Nineteen L-N-2-hydroxyethylamino acids and L-N,N-bis(2-hydroxyethyl)amino acids were prepared from the reaction of chlorohydrin with L-alanine,L-valine,L-leucine,L-isoleucine,L- phenylalanine,L-serine,L-thrcunine,L-gl...Nineteen L-N-2-hydroxyethylamino acids and L-N,N-bis(2-hydroxyethyl)amino acids were prepared from the reaction of chlorohydrin with L-alanine,L-valine,L-leucine,L-isoleucine,L- phenylalanine,L-serine,L-thrcunine,L-glutamic acid,L-aspartic acid and glycine.L-N,N,N',N'-tetra (2-hydroxyethyl)cystine was prepared by the reaction of L-cystine with chlorohydrin.展开更多
To solve the problems of the long development period,low mass transfer efficiency and high impurity conte nt in the in-situ leaching process of weathe red crust elution-deposited rare earth ores(WCE-DREO),cationic hyd...To solve the problems of the long development period,low mass transfer efficiency and high impurity conte nt in the in-situ leaching process of weathe red crust elution-deposited rare earth ores(WCE-DREO),cationic hydroxyethyl cellulose(PQ-10)was composited with conventional leaching agent ammonium sulfate((NH_(4))_(2)SO_(4))to form a novel composite leaching agent.The effects of PQ-10 concentration,leaching temperature and leaching flow rate of the composite leaching agent on the leaching kinetics and mass transfer processes of rare earth(RE)and aluminum(Al)were investigated.Compared to the single leaching agent(NH_(4))_(2)SO_(4),the composite leaching agent(2 wt%(NH_(4))_(2)SO_(4)+0.02 wt%PQ-10)can reduce the RE leaching equilibrium time from 465 to 130 min and increase the RE leaching efficiency and decrease the Al leaching efficiency.It also facilitates the leaching process of WCE-DREO by increasing the peak concentrations of RE and Al,reducing the theoretical tower plate height(HETP)and improving the leaching mass transfer efficiency.It is indicated that PQ-10 can promote the leaching of WCE-DREO.The leaching process of the composite leaching system conforms to the diffusion kinetic control model.When the PQ-10 concentration is in the range of 0.005 wt%-0.020 wt%,the reaction orders of RE and Al are 0.73 and 0.54,respectively,which shows a positive effect on the leaching velocity;when the PQ-10 concentration is in the range of 0.030 wt%-0.060 wt%,the reaction orders of RE and Al are-1.16 and-0.75,respectively,which show a negative effect on the leaching velocity.In the range of 10-50℃,the apparent activation energies of RE and Al are 15.02 and 17.31 kJ/mol,respectively,and the higher the leaching temperature,the smaller the HETP and the higher the leaching velocity and mass transfer efficiency.The increase in leaching flow rate contributes to the increase in the longitudinal diffusion velocity of the leaching agent within WCE-DREO,causing a shorter time for RE and Al to reach leaching equilibrium.In addition,the flow rate and HETP are consistent with the Van Deemter equation.At a flow rate of 0.8 mL/min,HETP was minimized and the optimal mass transfer efficiencies is achieved for RE and Al.展开更多
Tissue engineering(TE)continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue regeneration.In this study,we developed a poly(2-hydroxyethyl me...Tissue engineering(TE)continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue regeneration.In this study,we developed a poly(2-hydroxyethyl methacrylate-co-methacrylic acid)(pHEMA-co-MAA)based hydrogel loaded with newly synthesized conductive poly(3,4-ethylene-dioxythiophene)(PEDOT)and polypyrrole(PPy)nanoparticles(NPs),and subsequently processed these hydrogels into tissue engineered constructs via three-dimensional(3D)printing.The presence of the NPs was critical as they altered the rheological properties during printing.However,all samples exhibited suitable shear thinning properties,allowing for the development of an optimized processing window for 3D printing.Samples were 3D printed into pre-determined disk-shaped configurations of 2 and 10 mm in height and diameter,respectively.We observed that the NPs disrupted the gel crosslinking efficiencies,leading to shorter degradation times and compressive mechanical properties ranging between 450 and 550 kPa.The conductivity of the printed hydrogels increased along with the NP concentration to(5.10±0.37)×10^(−7)S/cm.In vitro studies with cortical astrocyte cell cultures demonstrated that exposure to the pHEMA-co-MAA NP hydrogels yielded high cellular viability and proliferation rates.Finally,hydrogel antimicrobial studies with staphylococcus epidermidis bacteria revealed that the developed hydrogels affected bacterial growth.Taken together,these materials show promise for various TE strategies.展开更多
Photodynamic therapy(PDT)can produce high levels of reactive oxygen species(ROS)to kill tumor cells and induce antitumor immunity.However,intracellular antioxidant systems,including glutathione(GSH)system and thioredo...Photodynamic therapy(PDT)can produce high levels of reactive oxygen species(ROS)to kill tumor cells and induce antitumor immunity.However,intracellular antioxidant systems,including glutathione(GSH)system and thioredoxin(Trx)system,limit the accumulation of ROS,resulting in compromised PDT and insufficient immune stimulation.Herein,we designed a nanomedicine PtHPs co-loading photosensitizer pyropheophorbide a(PPa)and cisplatin prodrug Pt-COOH(Ⅳ)(Pt(Ⅳ))based on hydroxyethyl starch(HES)to inhibit both GSH and Trx antioxidant systems and achieve potent PDT as well as antitumor immune responses.Specifically,HES-PPa and HES-Pt were obtained by coupling HES with PPa and Pt(Ⅳ),and assembled into nanoparticle PtHPs by emulsification method to achieve the purpose of co-delivery of PPa and Pt(Ⅳ).PtHPs improved PPa photostability while retaining PPa photodynamic properties.In vitro experiments showed that PtHPs reduced GSH,inhibited Trx system and had better cell-killing effect and ROS generation ability.Subcutaneous tumormodels showed that PtHPs had good safety and tumor inhibition effect.Bilateral tumor models suggested that PtHPs promoted the release of damage-associated molecular patterns and the maturation of dendritic cells,induced T cell-mediated immune responses,and thus suppressed the growth of both primary and distal tumors.This study reports a novel platinum-based nanomedicine and provides a newstrategy for boosting PDT therapy-mediated antitumor immunity by overcoming intrinsic antioxidant systems.展开更多
