Plasma protein-induced aggregation of nanoparticles(NPs)is a crucial issue in many applications,such as drug delivery.Although great efforts have been made to inves-tigate the protein adsorption kinetics or protein-in...Plasma protein-induced aggregation of nanoparticles(NPs)is a crucial issue in many applications,such as drug delivery.Although great efforts have been made to inves-tigate the protein adsorption kinetics or protein-induced NPs coalescence in bulk solutions,limited evidence has been uncovered for interfacial circumstances.Diet,disease,medicine,or senility could thoroughly change interfacial physicochemical properties of the inner lining of blood vessels.Implants including stents and artificial heart valves also have varied and evolutionary interfaces.Hence,there is an urgent need to understand the mechanism behind the non-specific protein adsorption and NP-protein aggregation in such interfacial cases.Here,we use evanescent light scat-tering to observe polystyrene NPs‒fibrinogen aggregation at substrates with varying surface properties.A density-fluctuation correlation function is utilized to reveal the relaxation dynamics of the aggregates.Both time-resolved and spatial-correlated evi-dence shows that the aging process of such soft materials is out-of-equilibrium,where the dynamics faster and slower than exponential can coexist in one sin-gle relaxation process.Besides,corona formation,inner stress,and interconnection together determine the microstructure,local adhesion,and structural relaxation of the aggregates,which can further correspond to the protein-to-NP ratio as well as the surface chemistry of NPs and substrates.展开更多
Waterborne polyurethane(WPU)has been widely used as coatings in industrial fields ranging from wood,real/synthetic leather,and textiles,because it exhibits versatile performance,excellent eco-friendliness,and superior...Waterborne polyurethane(WPU)has been widely used as coatings in industrial fields ranging from wood,real/synthetic leather,and textiles,because it exhibits versatile performance,excellent eco-friendliness,and superior film-forming property.In terms of wearable products,compact WPU coatings often cause discomfort due to the intrinsic poor vapor transmission.展开更多
Polymer-coated particles and surfaces have widespread applications in various industries ranging from manufacturing to biomedicine.A better understanding of the stability mechanisms underlying these coatings can inspi...Polymer-coated particles and surfaces have widespread applications in various industries ranging from manufacturing to biomedicine.A better understanding of the stability mechanisms underlying these coatings can inspire the design of novel polymer structures and help tune their functions.This can be achieved by quantifying the particle-particle and particle-surface interactions.This paper reviews several common experimental techniques utilized to measure the interactions between polymer-coated particles and surfaces quantitatively.These techniques include atomic force microscopy(AFM),total internal reflection microscopy(TIRM),optical tweezers(OT),and quartz crystal microbalance with dissipation monitoring(QCM-D).The examples of each measuring technique were categorized based on the types of polymer coatings and their associated factors.Additionally,this review demonstrates experimental measurements of interactions involving biological objects.By understanding the fundamental particle-particle and particle-surface interactions,researchers can gain valuable insights to guide the design and functional optimization of polymer-based materials and systems across various applications.展开更多
Current attempts in vaccine delivery systems concentrate on replicating the natural dissemination of live pathogens,but neglect that pathogens evolve to evade the immune system rather than to provoke it.In the case of...Current attempts in vaccine delivery systems concentrate on replicating the natural dissemination of live pathogens,but neglect that pathogens evolve to evade the immune system rather than to provoke it.In the case of enveloped RNA viruses,it is the natural dissemination of nucleocapsid protein(NP,core antigen)and surface antigen that delays NP exposure to immune surveillance.Here,we report a multi-layered aluminum hydroxide-stabilized emulsion(MASE)to dictate the delivery sequence of the antigens.In this manner,the receptor-binding domain(RBD,surface antigen)of the spike protein was trapped inside the nanocavity,while NP was absorbed on the outside of the droplets,enabling the burst release of NP before RBD.Compared with the natural packaging strategy,the inside-out strategy induced potent type I interferon-mediated innate immune responses and triggered an immune-potentiated environment in advance,which subsequently boosted CD40+DC activations and the engagement of the lymph nodes.In both H1N1 influenza and SARS-CoV-2 vaccines,rMASE significantly increased antigen-specific antibody secretion,memory T cell engagement,and Th1-biased immune response,which diminished viral loads after lethal challenge.By simply reversing the delivery sequence of the surface antigen and core antigen,the inside-out strategy may offer major implications for enhanced vaccinations against the enveloped RNA virus.展开更多
