期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
Dynamically Photocrosslinking of Polypropylene/EPDM Blends as a Thermoplastic Elastomer
1
作者 WANGWei-zhi WUQiang-hua QUBao-jun 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第1期111-113,共3页
The mechanical properties and the crystal morphological structures of the dynamically photocrosslinked polypropylene(PP)/ethylene-propylene-diene terpolymer(EPDM) blends have been studied by means of mechanical tests,... The mechanical properties and the crystal morphological structures of the dynamically photocrosslinked polypropylene(PP)/ethylene-propylene-diene terpolymer(EPDM) blends have been studied by means of mechanical tests, wide-angle X-ray diffraction(WAXD), and differential scanning calorimetry(DSC). The dynamically photocrosslinking of the PP/EPDM blends can improve the mechanical properties considerably, especially the notched Izod impact strength at low temperatures. The data obtained from the mechanical tests show that the notched Izod impact strength of the dynamically photocrosslinked sample with 30% EPDM at -20 ℃ is about six times that of the uncrosslinked sample with the same EPDM component. The results from the gel content, the results of WAXD, and the DSC measurements reveal the enhanced mechanism of the impact strength for the dynamically photocrosslinked PP/EPDM blends as follows: (1) There exists the crosslinking of the EPDM phase in the photocrosslinked PP/EPDM blends; (2) The β-type crystal structure of PP is formed and the content of α-type crystal decreases with increasing the EPDM component; (3) The graft copolymer of PP-g-EPDM is formed at the interface between the PP and EPDM components. All the above changes of the crystal morphological structures are favorable for increasing the compatibility and enhancing the toughness of the PP/EPDM blends at low temperatures. 展开更多
关键词 POLYPROPYLENE Ethylene-propylene-diene terpolymer Dynamical photocrosslinking Structure and properties
下载PDF
A STUDY ON THE DEGRADATION MECHANISM OF PHOTOCROSSLINKING PRODUCTS FORMED BY CYCLIZED POLYISOPRENE-DIAZIDE SYSTEM UNDER THE INFLUENCE OF ALKYL BENZENE SULFONIC ACIDS
2
作者 黄骏廉 孙猛 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1989年第1期23-30,共8页
The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length a... The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length and the concentration of alkyl benzene sulfonic acids on the rate of degradation reaction were discussed. It was found that in the initial stage of degradation, the cyclicity ratio and the average fused ring number did not change considerably, but the percentage of uncyclized parts content varied significantly. The suitable mechanism was supposed. 展开更多
关键词 cyclized polyisoprene diazidocompounds photocrosslink alkyl benzene sulfonic acid DEGRADATION
下载PDF
Protein photocrosslinking reveals dimer of dimers formation on MarR protein in Escherichia coli 被引量:1
3
作者 CHEN Xing HAO ZiYang CHEN Peng R. 《Science China Chemistry》 SCIE EI CAS 2012年第1期106-111,共6页
The multiple antibiotic resistance regulatory protein(MarR) binds to two promoter sites on the marO operator in Escherichia coli.Our study showed that more than one MarR dimer proteins bound to either of its two promo... The multiple antibiotic resistance regulatory protein(MarR) binds to two promoter sites on the marO operator in Escherichia coli.Our study showed that more than one MarR dimer proteins bound to either of its two promoter sites(Site I and Site II),suggesting that MarR might form higher complexes than homodimers when bound to DNA inside E.coli cells.To further verify this hypothesis,we site-specifically incorporated a photocrosslinking probe at the interface between two MarR dimer proteins.Photolysis in living E.coli cells revealed a covalent linkage between the two interdimer subunits of MarR,suggesting that MarR forms dimer of dimers in vivo. 展开更多
关键词 MarR protein antibiotic resistance protein photocrosslinking DNA binding site DIMERIZATION
原文传递
Systematic study on fabrication of hollow poly(vinyl cinnamate)particles by particulate interfacial photocrosslinking
4
作者 Yukiya Kitayama Atsushi Harada 《Aggregate》 2022年第6期128-136,共9页
