The interracial assembly of photo-induced dimerization of atypical anthracene-containing amphiphilic dendron and host-guest interaction with γ-cyclodextrin has been investigated. It has been proved that even without ...The interracial assembly of photo-induced dimerization of atypical anthracene-containing amphiphilic dendron and host-guest interaction with γ-cyclodextrin has been investigated. It has been proved that even without long alkyl chain the amphiphilic dendron could still form stable Langmuir monolayer at the air/water interface. Through the host-guest interaction,γ-cyclodextrin can be used to encapsulate two headgroups of amphiphilic dendron in the antiparallel direction. However, the formed host-guest complex was sensitive to the surface pressure. Slight compression of surface pressure led amphiphilic dendron to reassemble into nanofibers through the strong π-π stacking between headgroups. On the other hand, under in situ irradiation, the amphiphilic dendron was stabilized in the cavity of γ- cyclodextrin through headgroup dimerization and the host-guest complex further irregularly aggregated to nanoparticles. Meanwhile, γ-cyclodextrin, as a silencer, blocked the supramolecular chirality transfer. Our conclusion was demonstrated through UV/vis, FT-IR, CD spectrum and AFM images, respectively.展开更多
A new kind of dendronized poly(methylsiloxane) (3a and 3b) with appendent Fréchet-type poly(aryl ether) dendrons has been synthesized and characterized by GPC, DSC, TGA, fluorescence and UV-Vis spectra.
We show that group actions on many treelike compact spaces are not too complicated dynamically.We first observe that an old argument of Seidler(1990)implies that every action of a topological group G on a regular cont...We show that group actions on many treelike compact spaces are not too complicated dynamically.We first observe that an old argument of Seidler(1990)implies that every action of a topological group G on a regular continuum is null and therefore also tame.As every local dendron is regular,one concludes that every action of G on a local dendron is null.We then use a more direct method to show that every continuous group action of G on a dendron is Rosen thal represent able,hence also tame.Similar resul ts are obtained for median pretrees.As a related result,we show that Helly's selection principle can be extended to bounded monotone sequences defined on median pretrees(for example,dendrons or linearly ordered sets).Finally,we point out some applications of these results to continuous group actions on dendrites.展开更多
Two poly(benzyl ether) dendrons,decorated in their periphery with nitrile groups,were divergently synthesized and fully characterized.Their gelation properties were studied by using scanning electron microscopy(SEM),X...Two poly(benzyl ether) dendrons,decorated in their periphery with nitrile groups,were divergently synthesized and fully characterized.Their gelation properties were studied by using scanning electron microscopy(SEM),X-ray crystal structure analysis and concentration-and temperature-dependent 1 H NMR spectroscopy.It was found that the gelation capability of these dendrons was highly dependent on dendron generation,and the second-generation dendron G 2-CN proved to be highly efficient organogelator despite the lacking of any conventional gelation motifs,such as amides,long alkyl side chains and steroidal groups.The multiple strong-stacking interactions and hydrogen bonding interactions due to the peripheral isophthalonitrile motifs were proved to be the main driving forces to form the self-assembled gel.展开更多
Insulated molecular wires of poly(phenylenevinylene) (PPV) were prepared by wrapping the conjugated backbones with dendrons through a noncovalent approach. It was found that electrostatic interaction between the quate...Insulated molecular wires of poly(phenylenevinylene) (PPV) were prepared by wrapping the conjugated backbones with dendrons through a noncovalent approach. It was found that electrostatic interaction between the quaternary ammonium groups of PPV-1 and the carboxylate moieties in dendrons induced the packing of dendrons along PPV-1 conjugated backbones. Absorption and emission spectroscopic examinations in solution and solid film indicated that the PPV-1 backbones adopted a more planar and isolated conformation in the complexes. Furthermore, interchain interactions in the complexes could be greatly reduced, improving the quantum yield of PPV-1.展开更多
