With the emergence of multidrug resistance(MDR)in many pathogens,bacterial infections are becoming a growing threat to public health.The frightening scenario is due largely to the formation of biofilms,in which the ba...With the emergence of multidrug resistance(MDR)in many pathogens,bacterial infections are becoming a growing threat to public health.The frightening scenario is due largely to the formation of biofilms,in which the bacteria are extremely recalcitrant to the conventional antibiotic regimens.To address the emergence of MDR and biofilm-associated infections,numerous polymer-based materials have been designed and prepared recently.The subject of this perspective is the recent development of polymer-based materials that have been applied to combat multidrug-resistant pathogens,to prevent the formation of biofilms,or enhance the eradication efficacy to mature biofilms via killing biofilm-bacteria or dispersing biofilms.The advantages and shortcomings of these polymer-based materials are discussed,as well as the challenges we are facing in the clinical translation of these systems.展开更多
Sonodynamic therapy (SDT) is one of the promising strategies for tumor therapy, but its application is usually hindered by fast clearance in blood-circulation, abnormal tumor microenvironment, and inefficient generati...Sonodynamic therapy (SDT) is one of the promising strategies for tumor therapy, but its application is usually hindered by fast clearance in blood-circulation, abnormal tumor microenvironment, and inefficient generation of reactive oxygen species. To solve these problems, we proposed an on-demand assembly-disassembly strategy, where the assembly is favorable for longer-blood-circulation and then the disassembly in tumor is favorable for boosting SDT. Hematoporphyrin monomethyl ether (HMME) as the model of organic sonosensitizers were conjugated with hyaluronic acid (HA). Then HA-HMME was mixed with catalase (CAT) and assembled into polymeric nanoparticles (CAT@HA-HMME NPs) with size of ~80 nm. CAT@HA-HMME NPs exhibit good biocompatibility and a longer blood half-time (t1/2 = 4.17 h) which is obviously longer than that (~0.82 h) of HMME molecules. After HA receptor-mediated endocytosis of cancer cells, CAT@HA-HMME NPs can be cleaved by endogenous hyaluronidase, resulting in the on-demand disassembly in tumor to release HA-HMME molecules and CAT. The CAT catalyzes the endogenous H_(2)O_(2) into O_(2) to relieve the hypoxic microenvironment, and the released HA-HMME exhibits a higher ROS generation ability, greatly boosting SDT for the inhibition of tumor growth. Therefore, the on-demand assembly-disassembly strategy may provide some insight in the design and development of nanoagents for tumor therapy.展开更多
Dye-loaded polymeric nanoparticles(NPs)are promising bioimaging agents because of their available surface chemistry,high brightness,and tunable optical properties.However,high dye loadings can cause the aggregation-ca...Dye-loaded polymeric nanoparticles(NPs)are promising bioimaging agents because of their available surface chemistry,high brightness,and tunable optical properties.However,high dye loadings can cause the aggregation-caused quenching(ACQ)of the encapsulated fluorophores.Previously,we proposed to mitigate the ACQ inside polymeric NPs by insulating cationic dyes with bulky hydrophobic counterions.In order to implement new functionalities into dye-loaded NPs,here,we extend the concept of bulky counterions to anionic lanthanide-based complexes.We show that by employing Gd-based counterions with octadecyl rhodamine B loaded NPs at 30 wt% versus polymer,the fluorescence quantum yield can be increased to 10-fold(to 0.34).Moreover,Gd-anion provides NPs with enhanced contrast in electron microscopy.A combination of a luminescent Eu-based counterion with a far-red to near-infrared cyanine 5 dye(DiD)yields Forster resonance energy transfer NPs,where the UV-excited Eu-based counterion transfers energy to DiD,generating delayed fluorescence and large stokes shift of -340 nm.Cellular studies reveal low cytotoxicity of NPs and their capacity to internalize without detectable dye leakage,in contrast to leaky NPs with small counterions.Our findings show that the aggregation behavior of cationic dyes in the polymeric NPs can be controlled by bulky lanthanide anions,which will help in developing bright luminescent multifunctional nanomaterials.展开更多
Porcine reproductive and respiratory syndrome (PRRS) is an economically devastating disease with worldwide distribution caused by Betaarterivirus suid (PRRSV). The virion has great genetic and antigenic variability wi...Porcine reproductive and respiratory syndrome (PRRS) is an economically devastating disease with worldwide distribution caused by Betaarterivirus suid (PRRSV). The virion has great genetic and antigenic variability with a marked increase in virulence. Vaccines tested to date have been of little use in controlling the problems caused by PRRSV, so the present study was conceived to evaluate the antiviral effect of polymeric nanoparticles (PNPs) made with glycyrrhizic acid (GA). Recent work has proven that this nanoparticle system is stable. These nanoparticles have good GA carrying capacity, a size < 250 nm, a spherical morphology, and a wide safety range. The integrity of cell morphology can be maintained for up to 72 h. The antiviral effect of this nanoparticle system was tested in cultures of MARC-145 cells in pre- and coinfection assays with PRRSV to evaluate changes in cell morphology and effects on cell viability. The use of PNPsGA with the real-time quantitative polymerase chain reaction (RT-qPCR) decreased viral infection by 38% in 3 amplification cycles. These results suggest that this system has an antiviral effect against PRRSV under the study conditions established.展开更多
Melatonin is a natural hormone and with the advancement of age its production declines and thereby may result in some neurological disorders. Exogenous administration of melatonin has been suggested as a neuroprotecti...Melatonin is a natural hormone and with the advancement of age its production declines and thereby may result in some neurological disorders. Exogenous administration of melatonin has been suggested as a neuroprotective agent. Due to its low oral bioavailability, the loading of melatonin in polymeric nanoparticles could be an important tool to effectively use exogenous melatonin. The quantification of the incorporated drug within polymeric nanoparticles is an important step in nanoparticles characterization. An analytical method using high performance liquid chromatography equipped with photodiode array detector (HPLC-PDA) was developed and validated for melatonin determination in poly (lactic acid) nanoparticles obtained by a single emulsion-solvent evaporation technique. The melatonin in vitro release profile also was determined by the HPLC method. Mobile phase consisted of acetonitrile: water (65:35, v/v) pumped at a flow rate of 0.9 mL/min, in the isocratic mode and PDA detector was set at 220 nm. The method was validated in terms of the selectivity, linearity, precision, accuracy, robustness, limits of detection and quantification. Analytical curve was linear over the concentration range of 10-100 ~tg/mL, and limits of detection and quantification were 25.9 ng/mL and 78.7 ng/mL, respectively. The mean recovery for melatonin was 100.47% (RSD = 1.25%, n = 9). In the intra- and inter- assay, the coefficient of variation was less than 2%. Robustness was proved performing changes in mobile phase, column temperature and flow rate. The method was suitable for the determination of melatonin encapsulation efficiency in poly(lactic acid) nanopartieles and for the evaluation of melatonin in vitro release profile.展开更多