Dehydroabietyl polyethylene glycol glycidyl ether-grafted hydroxyethyl cellulose(HEC)polymer surfactant(DA(EO)5GE-g-HEC)was prepared using ring-opening polymerization with biobased rosin and hydroxyethyl cellulose as ...Dehydroabietyl polyethylene glycol glycidyl ether-grafted hydroxyethyl cellulose(HEC)polymer surfactant(DA(EO)5GE-g-HEC)was prepared using ring-opening polymerization with biobased rosin and hydroxyethyl cellulose as feedstocks.Dehydroabietyl polyethylene glycol glycidyl ether(DA(EO)5GE)was formed by condensation of dehydroabietyl alcohol polyoxyethylene ether(Rosin derivative:DA(EO)5H)and epichlorohydrin.The grafting degree of DA(EO)5GE-g-HEC was manipulated by adjusting the mass ratio of HEC and DA(EO)5GE and confirmed by EA.According to the formula,when m(HEC)/m(DA(EO)2GE)was 1:1~1:5,the grafting rate of DA(EO)5GE in DA(EO)5GE-g-HEC varied from 34.43%to 38.33%.The surface activity and foam properties of DA(EO)5GE-g-HEC aqueous solution were studied.The results showed that with the increase in grafting rate,the critical micellar concentration(CMC)in aqueous solution changed from 1.28 to 0.96 g/L.The results of the thermogravimetric analysis showed that the temperature range of the main stage of mass loss of DA(EO)5GE-g-HEC was 310°C~410°C,and the thermal decomposition processes of the samples with five mass ratios were similar.An oil in water emulsion was prepared by choosing cyclohexane as the oil phase and DA(EO)5GE-g-HEC as the emulsifier.The effect of DA(EO)5GE-g-HEC mass fraction on emulsion particle size and stability was analyzed.The results suggested that when the oil-water ratio was 8:2 with 0.4%emulsifier,the emulsion droplets were the smallest in terms of particle size and were the most stable.The rheological test results showed that the apparent viscosity decreased with the increase in shear rate and showed a typical elastic gel phenomenon.展开更多
A new solvent of cellulose (1.5 mol/L NaOH/0.5 mol/L urea aqueous solution) was used as one of the homogeneous reaction media of polysaccharides for methylation, hydroxyethylation and hydroxypropylation. A water insol...A new solvent of cellulose (1.5 mol/L NaOH/0.5 mol/L urea aqueous solution) was used as one of the homogeneous reaction media of polysaccharides for methylation, hydroxyethylation and hydroxypropylation. A water insoluble β -(1—>3)-D-glucan, sample PCS3- isolated from fresh sclerotium of Poria cocos was sulfated in dimethyl sulfoxide (Me 2 SO), carboxymethylated in NaOH, isopropanol solution, as well as methylated, hydroxyethylated and hydroxypropylated in the new solvent system, respectively, to obtain five water-soluble derivatives coded as S-PCS3- C- PCS3- M-PCS3- HE-PCS3- and HP-PCS3- Their chemical structure and distribution of substitution were characterized by infrared spectroscopy (IR), elementary analysis (EA), 1 H-NMR, 13 C-NMR, 2D-COSY, 2D-TOCSY and 2D- 1 H-detected 1H 13C HMQC spectra. The results reveal that the relative reactivity of hydroxyl groups of the β -(1-?3)-D-glucan is in the order C-6 > C-4 > C-2 on the whole. The substitution of the samples S-PCS3- C-PCS3- and M-PCS3- occurred mainly at C-6 position and secondly at C-4 and C-2 positions, and that of HE-PCS3- occurred at C-6 and C-4 positions and of HP-PCS3- almost completely occurred at C-6 position. The degrees of substitution (DS) obtained from 13 C-NMR range from 0.23 to 1.27. The water solubility of the derivatives is in the order S-PCS3- >C-PCS3- >M-PCS3- >HE-PCS3- >HP-PCS3- This work provides a novel and nonpolluting process for the methylation, hydroxyethylation and hydroxypropylation of β -(1—>3)-D-glucan.展开更多
The title compound, 2-O-（2-hydroxyethyl）-D-glucose （CsH1607, Mr= 224.21）, has been synthesized and its structure was characterized by using NMR spectrum and X-ray single-crystal diffraction. This molecule crystall...The title compound, 2-O-（2-hydroxyethyl）-D-glucose （CsH1607, Mr= 224.21）, has been synthesized and its structure was characterized by using NMR spectrum and X-ray single-crystal diffraction. This molecule crystallizes in the monoclinic system, space group P21, with a = 8.399（17）, b = 6.620（14）, c = 9.81（2） A, β = 115.110（17）°, V= 493.7（18） A3, Z = 2, Dc = 1.508 mg/m3,/1 = 0.13 mm-1, F（O00） = 240, the final R = 0.0464 and wR = 0. l 15 for 152 ] observed reflections （1 〉 2a（I））. X-ray crystal structure analysis revealed that the conformation of the pyranosyl ring existed in a slightly distorted act chair conformation （Cremer-Pople puckering parameters of Q = 0.573（4） A, 0 = 6.7（3）0 and = -5.2（2）°）. The molecule exists as a monomer in the solid state, whose conformation is stabilized via multiple inter- and intramolecular hydrogen bonds.展开更多