Pickering emulsions have been widely used for biphasic catalysis in the past decade.However,it remains a great challenge to achieve simple product collection and enzyme recovery.Poly(N-isopropylacrylamide)(PNIPAM)-bas...Pickering emulsions have been widely used for biphasic catalysis in the past decade.However,it remains a great challenge to achieve simple product collection and enzyme recovery.Poly(N-isopropylacrylamide)(PNIPAM)-based microgels can endow Pickering emulsions with stimuli-responsiveness,while most microgelstabilized emulsions are oil-in-water(O/W)type and not ideal for interfacial catalysis.Besides,altering temperature or pH value for demulsification is time-and energy-consuming and may cause irreversible deactivation of enzymes.In this work,inverse water-in-oil(W/O)Pickering emulsions were formed using hexanoic acidswollen microgels as the sole emulsifiers.When lipase was added in the water phase,stable oil-in-water-in-oil(O/W/O)Pickering double emulsions could be formed through one-step emulsification,owing to the synergistic effect of the hydrophobic microgels and hydrophilic lipase at the interface.Compared with other biphasic systems,such double emulsion systems represent a desirable platform for highly efficient biodiesel production because of the ultra-high interfacial areas and fast mass transport between two phases.More importantly,the switchable transition between hydrophobicity/hydrophilicity of microgels is controlled by the catalytic reaction.Therefore,double emulsions demulsify spontaneously when substrates are used up without the need for energy input or loss of enzymatic activity,enabling the facile collection of products and demonstrating the excellent recyclability of the biphasic catalysis system.展开更多
Many organic molecules with various functional groups have been used to passivate the perovskite surface for improving the efficiency and stability of perovskite solar cell(PSCs).However,the intrinsic attributes of th...Many organic molecules with various functional groups have been used to passivate the perovskite surface for improving the efficiency and stability of perovskite solar cell(PSCs).However,the intrinsic attributes of the passivation effect based on different chemical bonds are rarely studied.Here,we comparatively investigate the passivation effect among 12 types of functional groups on para-tertbutylbenzene for PSCs and find that the open circuit voltage(VOC) tends to increase with the chemical bonding strength between perovskite and these passivation additive molecules.Particularly,the paratert-butylbenzoic acid(tB-COOH),with the extra intermolecular hydrogen bonding,can stabilize the surface passivation of perovskite films exceptionally well through formation of a crystalline interlayer with water-insoluble property and high melting point.As a result,the tB-COOH device achieves a champion power conversion efficiency(PCE) of 21.46%.More importantly,such devices,which were stored in ambient air with a relative humidity of ~45%,can retain 88% of their initial performance after a testing period of more than 1 year(10,080 h).This work provides a case study to understand chemical bonding effects on passivation of perovskite.展开更多
The phenomenon of adsorption of solid particles at fluid interfaces to stabilize emulsions or foams have been known for more than a century.Today,particle-stabilized emulsions,often referred to as Pickering emulsions,...The phenomenon of adsorption of solid particles at fluid interfaces to stabilize emulsions or foams have been known for more than a century.Today,particle-stabilized emulsions,often referred to as Pickering emulsions,are receiving growing attention as they are encountered in oil recovery and have long been used in personal care products and food industry.Over the past 10 years the focus of the Pickering emulsion has also increasingly shifted to biomedical applications with thanks to novel syntheses of a wide range of biocompatible particle stabilizers.Here,a brief overview of the development of biocompatible particles is given for Pickering emulsion stabilization,including alginate,poly(lactic-co-gIycolic acid)(PLGA),and protein-based particles.The materials prepared by templating from emulsion stabilized with biocompatible particles include colloidal capsules and hierarchically porous materials.It is hoped that the understanding gained from the recent intense activity in the field will enable more researchers to modify existing materials and design new formulations,which would be beneficial for exploring more biological applications.展开更多
Composite biomaterials made of biodegradable polylactic acid （PLA） and bioactive magnesium （Mg） salt are developed for orthopaedic implants or metal implant coatings. The releasing of Mg salt into the biological e...Composite biomaterials made of biodegradable polylactic acid （PLA） and bioactive magnesium （Mg） salt are developed for orthopaedic implants or metal implant coatings. The releasing of Mg salt into the biological environment benefits the bone growth, while with the releasing of Mg salt and degradation of PLA there forms a porous scaffold for tissue engineering. The size and morphology of the salt and voids are adjustable with such preparation conditions as salt content, pH of casting solution, and the solidification rate, so that we can control the salt releasing and degradation rate of PLA. Dielectric spectroscopy is used to investigate the dispersive structures of Mg salt and voids in the polymer matrix and to monitor the in situ releasing of Mg salts in the simulated body fluid （SBF）. The current study provides us with an orthopedic biomaterial with controllable multi-phase structures, and a tool to investigate the in vivo behaviors of biomaterials.展开更多
