The Experts below are selected from a list of 12021 Experts worldwide ranked by ideXlab platform

R D K Misra - One of the best experts on this subject based on the ideXlab platform.

  • a stimulus responsive magnetic nanoparticle drug carrier magnetite encapsulated by chitosan grafted coPolymer
    Acta Biomaterialia, 2008
    Co-Authors: Q. Yuan, Raghuram Venkatasubramanian, San Hein, R D K Misra
    Abstract:

    Abstract We describe a magnetic nanoparticle drug carrier for controlled drug release that responds to the change in external temperature or pH, with characteristics of longer circulation time and reduced side effects. The novel nanocarrier is characterized by a functionalized magnetite (Fe 3 O 4 ) core that is conjugated with drug via acid-labile hydrazone-bond and encapsulated by the thermosensitive Smart Polymer, chitosan-g-poly( N -isopropylacrylamide-co- N , N -dimethylacrylamide) [chitosan-g-poly(NIPAAm-co-DMAAm)]. The chitosan-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of ∼38 °C, signifying phase transition behavior of the Smart Polymer and enabling its use for triggering on–off mechanisms. The drug release response was appreciably low at a temperature less than the LCST as compared with a temperature above the LCST. In each case, there was an initial rapid drug release, followed by a controlled released in the second stage, especially in a mild acidic buffer solution of pH 5.3. We believe that the drug release occurs via a collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage.

  • a stimulus responsive magnetic nanoparticle drug carrier magnetite encapsulated by chitosan grafted coPolymer
    Acta Biomaterialia, 2008
    Co-Authors: Q. Yuan, San Hein, Rajesh Venkatasubramanian, R D K Misra
    Abstract:

    We describe a magnetic nanoparticle drug carrier for controlled drug release that responds to the change in external temperature or pH, with characteristics of longer circulation time and reduced side effects. The novel nanocarrier is characterized by a functionalized magnetite (Fe(3)O(4)) core that is conjugated with drug via acid-labile hydrazone-bond and encapsulated by the thermosensitive Smart Polymer, chitosan-g-poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) [chitosan-g-poly(NIPAAm-co-DMAAm)]. The chitosan-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of approximately 38 degrees C, signifying phase transition behavior of the Smart Polymer and enabling its use for triggering on-off mechanisms. The drug release response was appreciably low at a temperature less than the LCST as compared with a temperature above the LCST. In each case, there was an initial rapid drug release, followed by a controlled released in the second stage, especially in a mild acidic buffer solution of pH 5.3. We believe that the drug release occurs via a collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage.

  • magnetic drug targeting carrier encapsulated with thermosensitive Smart Polymer core shell nanoparticle carrier and drug release response
    Acta Biomaterialia, 2007
    Co-Authors: Jilin Zhang, R D K Misra
    Abstract:

    Abstract A novel magnetic drug-targeting carrier consisting of magnetic nanoparticles encapsulated with a Smart Polymer with characteristics of controlled drug release is described. The carrier is characterized by functionalized magnetite (Fe3O4) and conjugated therapeutic agent doxorubicin, which is encapsulated with the thermosensitive Polymer, dextran-g-poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) [dextran-g-poly(NIPAAm-co-DMAAm)]. The surface of magnetite nanoparticles was functionalized by chemical bonding with 3-mercaptopropionic acid hydrazide (HSCH2CH2CONHNH2) via Fe–S covalent bonds. The anticancer therapeutic drug, doxorubicin, was attached to the surface of the functionalized magnetic nanoparticles through an acid-labile hydrazone-bond, formed by the reaction of hydrazide group of HSCH2CH2CONHNH2 with the carbonyl group of doxorubicin. The dextran-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of ∼38 °C, which is representative of a phase transition behavior. This behavior allows for an on–off trigger mechanism. At an experimental temperature lower than LCST, the drug release was very low. However, at a temperature greater than LCST, there was an initially rapid drug release followed by a controlled released in the second stage, especially, in the mild acidic buffer solution of pH 5.3. The release of drug is envisaged to occur by the collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage. The proposed carrier is appropriately suitable for magnetic targeting drug delivery system with longer circulation time, reduced side effects and controlled drug release in response to the change in external temperature.