<strong>Background: </strong>Recent decades witnessed a significant growth in terms of phytocompounds based therapeutics, extensively explored for almost all types of existing disorders. They have also bee...<strong>Background: </strong>Recent decades witnessed a significant growth in terms of phytocompounds based therapeutics, extensively explored for almost all types of existing disorders. They have also been widely investigated in Neurodegenerative disorders (NDDs) and Chlorogenic acid (CGA), a polyphenolic compound having potential anti-inflammatory and anti-oxidative properties, emerged as a promising compound in ameliorating NDDs. Owing to its poor stability, bioavailability and release kinetics, CGA needed a suitable nanocarrier based pharmaceutical design for targeting NDDs. <strong>Objective: </strong>The current study is aimed at the <em>in-silico</em> validation of CGA as an effective therapeutic agent targeting various NDDs followed by the fabrication of polymeric nanoparticles-based carrier system to overcome its pharmacological limitations and improve its stability. <strong>Methods:</strong> A successful <em>in-silico</em> validation using molecular docking techniques along with synthesis of CGA loaded polymeric nanoparticles (CGA-NPs) by ionic gelation method was performed. The statistical optimisation of the developed CGA-NPs was done by Box Behnken method and then the optimized formulation of CGA-NPs was characterised using particle size analysis (PSA), Transmission electron microscopy (TEM), Fourier Transform Infrared spectroscopy (FTIR) along with in-vitro release kinetics analysis.<strong> Results & Conclusion:</strong> The results attained exhibited average particle size of 101.9 ± 1.5 nm, Polydispersibility (PDI) score of 0.065 and a ZP of <span style="white-space:nowrap;">−</span>17.4 mV. On a similar note, TEM results showed a size range of CGA-NPs between 90 - 110 nm with a spherical shape of NPs. Also, the data from in-vitro release kinetics showed a sustained release of CGA from the NPs following the first-order kinetics suggesting the appropriate designing of nanoformulation.展开更多
Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated ...Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated SPNs with sur-face cloaked by red blood cell membrane(RBCM)are developed for highly e ective photoacoustic imaging and photothermal therapy.The resulting RBCM-coated SPN(SPN@RBCM)displays remarkable near-infrared light absorption and good photosta-bility,as well as high photothermal conver-sion e ciency for photoacoustic imaging and photothermal therapy.Particularly,due to the small size(<5 nm),SPN@RBCM has the advantages of deep tumor penetration and rapid clearance from the body with no appreciable toxicity.The RBCM endows the SPNs with prolonged systematic circulation time,less reticuloendothelial system uptake and reduced immune-recognition,hence improving tumor accumulation after intravenous injection,which provides strong photoacoustic signals and exerts excellent photothermal therapeutic e ects.Thus,this work provides a valuable paradigm for safe and highly e cient tumor pho-toacoustic imaging and photothermal therapy for further clinical translation.展开更多
Synthetic polymer hydrogel nanoparticles(NPs)were developed to function as abiotic affinity reagents for fibrinogen.These NPs were made using both temperature-sensitive N-isopropyl acrylamide(NIPAm)and L-amino acid mo...Synthetic polymer hydrogel nanoparticles(NPs)were developed to function as abiotic affinity reagents for fibrinogen.These NPs were made using both temperature-sensitive N-isopropyl acrylamide(NIPAm)and L-amino acid monomers.Five kinds of L-amino acids were acryloylated to obtain functional monomers:L-phenylalanine(Phe)and L-leucine(Leu)with hydrophobic side chains,L-glutamic acid(Glu)with negative charges,and L-lysine(Lys)and L-arginine(Arg)with positive charges.After incubating the NPs with fibrinogen,g-globulin,and human serum albumin(HSA)respectively,the NPs that incorporated Nacryloyl-Arg monomers(AArg@NPs)showed the strongest and most specific binding affinity to fibrinogen,when compared with g-globulin and HSA.Additionally,the fibrinogen-AArg binding model had the best docking scores,and this may be due to the interaction of positively charged AArg@NPs and the negatively charged fibrinogen D domain and the hydrophobic interaction between them.The specific adsorption of AArg@NPs to fibrinogen was also confirmed by the immunoprecipitation assay,as the AArg@NPs selectively trapped the fibrinogen from a human plasma protein mixture.AArg@NPs had a strong selectivity for,and specificity to,fibrinogen and may be developed as a potential human fibrinogen-specific affinity reagent.展开更多
Photoacoustic imaging(PAI)is a hybrid imaging method based on photoacoustic(PA)effects,which is able to capture the structure,function,and molecular information of biological tissues with high resolution.To date,thera...Photoacoustic imaging(PAI)is a hybrid imaging method based on photoacoustic(PA)effects,which is able to capture the structure,function,and molecular information of biological tissues with high resolution.To date,therapeutic techniques under the guidance of PAI have provided new strategies for accurate diagnosis and precise treatment of tumors.In particular,conjugated polymer nanoparticles have been extensively inspected for PA-based cancer theranostics largely due to their superior optical properties such as tunable spectrum and large absorption coefficient and their good biocompatibility,and abundant functional groups.This mini-review mainly focuses on the recent advances toward the development of novel conjugated polymer nanoparticles for PA-based multimodal imaging and cancer photothermal therapy.展开更多
Semiconducting polymer nanoparticles(SPNs)have shown great promise in second near-infrared window(NIR-II)phototheranostics.However,the issue of long metabolic time significantly restricts the clinical application of S...Semiconducting polymer nanoparticles(SPNs)have shown great promise in second near-infrared window(NIR-II)phototheranostics.However,the issue of long metabolic time significantly restricts the clinical application of SPNs.In this study,we rationally designed a biodegradable SPN(BSPN50)for NIR-II fluorescence imaging-guided photodynamic therapy(PDT).BSPN50 is prepared by encapsulating a biodegradable SP(BSP50)with an amphiphilic copolymer F-127.BSP50 is composed of NIR-II fluorescent diketopyrrolopyrrole(DPP)segment and degradable poly(phenylenevinylene)(PPV)segment with the ratio of 50/50.BSPN50 has both satisfactory degradability under myeloperoxidase(MPO)/hydrogen peroxide(H_(2)O_(2))and NIR-II fluorescence emission upon 808 nm laser excitation.Furthermore,BSPN50 shows good photodynamic efficacy under 808 nm laser irradiation.BSPN50 shows a faster degradation rate than BSPN100 which has no PPV segment both in vitro and in vivo.In addition,BSPN50 can effectively diagnose tumor via NIR-II fluorescence imaging and inhibit the tumor growth by PDT.Thus,our study provides a rational approach to construct biodegradable nanoplatforms for efficient tumor NIR-II phototheranostics.展开更多
