Dendritic mesoporous silica nanoparticles own three-dimensional center-radial channels and hierarchical pores,which endows themselves with super-high specific surface area,extremely large pore volumes,especially acces...Dendritic mesoporous silica nanoparticles own three-dimensional center-radial channels and hierarchical pores,which endows themselves with super-high specific surface area,extremely large pore volumes,especially accessible internal spaces,and so forth.Dissimilar vip species(such as organic groups or metal nanoparticles)could be readily decorated onto the interfaces of the channels and pores,realizing the functionalization of dendritic mesoporous silica nanoparticles for targeted applications.As adsorbents and catalysts,dendritic mesoporous silica nanoparticles-based materials have experienced nonignorable development in CO_(2)capture and catalytic conversion.This comprehensive review provides a critical survey on this pregnant subject,summarizing the designed construction of novel dendritic mesoporous silica nanoparticles-based materials,the involved chemical reactions(such as CO_(2)methanation,dry reforming of CH_(4)),the value-added chemicals from CO_(2)(such as cyclic carbonates,2-oxazolidinones,quinazoline-2,4(1H,3H)-diones),and so on.The adsorptive and catalytic performances have been compared with traditional silica mesoporous materials(such as SBA-15 or MCM-41),and the corresponding reaction mechanisms have been thoroughly revealed.It is sincerely expected that the in-depth discussion could give materials scientists certain inspiration to design brand-new dendritic mesoporous silica nanoparticles-based materials with superior capabilities towards CO_(2)capture,utilization,and storage.展开更多
This work reports a facile and efficient seed-mediated method for the synthesis of dendritic platinum （Pt） nanoparticles （NPs） at low temperatures of 55-60 ℃ in water, using L-ascorbic acid as a reducing agent an...This work reports a facile and efficient seed-mediated method for the synthesis of dendritic platinum （Pt） nanoparticles （NPs） at low temperatures of 55-60 ℃ in water, using L-ascorbic acid as a reducing agent and sodium citrate as a capping agent. It is found that the dendritic Pt NPs （10-150 nm） are composed of tiny Pt nanocrystals, which nucleate and grow through the introduced smaller Pt seeds with diameters of 3-5 nm. Further investigation shows that the dendritic Pt nanostructures display excellent catalytic performance in an aqueous-phase aromatic ketone hydrogenation reaction, including： （i） acetophenone conversion rate of 〉 90%, with smaller dendritic Pt NPs （10-46 nm） offering a higher conversion efficiency; （ii） high chemoselectivity toward carbonyl group （90.6%-91.5%）, e.g., the selectivity to l-phenylethanol is -90.1% with nearly 100% acetophenone conversion for 10 nm dendritic Pt NPs within 60 rain, under mild reaction conditions （20 ℃, 1.5 bar H2 pressure, and 1.5 tool% catalyst）. The high catalytic activity, selectivity and stability of the dendritic Pt nanostructures under the organic solvent-free conditions make them promising for many potential applications in green catalytic conversion of hydrophilic biomass derived compounds.展开更多
Dendritic mesoporous silica nanoparticles(DMSNs)are a new class of solid porous materials used for enzyme immobilization support due to their intrinsic characteristics,including their unique open central-radial struct...Dendritic mesoporous silica nanoparticles(DMSNs)are a new class of solid porous materials used for enzyme immobilization support due to their intrinsic characteristics,including their unique open central-radial structures with large pore channels and their excellent biocompatibility.In this review,we review the recent progress in research on enzyme immobilization using DMSNs with different structures,namely,flower-like DMSNs and tree-branch-like DMSNs.Three DMSN synthesis methods are briefly compared,and the distinct characteristics of the two DMSN types and their effects on the catalytic performance of immobilized enzymes are comprehensively discussed.Possible directions for future research on enzyme immobilization using DMSNs are also proposed.展开更多