Two kinds of UV curable polyurethane acrylate oligomers （PUPA and PUCA） were synthesized via the addition reaction between isophorone diisocyanate （IPDI） and polyethylene glycol monoacrylate （PEA6） or polycaprol...Two kinds of UV curable polyurethane acrylate oligomers （PUPA and PUCA） were synthesized via the addition reaction between isophorone diisocyanate （IPDI） and polyethylene glycol monoacrylate （PEA6） or polycaprolactone modified hydroxyethyl acrylate （PCLA2）. The structures of PUPA and PUCA were characterized by Fourier transform infrared spectroscopy （FT-IR）, IH nuclear magnetic resonance （^H NMR）, gel permeation chromatography （GPC） and differential scanning calorimeter （DSC）, and the thermal stability and dynamic mechanical thermal properties of their cured films were measured by thermogravimetric analysis （TGA） and dynamic mechanical analysis （DMA）, respectively. The viscosity of the oligomers and mechanical properties of the cured films were also studied. The results show that both oligomers have narrow molecular weight distribution. The viscosity of PUPA is 2.310 Pa.s at 25 ℃, while that of PUCA is： up to 3.980 Pa-s. The UV cured PUPA and PUCA films have homogeneous phase structure, and the PUCA film shows higher glass transition temperature and storage modulus. Furthermore, the PUCA film possesses better mechanical properties than PUPA, while the latter shows better alkali resistance.展开更多
Hydroxyethyl chitosan （HE-chitosan） is a water-soluble derivative of chitosan with many apparent biological properties. For example, it is non-toxic and rapidly biodegradable. Moreover, HE-chitosan has advantages in...Hydroxyethyl chitosan （HE-chitosan） is a water-soluble derivative of chitosan with many apparent biological properties. For example, it is non-toxic and rapidly biodegradable. Moreover, HE-chitosan has advantages in water-solubility, moisture retention and gelling property due to its hydroxyethyl group. However, the biocompatibility and biodegradability of this multifimctional de- rivative have rarely been documented although they are critical for its application in biomedical and clinical treatments. The purpose of this work was to evaluate the biosafety of HE-chitosan, and draw important clues for its diverse applications. HE-chitosan was synthesized and characterized its chemical structure with FTIR. Its molecular weight （Mw） was determined by gel permeation chro- matography （GPC）, and its deacetylation degree （DD） was investigated through potentiometric analysis. The cytotoxicity of HE-chitosan on mouse fibroblast cell L929 was tested. The biocompatibility and biodegradability of HE-chitosan in rat and rabbit were evaluated. The FTIR results indicated that the hydroxyethyl groups were linked to C6 of chitosan. The GPC analysis confirmed that its Mw was about 90.01 kDa. It was also demonstrated that HE-chitosan had excellent biocompatibility and biodegradability in vivo and had no cytotoxicity on L929. These findings indicated that HE-chitosan can potentially be applied as a biomaterial in tissue engineering, drug delivery, and other biomedical fields.展开更多
In this paper,we present a 3D printed tumor spheroidal model suitable for drug discovery.This model is based on a hydroxyethyl cellulose/alginate/gelatin(HCSG)composite biomaterial that has three distinct properties:(...In this paper,we present a 3D printed tumor spheroidal model suitable for drug discovery.This model is based on a hydroxyethyl cellulose/alginate/gelatin(HCSG)composite biomaterial that has three distinct properties:(1)the HCSG is similar to the commercial basement membrane extract in Ki67,MUC1,and PARP1 expressions of MCF-7 cells for embedding culture;(2)the HCSG is printable at room temperature;and(3)the HCSG can be large-scale manufactured at an ultralow cost.We printed a 3D MCF-7 spheroid model with HCSG and characterized it in terms of cell viability,spheroid size,key protein expression,and mitochondrial metabolic activity.We used the 3D MCF-7 spheroid model to evaluate the anti-breast cancer activity of 13 amino acid-based flavone phosphoramidates and found that the alanine structure induced a stronger drug resistance,whereas phenylalanine hardly caused drug resistance in the MCF-7 cells.This is the first time that 3D bioprinting technology has been used in a structure–activity relationship study.展开更多
The thermal decomposition process was studied by the TG–DTA analyzer. The results show that the decomposition process of sodium hydroxyethyl sulfonate consisted of three stages: the mass loss for the first, the secon...The thermal decomposition process was studied by the TG–DTA analyzer. The results show that the decomposition process of sodium hydroxyethyl sulfonate consisted of three stages: the mass loss for the first, the second and third stages may be about the groups of CH_3CH_2OH, CH_3CHO and SO_2 volatilized, respectively. The decomposition residuum of three stages was analyzed by FT-IR, and the results of FT-IR agreed with the decomposition process predicted by theoretical weight loss. The specific heat capacity of sodium hydroxyethyl sulfonate was determined by differential scanning calorimetry(DSC). The melting temperature and melting enthalpy were obtained to be 465.41 K and 25.69 kJ·mol^(-1), respectively. The molar specific heat capacity of sodium hydroxyethyl sulfonate was determinated from 310.15 K to 365.15 K and expressed as a function of temperature.展开更多
The semi-continuous seeded emulsion eopolymerization of vinyl acetate and butyl acrylate was carried out with hydroxyethyl cellulose as a colloid stabilizer. The morphology of the latex particle and the relationship b...The semi-continuous seeded emulsion eopolymerization of vinyl acetate and butyl acrylate was carried out with hydroxyethyl cellulose as a colloid stabilizer. The morphology of the latex particle and the relationship between the reaction time and the average particle diameter and/or the conversion ratio during the polymerization were invstiguted. The experimental results shaw that the morphology of the latex particle possesses the stable sterie construction. In the seeded polymerizution, the average particle diameter of latex decreased while the conversion ratio increased. At the second term of the emulsion copolymerization （the growth stage of particle size）, the latex particle average diameter increased with copolymerization continuously, but the instantaneous conversation ratio was not large, so it was very necessaO to properly prolong the time during the holding temperature stage.展开更多
