A novel immunoassay method for methyltestosterone (MT) in serum ovas developed.The antigen of MT (Ag(MT))was synthesized by covalently bonding MT to BSA and raising its antibody (Ab(MT)). Ab(MT) was con.jugated to pol...A novel immunoassay method for methyltestosterone (MT) in serum ovas developed.The antigen of MT (Ag(MT))was synthesized by covalently bonding MT to BSA and raising its antibody (Ab(MT)). Ab(MT) was con.jugated to poly-N-isopropylacrylamide (p-NIPAAm) to form Ab(MT) bound thermally reversible hydrogel p-NIPAAm-Ab((MT) A competitive immunoassay method based on the competition of fluorescein isothiocyanate (FITC) labeled MT antigen (FITC-Ag(MT)) and free MT with limited amount of p-NIPAAm-Ab(MT) was established. The separation in the assay process was achieved by precipitation of the immuno-complex above its critical solution temperature. The detection limit for MT is 50ng/ml. The recoveries of MT from human serum are satisfactory.展开更多
Personalized drugs,as well as disease-specific and condition-dependent drug release,have been highly desired in drug delivery systems for effective and safe therapies.Four-dimensional(4 D)printing,as a newly emerging ...Personalized drugs,as well as disease-specific and condition-dependent drug release,have been highly desired in drug delivery systems for effective and safe therapies.Four-dimensional(4 D)printing,as a newly emerging technique to develop drug capsules,displays unique advantages that can autonomously control drug release according to the actual physiological circumstances.Herein,core-shell structured hydrogel capsules were developed using a multimaterial extrusion-based 4 D printing method,which consists of a model drug as the core and UV cross-linked poly(N-isopropylacrylamide)(PNIPAM)hydrogel as the shell.Owing to the lower critical solution temperature(LCST)-induced shrinking/swelling properties,the prepared PNIPAM hydrogel capsules showed temperature-responsive drug release along with the topography changes in the cross-linked PNIPAM network.The in vitro drug release test confirmed that the PNIPAM hydrogel capsules can autonomously control their drug release behaviors according to changes in ambient temperature.Moreover,the increased shell thickness of these capsules causes an obvious reduction in drug release rate,distinctly indicating that the drug release behavior can be well adjusted by setting the shell thickness of the capsules.The proposed 4 D printing strategy pioneers the paradigm of smart drug release by showing great potential in the smart controlled release of drugs and macromolecular active agents.展开更多
The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytic...The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.展开更多
Multi-bond network（MBN） which contains a single network with hierarchical cross-links is a suggested way to fabricate robust hydrogels. In order to reveal the roles of different cross-links with hierarchical bond en...Multi-bond network（MBN） which contains a single network with hierarchical cross-links is a suggested way to fabricate robust hydrogels. In order to reveal the roles of different cross-links with hierarchical bond energy in the MBN, here we fabricate poly（acrylic acid） physical hydrogels with dual bond network composed of ionic cross-links between carboxylFe3＋ interactions and hydrogen bonds, and compare these dually cross-linked hydrogels with singly and ternarily cross-linked hydrogels. Simple models are employed to predict the tensile property, and the results confirm that the multi-bond network with hierarchical distribution in the bond energy of cross-links endows hydrogel with effective energy-dissipating mechanism. Moreover, the dually cross-linked MBN gels exhibit excellent mechanical properties（tensile strength up to 500 k Pa, elongation at break ~ 2400%） and complete self-healing after being kept at 50 °C for 48 h. The factors on promoting self-healing are deeply explored and the dynamic multi-bonds are regarded to trigger the self-healing along with the mutual diffusion of long polymer chains and ferric ions.展开更多