In a mixture of colloidal particles and polymer molecules, the particles may experience an attractive ＂depletion force＂ if the size of the polymer molecule is larger than the interparticle separation. This is becaus...In a mixture of colloidal particles and polymer molecules, the particles may experience an attractive ＂depletion force＂ if the size of the polymer molecule is larger than the interparticle separation. This is because individual polymer molecules experience less conformational entropy if they stay between the particles than they escape the inter-particle space, which results in an osmotic pressure imbalance inside and outside the gap and leads to interparticle attraction. This depletion force has been the subject of several studies since the 1980s, but the direct measurement of this force is still experimentally challenging as it requires the detection of energy variations of the order of kBT and beyond. We present here our results for applying total internal reflection microscopy （TIRM） to directly measure the interaction between a free-moving particle and a flat surface in solutions consisting of small water-soluble organic molecules or polymeric surfactants. Our results indicate that stable nanobubbles （ca. 150 nm） exist free in the above aqueous solutions. More importantly, the existence of such nanobubbles induces an attraction between the spherical particle and flat surface. Using TIRM, we are able to directly measure such weak interaction with a range up to 100 nm. Furthermore, we demonstrate that by employing thermo^sensitive microgel particles as a depleting agent, we are able to quantitatively measure and reversibly control kBT-scale depletion attraction as function of solution pH.展开更多
Activating the stimulator of interferon genes(STING)signaling pathway is critical for enhancing antitumor immunity and remodeling the immunosuppressive tumor microenvironment(TME).Herein,we report the preparation of S...Activating the stimulator of interferon genes(STING)signaling pathway is critical for enhancing antitumor immunity and remodeling the immunosuppressive tumor microenvironment(TME).Herein,we report the preparation of STING-activating nanoparticles via metal coordination-driven assembly of a synthetic STING agonist(i.e.,SR717)and a chemotherapeutic drug(i.e.,curcumin).After intravenous administration,the assembled nanoparticles could efficiently accumulate in tumors to improve the bioavailability of SR717 and trigger potent STING pathway activation for effective immune responses.Meanwhile,the released curcumin evokes immunogenic cell death in tumors and regulates amino acid metabolism by inhibiting the activation of indoleamine 2,3-dioxygenase 1,leading to the reversal of the immunosuppressive TME.The antitumor immunity induced by nanoparticles significantly inhibits the growth of primary,recurrent,and metastatic tumors.The assembled nanoparticles are promising for the co-delivery of STING agonists and drugs in improved tumor chemo-immunotherapy.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:22303033Fundamental Research Funds for the Central Universities of China,Grant/Award Number:JUSRP123017+2 种基金Wuxi“Taihu Light”Science and Technology Project-Basic Research,Grant/Award Number:K20231063Hong Kong Metropolitan University,Grant/Award Number:RD/2023/2.1Hong Kong Special Administration Region(HKSAR)General Research Fund,Grant/Award Numbers:CUHK14302120,2130704。
文摘Plasma protein-induced aggregation of nanoparticles(NPs)is a crucial issue in many applications,such as drug delivery.Although great efforts have been made to inves-tigate the protein adsorption kinetics or protein-induced NPs coalescence in bulk solutions,limited evidence has been uncovered for interfacial circumstances.Diet,disease,medicine,or senility could thoroughly change interfacial physicochemical properties of the inner lining of blood vessels.Implants including stents and artificial heart valves also have varied and evolutionary interfaces.Hence,there is an urgent need to understand the mechanism behind the non-specific protein adsorption and NP-protein aggregation in such interfacial cases.Here,we use evanescent light scat-tering to observe polystyrene NPs‒fibrinogen aggregation at substrates with varying surface properties.A density-fluctuation correlation function is utilized to reveal the relaxation dynamics of the aggregates.Both time-resolved and spatial-correlated evi-dence shows that the aging process of such soft materials is out-of-equilibrium,where the dynamics faster and slower than exponential can coexist in one sin-gle relaxation process.Besides,corona formation,inner stress,and interconnection together determine the microstructure,local adhesion,and structural relaxation of the aggregates,which can further correspond to the protein-to-NP ratio as well as the surface chemistry of NPs and substrates.
