.47±1.44 kPa. The culture of 3T3-L1 preadipocyte within the scaffold was investigated and observed by SEM. Cells clustered on the pore walls and grew inside the scaffold indicating the Dex-HA cryogel scaffold could be a promising porous biomaterial for applications in tissue engineering.展开更多
文摘This work aimed at analyzing the petroleum adsorption capacity and the compressive strength of cellulose cryogels produced with the addition of 4 and 8%(w/w)sodium hydroxide(NaOH).Cryogels were produced from a 1.5%(m/m)suspension of cellulose microfibers,which originated from Pinus elliotti,in distilled water.The addition of NaOH increased the compression strength of cryogel by 30% when compared to cryogel without the reagent.Due to the 50% decrease in volume,the cryogel FLNB-8h(8%NaOH)has its petroleum adsorption capacity decreased in average by 58%,whereas the FLNB-4(4%NaOH)cryogel had it only by 14%.The cellulose suspension which provided the best results for the properties of the cryogels tested had a 4%concentration of NaOH.
文摘Cryogels are gel matrices that have interconnected macropores and are formed in freezing-thawing systems. These interconnected macropores give elasticity to cryogels. Transdermal controlled-release systems can be used to deliver drugs with short biological half-life and can maintain plasma levels of very potent drugs within a narrow therapeutic range for prolonged periods. In this study, cryogels have been used in a different area--transdermal controlled-release system, to obtain controlled drug release medium. For this purpose, naproxen sodium has been selected as a model drug. Naproxen, a propionic acid derivative, is a NSAID （nonsteroidal anti-inflammatory drug）. For controlled releasing of naproxen sodium, cryogels that have naproxen sodium in macropores have been prepared in sheet form for local application. Acrylamide based cryogel bands have been synthesized by flee radical cryogelation process. These cryogel bands have different pore size and includes naproxen sodium in their pores. This cryogel material has been characterized by swelling tests and SEM. Then, releasing ofnaproxen sodium from cryogels has been investigated at two different pH values, 7.4 and 5.5. According to experimental data, it has seen that these cryogel matrices that including naproxen sodium in macropores could be used in controlled drug releasing systems as bandages or other transdermal controlled releasing agents at room temperature
基金supported by startup funds from the University of Nebraska Medical Center(UNMC)and Congressionally Directed Medical Research Program(CDMRP)/Peer Reviewed Medical Research Program(PRMRP)FY19 W81XWH2010207 to J.X.M.A.C.We thank the Proteomics&Metabolomics Facility(RRID:SCR_021314),Nebraska Center for Biotechnology at the University of Nebraska-Lincoln for the mass spectrometry analysis.The facility and instrumentation are supported by the Nebraska Research Initiative.
文摘Effective therapies are urgently needed to stabilize patients with marginally compressible junctional hemorrhage long enough to get them to the hospital alive.Herein,we report injectable and rapidly expandable cryogels consisting of polyacrylamide and thrombin(AT cryogels)created by cryo-polymerization for the efficient management of lethal junctional hemorrhage in swine.The produced cryogels have small pore sizes and highly interconnected porous architecture with robust mechanical strength.The cryogels exhibit rapid shape memory properties and prove to be resilient against fatigue.These cryogels also show high water/blood absorption capacity,fast blood clotting effect,and enhanced adhesion of red blood cells and platelets in vitro.Further,in vivo,hemostatic efficacy tests in a lethal swine junctional hemorrhage model suggest that treatment with AT cryogels,especially AT-2 cryogels,achieves the least blood loss and the highest survival rate(100%)compared to currently employed products such as XStat®and combat gauze.The high hemostatic performance of the cryogels may be attributed to highly interconnected porous architecture with small pore size and the use of thrombin as a pro-coagulant agent.Collectively,injectable and rapidly expandable thrombin-decorated polyacrylamide-based cryogels show significant promise as hemostatic material,offering effective management of marginally compressible junctional hemorrhages in prehospital settings.
基金the National Institutes of Health(NIH,1R01EB027705 award)National Science Foundation(NSF CAREER award,DMR 1847843).