Electrochemiluminescence(ECL)has attracted considerable interest for many applications such as microscopy,(bio)analysis,light-emitting materials or devices.In this work,we report the fabrication and characterization o...Electrochemiluminescence(ECL)has attracted considerable interest for many applications such as microscopy,(bio)analysis,light-emitting materials or devices.In this work,we report the fabrication and characterization of ECL-active hydrogel films with tunable thickness.The redox films were prepared by electrochemically-assisted radical polymerization by potential cycling of a PBS solution containing the monomer N-isopropylacrylamide,the initiator potassium persulfate,the cross-linker N,N′-methylenebis(acrylamide)and the Ru(bpy)3 monomer.The deposits were easily prepared in a rapid and well-controlled one-step procedure.The resulting homogeneous films are composed of a poly(N-isopropylacrylamide)(pNIPAM)matrix,which incorporates covalently[Ru(bpy)_(3)]^(2+)centers.The thickness and the number of ECL-active sites is tuned by control-ling the number of voltammetric scans.The deposited pNIPAM films are permeable to water-soluble chemicals such as the coreactant tri-n-propylamine(TPrA).The voltammetric characterization shows a continuous increase of the number of redox-active sites.Results indicate that ECL signals are proportional to the number of electrodeposited[Ru(bpy)_(3)]^(2+)centers.Such approach combining ECL and stimuli-responsive hydrogels open exciting prospects for developing new(bio)sensing materials.展开更多
Hydrogels are classical soft and wet materials that have been extensively studied over the past several decades. Recently, with the development of supramolecular science, nanotechnology and precisely synthetic chemist...Hydrogels are classical soft and wet materials that have been extensively studied over the past several decades. Recently, with the development of supramolecular science, nanotechnology and precisely synthetic chemistry, various novel hydrogels have been designed and fabricated, which show emerging applications in tissue engineering, drug delivery, anti-fouling coatings, flexible electronics and soft robotics. Through tailoring their two-dimensional surface structures and three- dimensional networks, unique properties such as ultra-high mechanical strength, responsiveness to various kinds of stimuli, biocompatibility, special wettability and adhesion can be achieved.展开更多
文摘A novel immunoassay method for methyltestosterone (MT) in serum ovas developed.The antigen of MT (Ag(MT))was synthesized by covalently bonding MT to BSA and raising its antibody (Ab(MT)). Ab(MT) was con.jugated to poly-N-isopropylacrylamide (p-NIPAAm) to form Ab(MT) bound thermally reversible hydrogel p-NIPAAm-Ab((MT) A competitive immunoassay method based on the competition of fluorescein isothiocyanate (FITC) labeled MT antigen (FITC-Ag(MT)) and free MT with limited amount of p-NIPAAm-Ab(MT) was established. The separation in the assay process was achieved by precipitation of the immuno-complex above its critical solution temperature. The detection limit for MT is 50ng/ml. The recoveries of MT from human serum are satisfactory.
基金supported by the National Key R&D Program of China(No.2018YFB1105100)。
文摘Personalized drugs,as well as disease-specific and condition-dependent drug release,have been highly desired in drug delivery systems for effective and safe therapies.Four-dimensional(4 D)printing,as a newly emerging technique to develop drug capsules,displays unique advantages that can autonomously control drug release according to the actual physiological circumstances.Herein,core-shell structured hydrogel capsules were developed using a multimaterial extrusion-based 4 D printing method,which consists of a model drug as the core and UV cross-linked poly(N-isopropylacrylamide)(PNIPAM)hydrogel as the shell.Owing to the lower critical solution temperature(LCST)-induced shrinking/swelling properties,the prepared PNIPAM hydrogel capsules showed temperature-responsive drug release along with the topography changes in the cross-linked PNIPAM network.The in vitro drug release test confirmed that the PNIPAM hydrogel capsules can autonomously control their drug release behaviors according to changes in ambient temperature.Moreover,the increased shell thickness of these capsules causes an obvious reduction in drug release rate,distinctly indicating that the drug release behavior can be well adjusted by setting the shell thickness of the capsules.The proposed 4 D printing strategy pioneers the paradigm of smart drug release by showing great potential in the smart controlled release of drugs and macromolecular active agents.