基金supported by the National Natural Science Foundation of China(Grant Nos.22108182,22278277 and 21978177).
文摘Waterborne polyurethane(WPU)has been widely used as coatings in industrial fields ranging from wood,real/synthetic leather,and textiles,because it exhibits versatile performance,excellent eco-friendliness,and superior film-forming property.In terms of wearable products,compact WPU coatings often cause discomfort due to the intrinsic poor vapor transmission.
文摘Polymer-coated particles and surfaces have widespread applications in various industries ranging from manufacturing to biomedicine.A better understanding of the stability mechanisms underlying these coatings can inspire the design of novel polymer structures and help tune their functions.This can be achieved by quantifying the particle-particle and particle-surface interactions.This paper reviews several common experimental techniques utilized to measure the interactions between polymer-coated particles and surfaces quantitatively.These techniques include atomic force microscopy(AFM),total internal reflection microscopy(TIRM),optical tweezers(OT),and quartz crystal microbalance with dissipation monitoring(QCM-D).The examples of each measuring technique were categorized based on the types of polymer coatings and their associated factors.Additionally,this review demonstrates experimental measurements of interactions involving biological objects.By understanding the fundamental particle-particle and particle-surface interactions,researchers can gain valuable insights to guide the design and functional optimization of polymer-based materials and systems across various applications.
基金supported by the National Key Research and Development Program of China(2021YFE020527,2021YFC2302605,2021YFC2300142),"From 0 to 1"Original Innovation Project of Basic Frontier Scientific Research Program of Chinese Academy of Sciences(ZDBS-LY-SLH040)Bejing Nova Program(Z201100006820139)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.21821005)+4 种基金CAS Project for Young Scientists in Basic Research(YSBR-010)the Pilot Project of Chinese Academy of Sciences(Grant No.XDB29040303)The National Natural Science Fund for Outstanding Young Scholar(T2222022)National Natural Science Foundation of China(Grant No.32030062),Youth Innovation Promotion Association of the Chinese Academy of Sciences(NO.2020000053)the foundation of Innovation Academy for Green Manufacture Institute,Chinese Academy of Sciences(Grand No.IAGM2020C30).
文摘Current attempts in vaccine delivery systems concentrate on replicating the natural dissemination of live pathogens,but neglect that pathogens evolve to evade the immune system rather than to provoke it.In the case of enveloped RNA viruses,it is the natural dissemination of nucleocapsid protein(NP,core antigen)and surface antigen that delays NP exposure to immune surveillance.Here,we report a multi-layered aluminum hydroxide-stabilized emulsion(MASE)to dictate the delivery sequence of the antigens.In this manner,the receptor-binding domain(RBD,surface antigen)of the spike protein was trapped inside the nanocavity,while NP was absorbed on the outside of the droplets,enabling the burst release of NP before RBD.Compared with the natural packaging strategy,the inside-out strategy induced potent type I interferon-mediated innate immune responses and triggered an immune-potentiated environment in advance,which subsequently boosted CD40+DC activations and the engagement of the lymph nodes.In both H1N1 influenza and SARS-CoV-2 vaccines,rMASE significantly increased antigen-specific antibody secretion,memory T cell engagement,and Th1-biased immune response,which diminished viral loads after lethal challenge.By simply reversing the delivery sequence of the surface antigen and core antigen,the inside-out strategy may offer major implications for enhanced vaccinations against the enveloped RNA virus.
