A room-temperature electrochemical strategy for hydrogenation(deuteration)and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi_(4)electrode is developed,which includes the hydrogenation of quinoxalin...A room-temperature electrochemical strategy for hydrogenation(deuteration)and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi_(4)electrode is developed,which includes the hydrogenation of quinoxaline using H2O as the hydrogen source with 80%Faradaic efficiency and the reverse dehydrogenation of hydrogen-rich 1,2,3,4-tetrahydroquinoxaline with up to 99%yield and selectivity.The in situ generated active hydrogen atom(H^(*))is plausibly involved in the hydrogenation of quinoxaline,where a consecutive hydrogen radical coupled electron transfer pathway is proposed.Notably,the MoNi_(4)alloy exhibits efficient quinoxaline hydrogenation at an overpotential of only 50 mV,owing to its superior water dissociation ability to provide H^(*)in alkaline media.In situ Raman tests indicate that the Ni^(Ⅱ)/Ni^(Ⅲ)redox couple can promote the dehydrogenation process,representing a promising anodic alternative to low-value oxygen evolution.Impressively,electrocatalytic deuteration is easily achieved with up to 99%deuteration ratios using D2O.This method is capable of producing a series of functionalized hydrogenated and deuterated quinoxalines.展开更多
As a representative of chronic wounds,the long-term high levels of oxidative stress and blood sugar in chronic diabetic wounds lead to serious complications,making them the biggest challenge in the research on wound h...As a representative of chronic wounds,the long-term high levels of oxidative stress and blood sugar in chronic diabetic wounds lead to serious complications,making them the biggest challenge in the research on wound healing.Many edible natural biomaterials rich in terpenes,phenols,and flavonoids can act as efficient antioxidants.In this study,okra extract was selected as the main component of a wound dressing.The okra extracts obtained via different methods comprehensively maintained the bioactivity of multiple molecules.The robust antioxidant properties of okra significantly reduced intracellular reactive oxygen species production,thereby accelerating the wound healing process.The results showed that okra extracts and their hydrogel dressings increased cell migration,angiogenesis,and re-epithelization of the chronic wound area,considerably promoting wound remodeling in diabetic rats.Therefore,okra-based hydrogels are promising candidates for skin regeneration and wider tissue engineering applications.展开更多
Enhancing the active tumor targeting ability and decreasing the clearance of reticuloendothelial system(RES)are important issues for drug delivery systems(DDSs)in cancer therapy.In recent years,cell membrane camouflag...Enhancing the active tumor targeting ability and decreasing the clearance of reticuloendothelial system(RES)are important issues for drug delivery systems(DDSs)in cancer therapy.In recent years,cell membrane camouflage,as one of the biomimetic modification strategies,has shown huge potential.Many natural properties of source cells can be inherited,allowing the DDSs to successfully avoid phagocytosis by macrophages,prolong circulation time,and achieve homologous targeting to lesion tissue.In this study,a cancer cell membrane camouflaged nanoplatform based on gelatin with a typical core-shell structure was developed for cancer chemotherapy.Doxorubicin(DOX)loaded gelatin nanogel(NG@DOX)acted as the inner core,and 4T1(mouse breast carcinoma cell)membrane was set as the outer shell(M-NG@DOX).The M-NG platform enhanced the ability of homologous targeting due to the surface protein of cell membrane being completely retained,which could promote the cell uptake of homotypic cells,avoid phagocytosis by RAW264.7 macrophages,and therefore increase accumulation in tumor tissue.Meanwhile,due to the better controlled drug release capability of M-NG@DOX,premature release of DOX in circulation could be reduced,minimizing side effects in common chemotherapy.As a result,the biomimetic nanoplatform in this study,obtained by a cancer cell membrane camouflaged drug delivery system,efficiently reached desirable tumor elimination,providing a significant strategy for effective targeted therapy and specific carcinoma therapy.展开更多
Though increasing understanding and remarkable clinical successes have been made, enormous challenges remain to be solved in the field of cancer immunotherapy. In this context, biomaterial-based immunomodulatory strat...Though increasing understanding and remarkable clinical successes have been made, enormous challenges remain to be solved in the field of cancer immunotherapy. In this context, biomaterial-based immunomodulatory strategies are being developed to boost antitumor immunity. For the local immunotherapy, macroscale bioma-terial scaffolds with 3D network structures show great superiority in the following aspects: facilitating the encapsulation, localized delivery, and controlled release of immunotherapeutic agents and even immunocytes for more efficient immunomodulation. The concentrating immunomodulation in situ could minimize systemic tox-icities, but still