文摘The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.
基金financially supported by the National Natural Science Foundation of China(Nos.51633003 and 21474058)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University(No.LK1404)+1 种基金Tsinghua University Scientific Research Project(No.2014Z22069)State Key Laboratory of Organic-Inorganic Composites,Beijing University of Chemical Technology(No.OIC-201601006)
文摘Multi-bond network（MBN） which contains a single network with hierarchical cross-links is a suggested way to fabricate robust hydrogels. In order to reveal the roles of different cross-links with hierarchical bond energy in the MBN, here we fabricate poly（acrylic acid） physical hydrogels with dual bond network composed of ionic cross-links between carboxylFe3＋ interactions and hydrogen bonds, and compare these dually cross-linked hydrogels with singly and ternarily cross-linked hydrogels. Simple models are employed to predict the tensile property, and the results confirm that the multi-bond network with hierarchical distribution in the bond energy of cross-links endows hydrogel with effective energy-dissipating mechanism. Moreover, the dually cross-linked MBN gels exhibit excellent mechanical properties（tensile strength up to 500 k Pa, elongation at break ~ 2400%） and complete self-healing after being kept at 50 °C for 48 h. The factors on promoting self-healing are deeply explored and the dynamic multi-bonds are regarded to trigger the self-healing along with the mutual diffusion of long polymer chains and ferric ions.
基金supported by the Agence Nationale de la Recherche(NEOCASTIP ANR-15-CE09-0015-03)HL acknowledges the Natural Science Foundations of Jiangsu Province(No.BK20180893).
文摘Electrochemiluminescence(ECL)has attracted considerable interest for many applications such as microscopy,(bio)analysis,light-emitting materials or devices.In this work,we report the fabrication and characterization of ECL-active hydrogel films with tunable thickness.The redox films were prepared by electrochemically-assisted radical polymerization by potential cycling of a PBS solution containing the monomer N-isopropylacrylamide,the initiator potassium persulfate,the cross-linker N,N′-methylenebis(acrylamide)and the Ru(bpy)3 monomer.The deposits were easily prepared in a rapid and well-controlled one-step procedure.The resulting homogeneous films are composed of a poly(N-isopropylacrylamide)(pNIPAM)matrix,which incorporates covalently[Ru(bpy)_(3)]^(2+)centers.The thickness and the number of ECL-active sites is tuned by control-ling the number of voltammetric scans.The deposited pNIPAM films are permeable to water-soluble chemicals such as the coreactant tri-n-propylamine(TPrA).The voltammetric characterization shows a continuous increase of the number of redox-active sites.Results indicate that ECL signals are proportional to the number of electrodeposited[Ru(bpy)_(3)]^(2+)centers.Such approach combining ECL and stimuli-responsive hydrogels open exciting prospects for developing new(bio)sensing materials.
基金supported by the National Key Research and Development Programme of China(2022YFA1404704 and 2020YFA0406104)the National Natural Science Foundation of China(52002168,12022403,11874211,62134009,62121005,and 61735008)+2 种基金Excellent Research Programme of Nanjing University(ZYJH005)the Fundamental Research Funds for the Central Universities(021314380184,021314380208,021314380190,021314380140,and 021314380150)State Key Laboratory of New Textile Materials and Advanced Processing Technologies(Wuhan Textile University,No.FZ2022011).
文摘Hydrogels are classical soft and wet materials that have been extensively studied over the past several decades. Recently, with the development of supramolecular science, nanotechnology and precisely synthetic chemistry, various novel hydrogels have been designed and fabricated, which show emerging applications in tissue engineering, drug delivery, anti-fouling coatings, flexible electronics and soft robotics. Through tailoring their two-dimensional surface structures and three- dimensional networks, unique properties such as ultra-high mechanical strength, responsiveness to various kinds of stimuli, biocompatibility, special wettability and adhesion can be achieved.