基金Hong Kong Special Administrative Region(HKSAR)General Research Fund of The Chinese University of Hong Kong,Grant/Award Numbers:CUHK14304619,2130642National Natural Science Foundation of China,Grant/Award Number:32172347Natural Science Foundation of Guangdong Province,Grant/Award Number:2021A1515011000。
文摘Pickering emulsions have been widely used for biphasic catalysis in the past decade.However,it remains a great challenge to achieve simple product collection and enzyme recovery.Poly(N-isopropylacrylamide)(PNIPAM)-based microgels can endow Pickering emulsions with stimuli-responsiveness,while most microgelstabilized emulsions are oil-in-water(O/W)type and not ideal for interfacial catalysis.Besides,altering temperature or pH value for demulsification is time-and energy-consuming and may cause irreversible deactivation of enzymes.In this work,inverse water-in-oil(W/O)Pickering emulsions were formed using hexanoic acidswollen microgels as the sole emulsifiers.When lipase was added in the water phase,stable oil-in-water-in-oil(O/W/O)Pickering double emulsions could be formed through one-step emulsification,owing to the synergistic effect of the hydrophobic microgels and hydrophilic lipase at the interface.Compared with other biphasic systems,such double emulsion systems represent a desirable platform for highly efficient biodiesel production because of the ultra-high interfacial areas and fast mass transport between two phases.More importantly,the switchable transition between hydrophobicity/hydrophilicity of microgels is controlled by the catalytic reaction.Therefore,double emulsions demulsify spontaneously when substrates are used up without the need for energy input or loss of enzymatic activity,enabling the facile collection of products and demonstrating the excellent recyclability of the biphasic catalysis system.
基金supported by the Research Grants Council of Hong Kong (T23-407/13-N)Innovation and Technology Commission (ITS/088/17)+5 种基金Start-up funds from Central Organization Department and South China University of Technologyfund from the Guangdong Science and Technology Program (2020B121201003)the National Natural Science Foundation of China (21776315)Petro China Innovation Foundation (2017D5007-0402)the Pearl River Talent Program (2019ZT08L075, 2019QN01L118)Fundamental Research Funds for the Central Universities (19CX05001A)。
文摘Many organic molecules with various functional groups have been used to passivate the perovskite surface for improving the efficiency and stability of perovskite solar cell(PSCs).However,the intrinsic attributes of the passivation effect based on different chemical bonds are rarely studied.Here,we comparatively investigate the passivation effect among 12 types of functional groups on para-tertbutylbenzene for PSCs and find that the open circuit voltage(VOC) tends to increase with the chemical bonding strength between perovskite and these passivation additive molecules.Particularly,the paratert-butylbenzoic acid(tB-COOH),with the extra intermolecular hydrogen bonding,can stabilize the surface passivation of perovskite films exceptionally well through formation of a crystalline interlayer with water-insoluble property and high melting point.As a result,the tB-COOH device achieves a champion power conversion efficiency(PCE) of 21.46%.More importantly,such devices,which were stored in ambient air with a relative humidity of ~45%,can retain 88% of their initial performance after a testing period of more than 1 year(10,080 h).This work provides a case study to understand chemical bonding effects on passivation of perovskite.
基金supported by the Hong Kong Scholars Pro gram(No.XJ2019048)China Postdoctoral Science Foundation funded project(No.2019T120950)+1 种基金financial support from the International Cooperation Project of the Chinese Academy of Science(No.122111KYSB20180021)Hong Kong Special Administration Region General Research Fund(No.CUHK14306617 and 2130535).
文摘The phenomenon of adsorption of solid particles at fluid interfaces to stabilize emulsions or foams have been known for more than a century.Today,particle-stabilized emulsions,often referred to as Pickering emulsions,are receiving growing attention as they are encountered in oil recovery and have long been used in personal care products and food industry.Over the past 10 years the focus of the Pickering emulsion has also increasingly shifted to biomedical applications with thanks to novel syntheses of a wide range of biocompatible particle stabilizers.Here,a brief overview of the development of biocompatible particles is given for Pickering emulsion stabilization,including alginate,poly(lactic-co-gIycolic acid)(PLGA),and protein-based particles.The materials prepared by templating from emulsion stabilized with biocompatible particles include colloidal capsules and hierarchically porous materials.It is hoped that the understanding gained from the recent intense activity in the field will enable more researchers to modify existing materials and design new formulations,which would be beneficial for exploring more biological applications.
