The Experts below are selected from a list of 35697 Experts worldwide ranked by ideXlab platform
Hu Zhang - One of the best experts on this subject based on the ideXlab platform.
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allogeneic primary mesenchymal stem stromal cell aggregates within poly n isopropylacrylamide co acrylic acid hydrogel for osteochondral regeneration
Applied Materials Today, 2020Co-Authors: Jiabin Zhang, Hu Zhang, Ming Zhang, Rongcai Lin, Seonho Yun, Liming Wang, Qingqiang Yao, Andrew C W ZannettinoAbstract:Abstract Osteoarthritis (OA) is an inflammation-related chronic disease that causes progressive degeneration of cartilage, which might even extend to subchondral bones. Due to the unique physiological structural differences between cartilage and subchondral bone, it is challenging to restore the full function of an osteochondral Defect. In this study, a thermosensitive poly(N-isopropylacrylamide-co-acrylic acid) (p(NIPAAm-AA)) hydrogel was used as a carrier for allogeneic primary mesenchymal stem/stromal cells to determine the therapeutic efficacy of the cell-hydrogel hybrid on osteochondral regeneration. At a similar mechanical strength, p(NIPAAm-AA) hydrogel facilitates formation of cell aggregates of allogeneic primary MSCs in situ, while the fibrin hydrogel supports cell binding and the development of a spindle morphology. While the p(NIPAAm-AA) hydrogel did not induce any inflammatory effects, the fibrin hydrogel was found to elicit a pro-inflammatory response. MSC aggregates promotes expression of paracrine signaling-related genes (TGFB1, VEGF, CXCL12, IGF1, BMP2, BMP7, WNT3A, CTNNB1) as well as expression of chondrogenesis-related genes (SOX9, ACAN, and COL2A1) and generation of extracellular matrices (ECMs) (type 2 collagen and glycosaminoglycans) in chondrogenic induction medium. The functional enhancement of paracrine effects by MSC aggregates (i.e. the immunomodulatory effect and the stimulation of stem/progenitor cells homing) and induced differentiation of MSCs might play a synergistic role in the generation of the neo-cartilage and subchondral bone at an osteochondral Defect Site in vivo. Delivery of primary allogeneic MSCs in the context of a thermosensitive p(NIPAAm-AA) hydrogel to an osteochondral Defect Site may be a novel and promising strategy for osteochondral regeneration.
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Allogeneic primary mesenchymal stem/stromal cell aggregates within poly(N-isopropylacrylamide-co-acrylic acid) hydrogel for osteochondral regeneration
'Elsevier BV', 2020Co-Authors: Zhang Jiabin, Zhang Ming, Lin Rongcai, Yun Seonho, Du Yuguang, Wang Liming, Yao Qingqiang, Zannettino Andrew, Hu ZhangAbstract:Osteoarthritis (OA) is an inflammation-related chronic disease that causes progressive degeneration of cartilage, which might even extend to subchondral bones. Due to the unique physiological structural differences between cartilage and subchondral bone, it is challenging to restore the full function of an osteochondral Defect. In this study, a thermosensitive poly(N-isopropylacrylamide-co-acrylic acid) (p(NIPAAm-AA)) hydrogel was used as a carrier for allogeneic primary mesenchymal stem/stromal cells to determine the therapeutic efficacy of the cell-hydrogel hybrid on osteochondral regeneration. At a similar mechanical strength, p(NIPAAm-AA) hydrogel facilitates formation of cell aggregates of allogeneic primary MSCs in situ, while the fibrin hydrogel supports cell binding and the development of a spindle morphology. While the p(NIPAAm-AA) hydrogel did not induce any inflammatory effects, the fibrin hydrogel was found to elicit a pro-inflammatory response. MSC aggregates promotes expression of paracrine signaling-related genes (TGFB1, VEGF, CXCL12, IGF1, BMP2, BM137, WNT3A, CTNNB1) as well as expression of chondrogenesis-related genes (S0X9, ACAN, and COL2A1) and generation of extracellular matrices (ECMs) (type 2 collagen and glycosaminoglycans) in chondrogenic induction medium. The functional enhancement of paracrine effects by MSC aggregates (i.e. the immunomodulatory effect and the stimulation of stem/progenitor cells homing) and induced differentiation of MSCs might play a synergistic role in the generation of the neo-cartilage and subchondral bone at an osteochondral Defect Site in vivo. Delivery of primary allogeneic MSCs in the context of a thermosensitive p(NIPAAm-AA) hydrogel to an osteochondral Defect Site may be a novel and promising strategy for osteochondral regeneration. (C) 2019 Elsevier Ltd. All rights reserved
Yan Alexander Wang - One of the best experts on this subject based on the ideXlab platform.
