Propyl-Sulfonic Acid Functionalized Nanoparticles as Catalyst for Pretreatment of Corn Stover

Propyl-sulfonic (PS) acid-functionalized nanoparticles were synthesized, characterized and evaluated as catalysts for pretreatment of corn stover. Silica coated nanoparticles were functionalized with 0.5% mercaptopropyltrimethoxysilane (MPTMS) at neutral pH in a mixture of water and ethanol. Sulfur contents of the acid functionalized nanoparticles, measured in a CHNS analyzer, varied from 6%-10%, and the acid load ranged from 0.040 to 0.066 mmol H+/g. A Box-Behnken design was employed to calculate the minimum number experiments required to obtain an estimate of the surface response for temperature, catalyst load, and %S content of the catalyst. Pretreatment of corn stover was carried out at three temperature levels 160, 180, and 200°C for 1 h. Three levels of catalyst load were used 0.1, 0.2, and 0.3 g of catalyst per gram of biomass. Hydro-thermolysis controls were carried at each temperature level. The catalyst load did not have an effect on the glucose yield at 160°C, and the average glucose yield obtained at this temperature was 59.0%. The glucose yield was linearly correlated to the catalyst load during pretreatment at 180°C, and a maximum glucose yield of 90% was reached when using 0.2 g of PS nanoparticles that had a total sulfur content of 6.1%. Complete hydrolysis of glucose was reached at 200°C but the average xylose yield was 4.6%, and about 20.2% of the combined glucose and xylose were lost as hydroxymethylfurfural and furfural. Results showed that acid-functionalized nanoparticles can be potential catalysts for the pretreatment of biomass for its later conversion to ethanol.

Functionalized selenium nanoparticles ameliorated acetaminophen-induced hepatotoxicity through synergistically triggering PKCδ/Nrf2 signaling pathway and inhibiting CYP 2E1

Selenium nanoparticles(SeNPs)have been demonstrated potential for use in diseases associated with oxidative stress.Functionalized SeNPs with lower toxicity and higher biocompatibility could bring better therapeutic activity and clinical application value.Herein,this work was conducted to investigate the protective effect of Pleurotus tuber-regium polysaccharide-protein complex funtionnalized SeNPs(PTR-SeNPs)against acetaminophen(APAP)-induced oxidative injure in HepG2 cells and C57BL/6J mouse liver.Further elucidation of the underlying molecular mechanism,in particular their modulation of Nrf2 signaling pathway was also performed.The results showed that PTR-SeNPs could significantly ameliorate APAP-induced oxidative injury as evidenced by a range of biochemical analysis,histopathological examination and immunoblotting study.PTR-SeNPs could hosphorylate and activate PKCδ,depress Keap1,and increase nuclear accumulation of Nrf2,resulting in upregulation of GCLC,GCLM,HO-1 and NQO-1 expression.Besides,PTR-SeNPs suppressed the biotransformation of APAP to generate intracellular ROS through CYP 2E1 inhibition,restoring the mitochondrial morphology.Furthermore,the protective effect of PTR-SeNPs against APAP induced hepatotoxicity was weakened as Nrf2 was depleted in vivo,indicating the pivotal role of Nrf2 signaling pathway in PTR-SeNPs mediated hepatoprotective efficacy.Being a potential hepatic protectant,PTR-SeNPs could serve as a new source of selenium supplement for health-promoting and biomedical applications.

Application of functionalized magnetic silica nanoparticles for selective induction of three coumarin metastable polymorphs

The precise control of active pharmaceutical ingredient(API)crystal nucleation and polymorphism is a key consideration in pharmaceutical manufacturing.In this study,tunable nanoparticles were developed to regulate the nucleation process of coumarin.Magnetic silica nanoparticles with four different functional groups(-NH_(2),-COOH,-SH,-NCO)were prepared and coated on the substrate for inducing the crystallization of coumarin.Confined melt crystallization and microspacing sublimation crystallization methods were used to investigate the regulation mechanism.The results indicated that three metastable forms of coumarin can be obtained as pure components based on the combined influence of crystallization methods and functionalized nanoparticles.FormⅡcould be selectively obtained by microspacing sublimation crystallization on Fe_(3)O_(4)@SiO_(2)-SH substrates,and FormⅣcould be obtained by confined melt crystallization on Fe_(3)O_(4)@SiO_(2)-NCO substrates.FormⅢcould be obtained by further heating FormⅣcrystals to 52℃on Fe_(3)O_(4)@SiO_(2)-NCO substrates.Moreover,the polarized light microscopy results also indicated that the introduction of nanoparticles could also increase the stability of the metastable crystalline forms of coumarin.Finally,the diffusion and surface dynamics during nanoparticle induced crystallization were comparatively investigated and the corresponding polymorphic selectivity mechanism was proposed.