exert abscopal effects to harness the power of overall anticancer immune response for eradicating malignancy. To promote such promising immunotherapies, the design requirements of macroscale 3D scaffolds should comprehensively consider their physicochemical and biological properties, such as porosity, stiffness, surface modification, cargo release kinetics, biocompatibility, biodegradability, and delivery modes. To date, increasing studies have focused on the relationships between these parameters and the biosystems which will guide/assist the 3D biomaterial scaffolds to achieve the desired immunotherapeutic outcomes. In this review, by highlighting some recent achievements, we summarized the latest advances in the development of various 3D scaffolds as niches for cancer immunotherapy. We also discussed opportunities, challenges, current trends, and future perspectives in 3D macroscale biomaterial scaffold-assisted local treatment strategies. More importantly, this review put more efforts to illustrate how the 3D biomaterial systems affect to modulate antitumor immune activities, where we discussed how significant the roles and behaviours of 3D macroscale scaffolds towards in situ cancer immunotherapy in order to direct the design of 3D immunotherapeutic.展开更多
A nonlinear infectious disease model with information-influenced vaccination behavior and contact patterns is proposed in this paper,and the impact of information related to disease prevalence on increasing vaccinatio...A nonlinear infectious disease model with information-influenced vaccination behavior and contact patterns is proposed in this paper,and the impact of information related to disease prevalence on increasing vaccination coverage and reducing disease incidence during the outbreak is considered.First,we perform the analysis for the existence of equilibria and the stability properties of the proposed model.In particular,the geometric approach is used to obtain the sufficient condition which guarantees the global asymptotic stability of the unique endemic equilibrium Ee when the basic reproduction number Ro>1.Second,mathematical derivation combined with numerical simulation shows the existence of the double Hopf bifurcation around Ee.Third,based on the numerical results,it is shown that the information coverage and the average information delay may lead to more complex dynamical behaviors.Finally,the optimal control problem is established with information-infuenced vaccination and treatment as control variables.The corresponding optimal paths are obtained analytically by using Pontryagin's maximum principle,and the applicability and validity of virous intervention strategies for the proposed controls are presented by numerical experiments.展开更多
文摘A room-temperature electrochemical strategy for hydrogenation(deuteration)and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi_(4)electrode is developed,which includes the hydrogenation of quinoxaline using H2O as the hydrogen source with 80%Faradaic efficiency and the reverse dehydrogenation of hydrogen-rich 1,2,3,4-tetrahydroquinoxaline with up to 99%yield and selectivity.The in situ generated active hydrogen atom(H^(*))is plausibly involved in the hydrogenation of quinoxaline,where a consecutive hydrogen radical coupled electron transfer pathway is proposed.Notably,the MoNi_(4)alloy exhibits efficient quinoxaline hydrogenation at an overpotential of only 50 mV,owing to its superior water dissociation ability to provide H^(*)in alkaline media.In situ Raman tests indicate that the Ni^(Ⅱ)/Ni^(Ⅲ)redox couple can promote the dehydrogenation process,representing a promising anodic alternative to low-value oxygen evolution.Impressively,electrocatalytic deuteration is easily achieved with up to 99%deuteration ratios using D2O.This method is capable of producing a series of functionalized hydrogenated and deuterated quinoxalines.
基金Thanks to the following fund projects for their support to this work:National Natural Science Foundation of China(Nos.51973243 and 52173150)International Cooperation and Exchange of the National Natural Science Foundation of China(No.51820105004)Shenzhen Basic Research Project(No.JCYJ20190807155801657).
文摘As a representative of chronic wounds,the long-term high levels of oxidative stress and blood sugar in chronic diabetic wounds lead to serious complications,making them the biggest challenge in the research on wound healing.Many edible natural biomaterials rich in terpenes,phenols,and flavonoids can act as efficient antioxidants.In this study,okra extract was selected as the main component of a wound dressing.The okra extracts obtained via different methods comprehensively maintained the bioactivity of multiple molecules.The robust antioxidant properties of okra significantly reduced intracellular reactive oxygen species production,thereby accelerating the wound healing process.The results showed that okra extracts and their hydrogel dressings increased cell migration,angiogenesis,and re-epithelization of the chronic wound area,considerably promoting wound remodeling in diabetic rats.Therefore,okra-based hydrogels are promising candidates for skin regeneration and wider tissue engineering applications.