BACKGROUND Accidental dural puncture(ADP)and subsequent post-dural puncture headache(PDPH)remain common complications of epidural procedures for obstetric anesthesia and analgesia.No clear consensus exists on the best...BACKGROUND Accidental dural puncture(ADP)and subsequent post-dural puncture headache(PDPH)remain common complications of epidural procedures for obstetric anesthesia and analgesia.No clear consensus exists on the best way to prevent PDPH after ADP.CASE SUMMARY We report our findings in twenty parturients who underwent an incorporated strategy of epidural analgesia followed by epidural hydroxyethyl starch(HES)to prevent PDPH after ADP with a 16-gauge Tuohy needle during epidural procedures.ADP with a 16-gauge Tuohy needle occurred in nine parturients undergoing a cesarean section(CS)and in eleven parturients receiving labor analgesia.An epidural catheter was re-sited at the same or adjacent intervertebral space in all patients.After CS,the epidural catheter was used for postoperative pain relief over a 48-h period.After delivery in eleven cases,epidural infusion was maintained for 24 h.Thereafter,15 mL of 6%HES 130/0.4 was administered via the epidural catheter immediately prior to catheter removal.None of the parturients developed PDPH or neurologic deficits over a follow-up period of at least two months to up to one year postpartum.CONCLUSION An incorporated strategy of epidural analgesia followed by epidural hydroxyethyl starch may have great efficacy in preventing PDPH after ADP.展开更多
Objective： To investigate the distribution and differentiation of myeloid-derived suppressor cells （MDSCs） in hemorrhagic shock mice, which are resuscitated with normal saline （NS）, hypertonic saline （HTS）, and...Objective： To investigate the distribution and differentiation of myeloid-derived suppressor cells （MDSCs） in hemorrhagic shock mice, which are resuscitated with normal saline （NS）, hypertonic saline （HTS）, and hydroxyethyl starch （HES）. Methods： BALB/c mice were randomly divided into control, NS, HTS, and HES resuscitation groups. Three subgroups （n=8） in each resuscitation group were marked as 2, 24, and 72 h. Flow cytometry was used to detect the MDSCs, monocytic MDSCs （M-MDSCs）, and granulocytic/neutrophilic MDSCs （G-MDSCs） in peripheral blood nucleated cells （PBNCs）, spleen single-cell suspension, and bone marrow nucleated cells （BMNCs）. Results： The MDSCs in BMNCs among three resuscitation groups were lower 2 h after shock, in PBNCs of the HTS group were higher, and in spleen of the NS group were lower （all P〈0.05 vs. control）. The M-MDSC/G-MDSC ratios in PBNCs of the HTS and HES groups were lower （both ,P〈0.05 vs. control）. At 24 h, the MDSCs in PBNCs of the NS and HTS groups were higher, while the spleen MDSCs in the HTS group were higher （all P〈0.05 vs. control）. The M-MDSC/ G-MDSC ratios were all less in PBNCs, spleen, and BMNCs of the NS and HTS groups, and were lower in BMNCs of the HES group （all P〈0.05 vs. control）. At 72 h, the elevated MDSCs in PBNCs were presented in the HTS and HES groups, and in spleen the augment turned up in three resuscitation groups （all P〈0.05 vs. control）. The inclined ratios to M-MDSC were exhibited in spleen of the NS and HTS groups, and in PBNCs of the NS group; the inclination to G-MDSC in BMNCs was shown in the HES group （all P〈0.05 vs. control）. Conclusions： HTS induces the earlier ele- vation of MDSCs in peripheral blood and spleen, and influences its distribution and differentiation, while HES has a less effect on the distribution but a stronger impact on the differentiation of MDSCs, especially in bone marrow.展开更多
The kinetics of mesophase formation of a thermotropic hydroxyethyl cellulose acetate from isotropic phase to cholesteric mesophase has been studied by means of depolarizing transmittance method. Avrami type analysis o...The kinetics of mesophase formation of a thermotropic hydroxyethyl cellulose acetate from isotropic phase to cholesteric mesophase has been studied by means of depolarizing transmittance method. Avrami type analysis of the data gives an exponent n close to 1, which suggests the nucleation followed by rod-like growth. It means that the kinetic behavior of phase transition from isotropic to cholesteric mesophase is very similar to that of the mesophase formation from isotropic to nematic mesophase.展开更多
The thermal behavior of thermotropic hydroxyethyl cellulose acetate (HECA)/polyethylene (PE) blends has been studied by DSC. It is found that the blends of HECA and PE are immiscible but the crystallization of PE is a...The thermal behavior of thermotropic hydroxyethyl cellulose acetate (HECA)/polyethylene (PE) blends has been studied by DSC. It is found that the blends of HECA and PE are immiscible but the crystallization of PE is affected by HECA chains in the blends with more than 50% HECA, which results in the subordinate crystallization of PE and the formation of imperfect structures in the PE crystals. The imperfection of PE crystals in the blends can be eliminated after annealing at 393K.展开更多
The position and quantity of the hydroxyethyl groups in hydroxyethyl starch (HES) were studied by GC/MS and NMR. Quantitative characterization was carried out based on the results of both methods.