文摘Hypoxia is a major factor shaping the immune landscape,and several cancer models have been developed to emulate hypoxic tumors.However,to date,they still have several limitations,such as the lack of reproducibility,inadequate biophysical cues,limited immune cell infiltration,and poor oxygen(O_(2))control,leading to non-pathophysiological tumor responses.Therefore,it is essential to develop better cancer models that mimic key features of the tumor extracellular matrix and recreate tumor-associated hypoxia while allowing cell infiltration and cancer-immune cell interactions.Herein,hypoxia-inducing cryogels(HICs)have been engineered using hyaluronic acid(HA)to fabricate three-dimensional microtissues and model a hypoxic tumor microenvironment.Specifically,tumor cell-laden HICs have been designed to deplete O_(2) locally and induce long-standing hypoxia.HICs promoted changes in hypoxia-responsive gene expression and phenotype,a metabolic adaptation to anaerobic glycolysis,and chemotherapy resistance.Additionally,HIC-supported tumor models induced dendritic cell(DC)inhibition,revealing a phenotypic change in the plasmacytoid DC(pDC)subset and an impaired conventional DC(cDC)response in hypoxia.Lastly,our HIC-based melanoma model induced CD8^(+)T cell inhibition,a condition associated with the downregulation of pro-inflammatory cytokine secretion,increased expression of immunomodulatory factors,and decreased degranulation and cytotoxic capacity of T cells.Overall,these data suggest that HICs can be used as a tool to model solid-like tumor microenvironments and has great potential to deepen our understanding of cancer-immune cell relationship in low O_(2) conditions and may pave the way for developing more effective therapies.
文摘The study presents the experimental results of measurements of the relaxation time of cryogels formed from various colloid-dispersed systems based on a poly(vinyl alcohol) aqueous solution.It is shown that the value of relaxation time,which characterizes the relationship between the viscosity and elasticity of real bodies,describes the rheological properties of materials more objectively than the traditional assessment of their physical and mechanical characteristics only by the elasticity modulus of the samples.
基金supported by grants from Science and Technology Program of Guangzhou,China (No. 201804010146)Natural Science Foundation of Guangdong Province,China (No.2016A030313341)+2 种基金Science and Technology Planning Project of Guangdong Province,China (No. 2014B020215001)National Natural Science Foundation of China (No. 51973243)Science and Technology Planning Project of Shenzhen (No. JCYJ20190807155801657)。
文摘A poor biocompatibility and bioactivity of invasive materials remains major problems for biomaterialbased therapy. In this study, we introduced gelatin scaffolds carrying both bone morphogenetic protein-2(BMP-2) biomimetic peptide and vascular endothelial growth factor-165(VEGF) that achieved controlled release, cell attachment, proliferation and differentiation. To promote osteogenesis with VEGF, we designed the BMP-2 biomimetic peptide that comprised BMP-2 core sequence oligopeptide(SSVPT), phosphoserine, and synthetic cell adhesion factor(RGDS). In vitro cell experiments, the scaffold was conducive to the adhesion and proliferation of rat bone marrow mesenchymal stem cells(r BMSCs). The micro-CT3 D reconstruction of the rat cranial bone defect model showed that bone regeneration patterns occurred from one side edge towards the center area implanted with the prepared cryogel, and tissue section staining analysis demonstrated that the scaffold with double-growth factor can synergistically accelerate bone regeneration. These findings suggested that the obtained gelatin cryogel could serve as a cell-responsive platform for biomaterial-based nonbearing bone repair.
基金the financial support provided by the National Natural Science Foundation of China(Nos.20934005 and 21274136)。
文摘Incautious discharge of organic dyes such as methyl orange(MO)has produced serious pollution to the environment,calling for the efficient techniques to remove them with retaining the green world.The photo-catalytic degradation of organic dyes is promising among the developed techniques.Thus,a strategy based on transpiration-prompted photocatalytic degradation of dye pollutant under sunlight is put forward.Aniline(ANI)is graft-polymerized onto poly(acrylamide-co-N-4-aminophenylacrylamide)(PAAm)cryogel embedded with gold nanoparticles(AuNPs,diameter:4-10 nm).The obtained cryogels integrated with AuNPs and PANI inside PAAm matrix(AuNP@PAAm-g-PANI)have been structurally explored based on the chemical composition and the phase/porous morphology.SEM and TEM observation shows that PANI and AuNPs are uniformly distributed in PAAm matrix.Since the macro-porosity of cryogel,hydrophilicity of PAAm and photo-thermal activity of PANI,PAAm-g-PANI cryogels without AuNPs can have a photo-thermal evaporation rate of water at 1.63 kg·m^(-2)·h^(-1).As a comparison,Au NP@PAAm-g-PANI cryogels with AuNPs exhibit higher one at 2.20 kg·m^(-2)·h^(-1),suggesting the promotion of AuNPs to photo-thermal evaporation.Meanwhile,PANI appreciatively assists AuNPs to display higher catalytic ability for the oxidative degradation of MO.Therefore,the removal of MO from water is obviously prompted by the water transpiration under sunlight with AuNP@PAAm-g-PANI cryogels,whose rate constant can reach to 0.320 h^(-1),being three folds of that for the sole absorption of MO.This transpiration-prompted photocatalytic degradation provides a fascinating route to eliminate organic pollutants and obtain pure water from wastewater simultaneously with sustainable sunlight energy.