基金financially supported by the National Natural Scientific Foundation of China(Nos.50773077,20934005 and 51273091)the Hong Kong Special Administration Region Earmarked Projects(CUHK4042/09P,2160396)
文摘Composite biomaterials made of biodegradable polylactic acid （PLA） and bioactive magnesium （Mg） salt are developed for orthopaedic implants or metal implant coatings. The releasing of Mg salt into the biological environment benefits the bone growth, while with the releasing of Mg salt and degradation of PLA there forms a porous scaffold for tissue engineering. The size and morphology of the salt and voids are adjustable with such preparation conditions as salt content, pH of casting solution, and the solidification rate, so that we can control the salt releasing and degradation rate of PLA. Dielectric spectroscopy is used to investigate the dispersive structures of Mg salt and voids in the polymer matrix and to monitor the in situ releasing of Mg salts in the simulated body fluid （SBF）. The current study provides us with an orthopedic biomaterial with controllable multi-phase structures, and a tool to investigate the in vivo behaviors of biomaterials.
基金supported by the Hong Kong Special Administration Region(HKSAR) General Research Fund (CUHK 402809,2160387)the Direct Grant for Research 2008/09 of the Chinese University of Hong Kong(CUHK 2060371)
文摘In a mixture of colloidal particles and polymer molecules, the particles may experience an attractive ＂depletion force＂ if the size of the polymer molecule is larger than the interparticle separation. This is because individual polymer molecules experience less conformational entropy if they stay between the particles than they escape the inter-particle space, which results in an osmotic pressure imbalance inside and outside the gap and leads to interparticle attraction. This depletion force has been the subject of several studies since the 1980s, but the direct measurement of this force is still experimentally challenging as it requires the detection of energy variations of the order of kBT and beyond. We present here our results for applying total internal reflection microscopy （TIRM） to directly measure the interaction between a free-moving particle and a flat surface in solutions consisting of small water-soluble organic molecules or polymeric surfactants. Our results indicate that stable nanobubbles （ca. 150 nm） exist free in the above aqueous solutions. More importantly, the existence of such nanobubbles induces an attraction between the spherical particle and flat surface. Using TIRM, we are able to directly measure such weak interaction with a range up to 100 nm. Furthermore, we demonstrate that by employing thermo^sensitive microgel particles as a depleting agent, we are able to quantitatively measure and reversibly control kBT-scale depletion attraction as function of solution pH.
基金Shandong Traditional Chinese Medicine Technology Project,Grant/Award Number:Q-2023127Innovation Project of Jinan Science and Technology Bureau,Grant/Award Number:2020GXRC022+2 种基金Project for Scientific Research Innovation Team of Young Scholars in Colleges and Universities of Shandong Province,Grant/Award Numbers:2020KJC001,2022KJ196National Natural Science Foundation of China,Grant/Award Number:22372091Natural Science Foundation of Shandong Province,Grant/Award Number:ZR2023MB081。
文摘Activating the stimulator of interferon genes(STING)signaling pathway is critical for enhancing antitumor immunity and remodeling the immunosuppressive tumor microenvironment(TME).Herein,we report the preparation of STING-activating nanoparticles via metal coordination-driven assembly of a synthetic STING agonist(i.e.,SR717)and a chemotherapeutic drug(i.e.,curcumin).After intravenous administration,the assembled nanoparticles could efficiently accumulate in tumors to improve the bioavailability of SR717 and trigger potent STING pathway activation for effective immune responses.Meanwhile,the released curcumin evokes immunogenic cell death in tumors and regulates amino acid metabolism by inhibiting the activation of indoleamine 2,3-dioxygenase 1,leading to the reversal of the immunosuppressive TME.The antitumor immunity induced by nanoparticles significantly inhibits the growth of primary,recurrent,and metastatic tumors.The assembled nanoparticles are promising for the co-delivery of STING agonists and drugs in improved tumor chemo-immunotherapy.