Potentiometric detection of polyions based on functionalized magnetic nanopaiticles

A novel potentiometric detection strategy based on functionalized magnetic nanoparticles has been developed for rapid and sensitive sensing of polyions.Highly dispersed magnetic nanoparticles coated with ion exchanger and plasticizer could promote an in situ cooperative ion-pairing interaction between the ion exchanger and the polyion analyte in sample solution by dramatically reducing the mass-transfer distance.With applying a magnetic field,the nanoparticles can be attached to the surface of ion exchanger free polymeric membrane.The observed potential signals are related to the polyion concentrations.The proposed polymeric membrane electrode exhibits a linear relationship between the greatest potential response slope（dE/dt） and the logarithm of protamine concentration in the range of 0.05-5μg/mL with a lower detection limit of 0.033μg/mL.

TPGS/hyaluronic acid dual-functionalized PLGA nanoparticles delivered through dissolving microneedles for markedly improved chemo-photothermal combined therapy of superficial tumor

Nanoparticles(NPs)have shown potential in cancer therapy,while a single administration conferring a satisfactory outcome is still unavailable.To address this issue,the dissolving microneedles(DMNs)were developed to locally deliver functionalized NPs with combined chemotherapy and photothermal therapy(PTT).α-Tocopheryl polyethylene glycol succinate(TPGS)/hyaluronic acid(HA)dualfunctionalized PLGA NPs(HD10 NPs)were fabricated to co-load paclitaxel and indocyanine green.HD10 NPs significantly enhanced the cytotoxicity of low-dose paclitaxel because of active and mitochondrial targeting by HA and TPGS,respectively.PTT could further sensitize tumor cells toward chemotherapy by promoting apoptosis into the advanced period,highly activating caspase 3 enzyme,and significantly reducing the expression of survivin and MMP-9 proteins.Further,the anti-tumor effects of HD10 NPs delivered through different administration routes were conducted on the 4 T1 tumorbearing mice.After a single administration,HD10 NPs delivered with DMNs showed the best antitumor effect when giving chemotherapy alone.As expected,the anti-tumor effect was profoundly enhanced after combined therapy,and complete tumor ablation was achieved in the mice treated with DMNs and intra-tumor injection.Moreover,DMNs showed better safety due to moderate hyperthermia.Therefore,the DMNs along with combined chemo-photothermal therapy provide a viable treatment option for superficial tumors.

Structural and Mechanistic Studies of γ-Fe2O3 Nanoparticle as Capecitabine Drug Nanocarrier

Using density functional theory,noncovalent interactions and four mechanisms of covalent functionalization of capecitabine anticancer drug onto γ-Fe2O3 nanoparticles have been investigated.Quantum molecular descriptors of noncovalent configurations were studied.It was specified that binding of capecitabine onto γ-Fe2O3 nanoparticles is thermodynamically suitable.Hardness and the gap of energy between LUMO and HOMO of capecitabine are higher than the noncovalent configurations,showing the reactivity of capecitabine increases in the presence of γ-Fe2O3 nanoparticles.Capecitabine can bond to γ-Fe2O3 nanoparticles through OH（k1 mechanism）,NH（k2 mechanism）,CO（k3 mechanism） and F（k4 mechanism） groups.The activation energies,activation enthalpies and activation Gibbs free energies of these reactions were calculated.It was specified that the k1 and k2 mechanisms are under thermodynamic control and k3 and k4 under kinetic control.These results could be generalized to other similar drugs.