Hollow polymer particles are widely used in various industries as coatings and thermal insulation materials.The encapsulation capabilities of various functional molecules and/or nanomaterials also provide access to ap... Hollow polymer particles are widely used in various industries as coatings and thermal insulation materials.The encapsulation capabilities of various functional molecules and/or nanomaterials also provide access to applications such as drug delivery,heat storage,and catalysis,as well as self-healing materials.In this study,we successfully fabricated hollow polymer particles from poly(vinyl cinnamate)(PVC)particles using LED light(λ=265 nm)through interfacial photocrosslinking.Furthermore,we systematically studied the effect of various parameters(solid contents of parent particles,photoirradiation time,photoirradiation power,and polymer chain length)on the polymer shell thickness of the hollow PVC particles fabricated by interfacial photocrosslinking.These findings are expected to further promote the use of hollow polymer particles in pharmaceutical and material applications. 展开更多
关键词 interfacial photocrosslinking poly(vinyl cinnamate)
原文传递
3D human nonalcoholic hepatic steatosis and fibrosis models 被引量:5
5
作者 Sushila Maharjan Diana Bonilla +5 位作者 Princy Sindurakar Hongbin Li Wanlu Li Sergio Duarte Ali Zarrinpar Y.Shrike Zhang 《Bio-Design and Manufacturing》 SCIE EI CSCD 2021年第2期157-170,共14页
This study presents a simple and robust three-dimensional human hepatic tissue model to emulate steatotic and fibrotic conditions and provide an in vitro model for drug testing and mechanistic studies.Using a photolit... This study presents a simple and robust three-dimensional human hepatic tissue model to emulate steatotic and fibrotic conditions and provide an in vitro model for drug testing and mechanistic studies.Using a photolithographic biofabrication method with a photomask featuring hexagonal units,liver cells,including a human hepatic cell line(HepG2-C3A)and a human hepatic stellate cell line(LX-2)were embedded in gelatin methacryloyl hydrogel.Hepatic steatosis was induced by supraphysiological concentration of free fatty acids;hepatic fibrosis was induced by transforming growth factor-β1.Induction of steatosis was confirmed by Oil Red O and BODIPY staining and was inhibited with toyocamycin and obeticholic acid.Induction of fibrosis was confirmed by immunostaining for collagen type I and alpha smooth muscle actin and inhibited by rapamycin and curcumin treatment.This model was further preliminarily validated using primary human hepatocytes in a similar setup.These constructs provide a viable,biologically relevant,and higher throughput model of hepatic steatosis and fibrosis and may facilitate the study of the mechanisms of disease and testing of liver-directed drugs. 展开更多
关键词 Nonalcoholic fatty liver disease(NAFLD) Gelatin methacryloyl(GelMA) photocrosslinking STEATOSIS
下载PDF
The Photochemical Study of HSA and BSA with Resonance Light Scattering and Fluorescence Spectra 被引量:4
6
作者 Liang, H Shen, XC +1 位作者 Li, F Jiang, ZL 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第3期251-254,共4页
The resonance light-scattering (RLS) of human serum albumin (HSA) and bovine serum albumin (BSA) is reported for the first time, and applied to study photochemical reaction of HSA and BSA. The fact of photocrosslinkin... The resonance light-scattering (RLS) of human serum albumin (HSA) and bovine serum albumin (BSA) is reported for the first time, and applied to study photochemical reaction of HSA and BSA. The fact of photocrosslinking self-association effect in HSA and BSA solutions is identified by the enhancement of RLS. The fluorescence quenching at about 350 nm and 700 nm proves that tryptophan (Trp) residues are one of the photochemical activity sites in HSA and BSA molecules. The Rayleigh scattering (RS) spectra of HSA and BSA that were neglected in fluorescence spectra before are found at about 296 nm, 592 nm and 888 nm for the first time, and are of adventageous to studying the aggregation of HSA or BSA. The possible photochemical reaction mechanism is also proposed. 展开更多
关键词 photochemical reaction photocrosslinking self-association effect resonance light-scattering serum albumin
下载PDF
RECENT DEVELOPMENTS IN PHOTOINITIATED CROSSLINKING OF POLYETHYLENE AND ITS INDUSTRIAL APPLICATIONS 被引量:3
7
作者 翟保钧 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2001年第2期189-207,共19页