Biomaterial based scaffolds for treating large bone defects require excellent biocompatibility and osteoconductivity.Here we report on the fabrication of hydroxyapatite-dendritic mesoporous silica nanoparticles(HA-DMS...Biomaterial based scaffolds for treating large bone defects require excellent biocompatibility and osteoconductivity.Here we report on the fabrication of hydroxyapatite-dendritic mesoporous silica nanoparticles(HA-DMSN)based scaffolds with hierarchical micro-pores(5µm)and nano-pores(6.4 nm),and their application for bone regeneration.The in vitro studies demonstrated good biocompatibility of dissolution extracts,as well as enhanced osteogenic potential indicated by dose-dependent upregulation of bone marker gene expression(osteocalcin gene(OCN),osteopontin gene(OPN),collagen type I alpha 1 gene(CoL1A1),runt-related transcription factor 2 gene(RUNX2),and integrin-binding sialoprotein gene(IBSP)),alkaline phosphatise(ALP)activity,and alizarin red staining.The in vivo studies showed that HA-DMSN scaffolds significantly increased bone formation in a rat cranial bone defect model after 4 weeks healing.Our study provides a simple method to fabricate promising inorganic scaffolds with hierarchical pores for bone tissue engineering.展开更多
Accumulating evidence suggests that the flavone glycoside baicalin has immunomodulatory effects and antitumor potential. However, its weak stability in solution, poor absorption, and low bioavailability limit its clin...Accumulating evidence suggests that the flavone glycoside baicalin has immunomodulatory effects and antitumor potential. However, its weak stability in solution, poor absorption, and low bioavailability limit its clinical application. To overcome these disadvantages, we developed baicalin-loaded poly（lactic-co-glycolic acid） nanoparticles （PLGA-B） of small size. Next, we evaluated the dual function of immunotherapy and chemotherapy for PLGA-B using immune-related cells and tumor cells. Results showed that PLGA-B were spherical, with a particle size -120 nm and narrow size distribution with an excellent polydispersity index of 0.103. In vitro experiments revealed that baicalin and PLGA-B could activate dendritic cells （DCs） to have higher expression of surface marker molecules and costimulatory molecules than those of control cells. Baicalin and PLGA-B could trigger apoptosis in melanoma （B16） cells via cell-cycle arrest at the G2/M phase. These data suggest that PLGA-B have important roles in activating DCs and killing melanoma cells. Our study could lay a foundation for melanoma treatment through a combined strategy of immunotherapy and chemotherapy.展开更多
基金supported by the National Key R&D program of China(2019YFA0706802)National Natural Science Foundation of China(52063029)+2 种基金Natural Science Basic Research Program of Shaanxi(2022JM-200,2021JQ-716)China Postdoctoral Science Foundation(2020M672269)Doctoral Research Program of Yan’an University(YDBK2019-02)
文摘Dendritic mesoporous silica nanoparticles own three-dimensional center-radial channels and hierarchical pores,which endows themselves with super-high specific surface area,extremely large pore volumes,especially accessible internal spaces,and so forth.Dissimilar vip species(such as organic groups or metal nanoparticles)could be readily decorated onto the interfaces of the channels and pores,realizing the functionalization of dendritic mesoporous silica nanoparticles for targeted applications.As adsorbents and catalysts,dendritic mesoporous silica nanoparticles-based materials have experienced nonignorable development in CO_(2)capture and catalytic conversion.This comprehensive review provides a critical survey on this pregnant subject,summarizing the designed construction of novel dendritic mesoporous silica nanoparticles-based materials,the involved chemical reactions(such as CO_(2)methanation,dry reforming of CH_(4)),the value-added chemicals from CO_(2)(such as cyclic carbonates,2-oxazolidinones,quinazoline-2,4(1H,3H)-diones),and so on.The adsorptive and catalytic performances have been compared with traditional silica mesoporous materials(such as SBA-15 or MCM-41),and the corresponding reaction mechanisms have been thoroughly revealed.It is sincerely expected that the in-depth discussion could give materials scientists certain inspiration to design brand-new dendritic mesoporous silica nanoparticles-based materials with superior capabilities towards CO_(2)capture,utilization,and storage.