Alcohol-associated liver disease(ALD)is a common chronic liver disease and major contributor to liver disease-related deaths worldwide.Despite its prevalence,there are few effective pharmacological options for the sev...Alcohol-associated liver disease(ALD)is a common chronic liver disease and major contributor to liver disease-related deaths worldwide.Despite its prevalence,there are few effective pharmacological options for the severe stages of this disease.While much pre-clinical research attention is paid to drug development in ALD,many of these experimental therapeutics have limitations such as poor pharmacokinetics,poor efficacy,or off-target side effects due to systemic administration.One means of addressing these limitations is through liver-targeted drug delivery,which can be accomplished with different platforms including liposomes,polymeric nanoparticles,exosomes,bacteria,and adenoassociated viruses,among others.These platforms allow drugs to target the liver passively or actively,thereby reducing systemic circulation and increasing the‘effective dose’in the liver.While many studies,some clinical,have applied targeted delivery systems to other liver diseases such as viral hepatitis or hepatocellular carcinoma,only few have investigated their efficacy in ALD.This review provides basic information on these liver-targeting drug delivery platforms,including their benefits and limitations,and summarizes the current research efforts to apply them to the treatment of ALD in rodent models.We also discuss gaps in knowledge in the field,which when addressed,may help to increase the efficacy of novel therapies and better translate them to humans.展开更多
Neurodegenerative diseases are progressive conditions that affect the neurons of the central nervous system(CNS)and result in their damage and death.Neurodevelopmental disorders include intellectual disability,autism ...Neurodegenerative diseases are progressive conditions that affect the neurons of the central nervous system(CNS)and result in their damage and death.Neurodevelopmental disorders include intellectual disability,autism spectrum disorder,and attention-deficit/hyperactivity disorder and stem from the disruption of essential neurodevelopmental processes.The treatment of neurodegenerative and neurodevelopmental conditions,together affecting~120 million people worldwide,is challenged by the blood—brain barrier(BBB)and the blood—cerebrospinal fluid barrier that prevent the crossing of drugs from the systemic circulation into the CNS.The nose-to-brain pathway that bypasses the BBB and increases the brain bioavailability of intranasally administered drugs is promising to improve the treatment of CNS conditions.This pathway is more efficient for nanoparticles than for solutions,hence,the research on intranasal nano-drug delivery systems has grown exponentially over the last decade.Polymeric nanoparticles have become key players in the field owing to the high design and synthetic flexibility.This review describes the challenges faced for the treatment of neurodegenerative and neurodevelopmental conditions,the molecular and cellular features of the nasal mucosa and the contribution of intranasal nano-drug delivery to overcome them.Then,a comprehensive overview of polymeric nanocarriers investigated to increase drug bioavailability in the brain is introduced.展开更多
Ionizable lipid nanocarriers have made historical contribution to COVID-19 mRNA vaccines.Here,we report ionizable polymeric nanoparticles that co-deliver bi-adjuvant and neoantigen peptides for cancer immunotherapy in...Ionizable lipid nanocarriers have made historical contribution to COVID-19 mRNA vaccines.Here,we report ionizable polymeric nanoparticles that co-deliver bi-adjuvant and neoantigen peptides for cancer immunotherapy in combination with immune checkpoint blockade(ICB).Current cancer ICB benefits only a small subset of patients,largely due to a lack of pre-existing target cells and checkpoint targets for ICB,tumor antigenic heterogeneity,and tumor immunosuppression.Therapeutic vaccines hold the potential to enhance ICB therapeutic efficacy by expanding antitumor cell repertoires,upregulating immune checkpoint levels and hence sensitizing ICB,and reducing tumor immunosuppression.Chemically defined peptide vaccines are attractive,but their current therapeutic efficacy has been limited due to 1)poor vaccine delivery to immunomodulatory lymph nodes(LNs)and antigen(Ag)-presenting cells(APCs),2)poor immunostimulant adjuvant efficacy with restricted target cell subsets in humans,3)limited adjuvant/Ag codelivery to enhance Ag immunogenicity,and 4)limited ability to overcome tumor antigenic heterogeneity.Here,we developed nanovaccines(NVs)using pH-responsive polymeric micellular nanoparticles(NPs)for the codelivery of bi-adjuvant[Toll-like receptor(TLR)7/8 agonist R848 and TLR9 agonist CpG]and peptide neoantigens(neoAgs)to draining LNs for efficient Ag presentation in a broad range of APC subsets.These NVs potentiated the immunogenicity of peptide Ags and elicits robust antitumor T cell responses with memory,and remodeled the tumor immune milium with reduced tumor immunosuppression.As a result,NVs significantly enhanced ICB therapeutic efficacy for murine colorectal tumors and orthotopic glioblastoma multiforme(GBM).These results suggest marked potential of bi-adjuvant/neoAg-codelivering NVs for combination cancer immunotherapy.展开更多
In this study,a polymeric lipid nanoparticle(NP)(simplified as Lipid NP)was reported as a promising oral vaccine delivery system.The Lipid NPs composed of a hydrophobic polymeric poly(D,L-lactide-co-glycolide)(PLGA)co...In this study,a polymeric lipid nanoparticle(NP)(simplified as Lipid NP)was reported as a promising oral vaccine delivery system.The Lipid NPs composed of a hydrophobic polymeric poly(D,L-lactide-co-glycolide)(PLGA)core and a surface coating of lipid monolayer.Membrane emulsification technique was used to obtain uniform-sized Lipid NPs.Ovalbumin(OVA)was used as a model vaccine.Compared with the pure PLGA NPs,the Lipid NPs achieved higher loading capacity(LC)and entrapment efficiency(EE)for the encapsulated OVA.An in vitro oral release profile showed that the OVA-Lipid NPs were with lower initial burst and could protect the loaded OVA from the harsh gastrointestinal(GI)environment for a long time.In addition,a human microfold cell(M-cell)transcytotic assay demonstrated that due to a lipid layer structure on the particle surface,the Lipid NPs showed higher affinity to the M-cells.Since the M-cell in the intestinal epithelium played an important role in particle transportation as well as intimately associated with the underlying immune cells,the OVA-Lipid NPs effectively induced mucosal and humoral immune responses.展开更多
Near infrared(NIR)fluorescence imaging guided photodynamic therapy(PDT)is a technique which has been developed in many clinical trials due to its advantage of real-time optical monitoring,specific spatiotemporal selec...Near infrared(NIR)fluorescence imaging guided photodynamic therapy(PDT)is a technique which has been developed in many clinical trials due to its advantage of real-time optical monitoring,specific spatiotemporal selectivity,and minimal invasiveness.For this,photosensitizers with NIR fluorescence emission and high^(1)O_(2)generation quantum yield are highly desirable.Herein,we designed and synthesized a"donor-acceptor"(D-A)structured semiconductor polymer(SP),which was then wrapped with an amphiphilic compound(Pluronic■F127)to prepare water-soluble nanoparticles(F-SP NPs).The obtained F-SP NPs exhibit good water solubility,excellent particle size stability,strong absorbance at deep red region,and strong NIR fluorescent emission characteristics.The maximal mass extinction coe±cient and fluorescence quantum yield of these F-SPs were calculated to be 21.7 L/(g·cm)and 6.5%,respectively.Moreover,the^(1)O_(2)quantum yield of 89%for F-SP NPs has been achieved under 635 nm laser irradiation,which is higher than Methylene Blue,Ce6,and PpIX.The outstanding properties of these F-SP NPs originate from their unique D-A molecular characteristic.This work should help guide the design of novel semiconductor polymer for NIR fluorescent imaging guided PDT applications.展开更多