The recent developments in the photoinitiated cross-linking of polyethylene and the significant breakthrough of its industrial application are reviewed. The enhanced photo-initiation system, the dynamics of photoiniti... The recent developments in the photoinitiated cross-linking of polyethylene and the significant breakthrough of its industrial application are reviewed. The enhanced photo-initiation system, the dynamics of photoinitiated crosslinking, the optimum conditions, the crystal morphological structures and related properties, and the photo- and thermo-oxidation stability of photocrosslinked polyethylene (XLPE) materials have been elucidated systematically. A new technique for producing photocrosslinked XLPE-insulated wire and cable is described in detail. It can be expected that the future applications of photocrosslinking technique of polyolefins will be very promising. 展开更多
关键词 POLYETHYLENE enhanced photocrosslinking systems morphological structures and properties photo- and thermooxidation stability photocrosslinked XLPE insulated wire and cable
下载PDF
PREPARATION AND PHOTOSENSITIVITY OF WATER SOLUBLE PHENOLIC RESINS CONTAINING ACRYLOYL AND QUATERNARY AMMONIUM CHLORIDE GROUPS 被引量:2
8
作者 谭晓明 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2002年第2期129-136,共8页
New water soluble and photocrosslinkable prepolymers containing acrylate and quaternary ammonium salt groups were synthesized from epoxy phenolic resin via ring-opening reaction with acrylic acid and with aqueous solu... New water soluble and photocrosslinkable prepolymers containing acrylate and quaternary ammonium salt groups were synthesized from epoxy phenolic resin via ring-opening reaction with acrylic acid and with aqueous solution of triethylamine hydrochloride successively. The second reaction needs no phase transfer catalyst to accelerate, since the product formed can act as a phase transfer catalyst. The prepolymer obtained contains both photocrosslinkable acrylate groups and hydrophilic quaternary ammonium salt groups. Optimum conditions for these reactions were studied. The photosensitivity of the prepolymer was also investigated. The effects of different photoinitiators, different crosslinkable diluent monomers and amine accelerator on the photosensitivity of the prepolymer were compared. The photoinitiator of hydrogen abstraction type is still effective without using amine or alcohol as accelerator, because the prepolymer contains a H beside the OH groups formed in the ring-opening reactions. 展开更多
关键词 photosensitive polymer photocrosslinking water soluble polymer epoxy phenolic resin quaternary ammonium salt
下载PDF
PHOTOINITIATED CROSSLINKING OF EPDM/INORGANIC FILLER BLENDS AND CHARACTERIZATION OF RELATED PROPERTIES 被引量:1
9
作者 瞿保钧 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2010年第1期119-127,共9页
Photoinitiated crosslinking of ethylene-propylene-diene terpolymer (EPDM) blends filled with calcium carbonate, talc and calcined kaolin (CK) in the presence of benzil dimethyl ketal as photoinitiator and trimethy... Photoinitiated crosslinking of ethylene-propylene-diene terpolymer (EPDM) blends filled with calcium carbonate, talc and calcined kaolin (CK) in the presence of benzil dimethyl ketal as photoinitiator and trimethylolpropane triacrylate as crosslinker and their related properties have been studied by different analytical methods, The results from gel content and heat extension determination show that the efficiency ofphotocrosslinking of EPDM increases with increasing the content of diene and its molecular weight. The EPDM blends with 100 phr different inorganic fillers can be photocrosslinked to gel content of above 60% by 5 s UV-irradiation under optimum conditions. Under the same conditions of irradiation, the orders of photocrosslinking rate and final gel content are EPDM/CaCO3 〉 EPDM/talc 〉 EPDM/CK. The data from thermogravimetric analysis, dynamic mechanical thermal analysis, electrical properties, mechanical tests and scanning electron microscopy show that UV irradiation crosslinking apparently enhances the thermal stability, mechanical properties and electrical properties of the photocrosslinked EPDM/inorganic filler samples. Although the attenuated total-reflection FTIR data show that inorganic fillers can promote the surface photo-oxidation of EPDM/inorganic filler samples with increasing the irradiation time, the above related properties of the photocrosslinked EPDM blends irradiated within 5 s are enough to satisfy many applications in the cable industry. 展开更多
关键词 photocrosslinking Ethylene-propylene-diene terpolymer Inorganic filler Benzil dimethyl ketal Trimethylolpropane triacrylate.