Environmentally friendly biocomposites were prepared by blending wheat gluten（WG）as a matrix, hydroxyethyl cellulose（HEC）as a filler,and glycerol as a plasticizer,followed by thermo-molding of the mixture at 120&#...Environmentally friendly biocomposites were prepared by blending wheat gluten（WG）as a matrix, hydroxyethyl cellulose（HEC）as a filler,and glycerol as a plasticizer,followed by thermo-molding of the mixture at 120°C for crosslinking the matrix.Moisture absorption,tensile properties,dynamic mechanical analysis,and dynamic rheology were evaluated in relation to the glycerol content.Tensile strength and modulus drop dramatically with increasing glycerol content,which is accompanied by significant depression in the glass transition temperature and improvement in the extensibility of the biocomposites.展开更多
文摘Nineteen L-N-2-hydroxyethylamino acids and L-N,N-bis(2-hydroxyethyl)amino acids were prepared from the reaction of chlorohydrin with L-alanine,L-valine,L-leucine,L-isoleucine,L- phenylalanine,L-serine,L-thrcunine,L-glutamic acid,L-aspartic acid and glycine.L-N,N,N',N'-tetra (2-hydroxyethyl)cystine was prepared by the reaction of L-cystine with chlorohydrin.
基金Project supported by the National Natural Science Foundation of China(U2002215)。
文摘To solve the problems of the long development period,low mass transfer efficiency and high impurity conte nt in the in-situ leaching process of weathe red crust elution-deposited rare earth ores(WCE-DREO),cationic hydroxyethyl cellulose(PQ-10)was composited with conventional leaching agent ammonium sulfate((NH_(4))_(2)SO_(4))to form a novel composite leaching agent.The effects of PQ-10 concentration,leaching temperature and leaching flow rate of the composite leaching agent on the leaching kinetics and mass transfer processes of rare earth(RE)and aluminum(Al)were investigated.Compared to the single leaching agent(NH_(4))_(2)SO_(4),the composite leaching agent(2 wt%(NH_(4))_(2)SO_(4)+0.02 wt%PQ-10)can reduce the RE leaching equilibrium time from 465 to 130 min and increase the RE leaching efficiency and decrease the Al leaching efficiency.It also facilitates the leaching process of WCE-DREO by increasing the peak concentrations of RE and Al,reducing the theoretical tower plate height(HETP)and improving the leaching mass transfer efficiency.It is indicated that PQ-10 can promote the leaching of WCE-DREO.The leaching process of the composite leaching system conforms to the diffusion kinetic control model.When the PQ-10 concentration is in the range of 0.005 wt%-0.020 wt%,the reaction orders of RE and Al are 0.73 and 0.54,respectively,which shows a positive effect on the leaching velocity;when the PQ-10 concentration is in the range of 0.030 wt%-0.060 wt%,the reaction orders of RE and Al are-1.16 and-0.75,respectively,which show a negative effect on the leaching velocity.In the range of 10-50℃,the apparent activation energies of RE and Al are 15.02 and 17.31 kJ/mol,respectively,and the higher the leaching temperature,the smaller the HETP and the higher the leaching velocity and mass transfer efficiency.The increase in leaching flow rate contributes to the increase in the longitudinal diffusion velocity of the leaching agent within WCE-DREO,causing a shorter time for RE and Al to reach leaching equilibrium.In addition,the flow rate and HETP are consistent with the Van Deemter equation.At a flow rate of 0.8 mL/min,HETP was minimized and the optimal mass transfer efficiencies is achieved for RE and Al.
基金research conducted with the financial support of Science Foundation Ireland under the SFI Research Infrastructure Programme (21/RI/9831)the funding provided by the Irish Research Council through the Irish Research Council Enterprise Partnership Scheme with Johnson and Johnson (EPSPG/2020/78)
文摘Tissue engineering(TE)continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue regeneration.In this study,we developed a poly(2-hydroxyethyl methacrylate-co-methacrylic acid)(pHEMA-co-MAA)based hydrogel loaded with newly synthesized conductive poly(3,4-ethylene-dioxythiophene)(PEDOT)and polypyrrole(PPy)nanoparticles(NPs),and subsequently processed these hydrogels into tissue engineered constructs via three-dimensional(3D)printing.The presence of the NPs was critical as they altered the rheological properties during printing.However,all samples exhibited suitable shear thinning properties,allowing for the development of an optimized processing window for 3D printing.Samples were 3D printed into pre-determined disk-shaped configurations of 2 and 10 mm in height and diameter,respectively.We observed that the NPs disrupted the gel crosslinking efficiencies,leading to shorter degradation times and compressive mechanical properties ranging between 450 and 550 kPa.The conductivity of the printed hydrogels increased along with the NP concentration to(5.10±0.37)×10^(−7)S/cm.In vitro studies with cortical astrocyte cell cultures demonstrated that exposure to the pHEMA-co-MAA NP hydrogels yielded high cellular viability and proliferation rates.Finally,hydrogel antimicrobial studies with staphylococcus epidermidis bacteria revealed that the developed hydrogels affected bacterial growth.Taken together,these materials show promise for various TE strategies.
基金This work was financially supported by grants from the National Research and Development Program of China(2020YFA0211200,2020YFA0710700)the National Science Foundation of China(82172757)+2 种基金the Program for HUST Academic Frontier Youth Team(2018QYTD01)the HCP Program for HUSTthe Opening fund of Hubei Key Laboratory of Bioinorganic Chemistry&Materia Medica(No.BCMM202302).