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Ozonization at the vacancy Defect Site of the single-walled carbon nanotube
Journal of Physical Chemistry B, 2006Co-Authors: Wei Quan Tian, Yan Alexander WangAbstract:The ozonization at the vacancy Defect Site of the single-walled carbon nanotube has been studied by static quantum mechanics and atom-centered density matrix propagation based ab initio molecular dynamics within a two-layered ONIOM approach. Among five different reaction pathways at the vacancy Defect, the reaction involving the unsaturated active carbon atom is the most probable pathway, where ozone undergoes fast dissociation at the active carbon atom at 300 K. Complementary to the experiments, our work provides a microscopic understanding of the ozonization at the vacancy Defect Site of the single-walled carbon nanotube.
R E Smalley - One of the best experts on this subject based on the ideXlab platform.
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surface Defect Site density on single walled carbon nanotubes by titration
Chemical Physics Letters, 2000Co-Authors: Douglas B Mawhinney, Viktor Naumenko, Anya Kuznetsova, John T Yates, R E SmalleyAbstract:Closed end single walled carbon nanotubes (c-SWNT) purified by acidic oxidation have been studied in order to determine the fraction of oxidized carbon Sites present. This has been done by measuring the evolution of CO2(g) and CO(g) on heating to 1273 K. Following a 1273 K treatment, the Defect Sites were titrated repeatedly with O3. The results indicate that ∼5% of the carbon atoms in the c-SWNT samples pretreated to 1273 K are located at Defective Sites, capable of facile oxidation by O3. This high Defect Site density indicates that a significant number of these Sites exist on the graphene walls of the nanotubes.
Wei Quan Tian - One of the best experts on this subject based on the ideXlab platform.
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Ozonization at the vacancy Defect Site of the single-walled carbon nanotube
Journal of Physical Chemistry B, 2006Co-Authors: Wei Quan Tian, Yan Alexander WangAbstract:The ozonization at the vacancy Defect Site of the single-walled carbon nanotube has been studied by static quantum mechanics and atom-centered density matrix propagation based ab initio molecular dynamics within a two-layered ONIOM approach. Among five different reaction pathways at the vacancy Defect, the reaction involving the unsaturated active carbon atom is the most probable pathway, where ozone undergoes fast dissociation at the active carbon atom at 300 K. Complementary to the experiments, our work provides a microscopic understanding of the ozonization at the vacancy Defect Site of the single-walled carbon nanotube.
Douglas B Mawhinney - One of the best experts on this subject based on the ideXlab platform.
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surface Defect Site density on single walled carbon nanotubes by titration
Chemical Physics Letters, 2000Co-Authors: Douglas B Mawhinney, Viktor Naumenko, Anya Kuznetsova, John T Yates, R E SmalleyAbstract:Closed end single walled carbon nanotubes (c-SWNT) purified by acidic oxidation have been studied in order to determine the fraction of oxidized carbon Sites present. This has been done by measuring the evolution of CO2(g) and CO(g) on heating to 1273 K. Following a 1273 K treatment, the Defect Sites were titrated repeatedly with O3. The results indicate that ∼5% of the carbon atoms in the c-SWNT samples pretreated to 1273 K are located at Defective Sites, capable of facile oxidation by O3. This high Defect Site density indicates that a significant number of these Sites exist on the graphene walls of the nanotubes.