基金support from the National Natural Science Foundation of China(51703145)China Postdoctoral Science Foundation(2019 T120844 and 2017 M620426)+3 种基金Sichuan Science and Technology Program(2021JDRC0102)Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0513)supported by the National Natural Science Foundation of China(51703145)Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0513).
文摘Background:Most traditional wound dressings only partially meet the needs of wound healing because of their single function.Patients usually suffer from the increasing cost of treatment and pain resulting from the frequent changing of wound dressings.Herein,we have developed a mutifunctional cryogel to promote bacterial infected wound healing based on a biocompatible polysaccharide.Methods:The multifunctional cryogel is made up of a compositive scaffold of chitosan(CS),gelatin(Gel)and tannic acid(TA)and in situ formed silver nanoparticles(Ag NPs).A liver bleeding rat model was used to evaluate the dynamic hemostasis performance of the various cryogels.In order to evaluate the antibacterial properties of the prepared cryogels,gram-positive bacterium Staphylococcus aureus(S.aureus)and gram-negative bacterium Escherichia coli(E.coli)were cultured with the cryogels for 12 h.Meanwhile,S.aureus was introduced to cause bacterial infection in vivo.After treatment for 2 days,the exudates from wound sites were dipped for bacterial colony culture.Subsequently,the anti-inflammatory effect of the various cryogels was evaluated by western blotting and enzyme-linked immunosorbent assay.Finally,full-thickness skin defect models on the back of SD rats were established to assess the wound healing performances of the cryogels.Results:Due to its porous structure,the multifunctional cryogel showed fast liver hemostasis.The introduced Ag NPs endowed the cryogel with an antibacterial efficiency of>99.9%against both S.aureus and E.coli.Benefited from the polyphenol groups of TA,the cryogel could inhibit nuclear factor-κB nuclear translocation and down-regulate inflammatory cytokines for an anti-inflammatory effect.Meanwhile,excessive reactive oxygen species could also be scavenged effectively.Despite the presence of Ag NPs,the cryogel did not show cytotoxicity and hemolysis.Moreover,in vivo experiments demonstrated that the biocompatible cryogel displayed effective bacterial disinfection and accelerated wound healing.Conclusions:The multifunctional cryogel,with fast hemostasis,antibacterial and anti-inflammation properties and the ability to promote cell proliferation could be widely applied as a wound dressing for bacterial infected wound healing.
基金Supported by the National lqatural Science Foundation of China （21036005, 20876145）, the Science and Technology Cooperation Project between China-Europe Country＇s Governments from the Ministry of Science and Technology of China （1017） and the Natural Science Foundation of Zhejiang Provincial （Y4080326）.
文摘An effective cation-exchange chromatographic method for lysozyme isolation from chicken egg white is presented, using supermacroporous cryogel grafted with sulfo functional groups. The chromatographic processes were carried out by one-step and sequential elution, respectively. Sodium phosphate buffer （pH 7.8） containing different concentrations of NaC1 is used as elution agent. The corresponding breakthrough characteristics and elution behaviors in the cryogel bed were investigated and analyzed. Purity of lysozyme in the elution effluent was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. The maximum purity of the obtained lysozyme was about 96%, and the cryogel is demonstrated as a potential separation medium for purification of high-purit lysozyme from chicken egg white.
基金Supported by the National Natural Science Foundation of China（20876145） the Natural Science Foundation of Zhejiang Province（Y4080329）
文摘Supermacroporous composite cryogels embedded with SiO2 nanoparticles were prepared by radical cryogenic copolymerization of the reactive monomer mixture of acrylamide（AAm） and N,N-methylene-bis-acrylamide（MBAAm） containing SiO2 nanoparticles（mass ratios of nanoparticles to the monomer AAm from 0.01 to 0.08） under the freezing-temperature variation condition in glass columns.The properties of these composite cryogels were measured.The height equivalent to theoretical plate（HETP） of the cryogel beds at different liquid flow rates was determined by residence time distribution（RTD） using tracer pulse-response method.The composite cryogel matrix embedded with the mass fraction of SiO2 nanoparticles of 0.02 presented the best properties and was employed in the following graft polymerization.Chromatographic process of lysozyme in the composite cryogel grafted with 2-acrylamido-2-methyl-1-propanesulfonic acid（AMPSA） was carried out to evaluate the protein breakthrough and elution characteristics.The chromatography can be carried out at relatively high superficial velocity,i.e.,15 cm·min-1,indicating the satisfactory mechanical strength due to the embedded nanoparticles.