Experimental assessments were made on the anti-HSV-Ⅱ action of 500 herbs by determinations of thevirus inhibition logarithm(VIL).13 highly effectiveherbs (VIL■4.00)were screened cut,providing a ra-tional basis for c...Experimental assessments were made on the anti-HSV-Ⅱ action of 500 herbs by determinations of thevirus inhibition logarithm(VIL).13 highly effectiveherbs (VIL■4.00)were screened cut,providing a ra-tional basis for clinical therapy.Among these effec-tive herbs,10 were aqueous extracts of Artemisiaanomala,Centella asiatica,Epimedium Sagittatum,Hibiscus mutabills,Hosta plantaginea,Hypericumjaponicum,Inula japonica.Mosla punctata,Rhodo-dendron simsii,and Rhus chinenses,while 3 werealcohol extracts of Epimedium Sagittatum,Hypericumjaponicum,and Mosla punctata.展开更多
Cancer cells could be eradicated by promoting generation of excessive intracellular reactive oxygen species(ROS)via emerging nanomedicines.However,tumor heterogeneity and poor penetration of nanomedicines often lead t...Cancer cells could be eradicated by promoting generation of excessive intracellular reactive oxygen species(ROS)via emerging nanomedicines.However,tumor heterogeneity and poor penetration of nanomedicines often lead to diverse levels of ROS production in the tumor site,and ROS at a low level promote tumor cell growth,thus diminishing the therapeutic effect of these nanomedicines.Herein,we construct an amphiphilic and block polymer-dendron conjugate-derived nanomedicine(Lap@pOEGMA-b-p(GFLG-Dendron-Ppa),GFLG-DP/Lap NPs)that incorporates a photosensitizer,Pyropheophorbide a(Ppa),for ROS therapy and Lapatinib(Lap)for molecular targeted therapy.Lap,an epidermal growth factor receptor(EGFR)inhibitor that plays a role in inhibiting cell growth and proliferation,is hypothesized to synergize with ROS therapy for effectively killing cancer cells.Our results suggest that the enzyme-sensitive polymeric conjugate,pOEGMA-b-p(GFLG-Dendron-Ppa)(GFLG-DP),releases in response to cathepsin B(CTSB)after entering the tumor tissue.Dendritic-Ppa has a strong adsorption capacity to tumor cell membranes,which promotes efficient penetration and long-term retention.Lap can also be efficiently delivered to internal tumor cells to play its role due to the increased vesicle activity.Laser irradiation of Ppa-containing tumor cells results in production of intracellular ROS that is sufficient for inducing cell apoptosis.Meanwhile,Lap efficiently inhibits proliferation of remaining viable cells even in deep tumor regions,thus generating a significant synergistic anti-tumor therapeutic effect.This novel strategy can be extended to the development of efficient membrane lipid-based therapies to effectively combat tumors.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21021003 and 50673095)the Basic Research Development Program(Nos.2007CB808005 and 2009CB930802)the Fund of the Chinese Academy of Sciences
文摘The interracial assembly of photo-induced dimerization of atypical anthracene-containing amphiphilic dendron and host-guest interaction with γ-cyclodextrin has been investigated. It has been proved that even without long alkyl chain the amphiphilic dendron could still form stable Langmuir monolayer at the air/water interface. Through the host-guest interaction,γ-cyclodextrin can be used to encapsulate two headgroups of amphiphilic dendron in the antiparallel direction. However, the formed host-guest complex was sensitive to the surface pressure. Slight compression of surface pressure led amphiphilic dendron to reassemble into nanofibers through the strong π-π stacking between headgroups. On the other hand, under in situ irradiation, the amphiphilic dendron was stabilized in the cavity of γ- cyclodextrin through headgroup dimerization and the host-guest complex further irregularly aggregated to nanoparticles. Meanwhile, γ-cyclodextrin, as a silencer, blocked the supramolecular chirality transfer. Our conclusion was demonstrated through UV/vis, FT-IR, CD spectrum and AFM images, respectively.
文摘A new kind of dendronized poly(methylsiloxane) (3a and 3b) with appendent Fréchet-type poly(aryl ether) dendrons has been synthesized and characterized by GPC, DSC, TGA, fluorescence and UV-Vis spectra.
基金supported by the Israel Science Foundation(Grant No.ISF 668/13)
文摘We show that group actions on many treelike compact spaces are not too complicated dynamically.We first observe that an old argument of Seidler(1990)implies that every action of a topological group G on a regular continuum is null and therefore also tame.As every local dendron is regular,one concludes that every action of G on a local dendron is null.We then use a more direct method to show that every continuous group action of G on a dendron is Rosen thal represent able,hence also tame.Similar resul ts are obtained for median pretrees.As a related result,we show that Helly's selection principle can be extended to bounded monotone sequences defined on median pretrees(for example,dendrons or linearly ordered sets).Finally,we point out some applications of these results to continuous group actions on dendrites.