  • magnetic drug targeting carrier encapsulated with thermosensitive Smart Polymer core shell nanoparticle carrier and drug release response
    Acta Biomaterialia, 2007
    Co-Authors: Jilin Zhang, R D K Misra
    Abstract:

    A novel magnetic drug-targeting carrier consisting of magnetic nanoparticles encapsulated with a Smart Polymer with characteristics of controlled drug release is described. The carrier is characterized by functionalized magnetite (Fe(3)O(4)) and conjugated therapeutic agent doxorubicin, which is encapsulated with the thermosensitive Polymer, dextran-g-poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) [dextran-g-poly(NIPAAm-co-DMAAm)]. The surface of magnetite nanoparticles was functionalized by chemical bonding with 3-mercaptopropionic acid hydrazide (HSCH(2)CH(2)CONHNH(2)) via Fe-S covalent bonds. The anticancer therapeutic drug, doxorubicin, was attached to the surface of the functionalized magnetic nanoparticles through an acid-labile hydrazone-bond, formed by the reaction of hydrazide group of HSCH(2)CH(2)CONHNH(2) with the carbonyl group of doxorubicin. The dextran-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of approximately 38 degrees C, which is representative of a phase transition behavior. This behavior allows for an on-off trigger mechanism. At an experimental temperature lower than LCST, the drug release was very low. However, at a temperature greater than LCST, there was an initially rapid drug release followed by a controlled released in the second stage, especially, in the mild acidic buffer solution of pH 5.3. The release of drug is envisaged to occur by the collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage. The proposed carrier is appropriately suitable for magnetic targeting drug delivery system with longer circulation time, reduced side effects and controlled drug release in response to the change in external temperature.

Jilin Zhang - One of the best experts on this subject based on the ideXlab platform.

  • magnetic drug targeting carrier encapsulated with thermosensitive Smart Polymer core shell nanoparticle carrier and drug release response
    Acta Biomaterialia, 2007
    Co-Authors: Jilin Zhang, R D K Misra
    Abstract:

    Abstract A novel magnetic drug-targeting carrier consisting of magnetic nanoparticles encapsulated with a Smart Polymer with characteristics of controlled drug release is described. The carrier is characterized by functionalized magnetite (Fe3O4) and conjugated therapeutic agent doxorubicin, which is encapsulated with the thermosensitive Polymer, dextran-g-poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) [dextran-g-poly(NIPAAm-co-DMAAm)]. The surface of magnetite nanoparticles was functionalized by chemical bonding with 3-mercaptopropionic acid hydrazide (HSCH2CH2CONHNH2) via Fe–S covalent bonds. The anticancer therapeutic drug, doxorubicin, was attached to the surface of the functionalized magnetic nanoparticles through an acid-labile hydrazone-bond, formed by the reaction of hydrazide group of HSCH2CH2CONHNH2 with the carbonyl group of doxorubicin. The dextran-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of ∼38 °C, which is representative of a phase transition behavior. This behavior allows for an on–off trigger mechanism. At an experimental temperature lower than LCST, the drug release was very low. However, at a temperature greater than LCST, there was an initially rapid drug release followed by a controlled released in the second stage, especially, in the mild acidic buffer solution of pH 5.3. The release of drug is envisaged to occur by the collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage. The proposed carrier is appropriately suitable for magnetic targeting drug delivery system with longer circulation time, reduced side effects and controlled drug release in response to the change in external temperature.

  • magnetic drug targeting carrier encapsulated with thermosensitive Smart Polymer core shell nanoparticle carrier and drug release response
    Acta Biomaterialia, 2007
    Co-Authors: Jilin Zhang, R D K Misra
    Abstract:

    A novel magnetic drug-targeting carrier consisting of magnetic nanoparticles encapsulated with a Smart Polymer with characteristics of controlled drug release is described. The carrier is characterized by functionalized magnetite (Fe(3)O(4)) and conjugated therapeutic agent doxorubicin, which is encapsulated with the thermosensitive Polymer, dextran-g-poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) [dextran-g-poly(NIPAAm-co-DMAAm)]. The surface of magnetite nanoparticles was functionalized by chemical bonding with 3-mercaptopropionic acid hydrazide (HSCH(2)CH(2)CONHNH(2)) via Fe-S covalent bonds. The anticancer therapeutic drug, doxorubicin, was attached to the surface of the functionalized magnetic nanoparticles through an acid-labile hydrazone-bond, formed by the reaction of hydrazide group of HSCH(2)CH(2)CONHNH(2) with the carbonyl group of doxorubicin. The dextran-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of approximately 38 degrees C, which is representative of a phase transition behavior. This behavior allows for an on-off trigger mechanism. At an experimental temperature lower than LCST, the drug release was very low. However, at a temperature greater than LCST, there was an initially rapid drug release followed by a controlled released in the second stage, especially, in the mild acidic buffer solution of pH 5.3. The release of drug is envisaged to occur by the collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage. The proposed carrier is appropriately suitable for magnetic targeting drug delivery system with longer circulation time, reduced side effects and controlled drug release in response to the change in external temperature.

Q. Yuan - One of the best experts on this subject based on the ideXlab platform.

  • a stimulus responsive magnetic nanoparticle drug carrier magnetite encapsulated by chitosan grafted coPolymer
    Acta Biomaterialia, 2008
    Co-Authors: Q. Yuan, Raghuram Venkatasubramanian, San Hein, R D K Misra
    Abstract:

    Abstract We describe a magnetic nanoparticle drug carrier for controlled drug release that responds to the change in external temperature or pH, with characteristics of longer circulation time and reduced side effects. The novel nanocarrier is characterized by a functionalized magnetite (Fe 3 O 4 ) core that is conjugated with drug via acid-labile hydrazone-bond and encapsulated by the thermosensitive Smart Polymer, chitosan-g-poly( N -isopropylacrylamide-co- N , N -dimethylacrylamide) [chitosan-g-poly(NIPAAm-co-DMAAm)]. The chitosan-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of ∼38 °C, signifying phase transition behavior of the Smart Polymer and enabling its use for triggering on–off mechanisms. The drug release response was appreciably low at a temperature less than the LCST as compared with a temperature above the LCST. In each case, there was an initial rapid drug release, followed by a controlled released in the second stage, especially in a mild acidic buffer solution of pH 5.3. We believe that the drug release occurs via a collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage.

  • a stimulus responsive magnetic nanoparticle drug carrier magnetite encapsulated by chitosan grafted coPolymer
    Acta Biomaterialia, 2008
    Co-Authors: Q. Yuan, San Hein, Rajesh Venkatasubramanian, R D K Misra
    Abstract:

    We describe a magnetic nanoparticle drug carrier for controlled drug release that responds to the change in external temperature or pH, with characteristics of longer circulation time and reduced side effects. The novel nanocarrier is characterized by a functionalized magnetite (Fe(3)O(4)) core that is conjugated with drug via acid-labile hydrazone-bond and encapsulated by the thermosensitive Smart Polymer, chitosan-g-poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) [chitosan-g-poly(NIPAAm-co-DMAAm)]. The chitosan-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of approximately 38 degrees C, signifying phase transition behavior of the Smart Polymer and enabling its use for triggering on-off mechanisms. The drug release response was appreciably low at a temperature less than the LCST as compared with a temperature above the LCST. In each case, there was an initial rapid drug release, followed by a controlled released in the second stage, especially in a mild acidic buffer solution of pH 5.3. We believe that the drug release occurs via a collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage.

Taolei Sun - One of the best experts on this subject based on the ideXlab platform.

  • hydrogen bond based Smart Polymer for highly selective and tunable capture of multiply phosphorylated peptides
    Nature Communications, 2017
    Co-Authors: Guangyan Qing, Xinmiao Liang, Jing Liu, Taolei Sun
    Abstract:

    Multisite phosphorylation is an important and common mechanism for finely regulating protein functions and subsequent cellular responses. However, this study is largely restricted by the difficulty to capture low-abundance multiply phosphorylated peptides (MPPs) from complex biosamples owing to the limitation of enrichment materials and their interactions with phosphates. Here we show that Smart Polymer can serve as an ideal platform to resolve this challenge. Driven by specific but tunable hydrogen bonding interactions, the Smart Polymer displays differential complexation with MPPs, singly phosphorylated and non-modified peptides. Importantly, MPP binding can be modulated conveniently and precisely by solution conditions, resulting in highly controllable MPP adsorption on material surface. This facilitates excellent performance in MPP enrichment and separation from model proteins and real biosamples. High enrichment selectivity and coverage, extraordinary adsorption capacities and recovery towards MPPs, as well as high discovery rates of unique phosphorylation sites, suggest its great potential in phosphoproteomics studies. Capture of low-abundance multiply phosphorylated peptides (MPPs) is difficult due to limitation of enrichment materials and their interactions with phosphates. Here the authors show, a Smart Polymer driven by specific but tunable hydrogen bonding interactions can differentially complex with MPPs, singly phosphorylated and non-modified peptides.

  • sialic acid responsive Polymeric interface material from molecular recognition to macroscopic property switching
    Scientific Reports, 2017
    Co-Authors: Yuting Xiong, Guangyan Qing, Ge Jiang, Xinmiao Liang, Taolei Sun
    Abstract:

    Biological systems that utilize multiple weak non-covalent interactions and hierarchical assemblies to achieve various bio-functions bring much inspiration for the design of artificial biomaterials. However, it remains a big challenge to correlate underlying biomolecule interactions with macroscopic level of materials, for example, recognizing such weak interaction, further transforming it into regulating material's macroscopic property and contributing to some new bio-applications. Here we designed a novel Smart Polymer based on polyacrylamide (PAM) grafted with lactose units (PAM-g-lactose0.11), and reported carbohydrate-carbohydrate interaction (CCI)-promoted macroscopic properties switching on this Smart Polymer surface. Detailed investigations indicated that the binding of sialic acid molecules with the grafted lactose units via the CCIs induced conformational transformation of the Polymer chains, further resulted in remarkable and reversible switching in surface topography, wettability and stiffness. With these excellent recognition and response capacities towards sialic acid, the PAM-g-lactose0.11 further facilitated good selectivity, strong anti-interference and high adsorption capacity in the capture of sialylated glycopeptides (important biomarkers for cancers). This work provides some enlightenment for the development of biointerface materials with tunable property, as well as high-performance glycopeptide enrichment materials.

  • surface stiffness a parameter for sensing the chirality of saccharides
    ACS Applied Materials & Interfaces, 2015
    Co-Authors: Zhonghui Chen, Taolei Sun, Ji Chen, Cheng Chen, Peng Xiong, Guangyan Qing
    Abstract:

    Surface stiffness is considered a key parameter for designing high-performance implantable materials and artificial extracellular matrices because of its substantial effects on cell behavior. How to transform biomolecule recognition events, particularly chiral recognition, into stiffness change on material surfaces is biologically essential but very challenging for chemists. Here, we report a chirality-triggered stiffness transition on a Smart Polymer film, which consists of flexible polyethylenimine (PEI) main chains grafted with dipeptide units capable of discriminating chiral monosaccharides. The Polymer film became substantially softer after interacting with L-ribose and became more rigid after interacting with D-ribose (the basic building block of DNA and RNA). This chiral effect provides a new method for determining the enantiomeric purity of an L/D-ribose mixture and facilitates the chiral separation of deoxyribose racemates as well as the separation of diverse mono-, di-, and oligosaccharides. These are three puzzle problems in carbohydrate chemistry. Furthermore, taking advantage of the significant differences in the surface stiffness, the proliferation of fibroblast cells on the Polymeric surfaces can also be regulated by chiral biomolecules.