下载PDF
REACTION MECHANISM OF BENZOPHENONE-PHOTOINITIATED CROSSLINKING OF POLYETHYLENE
10
作者 Bao-jun Qu State Key Laboratory of Fire Science and Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 China 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2002年第4期291-307,共17页
The radical intermediates, the crosslink microstructures, and the reaction mechanism of benzophenone (BP)-photoinitiated crosslinking of low-density polyethylene (LDPE) and model compounds (MD) have been reviewed in d... The radical intermediates, the crosslink microstructures, and the reaction mechanism of benzophenone (BP)-photoinitiated crosslinking of low-density polyethylene (LDPE) and model compounds (MD) have been reviewed in detail. The spin-trapping electron spin resonance (ESR) spectra obtained from the LDPE/BP systems with spin-trap agents show that two kinds of polymer radical intermediates are mainly formed: tertiary carbon and secondary carbon radicals. The spin-trapping ESR studies of MD/BP systems give further evidence that photocrosslinking reactions of PE predominantly take place a sites of tertiary carbon, secondary carbon, and especially allylic carbon when available. The high resolution C-13-NMR spectra obtained from LDPE and MD systems show that the crosslink microstructures have H- and Y-type links and that their concentrations are of the same order. The fluorescence, ESR, C-13 and H-1-NMR spectra from the PE and MD systems demonstrate that the main photoreduction product of BP (PPB) is benzpinacol formed by the recombination of two diphenylhydroxymethyl (K-.) radical intermediates. Two new PPB products: an isomer of benzpinacol with quinoid structure, 1-phenylhydroxymethylene-4-diphenylhydroxymethyl-2,5-cyclobexadiene and three kinds of alpha-alkyl-benzhydrols have been detected and identified. These results provide new experimental evidence for elucidating the reaction mechanism in the BP-photoinitiated crosslinking of polyethylene. 展开更多
关键词 photocrosslinking mechanism polymer radical intermediates crosslink microstructures photolytic products of benzophenone POLYETHYLENE model compound
下载PDF
KINETICS AND MECHANISM OF PHOTOINDUCED POLYMERIZATION BY α,α-DIMETHOXY-α-PHENYL ACETOPHENONE
11
作者 汪秀智 李妙贞 +1 位作者 常志英 王尔(钅监) 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1993年第1期26-30,共5页
α,α-dimethoxy-α-Phenyl acetophenone (DMPA) is an efficient and thermally stable photoinitiator. Here its spectral characteristics in the transient state were shown. The transient species were identified as a benzoy... α,α-dimethoxy-α-Phenyl acetophenone (DMPA) is an efficient and thermally stable photoinitiator. Here its spectral characteristics in the transient state were shown. The transient species were identified as a benzoyl radical and a dimethoxyi benzyl radical that played a primary initiation role in polymerization. The kinetics and mechanism of the bulk polymerization of MMA were investigated. The exponent of DMPA concentration and k_p/k_1^(1/2) value were found to be 0.5 and 0.066 mol(-1/2)l^(1/2)s^(-1/2), respectively. The existence of oxygen led to obtain the polymer with higher molecular weight, which can be attributed to the occurrence of the subsequent polymerization induced by active polymer end group. In the photocrosslinking reaction, the dependence of DMPA content on initial rate has been found. A principal reason is that the sample contained higher percentage of DMPA has higher light-absorbed efficiency. In solid film, higher concentration of DMPA is permitted to be used because there is little excited state self-quenching effect in the rigid medium. 展开更多
关键词 α α- dimethoxy-α-phenyl acetophenone Photoinduced polymerization Transient spectroscopy Photocrosslink.