Green synthesis of functional metallic nanoparticles by dissimilatory metal-reducing bacteria“Shewanella”:A comprehensive review

The biosynthesis strategy of nanoparticles has attracted much attention due to the mild synthesis condi-tions,environmental-friendly properties,and low costs.Biosynthesized nanoparticles(bio-NPs)not only show excellent physicochemical properties,but also exhibit high stability,enlarged specific surface area,and excellent biocompatibility,which are crucial for industrial,agricultural,and medical fields.She-wanella,a kind of dissimilatory metal-reducing bacteria,is regarded as a typical biosynthesis-functional bacteria class with wide distribution and strong adaptability.Thus,in this paper,functional bio-NPs by Shewanella were reviewed to provide a comprehensive view of current research progress.The biosynthetic mechanisms of Shewanella are summarized as the Mtr pathway(predominant),extracellular polymeric substance-induced pathway,and enzyme/protein-induced pathway.During the biosynthesis process,bio-logical factors along with the physicochemical parameters highly influenced the properties of the resul-tant bio-NPs.Till now,bio-NPs have been applied in various fields including environmental remediation,antibacterial applications,and microbial fuel cells.However,some challenging issues of bio-NPs by She-wanella remain unsolved,such as optimizing suitable bacterial strains,intelligently controlling bio-NPs,clarifying biosynthesis mechanisms,and expanding bio-NPs applications.

Fe_(3)O_(4)@silica nanoparticles for reliable identification and magnetic separation of Listeria monocytogenes based on molecular-scale physiochemical interactions

Listeria monocytogenes(L.monocytogenes)is one of the top five dangerous foodborne pathogens which widely exists in most raw food and has approximately 30%mortality rate in high-risk groups.Food safety caused by foodborne pathogens is still a major problem faced by humans in all world.The conventional analytical methods currently used involve complex bacteriological tests and usually take several days for incubation and analysis.Thus,in order to prevent the spread of disease,the development of a detection method with high speed,high accuracy and sensitivity is urgent and necessary.Herein,we developed an approach for the identification and magnetic capture of L.monocytogenes by using core@shell Fe_(3)O_(4)@silica nanoparticles terminated with hydroxyl or amine groups.Our results show that both amine-and hydroxyl-terminated Fe_(3)O_(4)@silica core@shell nanoparticles functionalized with specific antibodies,present 95.2%±6.2%and 98.6%±0.3%capture efficacies,respectively.However,without conjugating the specific antibodies,the hydroxyl-terminated Fe_(3)O_(4)@silica nanoparticles exhibit 17.6%±1.6%efficacy,while the amine-terminated one remains 93.2%±9.2%capture efficiency ascribed to the high affinity.This study quantitatively uncovers the specific and non-specific recognitions relevant to the molecular-scale physiochemical interactions between the microorganisms and the functionalized particles,and the results from this work can be generalized and extended to other bacterial species by changing antibodies,also have important implications in developing advanced analytic methods.

Uptake of citrate-coated iron oxide nanoparticles into atherosclerotic lesions in mice occurs via accelerated transcytosis through plaque endothelial cells

Very small superparamagnetic iron oxide nanoparticles （VSOPs） rapidly accumulate in atherosclerotic lesions, thereby enabling plaque visualization by magnetic resonance imaging （MRI）. This study was performed to identify the uptake mechanisms of VSOPs into atherosclerotic plaques. Low-density lipoprotein receptor-deficient （LDLR^-/-） mice with advanced atherosclerosis were analyzed using MRI and transmission electron microscopy （TEM） at various time points after intravenous administration of VSOPs. Post-mortem MRI detected VSOP labeling of atherosclerotic plaques 10 min after injection, and the signal increased over the first 3 h. TEM revealed that the intensive plaque labeling was mediated by accelerated transcytosis of VSOPs through endothelial cells overlaying atherosclerotic lesions. Experiments with endocytosis inhibitors and small interfering RNA （siRNA） revealed a dynamin-dependent mechanism involving both clathrin- and caveolin-mediated processes. In cell culture experiments, endothelial VSOP uptake was enhanced under proatherogenic flow and TNFα stimulation, conditions that are both present in plaque areas. Our study demonstrates that VSOPs enable non-invasive MRI assessment of accelerated endothelial transcytosis, an important pathomechanism in atherosclerotic plaque formation.