This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile (PAN) nanofibers and A1203-PAN nanofibers. In particular, t...This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile (PAN) nanofibers and A1203-PAN nanofibers. In particular, the paper focuses on the effect of adding Al2O3 nanopartiles in PAN nanofibers, which were incorporated in unidirectional (UD) laminates. The effectiveness of adding a thin film made of Al2O3-PAN on the fracture behavior of the carbon fiber reinforced polymer (CFRP) has been addressed by comparing the energy release rates, obtained by testing double cantilever beam (DCB) samples under mode I loading condition. A general improvement in interlaminar fracture energy of the CFRP is observed when the both neat PAN nanofibers and Al2O3-PAN nanofibers are interleaved. However, higher interlaminar strength has been observed for the samples with a thin film of Al2O3-PAN nanofibers, suggesting a better stress distribution and stress transformation from resin-rich area to reinforcement phase of hybrid composites.展开更多
The goal of the research was to investigate the profile control and oil displacement characteristics of the polymer nanoparticles after high temperature swelling.The displacement parameters showed considerable influen...The goal of the research was to investigate the profile control and oil displacement characteristics of the polymer nanoparticles after high temperature swelling.The displacement parameters showed considerable influence on the plugging effect of the high-temperature swelled polymer nanoparticles,such as the core permeability,concentration of nanoparticles in the suspension,swelling time and swelling temperature,which makes it flexible to control the plugging effect by controlling displacement experiments conditions.Experimental results show that polymer nanoparticles dispersion system with a concentration of 500 mg/L is suitable for cores plugging with a permeability of 30×10^(-3)-150×10^(-3)μm^(2),even after aging at 150℃ for three months.The shunt flow experiments show that when the displacement factors are optimal values,the polymer nanoparticles after high temperature swelling to plug the high-permeability layer selectivity and almost do not clog the low-permeability layer.Oil recovery of homogeneous artificial core displacement experiment and a heterogeneous double-tube cores model are increased by 20%and 10.4%on the basis of water flooding.The polymer nanoparticles can be a great help for petroleum engineers to better apply this deep profile control and flooding technology.展开更多
Chemically fueled dissipative self-assembly paves the way for innovative materials with lifelike properties and functions.Achievement of nonequilibrium systems with biocompatibility and biofunctions remains an importa...Chemically fueled dissipative self-assembly paves the way for innovative materials with lifelike properties and functions.Achievement of nonequilibrium systems with biocompatibility and biofunctions remains an important and challenging task.Here,we present biocompatible chemically fueled transient polymer nanoparticles and their applications in temporally programmable in vivo imaging.The lifetime of the transient polymer nanoparticles can be tuned by varying the concentration of polymer,adenosine triphosphate,and phosphatase.Moreover,the transient assembly of polymer nanoparticles can be paused for storage and then subsequently restored.The transient polymer nanoparticles exhibit good biocompatibility.Notably,we implement in vivo imaging in a temporally programmable fashion by using an autonomous fluorescence modulator of transient nanoparticles assembled from polymers with a fluorescence moiety.The results in this work provide a valuable way to achieve nonequilibrium self-assembly of synthetic systems with good biocompatibility and programmable biofunctions,accelerating innovative developments of nonequilibrium soft biomaterials.展开更多
Photosensitive fluorescent probes have become powerful tools in chemical biology and molecular biophysics,which are used to investigate cellular processes with high temporal and spatial resolution.Accordingly,photosen...Photosensitive fluorescent probes have become powerful tools in chemical biology and molecular biophysics,which are used to investigate cellular processes with high temporal and spatial resolution.Accordingly,photosensitive fluorescent probes,including photoactivatable,photoconvertible,and photoswitchable fluorophores,have been extensively developed during the past decade.The photoswitchable fluorophores have received much attention because they highlight cellular events clearly.This minireview summarizes recent advances of using reversibly photoswitchable fluorophores and their applications in innovative bioimaging.Photoswitchable fluorophores include photoswitchable fluorescent proteins,photoswitchable fluorescent organic molecules(dyes),and photoswitchable fluorescent nanoparticles.Several strategies have been developed to synthesize photoswitchable fluorophores,including engineering combination proteins,chemical synthesis,polymerization,and self-assembly.Here we concentrate on polymer nanoparticles with optically switchable emission properties:either fluorescence on/offor dualalternating-color fluorescence photoswitching.The essential mechanisms of fluorescence photoswitching enable different types of photoswitchable fluorophores to change emission intensity or wavelength(color)and thus validating the basis of the fluorescence on/offor dual-color photoswitching design.Generally the possible applications of any fluorophores are to label biological targets,followed by specific imaging.The newly developed photoswitchable fluorophores enable super-resolution fluorescence imaging because of their photosensitive emission.Finally,we summarize the important area regarding future research and development on photoswitchable fluorescent nanoparticles.展开更多
In order to increase antibacterial abilities and avoid the aggregation of nanoparticle, Ag- ZnO nanocomposites were studied in the network structure which contains bonds, and these bonds are formed by hydrolysis react...In order to increase antibacterial abilities and avoid the aggregation of nanoparticle, Ag- ZnO nanocomposites were studied in the network structure which contains bonds, and these bonds are formed by hydrolysis reaction between Ti(TBOU)4(TBOT) and the water that in Persimmon tannin solution. The size and morphology of Ag-ZnO nanocompos:tes were investigated by scanning electron microscopy (SEM) and field emission scanning electron microscopy(FE-SEM). The antibacterial properties of nanocomposites were examined by minimal bactericidal concentration(MBC). Results showed that this kind of antibacterial nanocomposites composites(ANPs) have excellent antibacterial abilities and without aggregation.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21620102005,51933006,and 52003184)。
文摘With the emergence of multidrug resistance(MDR)in many pathogens,bacterial infections are becoming a growing threat to public health.The frightening scenario is due largely to the formation of biofilms,in which the bacteria are extremely recalcitrant to the conventional antibiotic regimens.To address the emergence of MDR and biofilm-associated infections,numerous polymer-based materials have been designed and prepared recently.The subject of this perspective is the recent development of polymer-based materials that have been applied to combat multidrug-resistant pathogens,to prevent the formation of biofilms,or enhance the eradication efficacy to mature biofilms via killing biofilm-bacteria or dispersing biofilms.The advantages and shortcomings of these polymer-based materials are discussed,as well as the challenges we are facing in the clinical translation of these systems.