下载PDF
Biomimetic microchannel network with functional endothelium formed by sacrificial electrospun fibers inside 3D gelatin methacryloyl(GelMA)hydrogel models
12
作者 Haoyu SUN Haiyang MA +6 位作者 Li WANG Yang LIU Tian HOU Wenjie TANG Qing YU Meiwen AN Meiling WEN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2024年第1期79-96,共18页
Three-dimensional(3D)hydrogel models play a crucial role in tissue engineering for promoting tissue regeneration.A biomimetic microchannel network system in the 3D hydrogel model is necessary for optimal cellular func... Three-dimensional(3D)hydrogel models play a crucial role in tissue engineering for promoting tissue regeneration.A biomimetic microchannel network system in the 3D hydrogel model is necessary for optimal cellular function.This report describes the preparation of a biomimetic hydrogel scaffold with an internal microchannel network,using electrospinning techniques and the sacrificial template method for 3D cell culture.Microchannels and cavities were created within the gelatin methacryloyl(GelMA)hydrogel by sacrificing polyvinyl alcohol(PVA)electrospun fibers(>10µm),resulting in the creation of microvessel-like channels.Mechanical characterizations,swelling properties,and biodegradation analysis were conducted to investigate the feasibility of a biomimetic microchannel network hydrogel scaffold for 3D cell culture applications.Compared to pure GelMA hydrogel,the hydrogel with microchannels promoted cell proliferation,adhesion,and endothelial tube formation.Moreover,the results confirmed that the biomimetic microchannel network scaffold had a major impact on the distribution and arrangement of human umbilical vein endothelial cells(HUVECs)and can enable the formation of artificial microvasculature by the culture of HUVECs and cell media perfusion. 展开更多
关键词 Biomimetic scaffold photocrosslinking Microchannel network Tissue engineering Artificial microvascular
原文传递
MMP-2 and upconverted UV dual-mediated drug sequential delivery and on-site immobilization for enhanced multidrugresistant cancer therapy
13
作者 Anna Wang Jing Fang +7 位作者 Yali Feng Yuqi Zhang Yan Zhao Jiachen Li Chaoxiang Cui Yi Hou Haibin Shi Mingyuan Gao 《Science China Chemistry》 SCIE EI CAS CSCD 2023年第8期2317-2328,共12页
Controlled drug delivery holds great potential for effective tumor treatment owing to the merits of overcoming drug resistance and improving therapeutic efficacy while minimizing systemic toxicity.However,accurate and... Controlled drug delivery holds great potential for effective tumor treatment owing to the merits of overcoming drug resistance and improving therapeutic efficacy while minimizing systemic toxicity.However,accurate and controllable delivery of chemotherapeutics into tumor tissue with high efficiency remains a huge challenge.Taking advantage of the UV-emitting characteristics of upconversion nanoparticles(UCNPs),herein we for the first time report an MMP-2 enzyme and near infrared(NIR)dual-mediated sequential drug delivery and in-situ immobilization(ENDDI)system that is fabricated by decorating UCNPs with MMP-2 responsive and photocrosslinkable peptide bearing anticancer drug doxorubicin(DOX)for overcoming multidrug resistance.Upon cleavage with tumor-specific MMP-2,the peptide fragment containing a photolabile benzophenone(BP)and DOX could be released and in-situ immobilized within the tumor through the covalent crosslinking reaction between BP and neighboring biomolecules under the excitation of converted UVemission from UCNPs,which remarkably blocks the exocytosis of DOX leading to prolonged drug retention,achieving significant suppression of DOX-resistant breast tumors.Our current dual stimuli-mediated sequential drug delivery and in-situ immobilization represent a generalizable strategy for the effective treatment of multidrug resistant tumors. 展开更多
关键词 upconversion nanoparticles photocrosslinking drug delivery in situ immobilization multidrug resistance
原文传递
Quick photofabrication of functional nanospheres from de novo designed peptides for NIR fluorescence and MR imaging
14