文摘Photodynamic therapy(PDT)can produce high levels of reactive oxygen species(ROS)to kill tumor cells and induce antitumor immunity.However,intracellular antioxidant systems,including glutathione(GSH)system and thioredoxin(Trx)system,limit the accumulation of ROS,resulting in compromised PDT and insufficient immune stimulation.Herein,we designed a nanomedicine PtHPs co-loading photosensitizer pyropheophorbide a(PPa)and cisplatin prodrug Pt-COOH(Ⅳ)(Pt(Ⅳ))based on hydroxyethyl starch(HES)to inhibit both GSH and Trx antioxidant systems and achieve potent PDT as well as antitumor immune responses.Specifically,HES-PPa and HES-Pt were obtained by coupling HES with PPa and Pt(Ⅳ),and assembled into nanoparticle PtHPs by emulsification method to achieve the purpose of co-delivery of PPa and Pt(Ⅳ).PtHPs improved PPa photostability while retaining PPa photodynamic properties.In vitro experiments showed that PtHPs reduced GSH,inhibited Trx system and had better cell-killing effect and ROS generation ability.Subcutaneous tumormodels showed that PtHPs had good safety and tumor inhibition effect.Bilateral tumor models suggested that PtHPs promoted the release of damage-associated molecular patterns and the maturation of dendritic cells,induced T cell-mediated immune responses,and thus suppressed the growth of both primary and distal tumors.This study reports a novel platinum-based nanomedicine and provides a newstrategy for boosting PDT therapy-mediated antitumor immunity by overcoming intrinsic antioxidant systems.
基金supported by the National Natural Science Foundation of China(31901257 and 32071706)School-Level Research Projects of the Yancheng Institute of Technology(xjr2019008).
文摘Dehydroabietyl polyethylene glycol glycidyl ether-grafted hydroxyethyl cellulose(HEC)polymer surfactant(DA(EO)5GE-g-HEC)was prepared using ring-opening polymerization with biobased rosin and hydroxyethyl cellulose as feedstocks.Dehydroabietyl polyethylene glycol glycidyl ether(DA(EO)5GE)was formed by condensation of dehydroabietyl alcohol polyoxyethylene ether(Rosin derivative:DA(EO)5H)and epichlorohydrin.The grafting degree of DA(EO)5GE-g-HEC was manipulated by adjusting the mass ratio of HEC and DA(EO)5GE and confirmed by EA.According to the formula,when m(HEC)/m(DA(EO)2GE)was 1:1~1:5,the grafting rate of DA(EO)5GE in DA(EO)5GE-g-HEC varied from 34.43%to 38.33%.The surface activity and foam properties of DA(EO)5GE-g-HEC aqueous solution were studied.The results showed that with the increase in grafting rate,the critical micellar concentration(CMC)in aqueous solution changed from 1.28 to 0.96 g/L.The results of the thermogravimetric analysis showed that the temperature range of the main stage of mass loss of DA(EO)5GE-g-HEC was 310°C~410°C,and the thermal decomposition processes of the samples with five mass ratios were similar.An oil in water emulsion was prepared by choosing cyclohexane as the oil phase and DA(EO)5GE-g-HEC as the emulsifier.The effect of DA(EO)5GE-g-HEC mass fraction on emulsion particle size and stability was analyzed.The results suggested that when the oil-water ratio was 8:2 with 0.4%emulsifier,the emulsion droplets were the smallest in terms of particle size and were the most stable.The rheological test results showed that the apparent viscosity decreased with the increase in shear rate and showed a typical elastic gel phenomenon.
基金This work was supported by the National Natural Science Foundation of China (No. 20074025), the Area of Excellence(AoE) on Plant and Fungal Biotechnology Project of the Hong Kong SAR Government and Key Laboratory of Cellulose andLignocellulosic Chemistry of Chinese Academy of Sciences.
文摘A new solvent of cellulose (1.5 mol/L NaOH/0.5 mol/L urea aqueous solution) was used as one of the homogeneous reaction media of polysaccharides for methylation, hydroxyethylation and hydroxypropylation. A water insoluble β -(1—>3)-D-glucan, sample PCS3- isolated from fresh sclerotium of Poria cocos was sulfated in dimethyl sulfoxide (Me 2 SO), carboxymethylated in NaOH, isopropanol solution, as well as methylated, hydroxyethylated and hydroxypropylated in the new solvent system, respectively, to obtain five water-soluble derivatives coded as S-PCS3- C- PCS3- M-PCS3- HE-PCS3- and HP-PCS3- Their chemical structure and distribution of substitution were characterized by infrared spectroscopy (IR), elementary analysis (EA), 1 H-NMR, 13 C-NMR, 2D-COSY, 2D-TOCSY and 2D- 1 H-detected 1H 13C HMQC spectra. The results reveal that the relative reactivity of hydroxyl groups of the β -(1-?3)-D-glucan is in the order C-6 > C-4 > C-2 on the whole. The substitution of the samples S-PCS3- C-PCS3- and M-PCS3- occurred mainly at C-6 position and secondly at C-4 and C-2 positions, and that of HE-PCS3- occurred at C-6 and C-4 positions and of HP-PCS3- almost completely occurred at C-6 position. The degrees of substitution (DS) obtained from 13 C-NMR range from 0.23 to 1.27. The water solubility of the derivatives is in the order S-PCS3- >C-PCS3- >M-PCS3- >HE-PCS3- >HP-PCS3- This work provides a novel and nonpolluting process for the methylation, hydroxyethylation and hydroxypropylation of β -(1—>3)-D-glucan.