基金the National Natural Science Foundation of China(51972056,52002061,52161145406)Shanghai Shuguang Program(18SG29)+2 种基金Program of Shanghai Academic/Technology Research Leader(20XD1420200)Major Science and Technology Innovation Project of Shandong Province(2019JZZY011108)Graduate Student Innovation Fund of Donghua University(CUSF-DH-D-2021010).
文摘Sonodynamic therapy (SDT) is one of the promising strategies for tumor therapy, but its application is usually hindered by fast clearance in blood-circulation, abnormal tumor microenvironment, and inefficient generation of reactive oxygen species. To solve these problems, we proposed an on-demand assembly-disassembly strategy, where the assembly is favorable for longer-blood-circulation and then the disassembly in tumor is favorable for boosting SDT. Hematoporphyrin monomethyl ether (HMME) as the model of organic sonosensitizers were conjugated with hyaluronic acid (HA). Then HA-HMME was mixed with catalase (CAT) and assembled into polymeric nanoparticles (CAT@HA-HMME NPs) with size of ~80 nm. CAT@HA-HMME NPs exhibit good biocompatibility and a longer blood half-time (t1/2 = 4.17 h) which is obviously longer than that (~0.82 h) of HMME molecules. After HA receptor-mediated endocytosis of cancer cells, CAT@HA-HMME NPs can be cleaved by endogenous hyaluronidase, resulting in the on-demand disassembly in tumor to release HA-HMME molecules and CAT. The CAT catalyzes the endogenous H_(2)O_(2) into O_(2) to relieve the hypoxic microenvironment, and the released HA-HMME exhibits a higher ROS generation ability, greatly boosting SDT for the inhibition of tumor growth. Therefore, the on-demand assembly-disassembly strategy may provide some insight in the design and development of nanoagents for tumor therapy.
基金European Research Council ERC Consolidator grant Bright Sens,Grant/Award Number:648528。
文摘Dye-loaded polymeric nanoparticles(NPs)are promising bioimaging agents because of their available surface chemistry,high brightness,and tunable optical properties.However,high dye loadings can cause the aggregation-caused quenching(ACQ)of the encapsulated fluorophores.Previously,we proposed to mitigate the ACQ inside polymeric NPs by insulating cationic dyes with bulky hydrophobic counterions.In order to implement new functionalities into dye-loaded NPs,here,we extend the concept of bulky counterions to anionic lanthanide-based complexes.We show that by employing Gd-based counterions with octadecyl rhodamine B loaded NPs at 30 wt% versus polymer,the fluorescence quantum yield can be increased to 10-fold(to 0.34).Moreover,Gd-anion provides NPs with enhanced contrast in electron microscopy.A combination of a luminescent Eu-based counterion with a far-red to near-infrared cyanine 5 dye(DiD)yields Forster resonance energy transfer NPs,where the UV-excited Eu-based counterion transfers energy to DiD,generating delayed fluorescence and large stokes shift of -340 nm.Cellular studies reveal low cytotoxicity of NPs and their capacity to internalize without detectable dye leakage,in contrast to leaky NPs with small counterions.Our findings show that the aggregation behavior of cationic dyes in the polymeric NPs can be controlled by bulky lanthanide anions,which will help in developing bright luminescent multifunctional nanomaterials.
文摘Porcine reproductive and respiratory syndrome (PRRS) is an economically devastating disease with worldwide distribution caused by Betaarterivirus suid (PRRSV). The virion has great genetic and antigenic variability with a marked increase in virulence. Vaccines tested to date have been of little use in controlling the problems caused by PRRSV, so the present study was conceived to evaluate the antiviral effect of polymeric nanoparticles (PNPs) made with glycyrrhizic acid (GA). Recent work has proven that this nanoparticle system is stable. These nanoparticles have good GA carrying capacity, a size < 250 nm, a spherical morphology, and a wide safety range. The integrity of cell morphology can be maintained for up to 72 h. The antiviral effect of this nanoparticle system was tested in cultures of MARC-145 cells in pre- and coinfection assays with PRRSV to evaluate changes in cell morphology and effects on cell viability. The use of PNPsGA with the real-time quantitative polymerase chain reaction (RT-qPCR) decreased viral infection by 38% in 3 amplification cycles. These results suggest that this system has an antiviral effect against PRRSV under the study conditions established.
基金supported by Comissao de Aperfeicoamento de Pessoal do Nível Superior(CAPES)in the form of scholarship for LGM
文摘Melatonin is a natural hormone and with the advancement of age its production declines and thereby may result in some neurological disorders. Exogenous administration of melatonin has been suggested as a neuroprotective agent. Due to its low oral bioavailability, the loading of melatonin in polymeric nanoparticles could be an important tool to effectively use exogenous melatonin. The quantification of the incorporated drug within polymeric nanoparticles is an important step in nanoparticles characterization. An analytical method using high performance liquid chromatography equipped with photodiode array detector (HPLC-PDA) was developed and validated for melatonin determination in poly (lactic acid) nanoparticles obtained by a single emulsion-solvent evaporation technique. The melatonin in vitro release profile also was determined by the HPLC method. Mobile phase consisted of acetonitrile: water (65:35, v/v) pumped at a flow rate of 0.9 mL/min, in the isocratic mode and PDA detector was set at 220 nm. The method was validated in terms of the selectivity, linearity, precision, accuracy, robustness, limits of detection and quantification. Analytical curve was linear over the concentration range of 10-100 ~tg/mL, and limits of detection and quantification were 25.9 ng/mL and 78.7 ng/mL, respectively. The mean recovery for melatonin was 100.47% (RSD = 1.25%, n = 9). In the intra- and inter- assay, the coefficient of variation was less than 2%. Robustness was proved performing changes in mobile phase, column temperature and flow rate. The method was suitable for the determination of melatonin encapsulation efficiency in poly(lactic acid) nanopartieles and for the evaluation of melatonin in vitro release profile.
文摘<strong>Background: </strong>Recent decades witnessed a significant growth in terms of phytocompounds based therapeutics, extensively explored for almost all types of existing disorders. They have also been widely investigated in Neurodegenerative disorders (NDDs) and Chlorogenic acid (CGA), a polyphenolic compound having potential anti-inflammatory and anti-oxidative properties, emerged as a promising compound in ameliorating NDDs. Owing to its poor stability, bioavailability and release kinetics, CGA needed a suitable nanocarrier based pharmaceutical design for targeting NDDs. <strong>Objective: </strong>The current study is aimed at the <em>in-silico</em> validation of CGA as an effective therapeutic agent targeting various NDDs followed by the fabrication of polymeric nanoparticles-based carrier system to overcome its pharmacological limitations and improve its stability. <strong>Methods:</strong> A successful <em>in-silico</em> validation using molecular docking techniques along with synthesis of CGA loaded polymeric nanoparticles (CGA-NPs) by ionic gelation method was performed. The statistical optimisation of the developed CGA-NPs was done by Box Behnken method and then the optimized formulation of CGA-NPs was characterised using particle size analysis (PSA), Transmission electron microscopy (TEM), Fourier Transform Infrared spectroscopy (FTIR) along with in-vitro release kinetics analysis.<strong> Results & Conclusion:</strong> The results attained exhibited average particle size of 101.9 ± 1.5 nm, Polydispersibility (PDI) score of 0.065 and a ZP of <span style="white-space:nowrap;">−</span>17.4 mV. On a similar note, TEM results showed a size range of CGA-NPs between 90 - 110 nm with a spherical shape of NPs. Also, the data from in-vitro release kinetics showed a sustained release of CGA from the NPs following the first-order kinetics suggesting the appropriate designing of nanoformulation.