基金funded by a Collaborative Research grant from Nazarbayev University(021220CRP0722).
文摘Following myocardial infarction(MI),cardiac tissue undergoes irreversible cellular alterations,with cardiomy-ocytes being replaced by fibrotic tissue.In order to improve tissue regeneration,a previously characterized chitosan-based cryogel,which was designed by our group,was used.The treatment regimen involved the sequen-tial delivery of the cryogel loaded with specific cytokines and growth factors,followed by a separate injection of pre-differentiated cells.Initially,the cryogel loaded with interleukin-10 and transforming growth factor-βwas injected into infarcted tissue immediately after MI induction,targeting the acute inflammatory response.On day four post-MI,a second injection was administered,this time utilizing cryogel loaded with vascular endothelial growth factor and fibroblast growth factor-2,aimed at promoting tissue regeneration and angiogenesis.Subse-quently,on day six post-MI,the experimental group received cardiomyocyte-like cells,smooth muscle cells,and endothelial cells.The purpose of these cells,in synergy with cytokines and growth factors,was to repopulate the lost cellular populations,thereby enhancing myocardial repair.The treatment improved myocardial tissue regeneration,increased cardiac output,ejection fraction,and reduced fibrotic regions.Thus,the chitosan-based cryogel,enriched with anti-inflammatory and proangiogenic factors and supplemented with pre-differentiated cells,offers a promising platform for controlled release of therapeutics,promoting substantial tissue repair and regeneration following MI.
基金supported by the National Natural Science Foundation of China(grant Nos.52273112,U20A6001,22105167)the Start-up funding of Ningbo Research Institute of Zhejiang University(grant No.20201203Z0193).
文摘Macroporous hydrogels are water-swollen polymer networks with porous structures beyond the mesh size.They provide high specific surface areas and hieratical mass transfer channels which are desired for emerging applications including cell culturing,bio-separation,and drug delivery.A variety of approaches have been developed to fabricate macroporous hydrogels,including gas foaming,porogen templating,phase separation,3D printing,etc.Alternatively,ice templating utilizes the crystallization of water as the porogenation mechanism which doesn't need the leaching of porogens.
基金the Key research and development program of Zhejiang Province(No.2021C03113)the Natural Science Foundation of Zhejiang Province(No.LD21E030001).
文摘The dense networks of conventional hydrogel hinder the efficient cell penetration and thus tissue regeneration.In this study,a macroporous cryogel with excellent mechanical properties was designed and fabricated through cryogelation and crosslinking of methacrylated gelatin(Gel-MA)and gelatin grafted with 2-ureido-4[1H]-6-methyl-pyrimidinone(Gel-UPY).The successful modification of the two functional units on the side chain of gelatin was confirmed by ^(1)H-NMR and infrared spectroscopy.The macroporous structure of cryogel was verified by scanning electron microscopy and confocal microscopy.The compressive modulus of cryogel(110 kPa)was 2 magnitudes higher than that of the conventional hydrogel of the same chemical compositions(8 kPa).Both the hydrogel and cryogel exhibited excellent stress-recovery ability.The cryogel could well maintain the viability of chondrocytes and facilitated their migration into the scaffold interior.After being implanted into osteochondral defects in rabbits for 12 w,the Gel-MA/Gel-UPY cryogel better facilitated the regeneration of upper cartilage and subchondral bone compared to the conventional hydrogel.
文摘This study demonstrates the preparation and characterization of a novel ion imprinted cryogel which exhibits high affinity and selectivity towards Ce（Ⅲ） ions in aqueous solutions and bastnasite ore samples.2-Hydroxyethyl methacrylate（HEMA） and N-methacryloylamido antipyrine（MAAP） were used as functional monomers for the preparation of Ce（Ⅲ） imprinted cryogel. The effects of various factors such as initial Ce（Ⅲ） concentration, flow rate, pH, interaction time and ionic strength on the Ce（Ⅲ） binding to the prepared ion imprinted cryogels were also studied. The binding equilibrium for Ce（Ⅲ） is obtained in30 min at the flow rate of 0.5 mL/min. The maximum binding capacity of the prepared ion imprinted cryogel towards Ce（Ⅲ） is obtained as 36.58 mg/g at optimum conditions. The selectivity of the prepared ion imprinted cryogel towards Ce（Ⅲ） in the presence of other possible interfering lanthanide ions such as La（Ⅲ） and Nd（Ⅲ） were also performed. The obtained results showed that the prepared ion imprinted cryogel exhibits high selectivity and sensitivity towards Ce（Ⅲ） ions. The limit of detection（LOD） was found as 50 μg/L.
