Fundamental understanding of the wettability of curved substrates is crucial for the applications of microdroplets in colloidal science, microfluidics, and heat exchanger technologies. Here we report via lattice Boltz...Fundamental understanding of the wettability of curved substrates is crucial for the applications of microdroplets in colloidal science, microfluidics, and heat exchanger technologies. Here we report via lattice Boltzmann simulations and energetic analysis that microdroplets show an ability of transporting selectively to appropriate substrates solely according to substrate shape（curvature）, which is called the substrate-curvature-dependent droplet targeting because of its similarity to protein targeting by which proteins are transported to the appropriate destinations in the cell. Two dynamic pathways of droplet targeting are identified： one is the Ostwald ripening-like liquid transport between separated droplets via evaporating droplets on more curved convex（or less curved concave） surfaces and growing droplets on less curved convex（or more curved concave） surfaces, and the other is the directional motion of a droplet through contacting simultaneously substrates of different curvatures. Then we demonstrate analytically that droplet targeting is a thermodynamically driven process. The driving force for directional motion of droplets is the surface-curvature-induced modulation of the work of adhesion, while the Ostwald ripening-like transport is ascribed to the substrate-curvature-induced change of droplet curvature radius. Our findings of droplet targeting are potentially useful for a tremendous range of applications, such as microfluidics, thermal control, and microfabrication.展开更多
Two-photon photodynamic therapy(TP-PDT)has garnered significant attention because of its excellent depth of tissue penetration and high spatiotemporal selectivity.However,the limited targeting ability and oxygen depen...Two-photon photodynamic therapy(TP-PDT)has garnered significant attention because of its excellent depth of tissue penetration and high spatiotemporal selectivity.However,the limited targeting ability and oxygen dependency of photosensitizers(PSs)significantly hinder the effectiveness of photodynamic therapy in hypoxic tumor treatment.Herein,we designed and synthesized two lipid droplet(LD)-targeted two-photon PSs(TBPCP and TBCP)by reducing benzene rings to achieve“acceptor planarization”.Notably,acceptor planarization not only enhanced the intramolecular charge transfer but also transferred the photochemical reaction from typeⅡ(TBPCP)to typeⅠ(TBCP).Under the irradiation of 940 nm femtosecond pulsed laser,TBPCP and TBCP showed bright two-photon-excited fluorescence and excellent LD targeting in living cells.Comparing TBPCP(typeⅡPS),the outstanding TP-PDT efficacy of TBCP(typeⅠPS)under hypoxic conditions could be obtained in both cellular experiments and multicellular tumor spheroids(MCTS)model.Additionally,both TBPCP and TBCP could induce the lipid peroxidation in the typeⅠor typeⅡPDT due to the location of LD,depleting GSH and inactivating GPX4 to induce nonprogrammed ferroptosis in cells.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.91434204)
文摘Fundamental understanding of the wettability of curved substrates is crucial for the applications of microdroplets in colloidal science, microfluidics, and heat exchanger technologies. Here we report via lattice Boltzmann simulations and energetic analysis that microdroplets show an ability of transporting selectively to appropriate substrates solely according to substrate shape（curvature）, which is called the substrate-curvature-dependent droplet targeting because of its similarity to protein targeting by which proteins are transported to the appropriate destinations in the cell. Two dynamic pathways of droplet targeting are identified： one is the Ostwald ripening-like liquid transport between separated droplets via evaporating droplets on more curved convex（or less curved concave） surfaces and growing droplets on less curved convex（or more curved concave） surfaces, and the other is the directional motion of a droplet through contacting simultaneously substrates of different curvatures. Then we demonstrate analytically that droplet targeting is a thermodynamically driven process. The driving force for directional motion of droplets is the surface-curvature-induced modulation of the work of adhesion, while the Ostwald ripening-like transport is ascribed to the substrate-curvature-induced change of droplet curvature radius. Our findings of droplet targeting are potentially useful for a tremendous range of applications, such as microfluidics, thermal control, and microfabrication.
基金supported by the National Key Research and Development Program of China(2022YFA1207600)the National Natural Science Foundation of China(62375272,62005294)。
文摘Two-photon photodynamic therapy(TP-PDT)has garnered significant attention because of its excellent depth of tissue penetration and high spatiotemporal selectivity.However,the limited targeting ability and oxygen dependency of photosensitizers(PSs)significantly hinder the effectiveness of photodynamic therapy in hypoxic tumor treatment.Herein,we designed and synthesized two lipid droplet(LD)-targeted two-photon PSs(TBPCP and TBCP)by reducing benzene rings to achieve“acceptor planarization”.Notably,acceptor planarization not only enhanced the intramolecular charge transfer but also transferred the photochemical reaction from typeⅡ(TBPCP)to typeⅠ(TBCP).Under the irradiation of 940 nm femtosecond pulsed laser,TBPCP and TBCP showed bright two-photon-excited fluorescence and excellent LD targeting in living cells.Comparing TBPCP(typeⅡPS),the outstanding TP-PDT efficacy of TBCP(typeⅠPS)under hypoxic conditions could be obtained in both cellular experiments and multicellular tumor spheroids(MCTS)model.Additionally,both TBPCP and TBCP could induce the lipid peroxidation in the typeⅠor typeⅡPDT due to the location of LD,depleting GSH and inactivating GPX4 to induce nonprogrammed ferroptosis in cells.