基金supported by the National Natural Science Foundation of China(Grant Nos.61727823,51873160)the joint research project of Health and Education Commission of Fujian Province(Grant No.2019-WJ-20).
文摘Semiconducting conjugated polymer nanoparticles(SPNs)represent an emerging class of phototheranostic materi-als with great promise for cancer treatment.In this report,low-bandgap electron donoracceptor(DA)-conjugated SPNs with sur-face cloaked by red blood cell membrane(RBCM)are developed for highly e ective photoacoustic imaging and photothermal therapy.The resulting RBCM-coated SPN(SPN@RBCM)displays remarkable near-infrared light absorption and good photosta-bility,as well as high photothermal conver-sion e ciency for photoacoustic imaging and photothermal therapy.Particularly,due to the small size(<5 nm),SPN@RBCM has the advantages of deep tumor penetration and rapid clearance from the body with no appreciable toxicity.The RBCM endows the SPNs with prolonged systematic circulation time,less reticuloendothelial system uptake and reduced immune-recognition,hence improving tumor accumulation after intravenous injection,which provides strong photoacoustic signals and exerts excellent photothermal therapeutic e ects.Thus,this work provides a valuable paradigm for safe and highly e cient tumor pho-toacoustic imaging and photothermal therapy for further clinical translation.
基金This work was supported by the Natural Science Foundation of Guangdong Province,China(Grant No.:2017A030313775)the Science and Technology Planning Project of Guangdong Province,China(Grant No.:2016A010103016)the Science and Technology Planning Project of Guangzhou City of Guangdong Province,China(Grant No.:201607010148).
文摘Synthetic polymer hydrogel nanoparticles(NPs)were developed to function as abiotic affinity reagents for fibrinogen.These NPs were made using both temperature-sensitive N-isopropyl acrylamide(NIPAm)and L-amino acid monomers.Five kinds of L-amino acids were acryloylated to obtain functional monomers:L-phenylalanine(Phe)and L-leucine(Leu)with hydrophobic side chains,L-glutamic acid(Glu)with negative charges,and L-lysine(Lys)and L-arginine(Arg)with positive charges.After incubating the NPs with fibrinogen,g-globulin,and human serum albumin(HSA)respectively,the NPs that incorporated Nacryloyl-Arg monomers(AArg@NPs)showed the strongest and most specific binding affinity to fibrinogen,when compared with g-globulin and HSA.Additionally,the fibrinogen-AArg binding model had the best docking scores,and this may be due to the interaction of positively charged AArg@NPs and the negatively charged fibrinogen D domain and the hydrophobic interaction between them.The specific adsorption of AArg@NPs to fibrinogen was also confirmed by the immunoprecipitation assay,as the AArg@NPs selectively trapped the fibrinogen from a human plasma protein mixture.AArg@NPs had a strong selectivity for,and specificity to,fibrinogen and may be developed as a potential human fibrinogen-specific affinity reagent.
基金We acknowledge financial support from grants MYRG2014-00093-FHS,MYRG 2015-00036-FHS,MYRG2016-00110-FHS and MYRG2018-00081-FHS from the University of Macao in Macao and grants FDCT 0011/2018/A1 and FDCT 025/2015/A1 from the Macao government.
文摘Photoacoustic imaging(PAI)is a hybrid imaging method based on photoacoustic(PA)effects,which is able to capture the structure,function,and molecular information of biological tissues with high resolution.To date,therapeutic techniques under the guidance of PAI have provided new strategies for accurate diagnosis and precise treatment of tumors.In particular,conjugated polymer nanoparticles have been extensively inspected for PA-based cancer theranostics largely due to their superior optical properties such as tunable spectrum and large absorption coefficient and their good biocompatibility,and abundant functional groups.This mini-review mainly focuses on the recent advances toward the development of novel conjugated polymer nanoparticles for PA-based multimodal imaging and cancer photothermal therapy.
基金the National Natural Science Foundation of China(Nos.22174070 and 22205115)Natural Science Foundation of Jiangsu Province(No.BK20230060)+4 种基金Natural Science Foundation of Jiangsu University(No.21KJB150022)the Research startup fund of NJUPT(No.NY220149)Natural Science Foundation of NJUPT(No.NY221088)the Project of State Key Laboratory of Organic Electronics and Information Displays,Nanjing University of Posts and Telecommunications(Nos.GZR2022010012 and GZR2023010022)the Synergetic Innovation Center for Organic Electronics and Information Displays for the financial support.
文摘Semiconducting polymer nanoparticles(SPNs)have shown great promise in second near-infrared window(NIR-II)phototheranostics.However,the issue of long metabolic time significantly restricts the clinical application of SPNs.In this study,we rationally designed a biodegradable SPN(BSPN50)for NIR-II fluorescence imaging-guided photodynamic therapy(PDT).BSPN50 is prepared by encapsulating a biodegradable SP(BSP50)with an amphiphilic copolymer F-127.BSP50 is composed of NIR-II fluorescent diketopyrrolopyrrole(DPP)segment and degradable poly(phenylenevinylene)(PPV)segment with the ratio of 50/50.BSPN50 has both satisfactory degradability under myeloperoxidase(MPO)/hydrogen peroxide(H_(2)O_(2))and NIR-II fluorescence emission upon 808 nm laser excitation.Furthermore,BSPN50 shows good photodynamic efficacy under 808 nm laser irradiation.BSPN50 shows a faster degradation rate than BSPN100 which has no PPV segment both in vitro and in vivo.In addition,BSPN50 can effectively diagnose tumor via NIR-II fluorescence imaging and inhibit the tumor growth by PDT.Thus,our study provides a rational approach to construct biodegradable nanoplatforms for efficient tumor NIR-II phototheranostics.