基金the National Natural Science Foundation of China(No.51973172)the Natural Science Foundation of Shaanxi Province(Nos.2020JC-03 and 2019TD-020)+3 种基金State Key Laboratory for Mechanical Behavior of Materialsthe Fundamental Research Funds for the Central Universitiesthe World-Class Universities(Disciplines)and the Characteristic Development Guidance Funds for the Central UniversitiesOpening Project of Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research,College of Stomatology,Xi’an Jiaotong University(No.2019LHM-KFKT008)。
文摘Cryogel dressings with good absorption ability and photothermal antibacterial properties for preventing wound infections and treating infected wounds have attracted widespread attention.In this work,a series of cryogels with macroporous structure,antioxidant and photothermal properties were prepared based on adipic dihydrazide modified hyaluronic acid(HA-ADH),and dopamine(DA).The antioxidant properties,hemostatic properties,near infrared(NIR)assisted photothermal antibacterial ability provided by polydopamine,recyclable compression mechanical properties,and cytocompatibility were tested.The results demonstrated that the HA-ADH/DA cryogels have stable mechanical properties,great antibacterial properties against E.coli(EC)and methicillin-resistant S.aureus(MRSA).The high swelling ratio due to the high water retention of HA equipped the cryogels with the capability of absorbing exuded blood and excessive tissue fluid in the infected full-thickness skin defect model of mouse.The cryogels demonstrated good cytocompatibility and antioxidant performance through cell tests and 1,1-diphenyl-2-methylbenzohydrazino(DPPH)scavenging efficiency test.The cryogels showed enhanced blood-clotting index(BCI)and better hemostatic ability in the mouse liver trauma model and the rat deep noncompressible liver defect model compared with gauze and gelatin sponge.Furthermore,compared with commercial TegadermTMdressing in vivo,the HA-ADH/DA cryogels could greatly promote infected skin wound healing in a full-thickness infected skin defect wound model.In summary,the macroporous HAADH/DA cryogels with good antioxidant,high swelling ratio,photothermal antibacterial property,and biocompatibility are a promising hemostatic material and wound healing dressing.
文摘Severe blood loss due to traumatic injuries remains one of the leading causes of death in emergency settings.Chitosan continues to be the candidate material for hemostatic applications due to its inherent hemostatic properties.However,available chitosan-based dressings have been reported to have an acidic odor at the wound site due to the incorporation of acid based solvents for their fabrication and deformation under compression owing to low mechanical strength limiting its usability.In the present study semi-IPN cryogel was fabricated via Schiff's base cross-linking between the polyaldehyde groups of oxidized dextran and thiolated chitosan in presence of locust bean gum(LBG)known for its hydrophilicity.Polymerization at12C yielded macroporous semi-IPN cryogels with an average pore size of 124.57±20.31 mm and 85.46%porosity.The hydrophobicity index of LBG reinforced semi-IPN cryogel was reduced 2.42 times whereas the swelling ratio was increased by 156.08%compare to control cryogel.The increased hydrophilicity and swelling ratio inflated the compressive modulus from 28.1 kPa to 33.85 for LBG reinforced semi-IPN cryogel.The structural stability and constant degradation medium pH were also recorded over a period of 12 weeks.The cryogels demonstrated lower adsorption affinity towards BSA.The cytotoxicity assays(direct,indirect)with 3T3-L1 fibroblast cells confirmed the cytocompatibility of the cryogels.The hemolysis assay showed<5%hemolysis confirming blood compatibility of the fabricated cryogel,while whole blood clotting and platelet adhesion assays confirmed the hemostatic potential of semi-IPN cryogel.