作者 Jingyi Zhao Chen Li +11 位作者 Xue-Wang Gao Ke Feng Hao Liu Sijie He Wenhua Zhao Shumin Yang Jianqun Shao Ling Ye Bin Chen Nan Xie Chen-Ho Tung Li-Zhu Wu 《Nano Research》 SCIE EI CSCD 2023年第3期4029-4038,共10页
Combining the noncovalent and covalent interactions,a series of peptide amphiphiles were designed de novo and synthesized to architect functional assemblies by means of photochemistry.The strand of peptide sequence wa... Combining the noncovalent and covalent interactions,a series of peptide amphiphiles were designed de novo and synthesized to architect functional assemblies by means of photochemistry.The strand of peptide sequence was structurally capped with photoactive tyrosine-tyrosine(YY)motifs at both termini,and the spacing was filled by alternating of hydrophilic D(L-aspartate)and hydrophobic X(ε-aminocaproic acid)structure.Upon visible-light irradiation,these de novo designed peptides underwent rapid photocrosslinking within merely 10 min.Interestingly,the modulation of alternating D-X pairs in occupying spacer would adjust molecular amphiphilicity,regulate charge distribution,and control particle size and loading capacity of peptide nanospheres(PNS)in aqueous media.With entirely peptide-based matrix,this PNS system could host cationic indicators of fluorescent rhodamine and magnetic GdIII for exemplar near infrared(NIR)fluorescence and magnetic resonance(MR)imaging,which paves a pathway to biomaterial and biomedical applications using de novo designed peptides. 展开更多
关键词 synthetic peptide photocrosslinking de novo design encapsulable nanosphere imaging nanoprobe DITYROSINE
原文传递
Application of photocrosslinkable hydrogels based on photolithography 3D bioprinting technology in bone tissue engineering 被引量:3
15
作者 Jianpeng Gao Xiao Liu +6 位作者 Junyao Cheng Junhao Deng Zhenchuan Han Ming Li Xiumei Wang Jianheng Liu Licheng Zhang 《Regenerative Biomaterials》 SCIE EI CSCD 2023年第1期904-918,共15页
Bone tissue engineering(BTE)has been proven to be an effective method for the treatment of bone defects caused by different musculoskeletal disorders.Photocrosslinkable hydrogels(PCHs)with good biocompatibility and bi... Bone tissue engineering(BTE)has been proven to be an effective method for the treatment of bone defects caused by different musculoskeletal disorders.Photocrosslinkable hydrogels(PCHs)with good biocompatibility and biodegradability can significantly promote the migration,proliferation and differentiation of cells and have been widely used in BTE.Moreover,photolithography 3D bioprinting technology can notably help PCHs-based scaffolds possess a biomimetic structure of natural bone,meeting the structural requirements of bone regeneration.Nanomaterials,cells,drugs and cytokines added into bioinks can enable different functionalization strategies for scaffolds to achieve the desired properties required for BTE.In this review,we demonstrate a brief introduction of the advantages of PCHs and photolithography-based 3D bioprinting technology and summarize their applications in BTE.Finally,the challenges and potential future approaches for bone defects are outlined. 展开更多
关键词 photocrosslinkable hydrogels photolithography 3D bioprinting bone tissue engineering bone regeneration bone defect
原文传递
Photocrosslinkable Col/PCL/Mg composite membrane providing spatiotemporal maintenance and positive osteogenetic effects during guided bone regeneration 被引量:3
16
作者 Feilong Wang Dandan Xia +9 位作者 Siyi Wang Ranli Gu Fan Yang Xiao Zhao Xuenan Liu Yuan Zhu Hao Liu Yongxiang Xu Yunsong Liu Yongsheng Zhou 《Bioactive Materials》 SCIE 2022年第7期53-63,共11页
Guided bone regeneration membranes have been effectively applied in oral implantology to repair bone defects.However,typical resorbable membranes composed of collagen(Col)have insufficient mechanical properties and hi... Guided bone regeneration membranes have been effectively applied in oral implantology to repair bone defects.However,typical resorbable membranes composed of collagen(Col)have insufficient mechanical properties and high degradation rate,while non-resorbable membranes need secondary surgery.Herein,we designed a photocrosslinkable collagen/polycaprolactone methacryloyl/magnesium(Col/PCLMA/Mg)composite membrane that provided spatiotemporal