  • CH-π Interaction Driven Macroscopic Property Transition on Smart Polymer Surface.
    Scientific reports, 2015
    Co-Authors: Guangyan Qing, Yuting Xiong, Yuekun Lai, Taolei Sun
    Abstract:

    Life systems have evolved to utilize weak noncovalent interactions, particularly CH-π interaction, to achieve various biofunctions, for example cellular communication, immune response, and protein folding. However, for artificial materials, it remains a great challenge to recognize such weak interaction, further transform it into tunable macroscopic properties and realize special functions. Here we integrate monosaccharide-based CH-π receptor capable of recognizing aromatic peptides into a Smart Polymer with three-component "Recognition-Mediating-Function" design, and report the CH-π interaction driven surface property switching on Smart Polymer film, including wettability, adhesion, viscoelasticity and stiffness. Detailed studies indicate that, the CH-π interaction induces the complexation between saccharide unit and aromatic peptide, which breaks the initial amphiphilic balance of the Polymer network, resulting in contraction-swelling conformational transition for Polymer chains and subsequent dramatic switching in surface properties. This work not only presents a new approach to control the surface property of materials, but also points to a broader research prospect on CH-π interaction at a macroscopic level.

  • Biomimetic Smart interface materials for biological applications
    Advanced Materials, 2011
    Co-Authors: Taolei Sun, Guangyan Qing
    Abstract:

    Controlling the surface chemical and physical properties of materials and modulating the interfacial behaviors of biological entities, e.g., cells and biomolecules, are central tasks in the study of biomaterials. In this context, Smart Polymer interface materials have recently attracted much interest in biorelated applications and have broad prospects due to the excellent controllability of their surface properties by external stimuli. Among such materials, poly(N-isopropylacrylamide) and its coPolymer films are especially attractive due to their reversible hydrogen-bonding-mediated reversible phase transition, which mimics natural biological processes. This platform is promising for tuning surface properties or to introduce novel biofunctionalities via coPolymerization with various functional units and/or combination with other materials. Important progress in this field in recent years is highlighted.

San Hein - One of the best experts on this subject based on the ideXlab platform.

  • a stimulus responsive magnetic nanoparticle drug carrier magnetite encapsulated by chitosan grafted coPolymer
    Acta Biomaterialia, 2008
    Co-Authors: Q. Yuan, Raghuram Venkatasubramanian, San Hein, R D K Misra
    Abstract:

    Abstract We describe a magnetic nanoparticle drug carrier for controlled drug release that responds to the change in external temperature or pH, with characteristics of longer circulation time and reduced side effects. The novel nanocarrier is characterized by a functionalized magnetite (Fe 3 O 4 ) core that is conjugated with drug via acid-labile hydrazone-bond and encapsulated by the thermosensitive Smart Polymer, chitosan-g-poly( N -isopropylacrylamide-co- N , N -dimethylacrylamide) [chitosan-g-poly(NIPAAm-co-DMAAm)]. The chitosan-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of ∼38 °C, signifying phase transition behavior of the Smart Polymer and enabling its use for triggering on–off mechanisms. The drug release response was appreciably low at a temperature less than the LCST as compared with a temperature above the LCST. In each case, there was an initial rapid drug release, followed by a controlled released in the second stage, especially in a mild acidic buffer solution of pH 5.3. We believe that the drug release occurs via a collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage.

  • a stimulus responsive magnetic nanoparticle drug carrier magnetite encapsulated by chitosan grafted coPolymer
    Acta Biomaterialia, 2008
    Co-Authors: Q. Yuan, San Hein, Rajesh Venkatasubramanian, R D K Misra
    Abstract:

    We describe a magnetic nanoparticle drug carrier for controlled drug release that responds to the change in external temperature or pH, with characteristics of longer circulation time and reduced side effects. The novel nanocarrier is characterized by a functionalized magnetite (Fe(3)O(4)) core that is conjugated with drug via acid-labile hydrazone-bond and encapsulated by the thermosensitive Smart Polymer, chitosan-g-poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) [chitosan-g-poly(NIPAAm-co-DMAAm)]. The chitosan-g-poly(NIPAAm-co-DMAAm) Smart Polymer exhibits a lower critical solution temperature (LCST) of approximately 38 degrees C, signifying phase transition behavior of the Smart Polymer and enabling its use for triggering on-off mechanisms. The drug release response was appreciably low at a temperature less than the LCST as compared with a temperature above the LCST. In each case, there was an initial rapid drug release, followed by a controlled released in the second stage, especially in a mild acidic buffer solution of pH 5.3. We believe that the drug release occurs via a collapse of the encapsulated thermosensitive Polymer and cleavage of the acid-labile hydrazone linkage.