基金supported by the National Natural Science Foundation of China(Grant Nos.U20A20261,31870948,31971250,and 52073205)Natural Science Foundation of Tianjin(Grant No.20JCYBJC00660)。
文摘Currently,it is a challenge to develop hemostatic materials with high water absorption capacity and anti-fatigue properties for quickly preventing massive hemorrhage from arteries and visceral organs.A series of polyacrylic acid/chitosan(PAA/CS)cryogels were prepared by a cryostructurization technique to improve mechanical performance and hemostatic efficiency of chitosan(CS).In this system,the chemically cross-linked PAA network was used as a framework to improve water absorption behaviors and mechanical strength.The CS network was co-blended by hydrogen bonding and electrostatic interactions,both of which synergistically promoted hemostasis.These cryogels had high porosity(>94%),rapid water absorption rate(<3 s),high blood absorption capacity(>2000%),outstanding mechanical strength,and fatigue resistance.Moreover,the results of cytotoxicity and hemolysis demonstrated that the cryogels had good biocompatibility.Notably,the PAA/CS cryogels exhibited superior whole blood coagulation ability and red blood cell and platelet adhesion ability compared to those of commercial hemostatic dressing(gauze,gelatin sponges,and CS sponges).Based on these results,mouse femoral artery hemorrhage models and liver hemorrhage models were prepared to investigate the hemostatic ability of the prepared PAA/CS cryogels.Results suggested that the hemostatic ability of PAA5/CS cryogels was superior to that of commercial hemostatic materials.Therefore,the PAA/CS cryogels showed potential application in preventing massive hemorrhage from arteries and visceral organs.
基金financially supported by the National Science Centre(NCN)in Poland within OPUS 16(No.UMO2018/31/B/ST8/00945)Analysis(ATR-FTIR)performed by Aleksandra Benko was supported by the National Science Centre(NCN)in Poland(No.UMO-2017/24/C/ST8/00400)+1 种基金financial support through Project PCIN2017-128/AEIRamon y Cajal fellowship of CC。
文摘Three-dimensional macroporous scaffolds are commonly used in bone tissue engineering applications since they provide sufficient space for cell migration and proliferation, facilitating bone ingrowth and implant vascularisation. The aim of this work was to combine two simple methods, freeze-drying and gas-foaming, in order to fabricate highly macroporous bone scaffolds made of chitosan/agarose matrix reinforced with nanohydroxyapatite. The secondary goal of this research was to comprehensively assess biomedical potential of developed biomaterials. In this work, it was demonstrated that simultaneous application of freeze-drying and gas-foaming technique allows to obtain hybrid(as proven by ATR-FTIR)macroporous bone scaffolds(pore diameter > 50 um) characterized by high open(70%) and interconnected porosity. Novel scaffolds were non-toxic, favoured osteoblasts adhesion and growth and induced apatite formation on their surfaces, indicating their high bioactivity that is essential for good implant osseointegration. Biomaterials were also prone to enzymatic degradation, degradation in acidified microenvironment(e.g. osteoclast-mediated), and slow degradation under physiological p H of 7.4.Moreover, the scaffolds revealed microstructure(70% open porosity, SSA approx. 30 m2/g, high share of macropores with diameter in the range 100-410 um) and compressive strength(1–1.4 MPa) comparable to cancellous bone, indicating that they are promising implants for cancellous bone regeneration.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant Nos. 20876145, 21036005）, the Science and Technology Cooperation Project between China-Europe Country＇s Governments from the Ministry of Science and Technology of China （No. 1017） and the Zhejiang Provincial Natural Science Foundation of China （No. Y4080326）.
文摘Dextran-hyaluronate （Dex-HA） based supermacroporous cryogel scaffolds for soft tissue engineering were prepared by free radical cryo-copolymerization of aqueous solutions containing the dextran methacrylate （Dex-MA） and hyaluronate methacrylate （HA-MA） at various macromonomer concentrations under the freezing condition. It was observed that the suitable total concen- tration of macromonomers for the preparation of Dex-HA cryogel scaffold with satisfied properties was 5% （w/w） at the HA-MA concentration of 1% （w/v）, which was then used to produce the test scaffold. The obtained cryogel scaffold with 5% （w/w） macromonomer solution had high water permeability （5.1 × 10 ^-2m2） and high porosity （92.4%）. The pore diameter examined by scanning electron microscopy （SEM） was in a broad range of 50-135 um with the mean pore diameter of 91 um. Furthermore, the cryogel scaffold also had good elastic nature with the elastic modulus of 17.47±1.44 kPa. The culture of 3T3-L1 preadipocyte within the scaffold was investigated and observed by SEM. Cells clustered on the pore walls and grew inside the scaffold indicating the Dex-HA cryogel scaffold could be a promising porous biomaterial for applications in tissue engineering.