support effect after photocrosslinking.Magnesium particles were added to the PCLMA solution and Col/PCLMA and Col/PCLMA/Mg membranes were developed;Col membranes and PCL membranes were used as controls.After photocrosslinking,an interpenetrating polymer network was observed by scanning electron microscopy(SEM)in Col/PCL and Col/PCL/Mg membranes.The elastic modulus,swelling behavior,cytotoxicity,cell attachment,and cell proliferation of the membranes were evaluated.Degradation behavior in vivo and in vitro was monitored according to mass change and by SEM.The membranes were implanted into calvarial bone defects of rats for 8 weeks.The Col/PCL and Col/PCL/Mg membranes displayed much higher elastic modulus(p<0.05),and a lower swelling rate(p<0.05),than Col membranes,and there were no differences in cell biocompatibility among groups(p>0.05).The Col/PCL and Col/PCL/Mg membranes had lower degradation rates than the Col membranes,both in vivo and in vitro(p<0.05).The Col/PCL/Mg groups showed enhanced osteogenic capability compared with the Col groups at week 8(p<0.05).The Col/PCL/Mg composite membrane represents a new strategy to display space maintenance and enhance osteogenic potential,which meets clinical needs. 展开更多
关键词 Guided bone regeneration Magnesium photocrosslinking Polycaprolactone methacryloyl COLLAGEN
原文传递
In situ sol-gel synthesis of hyaluronan derivatives bio-nanocomposite hydrogels 被引量:1
17
作者 U.D’Amora A.Ronca +5 位作者 M.G.Raucci S.M.Dozio H.Lin Y.Fan X.Zhang L.Ambrosio 《Regenerative Biomaterials》 SCIE 2019年第5期249-258,共10页
The main driving idea of the present study was the comparison between two different chemical modifications of hyaluronic acid(HA)followed by the development of nanocomposite hydrogels directly in situ by biomineraliza... The main driving idea of the present study was the comparison between two different chemical modifications of hyaluronic acid(HA)followed by the development of nanocomposite hydrogels directly in situ by biomineralization of photocrosslinkable HA polymers through sol-gel synthesis.In this way,it has been possible to overcome some limitations due to classical approaches based on the physical blending of inorganic fillers into polymer matrix.To this aim,methacrylated and maleated HA,synthesized with similar degree of substitution(DS)were compared in terms of mechanical and physico-chemical properties.The success of in situ biomineralization was highlighted by reflect Fourier transform infrared spectroscopy and thermogravimetric analysis.Furthermore,mechanical characterization demonstrated the reinforcing effect of inorganic fillers evidencing a strong correlation with DS.The swelling behavior resulted to be correlated with filler concentration.Finally,the cytotoxicity tests revealed the absence of toxic components and an increase of cell proliferation over culture time was observed,highlighting these bio-nanocomposite hyaluronan derivatives as biocompatible hydrogel with tunable properties. 展开更多
关键词 hyaluronic acid derivatives photocrosslinking SOL-GEL NANOCOMPOSITES
原文传递
Photocrosslinkable Polynorbornene-based Block Copolymers with Enhanced Dielectric and Thermal Properties 被引量:1
18
作者 hui-jing han sha zhang +3 位作者 ru-yi sun jian-hua wu 谢美然 廖小娟 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2016年第3期378-389,共12页
Block copolymers poly(endo-N-3,5-bis(trifluoromethyl)biphenyl-norbornene-pyrrolidine)-block-poly(exo-N-(cinnamoyloxyethyl)-7-oxanorborn-5-ene-2,3-dicarboximide)(endo-PTNP-b-exo-PCONBI) and poly(exo-N-3,5-bi... Block copolymers poly(endo-N-3,5-bis(trifluoromethyl)biphenyl-norbornene-pyrrolidine)-block-poly(exo-N-(cinnamoyloxyethyl)-7-oxanorborn-5-ene-2,3-dicarboximide)(endo-PTNP-b-exo-PCONBI) and poly(exo-N-3,5-bis(trifluoromethyl)biphenyl-norbornene-pyrrolidine)-block-poly(exo-N-(cinnamoyloxyethyl)-7-oxanorborn-5-ene-2,3-dicarboximide)(exo-PTNP-b-exo-PCONBI) were synthesized by ring-opening metathesis polymerization. The endo- or exoPTNP served as the high dielectric functional chain, and exo-PCONBI acted as the crosslinking segment. The endo-PTNPb-exo-PCONBI, in which endo-PTNP has a high content of trans double bond and adopts isotactic