基金Supported by National Institutes of Health,No. R01AA028905-01A1 (to Kirpich IA),No. 1F31AA028423-01A1 (to Warner JB),No. F32AA027950-01A1 (to Hardesty JE) and No. U01AA026934 (to McClain CJ)Jewish Heritage Fund for Excellence Research Enhancement Grant Program at the University of Louisville+1 种基金an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health,No. P20GM113226 (to McClain CJ)National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health,No. P50AA024337 (to McClain CJ)
文摘Alcohol-associated liver disease(ALD)is a common chronic liver disease and major contributor to liver disease-related deaths worldwide.Despite its prevalence,there are few effective pharmacological options for the severe stages of this disease.While much pre-clinical research attention is paid to drug development in ALD,many of these experimental therapeutics have limitations such as poor pharmacokinetics,poor efficacy,or off-target side effects due to systemic administration.One means of addressing these limitations is through liver-targeted drug delivery,which can be accomplished with different platforms including liposomes,polymeric nanoparticles,exosomes,bacteria,and adenoassociated viruses,among others.These platforms allow drugs to target the liver passively or actively,thereby reducing systemic circulation and increasing the‘effective dose’in the liver.While many studies,some clinical,have applied targeted delivery systems to other liver diseases such as viral hepatitis or hepatocellular carcinoma,only few have investigated their efficacy in ALD.This review provides basic information on these liver-targeting drug delivery platforms,including their benefits and limitations,and summarizes the current research efforts to apply them to the treatment of ALD in rodent models.We also discuss gaps in knowledge in the field,which when addressed,may help to increase the efficacy of novel therapies and better translate them to humans.
基金the NEVET Nanotechnology Grant of the Russell Berrie Nanotechnology Institute(RBNI)at Technion—Israel Institute of Technology(Israel)the Tamara and Harry Handelsman Academic Chair(Israel)for financial support。
文摘Neurodegenerative diseases are progressive conditions that affect the neurons of the central nervous system(CNS)and result in their damage and death.Neurodevelopmental disorders include intellectual disability,autism spectrum disorder,and attention-deficit/hyperactivity disorder and stem from the disruption of essential neurodevelopmental processes.The treatment of neurodegenerative and neurodevelopmental conditions,together affecting~120 million people worldwide,is challenged by the blood—brain barrier(BBB)and the blood—cerebrospinal fluid barrier that prevent the crossing of drugs from the systemic circulation into the CNS.The nose-to-brain pathway that bypasses the BBB and increases the brain bioavailability of intranasally administered drugs is promising to improve the treatment of CNS conditions.This pathway is more efficient for nanoparticles than for solutions,hence,the research on intranasal nano-drug delivery systems has grown exponentially over the last decade.Polymeric nanoparticles have become key players in the field owing to the high design and synthetic flexibility.This review describes the challenges faced for the treatment of neurodegenerative and neurodevelopmental conditions,the molecular and cellular features of the nasal mucosa and the contribution of intranasal nano-drug delivery to overcome them.Then,a comprehensive overview of polymeric nanocarriers investigated to increase drug bioavailability in the brain is introduced.
基金G.Z.acknowledges funding support from NIH(R01CA266981,R01AI168684,R35GM143014,R21NS114455)DoD CDMRP Breast Cancer Breakthrough Award Level II(BC210931/P1)+3 种基金NIH-NCATS KL2 scholarship(KL2TR002648)via VCU C.Kenneth and Dianne Wright Center for Clinical and Translational Research(UL1TR002649)American Cancer Society Research Scholar Grant(RSG-22-055-01-IBCD)METAvivor Early Career Investigator Award,among others.The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.T.S.and F.C.acknowledge the National Natural Science Foundation of China(52103199,82102203)Guangdong Basic and Applied Basic Research Foundation(2020A1515110811).
文摘Ionizable lipid nanocarriers have made historical contribution to COVID-19 mRNA vaccines.Here,we report ionizable polymeric nanoparticles that co-deliver bi-adjuvant and neoantigen peptides for cancer immunotherapy in combination with immune checkpoint blockade(ICB).Current cancer ICB benefits only a small subset of patients,largely due to a lack of pre-existing target cells and checkpoint targets for ICB,tumor antigenic heterogeneity,and tumor immunosuppression.Therapeutic vaccines hold the potential to enhance ICB therapeutic efficacy by expanding antitumor cell repertoires,upregulating immune checkpoint levels and hence sensitizing ICB,and reducing tumor immunosuppression.Chemically defined peptide vaccines are attractive,but their current therapeutic efficacy has been limited due to 1)poor vaccine delivery to immunomodulatory lymph nodes(LNs)and antigen(Ag)-presenting cells(APCs),2)poor immunostimulant adjuvant efficacy with restricted target cell subsets in humans,3)limited adjuvant/Ag codelivery to enhance Ag immunogenicity,and 4)limited ability to overcome tumor antigenic heterogeneity.Here,we developed nanovaccines(NVs)using pH-responsive polymeric micellular nanoparticles(NPs)for the codelivery of bi-adjuvant[Toll-like receptor(TLR)7/8 agonist R848 and TLR9 agonist CpG]and peptide neoantigens(neoAgs)to draining LNs for efficient Ag presentation in a broad range of APC subsets.These NVs potentiated the immunogenicity of peptide Ags and elicits robust antitumor T cell responses with memory,and remodeled the tumor immune milium with reduced tumor immunosuppression.As a result,NVs significantly enhanced ICB therapeutic efficacy for murine colorectal tumors and orthotopic glioblastoma multiforme(GBM).These results suggest marked potential of bi-adjuvant/neoAg-codelivering NVs for combination cancer immunotherapy.
基金This work was financially supported by the 973 Program(Grant No.2009CB930300)National Natural Science Foundation of China(No.81273449).
文摘In this study,a polymeric lipid nanoparticle(NP)(simplified as Lipid NP)was reported as a promising oral vaccine delivery system.The Lipid NPs composed of a hydrophobic polymeric poly(D,L-lactide-co-glycolide)(PLGA)core and a surface coating of lipid monolayer.Membrane emulsification technique was used to obtain uniform-sized Lipid NPs.Ovalbumin(OVA)was used as a model vaccine.Compared with the pure PLGA NPs,the Lipid NPs achieved higher loading capacity(LC)and entrapment efficiency(EE)for the encapsulated OVA.An in vitro oral release profile showed that the OVA-Lipid NPs were with lower initial burst and could protect the loaded OVA from the harsh gastrointestinal(GI)environment for a long time.In addition,a human microfold cell(M-cell)transcytotic assay demonstrated that due to a lipid layer structure on the particle surface,the Lipid NPs showed higher affinity to the M-cells.Since the M-cell in the intestinal epithelium played an important role in particle transportation as well as intimately associated with the underlying immune cells,the OVA-Lipid NPs effectively induced mucosal and humoral immune responses.
基金This work was supported by National Natural Science Foundation of China(Nos.61805287 and 62175262)The Open Fund of the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology,No.2021-skllmd-10)+1 种基金The Open Sharing Fund for Large-scale Instruments and Equipment of Central South University(CSUZC202218),Fundamental Research Funds for the Central South Universities(Nos.2020CX021,2020zzts387,and 2020zzts404)Key R&D plan of Hunan Province(No.2022SK2101).