基金Supported by the National Natural Science Foundation of China(No.212620302 and 0962017)the Natural Science Foundation of Gansu Province(No.1107RJZA263)
文摘The title compound, 2-O-（2-hydroxyethyl）-D-glucose （CsH1607, Mr= 224.21）, has been synthesized and its structure was characterized by using NMR spectrum and X-ray single-crystal diffraction. This molecule crystallizes in the monoclinic system, space group P21, with a = 8.399（17）, b = 6.620（14）, c = 9.81（2） A, β = 115.110（17）°, V= 493.7（18） A3, Z = 2, Dc = 1.508 mg/m3,/1 = 0.13 mm-1, F（O00） = 240, the final R = 0.0464 and wR = 0. l 15 for 152 ] observed reflections （1 〉 2a（I））. X-ray crystal structure analysis revealed that the conformation of the pyranosyl ring existed in a slightly distorted act chair conformation （Cremer-Pople puckering parameters of Q = 0.573（4） A, 0 = 6.7（3）0 and = -5.2（2）°）. The molecule exists as a monomer in the solid state, whose conformation is stabilized via multiple inter- and intramolecular hydrogen bonds.
基金Project(2007168303) supported by Guangdong-Hong Kong Technology Cooperation Funding
文摘Two kinds of UV curable polyurethane acrylate oligomers （PUPA and PUCA） were synthesized via the addition reaction between isophorone diisocyanate （IPDI） and polyethylene glycol monoacrylate （PEA6） or polycaprolactone modified hydroxyethyl acrylate （PCLA2）. The structures of PUPA and PUCA were characterized by Fourier transform infrared spectroscopy （FT-IR）, IH nuclear magnetic resonance （^H NMR）, gel permeation chromatography （GPC） and differential scanning calorimeter （DSC）, and the thermal stability and dynamic mechanical thermal properties of their cured films were measured by thermogravimetric analysis （TGA） and dynamic mechanical analysis （DMA）, respectively. The viscosity of the oligomers and mechanical properties of the cured films were also studied. The results show that both oligomers have narrow molecular weight distribution. The viscosity of PUPA is 2.310 Pa.s at 25 ℃, while that of PUCA is： up to 3.980 Pa-s. The UV cured PUPA and PUCA films have homogeneous phase structure, and the PUCA film shows higher glass transition temperature and storage modulus. Furthermore, the PUCA film possesses better mechanical properties than PUPA, while the latter shows better alkali resistance.
基金supported by the National Key Technology R&D Program of the Ministry of Science and Technology(2013BAB01B02)
文摘Hydroxyethyl chitosan （HE-chitosan） is a water-soluble derivative of chitosan with many apparent biological properties. For example, it is non-toxic and rapidly biodegradable. Moreover, HE-chitosan has advantages in water-solubility, moisture retention and gelling property due to its hydroxyethyl group. However, the biocompatibility and biodegradability of this multifimctional de- rivative have rarely been documented although they are critical for its application in biomedical and clinical treatments. The purpose of this work was to evaluate the biosafety of HE-chitosan, and draw important clues for its diverse applications. HE-chitosan was synthesized and characterized its chemical structure with FTIR. Its molecular weight （Mw） was determined by gel permeation chro- matography （GPC）, and its deacetylation degree （DD） was investigated through potentiometric analysis. The cytotoxicity of HE-chitosan on mouse fibroblast cell L929 was tested. The biocompatibility and biodegradability of HE-chitosan in rat and rabbit were evaluated. The FTIR results indicated that the hydroxyethyl groups were linked to C6 of chitosan. The GPC analysis confirmed that its Mw was about 90.01 kDa. It was also demonstrated that HE-chitosan had excellent biocompatibility and biodegradability in vivo and had no cytotoxicity on L929. These findings indicated that HE-chitosan can potentially be applied as a biomaterial in tissue engineering, drug delivery, and other biomedical fields.
基金This work was supported by the National Natural Science Foundation of China(No.21675017)State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products(KF20190108)the National Key Research and Development Program of China(No.2017YFC1702001).And we thanked Prof.Yueqing Li for the synthesis of the isoflavone derivatives and useful discussions。
文摘In this paper,we present a 3D printed tumor spheroidal model suitable for drug discovery.This model is based on a hydroxyethyl cellulose/alginate/gelatin(HCSG)composite biomaterial that has three distinct properties:(1)the HCSG is similar to the commercial basement membrane extract in Ki67,MUC1,and PARP1 expressions of MCF-7 cells for embedding culture;(2)the HCSG is printable at room temperature;and(3)the HCSG can be large-scale manufactured at an ultralow cost.We printed a 3D MCF-7 spheroid model with HCSG and characterized it in terms of cell viability,spheroid size,key protein expression,and mitochondrial metabolic activity.We used the 3D MCF-7 spheroid model to evaluate the anti-breast cancer activity of 13 amino acid-based flavone phosphoramidates and found that the alanine structure induced a stronger drug resistance,whereas phenylalanine hardly caused drug resistance in the MCF-7 cells.This is the first time that 3D bioprinting technology has been used in a structure–activity relationship study.
文摘The thermal decomposition process was studied by the TG–DTA analyzer. The results show that the decomposition process of sodium hydroxyethyl sulfonate consisted of three stages: the mass loss for the first, the second and third stages may be about the groups of CH_3CH_2OH, CH_3CHO and SO_2 volatilized, respectively. The decomposition residuum of three stages was analyzed by FT-IR, and the results of FT-IR agreed with the decomposition process predicted by theoretical weight loss. The specific heat capacity of sodium hydroxyethyl sulfonate was determined by differential scanning calorimetry(DSC). The melting temperature and melting enthalpy were obtained to be 465.41 K and 25.69 kJ·mol^(-1), respectively. The molar specific heat capacity of sodium hydroxyethyl sulfonate was determinated from 310.15 K to 365.15 K and expressed as a function of temperature.