configuration, shows a dielectric constant(?) of 15.5, whereas exo-PTNP-b-exo-PCONBI, in which exo-PTNP has 67% trans double bonds and atactic microstructure, displays relatively low ? of 7.1. The cinnamate groups in exo-PCONBI were crosslinked to form three-dimensional network by cycloaddition reaction under UV irradiation. Exposed to UV-light for 10 min, the cinnamate group in polymer films has a crosslinking conversion of 36%, as determined by UV-Vis absorption measurements. By photocrosslinking, the polymer film has an increased ? of 16.6, a dielectric loss of 0.03, an elevated glass-transition temperature of 137 ?C, and an enhanced decomposition temperature of 405 ?C, compared to those of polymer films without irradiation. 展开更多
关键词 ROMP Block copolymer photocrosslinking Thermal stability Dielectric performance
原文传递
POLYETHYLENE CROSSLINKED WITH ULTRAVIOLET LIGHT
19
作者 徐文英 严庆 BENGT RNBY 《Chinese Science Bulletin》 SCIE EI CAS 1991年第2期127-129,共3页
It was first proposed by Oster in 1956 that polyethylene could be crosslinked with ultraviolet fight in the presence of some photosensitizers. But the photocrossfinking method was not used in industry for a long perio... It was first proposed by Oster in 1956 that polyethylene could be crosslinked with ultraviolet fight in the presence of some photosensitizers. But the photocrossfinking method was not used in industry for a long period because the penetration of the light is limited. The recent work done by Rnby et al. is outstanding in the improvement on this method, and it is competitive to the high-energy irradiation method and the thermalchemistry method. Therefore, the photocrosslinking has a promising prospect in application now. This note is a brief introduction to the results about the theoretical analysis and 展开更多
关键词 photocrosslinking CROSSLINKED POLYETHYLENE photostabilization.
原文传递
Bioprinting and regeneration of auricular cartilage using a bioactive bioink based on microporous photocrosslinkable acellular cartilage matrix 被引量:6
20
作者 Litao Jia Yujie Hua +5 位作者 Jinshi Zeng Wenshuai Liu Di Wang Guangdong Zhou Xia Liu Haiyue Jiang 《Bioactive Materials》 SCIE 2022年第10期66-81,共16页
Tissue engineering provides a promising strategy for auricular reconstruction.Although the first international clinical breakthrough of tissue-engineered auricular reconstruction has been realized based on polymer sca... Tissue engineering provides a promising strategy for auricular reconstruction.Although the first international clinical breakthrough of tissue-engineered auricular reconstruction has been realized based on polymer scaffolds,this approach has not been recognized as a clinically available treatment because of its unsatisfactory clinical efficacy.This is mainly since reconstruction constructs easily cause inflammation and deformation.In this study,we present a novel strategy for the development of biological auricle equivalents with precise shapes,low immunogenicity,and excellent mechanics using auricular chondrocytes and a bioactive bioink based on biomimetic microporous methacrylate-modified acellular cartilage matrix(ACMMA)with the assistance of gelatin methacrylate(GelMA),poly(ethylene oxide)(PEO),and polycaprolactone(PCL)by integrating multi-nozzle bioprinting technology.Photocrosslinkable ACMMA is used to emulate the intricacy of the cartilage-specific microenvironment for active cellular behavior,while GelMA,PEO,and PCL are used to balance printability and physical properties for precise structural stability,form the microporous structure for unhindered nutrient exchange,and provide mechanical support for higher shape fidelity,respectively.Finally,mature auricular cartilage-like tissues with high morphological fidelity,excellent elasticity,abundant cartilage lacunae,and cartilage-specific ECM deposition are successfully regenerated in vivo,which provides new opportunities and novel strategies for the fabrication and regeneration of patient-specific auricular cartilage. 展开更多
关键词 3D bioprinting Photocrosslinkable acellular cartilage matrix Bioactive bioink MICROPOROUS Auricular cartilage regeneration
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部