文摘Near infrared(NIR)fluorescence imaging guided photodynamic therapy(PDT)is a technique which has been developed in many clinical trials due to its advantage of real-time optical monitoring,specific spatiotemporal selectivity,and minimal invasiveness.For this,photosensitizers with NIR fluorescence emission and high^(1)O_(2)generation quantum yield are highly desirable.Herein,we designed and synthesized a"donor-acceptor"(D-A)structured semiconductor polymer(SP),which was then wrapped with an amphiphilic compound(Pluronic■F127)to prepare water-soluble nanoparticles(F-SP NPs).The obtained F-SP NPs exhibit good water solubility,excellent particle size stability,strong absorbance at deep red region,and strong NIR fluorescent emission characteristics.The maximal mass extinction coe±cient and fluorescence quantum yield of these F-SPs were calculated to be 21.7 L/(g·cm)and 6.5%,respectively.Moreover,the^(1)O_(2)quantum yield of 89%for F-SP NPs has been achieved under 635 nm laser irradiation,which is higher than Methylene Blue,Ce6,and PpIX.The outstanding properties of these F-SP NPs originate from their unique D-A molecular characteristic.This work should help guide the design of novel semiconductor polymer for NIR fluorescent imaging guided PDT applications.
文摘This paper presents an experimental investigation on fracture behavior of epoxy resin-carbon fibers composites interleaved with both neat polyacrylonitrile (PAN) nanofibers and A1203-PAN nanofibers. In particular, the paper focuses on the effect of adding Al2O3 nanopartiles in PAN nanofibers, which were incorporated in unidirectional (UD) laminates. The effectiveness of adding a thin film made of Al2O3-PAN on the fracture behavior of the carbon fiber reinforced polymer (CFRP) has been addressed by comparing the energy release rates, obtained by testing double cantilever beam (DCB) samples under mode I loading condition. A general improvement in interlaminar fracture energy of the CFRP is observed when the both neat PAN nanofibers and Al2O3-PAN nanofibers are interleaved. However, higher interlaminar strength has been observed for the samples with a thin film of Al2O3-PAN nanofibers, suggesting a better stress distribution and stress transformation from resin-rich area to reinforcement phase of hybrid composites.
基金funded by National Natural Science Foundation of China No.51874316 and 51274211National Key Scientific and Technological Project(Grant No.2017ZX05009-004)。
文摘The goal of the research was to investigate the profile control and oil displacement characteristics of the polymer nanoparticles after high temperature swelling.The displacement parameters showed considerable influence on the plugging effect of the high-temperature swelled polymer nanoparticles,such as the core permeability,concentration of nanoparticles in the suspension,swelling time and swelling temperature,which makes it flexible to control the plugging effect by controlling displacement experiments conditions.Experimental results show that polymer nanoparticles dispersion system with a concentration of 500 mg/L is suitable for cores plugging with a permeability of 30×10^(-3)-150×10^(-3)μm^(2),even after aging at 150℃ for three months.The shunt flow experiments show that when the displacement factors are optimal values,the polymer nanoparticles after high temperature swelling to plug the high-permeability layer selectivity and almost do not clog the low-permeability layer.Oil recovery of homogeneous artificial core displacement experiment and a heterogeneous double-tube cores model are increased by 20%and 10.4%on the basis of water flooding.The polymer nanoparticles can be a great help for petroleum engineers to better apply this deep profile control and flooding technology.
基金This work was financially supported by the National Natural Science Foundation of China(NSFC)under grant no.21972054.
文摘Chemically fueled dissipative self-assembly paves the way for innovative materials with lifelike properties and functions.Achievement of nonequilibrium systems with biocompatibility and biofunctions remains an important and challenging task.Here,we present biocompatible chemically fueled transient polymer nanoparticles and their applications in temporally programmable in vivo imaging.The lifetime of the transient polymer nanoparticles can be tuned by varying the concentration of polymer,adenosine triphosphate,and phosphatase.Moreover,the transient assembly of polymer nanoparticles can be paused for storage and then subsequently restored.The transient polymer nanoparticles exhibit good biocompatibility.Notably,we implement in vivo imaging in a temporally programmable fashion by using an autonomous fluorescence modulator of transient nanoparticles assembled from polymers with a fluorescence moiety.The results in this work provide a valuable way to achieve nonequilibrium self-assembly of synthetic systems with good biocompatibility and programmable biofunctions,accelerating innovative developments of nonequilibrium soft biomaterials.
基金This work was supported in part by the Fundamental Research Funds for the Central Universities(HUST2010MS101),the NSFC(20874025)the Program for New Century Excellent Talents(NCET-07-00273)+1 种基金National Key Basic Research Program of China(2007CB310500)the National Science Foundation(NSF)Chemistry Division(CHE-0805547).
文摘Photosensitive fluorescent probes have become powerful tools in chemical biology and molecular biophysics,which are used to investigate cellular processes with high temporal and spatial resolution.Accordingly,photosensitive fluorescent probes,including photoactivatable,photoconvertible,and photoswitchable fluorophores,have been extensively developed during the past decade.The photoswitchable fluorophores have received much attention because they highlight cellular events clearly.This minireview summarizes recent advances of using reversibly photoswitchable fluorophores and their applications in innovative bioimaging.Photoswitchable fluorophores include photoswitchable fluorescent proteins,photoswitchable fluorescent organic molecules(dyes),and photoswitchable fluorescent nanoparticles.Several strategies have been developed to synthesize photoswitchable fluorophores,including engineering combination proteins,chemical synthesis,polymerization,and self-assembly.Here we concentrate on polymer nanoparticles with optically switchable emission properties:either fluorescence on/offor dualalternating-color fluorescence photoswitching.The essential mechanisms of fluorescence photoswitching enable different types of photoswitchable fluorophores to change emission intensity or wavelength(color)and thus validating the basis of the fluorescence on/offor dual-color photoswitching design.Generally the possible applications of any fluorophores are to label biological targets,followed by specific imaging.The newly developed photoswitchable fluorophores enable super-resolution fluorescence imaging because of their photosensitive emission.Finally,we summarize the important area regarding future research and development on photoswitchable fluorescent nanoparticles.
文摘In order to increase antibacterial abilities and avoid the aggregation of nanoparticle, Ag- ZnO nanocomposites were studied in the network structure which contains bonds, and these bonds are formed by hydrolysis reaction between Ti(TBOU)4(TBOT) and the water that in Persimmon tannin solution. The size and morphology of Ag-ZnO nanocompos:tes were investigated by scanning electron microscopy (SEM) and field emission scanning electron microscopy(FE-SEM). The antibacterial properties of nanocomposites were examined by minimal bactericidal concentration(MBC). Results showed that this kind of antibacterial nanocomposites composites(ANPs) have excellent antibacterial abilities and without aggregation.