Dopamine-triggered one-step functionalization of hollow silica nanospheres for simultaneous lubrication and drug release

Osteoarthritis(OA)has been regarded as a lubrication deficiency related joint disease.Combination of both joint lubrication and drug intervention may provide a promising nonsurgical strategy for treatment of OA.Developing novel and simple approaches to fabricate superlubricating nanoparticles with drug release property is highly required.Herein,dopamine triggered one-step polymerization method was employed to fabricate polydopamine/poly(3-sulfopropyl methacrylate potassium salt)(PDA-PSPMA)conjugate coating on hollow silica(h-SiO_(2))nanosphere surfaces to engineer functional nanoparticles(h-SiO_(2)/PDA-PSPMA).The as-prepared h-SiO_(2)/PDA-PSPMA exhibits excellent aqueous lubrication performance on biomaterial substrates as well as natural bovine articular cartilage based on hydration effect of negatively charged PDA-PSPMA coating and"rolling"effect of h-SiO_(2)nanospheres.In vitro drug loading-release experiments demonstrate that PDA-PSPMA coating functionalized h-SiO_(2)nanospheres show high drug-loading and sustained-release capability of an anti-inflammatory drug,diclofenac sodium(DS).Such h-SiO_(2)/PDA-PSPMA nanospheres can be potentially used as a synergistic therapy agent for OA treatment combining by simultaneous joint lubrication anddrugrelease.

CD44 and CD221 directed magnetic cubosomes for the targeted delivery of helenalin to rhabdomyosarcoma cells

Confining chemotherapy to tumour sites by means of active targeting nanoparticles(NPs)may increase the treatment effectuality while reducing potential side effects.Cubosomes are one of the next-generation drug delivery nanocarriers by virtue of their biocompatibility and bioadhesion,sizeable payload encapsulation and high thermostability.Herein,an active tumour targeting system towards rhabdomyosarcoma(RMS)cells was evaluated.Cubosomes were loaded with helenalin(a secondary metabolite from Arnica plants),which we have previously shown to induce apoptosis in RMS cells.The functionalization of the cubosomes was accomplished to enable binding to membrane receptors and translocation under a magnetic field.RMS cells overexpress CD44 and CD221 on their membrane surface and,therefore,hyaluronic acid(HA,a ligand for CD44)and antibodies(Abs)against CD221 were coupled to cubosomes via electrostatic attraction and the thiol-Michael reaction,respectively.Magnetization of the cubic phase NPs was achieved by embedding superparamagnetic iron oxide NPs(SPIONPs)into the cubic matrix.Single-function and multi-function cubosomes had Im3m cubic phase structures with well-organized lattice patterns.Conjugation with 2%HA or anti-CD221 half Abs and/or 1%SPIONPs showed significantly higher uptake into RMS cells compared to unfunctionalized cubosomes.CD44 and CD221 directed magnetic(triple-function)cubosomes were capable of internalizing into RMS cells in an energy-independent mechanism.Helenalin-laden triple functionalized cubosomes showed limited impact on the viability of control fibroblast cells,while they induced a high degree cytotoxicity against RMS cells.Profound tumour cell death was observed in both two-dimensional(2D)culture and three-dimensional(3D)tumour spheroids.

Effect of the Nanoparticle Functionalization on the Cavitation and Crazing Process in the Polymer Nanocomposites

The nanoparticle(NP) functionalization is an effective method for enhancing their compatibility with polymer which can influence the fracture property of the polymer nanocomposites(PNCs). This work aims to further understand the cavitation and crazing process, hoping to uncover the fracture mechanism on the molecular level. By adopting a coarse-grained molecular dynamics simulation, the fracture energy of PNCs first increases and then decreases with increasing the NP functionalization degree α while it shows a continuous increase with increasing the interaction εpA between polymer and modified beads. The bond orientation degree is first characterized which is referred to as the elongation. Meanwhile, the stress by polymer chains is gradually reduced with increasing the α or the εpA while that by NPs is enhanced.Furthermore, the percentage of stress by polymer chains first increases and then decreases with increasing the strain while that by NPs shows a contrast trend. Moreover, the number of voids is quantified which first increases and then decreases with increasing the strain which reflects their nucleation and coalescence process. The voids prefer to generate from the polymer-NP interface to the polymer matrix with increasing α o r εpA.As a result, the number of voids first increases and then decreases with increasing α while it continuously declines with the εpA. In summary, our work provides a clear understanding on how the NP functionalization influences the cavitation and crazing process during the fracture process.