基金supported by the National Natural Science Foundation of China (21074140 and 91027046)Institute of Chemistry,Chinese Academy of Sciences
文摘Two poly(benzyl ether) dendrons,decorated in their periphery with nitrile groups,were divergently synthesized and fully characterized.Their gelation properties were studied by using scanning electron microscopy(SEM),X-ray crystal structure analysis and concentration-and temperature-dependent 1 H NMR spectroscopy.It was found that the gelation capability of these dendrons was highly dependent on dendron generation,and the second-generation dendron G 2-CN proved to be highly efficient organogelator despite the lacking of any conventional gelation motifs,such as amides,long alkyl side chains and steroidal groups.The multiple strong-stacking interactions and hydrogen bonding interactions due to the peripheral isophthalonitrile motifs were proved to be the main driving forces to form the self-assembled gel.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20604013, 20774056, and 50533030)
文摘Insulated molecular wires of poly(phenylenevinylene) (PPV) were prepared by wrapping the conjugated backbones with dendrons through a noncovalent approach. It was found that electrostatic interaction between the quaternary ammonium groups of PPV-1 and the carboxylate moieties in dendrons induced the packing of dendrons along PPV-1 conjugated backbones. Absorption and emission spectroscopic examinations in solution and solid film indicated that the PPV-1 backbones adopted a more planar and isolated conformation in the complexes. Furthermore, interchain interactions in the complexes could be greatly reduced, improving the quantum yield of PPV-1.
文摘Experimental assessments were made on the anti-HSV-Ⅱ action of 500 herbs by determinations of thevirus inhibition logarithm(VIL).13 highly effectiveherbs (VIL■4.00)were screened cut,providing a ra-tional basis for clinical therapy.Among these effec-tive herbs,10 were aqueous extracts of Artemisiaanomala,Centella asiatica,Epimedium Sagittatum,Hibiscus mutabills,Hosta plantaginea,Hypericumjaponicum,Inula japonica.Mosla punctata,Rhodo-dendron simsii,and Rhus chinenses,while 3 werealcohol extracts of Epimedium Sagittatum,Hypericumjaponicum,and Mosla punctata.
基金supported by National Natural Science Foundation of China(52073193,51873120,81621003,52203182,32071284)National Key Research and Development Program of China(2022YFC2009900)+2 种基金1·3·5 Project for Disciplines of Excellence,West China Hospital,Sichuan University(ZYJC21013)Research Funds in West China Hospital of Sichuan University(2020HXBH072)China Postdoctoral Science Foundation(2019TQ0220,2022M712225,2022T150446).
文摘Cancer cells could be eradicated by promoting generation of excessive intracellular reactive oxygen species(ROS)via emerging nanomedicines.However,tumor heterogeneity and poor penetration of nanomedicines often lead to diverse levels of ROS production in the tumor site,and ROS at a low level promote tumor cell growth,thus diminishing the therapeutic effect of these nanomedicines.Herein,we construct an amphiphilic and block polymer-dendron conjugate-derived nanomedicine(Lap@pOEGMA-b-p(GFLG-Dendron-Ppa),GFLG-DP/Lap NPs)that incorporates a photosensitizer,Pyropheophorbide a(Ppa),for ROS therapy and Lapatinib(Lap)for molecular targeted therapy.Lap,an epidermal growth factor receptor(EGFR)inhibitor that plays a role in inhibiting cell growth and proliferation,is hypothesized to synergize with ROS therapy for effectively killing cancer cells.Our results suggest that the enzyme-sensitive polymeric conjugate,pOEGMA-b-p(GFLG-Dendron-Ppa)(GFLG-DP),releases in response to cathepsin B(CTSB)after entering the tumor tissue.Dendritic-Ppa has a strong adsorption capacity to tumor cell membranes,which promotes efficient penetration and long-term retention.Lap can also be efficiently delivered to internal tumor cells to play its role due to the increased vesicle activity.Laser irradiation of Ppa-containing tumor cells results in production of intracellular ROS that is sufficient for inducing cell apoptosis.Meanwhile,Lap efficiently inhibits proliferation of remaining viable cells even in deep tumor regions,thus generating a significant synergistic anti-tumor therapeutic effect.This novel strategy can be extended to the development of efficient membrane lipid-based therapies to effectively combat tumors.