基金the financial support of the Australian Research Council (ARC) projectsUSyd Early Career Researcher Scheme+2 种基金Major Equipment Schemethe scholarships provided by China Scholarship Council (CSC)the Commonwealth Scientific and Industrial Research Organization (CSIRO) OCE Top-up Scholarship
文摘This work reports a facile and efficient seed-mediated method for the synthesis of dendritic platinum （Pt） nanoparticles （NPs） at low temperatures of 55-60 ℃ in water, using L-ascorbic acid as a reducing agent and sodium citrate as a capping agent. It is found that the dendritic Pt NPs （10-150 nm） are composed of tiny Pt nanocrystals, which nucleate and grow through the introduced smaller Pt seeds with diameters of 3-5 nm. Further investigation shows that the dendritic Pt nanostructures display excellent catalytic performance in an aqueous-phase aromatic ketone hydrogenation reaction, including： （i） acetophenone conversion rate of 〉 90%, with smaller dendritic Pt NPs （10-46 nm） offering a higher conversion efficiency; （ii） high chemoselectivity toward carbonyl group （90.6%-91.5%）, e.g., the selectivity to l-phenylethanol is -90.1% with nearly 100% acetophenone conversion for 10 nm dendritic Pt NPs within 60 rain, under mild reaction conditions （20 ℃, 1.5 bar H2 pressure, and 1.5 tool% catalyst）. The high catalytic activity, selectivity and stability of the dendritic Pt nanostructures under the organic solvent-free conditions make them promising for many potential applications in green catalytic conversion of hydrophilic biomass derived compounds.
基金supported by the National Natural Science Foundation of China(No.22178083)the Natural Science Foundation of Hebei Province(C2019208174 and B2022202014)+1 种基金the S&T Program of Hebei(20372802D,21372804D,and 21372805D)the Natural Science Foundation of Tianjin City(20JCYBJC00530)
文摘Dendritic mesoporous silica nanoparticles(DMSNs)are a new class of solid porous materials used for enzyme immobilization support due to their intrinsic characteristics,including their unique open central-radial structures with large pore channels and their excellent biocompatibility.In this review,we review the recent progress in research on enzyme immobilization using DMSNs with different structures,namely,flower-like DMSNs and tree-branch-like DMSNs.Three DMSN synthesis methods are briefly compared,and the distinct characteristics of the two DMSN types and their effects on the catalytic performance of immobilized enzymes are comprehensively discussed.Possible directions for future research on enzyme immobilization using DMSNs are also proposed.
基金the support from University of Queensland (UQ) Early Career Researcher Grant (No.1717673).
文摘Biomaterial based scaffolds for treating large bone defects require excellent biocompatibility and osteoconductivity.Here we report on the fabrication of hydroxyapatite-dendritic mesoporous silica nanoparticles(HA-DMSN)based scaffolds with hierarchical micro-pores(5µm)and nano-pores(6.4 nm),and their application for bone regeneration.The in vitro studies demonstrated good biocompatibility of dissolution extracts,as well as enhanced osteogenic potential indicated by dose-dependent upregulation of bone marker gene expression(osteocalcin gene(OCN),osteopontin gene(OPN),collagen type I alpha 1 gene(CoL1A1),runt-related transcription factor 2 gene(RUNX2),and integrin-binding sialoprotein gene(IBSP)),alkaline phosphatise(ALP)activity,and alizarin red staining.The in vivo studies showed that HA-DMSN scaffolds significantly increased bone formation in a rat cranial bone defect model after 4 weeks healing.Our study provides a simple method to fabricate promising inorganic scaffolds with hierarchical pores for bone tissue engineering.
基金This work was supported financially by the National Science and Technology Major Project of China （2014ZX09102045- 008）, National Science Foundation of China （21476243 and 81274101）, Fundamental Research Funds for the Central Universities （DL13EA03-03 and 2572016EAJ1）, Natural Science Foundation of Heilongjiang Province （C2015051） and 973 Program （2013CB531500）.
文摘Accumulating evidence suggests that the flavone glycoside baicalin has immunomodulatory effects and antitumor potential. However, its weak stability in solution, poor absorption, and low bioavailability limit its clinical application. To overcome these disadvantages, we developed baicalin-loaded poly（lactic-co-glycolic acid） nanoparticles （PLGA-B） of small size. Next, we evaluated the dual function of immunotherapy and chemotherapy for PLGA-B using immune-related cells and tumor cells. Results showed that PLGA-B were spherical, with a particle size -120 nm and narrow size distribution with an excellent polydispersity index of 0.103. In vitro experiments revealed that baicalin and PLGA-B could activate dendritic cells （DCs） to have higher expression of surface marker molecules and costimulatory molecules than those of control cells. Baicalin and PLGA-B could trigger apoptosis in melanoma （B16） cells via cell-cycle arrest at the G2/M phase. These data suggest that PLGA-B have important roles in activating DCs and killing melanoma cells. Our study could lay a foundation for melanoma treatment through a combined strategy of immunotherapy and chemotherapy.