基金supported by grants from Science and Technology Program of Guangzhou,China(No.201804010146)Guangzhou Science and Technology Program City-University Joint Funding Project(No.2023A03J0001)。
文摘Enhancing the active tumor targeting ability and decreasing the clearance of reticuloendothelial system(RES)are important issues for drug delivery systems(DDSs)in cancer therapy.In recent years,cell membrane camouflage,as one of the biomimetic modification strategies,has shown huge potential.Many natural properties of source cells can be inherited,allowing the DDSs to successfully avoid phagocytosis by macrophages,prolong circulation time,and achieve homologous targeting to lesion tissue.In this study,a cancer cell membrane camouflaged nanoplatform based on gelatin with a typical core-shell structure was developed for cancer chemotherapy.Doxorubicin(DOX)loaded gelatin nanogel(NG@DOX)acted as the inner core,and 4T1(mouse breast carcinoma cell)membrane was set as the outer shell(M-NG@DOX).The M-NG platform enhanced the ability of homologous targeting due to the surface protein of cell membrane being completely retained,which could promote the cell uptake of homotypic cells,avoid phagocytosis by RAW264.7 macrophages,and therefore increase accumulation in tumor tissue.Meanwhile,due to the better controlled drug release capability of M-NG@DOX,premature release of DOX in circulation could be reduced,minimizing side effects in common chemotherapy.As a result,the biomimetic nanoplatform in this study,obtained by a cancer cell membrane camouflaged drug delivery system,efficiently reached desirable tumor elimination,providing a significant strategy for effective targeted therapy and specific carcinoma therapy.
基金This work was supported by the National Natural Science Foundation of China(51973243 and 52173150)National Science and Technology Major Project of the Ministry of Science and Technology of China(2018ZX10301402)+2 种基金International Cooperation and Exchange of the National Natural Science Foundation of China(51820105004)Guang-dong Innovative and Entrepreneurial Research Team Program(2016ZT06S029)Fundamental Research Funds for the Central Uni-versities(191gzd35).
文摘Though increasing understanding and remarkable clinical successes have been made, enormous challenges remain to be solved in the field of cancer immunotherapy. In this context, biomaterial-based immunomodulatory strategies are being developed to boost antitumor immunity. For the local immunotherapy, macroscale bioma-terial scaffolds with 3D network structures show great superiority in the following aspects: facilitating the encapsulation, localized delivery, and controlled release of immunotherapeutic agents and even immunocytes for more efficient immunomodulation. The concentrating immunomodulation in situ could minimize systemic tox-icities, but still exert abscopal effects to harness the power of overall anticancer immune response for eradicating malignancy. To promote such promising immunotherapies, the design requirements of macroscale 3D scaffolds should comprehensively consider their physicochemical and biological properties, such as porosity, stiffness, surface modification, cargo release kinetics, biocompatibility, biodegradability, and delivery modes. To date, increasing studies have focused on the relationships between these parameters and the biosystems which will guide/assist the 3D biomaterial scaffolds to achieve the desired immunotherapeutic outcomes. In this review, by highlighting some recent achievements, we summarized the latest advances in the development of various 3D scaffolds as niches for cancer immunotherapy. We also discussed opportunities, challenges, current trends, and future perspectives in 3D macroscale biomaterial scaffold-assisted local treatment strategies. More importantly, this review put more efforts to illustrate how the 3D biomaterial systems affect to modulate antitumor immune activities, where we discussed how significant the roles and behaviours of 3D macroscale scaffolds towards in situ cancer immunotherapy in order to direct the design of 3D immunotherapeutic.
文摘A nonlinear infectious disease model with information-influenced vaccination behavior and contact patterns is proposed in this paper,and the impact of information related to disease prevalence on increasing vaccination coverage and reducing disease incidence during the outbreak is considered.First,we perform the analysis for the existence of equilibria and the stability properties of the proposed model.In particular,the geometric approach is used to obtain the sufficient condition which guarantees the global asymptotic stability of the unique endemic equilibrium Ee when the basic reproduction number Ro>1.Second,mathematical derivation combined with numerical simulation shows the existence of the double Hopf bifurcation around Ee.Third,based on the numerical results,it is shown that the information coverage and the average information delay may lead to more complex dynamical behaviors.Finally,the optimal control problem is established with information-infuenced vaccination and treatment as control variables.The corresponding optimal paths are obtained analytically by using Pontryagin's maximum principle,and the applicability and validity of virous intervention strategies for the proposed controls are presented by numerical experiments.