文摘The semi-continuous seeded emulsion eopolymerization of vinyl acetate and butyl acrylate was carried out with hydroxyethyl cellulose as a colloid stabilizer. The morphology of the latex particle and the relationship between the reaction time and the average particle diameter and/or the conversion ratio during the polymerization were invstiguted. The experimental results shaw that the morphology of the latex particle possesses the stable sterie construction. In the seeded polymerizution, the average particle diameter of latex decreased while the conversion ratio increased. At the second term of the emulsion copolymerization （the growth stage of particle size）, the latex particle average diameter increased with copolymerization continuously, but the instantaneous conversation ratio was not large, so it was very necessaO to properly prolong the time during the holding temperature stage.
文摘BACKGROUND Accidental dural puncture(ADP)and subsequent post-dural puncture headache(PDPH)remain common complications of epidural procedures for obstetric anesthesia and analgesia.No clear consensus exists on the best way to prevent PDPH after ADP.CASE SUMMARY We report our findings in twenty parturients who underwent an incorporated strategy of epidural analgesia followed by epidural hydroxyethyl starch(HES)to prevent PDPH after ADP with a 16-gauge Tuohy needle during epidural procedures.ADP with a 16-gauge Tuohy needle occurred in nine parturients undergoing a cesarean section(CS)and in eleven parturients receiving labor analgesia.An epidural catheter was re-sited at the same or adjacent intervertebral space in all patients.After CS,the epidural catheter was used for postoperative pain relief over a 48-h period.After delivery in eleven cases,epidural infusion was maintained for 24 h.Thereafter,15 mL of 6%HES 130/0.4 was administered via the epidural catheter immediately prior to catheter removal.None of the parturients developed PDPH or neurologic deficits over a follow-up period of at least two months to up to one year postpartum.CONCLUSION An incorporated strategy of epidural analgesia followed by epidural hydroxyethyl starch may have great efficacy in preventing PDPH after ADP.
基金Project supported by the National Natural Science Foundation of China(No.81272075)
文摘Objective： To investigate the distribution and differentiation of myeloid-derived suppressor cells （MDSCs） in hemorrhagic shock mice, which are resuscitated with normal saline （NS）, hypertonic saline （HTS）, and hydroxyethyl starch （HES）. Methods： BALB/c mice were randomly divided into control, NS, HTS, and HES resuscitation groups. Three subgroups （n=8） in each resuscitation group were marked as 2, 24, and 72 h. Flow cytometry was used to detect the MDSCs, monocytic MDSCs （M-MDSCs）, and granulocytic/neutrophilic MDSCs （G-MDSCs） in peripheral blood nucleated cells （PBNCs）, spleen single-cell suspension, and bone marrow nucleated cells （BMNCs）. Results： The MDSCs in BMNCs among three resuscitation groups were lower 2 h after shock, in PBNCs of the HTS group were higher, and in spleen of the NS group were lower （all P〈0.05 vs. control）. The M-MDSC/G-MDSC ratios in PBNCs of the HTS and HES groups were lower （both ,P〈0.05 vs. control）. At 24 h, the MDSCs in PBNCs of the NS and HTS groups were higher, while the spleen MDSCs in the HTS group were higher （all P〈0.05 vs. control）. The M-MDSC/ G-MDSC ratios were all less in PBNCs, spleen, and BMNCs of the NS and HTS groups, and were lower in BMNCs of the HES group （all P〈0.05 vs. control）. At 72 h, the elevated MDSCs in PBNCs were presented in the HTS and HES groups, and in spleen the augment turned up in three resuscitation groups （all P〈0.05 vs. control）. The inclined ratios to M-MDSC were exhibited in spleen of the NS and HTS groups, and in PBNCs of the NS group; the inclination to G-MDSC in BMNCs was shown in the HES group （all P〈0.05 vs. control）. Conclusions： HTS induces the earlier ele- vation of MDSCs in peripheral blood and spleen, and influences its distribution and differentiation, while HES has a less effect on the distribution but a stronger impact on the differentiation of MDSCs, especially in bone marrow.
基金This work supported by the National Basic Research Project-Macromolecular Condensed State
文摘The kinetics of mesophase formation of a thermotropic hydroxyethyl cellulose acetate from isotropic phase to cholesteric mesophase has been studied by means of depolarizing transmittance method. Avrami type analysis of the data gives an exponent n close to 1, which suggests the nucleation followed by rod-like growth. It means that the kinetic behavior of phase transition from isotropic to cholesteric mesophase is very similar to that of the mesophase formation from isotropic to nematic mesophase.
文摘The thermal behavior of thermotropic hydroxyethyl cellulose acetate (HECA)/polyethylene (PE) blends has been studied by DSC. It is found that the blends of HECA and PE are immiscible but the crystallization of PE is affected by HECA chains in the blends with more than 50% HECA, which results in the subordinate crystallization of PE and the formation of imperfect structures in the PE crystals. The imperfection of PE crystals in the blends can be eliminated after annealing at 393K.
文摘The position and quantity of the hydroxyethyl groups in hydroxyethyl starch (HES) were studied by GC/MS and NMR. Quantitative characterization was carried out based on the results of both methods.
基金the National Natural Science Foundation of China(No.50773068).
文摘Environmentally friendly biocomposites were prepared by blending wheat gluten（WG）as a matrix, hydroxyethyl cellulose（HEC）as a filler,and glycerol as a plasticizer,followed by thermo-molding of the mixture at 120°C for crosslinking the matrix.Moisture absorption,tensile properties,dynamic mechanical analysis,and dynamic rheology were evaluated in relation to the glycerol content.Tensile strength and modulus drop dramatically with increasing glycerol content,which is accompanied by significant depression in the glass transition temperature and improvement in the extensibility of the biocomposites.
