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1.
Small ; 20(10): e2306341, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37903360

RESUMO

Pd-based electrocatalysts are the most effective catalysts for ethylene glycol oxidation reaction (EGOR), while the disadvantages of poor stability, low resistance to neutrophilic, and low catalytic activity seriously hamper the development of direct ethylene glycol fuel cells (DEGFCs). In this work, defect-riched PdCoZn nanosheets (D-PdCoZn NSs) with ultrathin 2D NSs and porous structures are fabricated through the solvothermal and alkali etching processes. Benefiting from the presence of defects and ultrathin 2D structures, D-PdCoZn NSs demonstrate excellent electrocatalytic activity and good durability against EGOR in alkaline media. The mass activity and specific activity of D-PdCoZn NSs for EGOR are 9.5 A mg-1 and 15.7 mA cm-2 , respectively, which are higher than that of PdCoZn NSs, PdCo NSs, and Pd black. The D-PdCoZn NSs still maintain satisfactory mass activity after long-term durability tests. Meanwhile, in situ IR spectroscopy demonstrates that the presence of defects attenuated the adsorption of intermediates, which improves the selectivity of the C1 pathway with excellent anti-CO poisoning performance. This work not only provides an effective synthetic strategy for the preparation of Pd-based nanomaterials with defective structures but also indicates significant guidance for optimum C1 pathway selectivity of ethylene glycol and other challenging chemical transformations.

2.
Small ; 19(52): e2305343, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37635101

RESUMO

Design high-loading with superior activity and high atomic efficiency has consistently been a new frontier of heterogeneous catalysis while challenging in synthetic technology. In this work, a universal solid-state strategy is proposed for large scalable production of high-loading Ir clusters on porous hollow carbon nanobowls (Ir CSs/PHCNBs). The strong electronic interaction between metallic Ir cluster and C on PHCNBs leads to electron redistribution, which significantly improves the electron transfer rate on the interface. The obtained Ir CSs/PHCNBs only require overpotentials of 35, 34, and 37 mV for the hydrogen evolution reaction (HER) with stable outputting of 10 mA cm-2 under acidic, alkaline, and neutral conditions, respectively, which exceeds the state-of-the-art HER electrocatalysts. Meanwhile, the Tafel slopes of Ir CSs/PHCNBs for the HER process are 23.07, 48.76, and 28.95 mV dec-1 , greatly lower than that of PHCNBs (152.73, 227.96, and 140.29 mV dec-1 ) and commercial Pt/C (20%) (36.33, 66.10, and 36.61 mV dec-1 ). These results provide a new strategy for the universal synthesis of clusters catalysts and insight into understanding the interface effects between clusters and carbon substrate, facilitating the industrial application of hydrogen production.

3.
Inorg Chem ; 62(41): 17012-17021, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37791743

RESUMO

Efficient and low-cost electrocatalysts for the hydrogen evolution reaction (HER) are required for producing hydrogen energy through water splitting. Carbon materials as HER catalyst supports are explored widely since the strong metal-support interactions are generally believed to be active and stable toward HER. Herein, we report N-doped porous carbon materials as novel substrates to stabilize the cluster metal sites through the Ru(III) polyamine complexes, which play an important role not only in efficient electron transfer but also in the increasing utilization of metallic active sites. Meanwhile, due to the strong metal-support interactions driven by Ru(III) polyamine complexes, the obtained Ru cluster with a mass loading of 3% on N-doped porous carbon nanoplates (Ru cluster@NCs) exhibits robust stability for HER at a constant voltage, proving to be a promising candidate catalyst for HER. Density functional theory calculations further indicate that the Gibbs free energy (ΔG) of adsorbed H* of Ru cluster@NCs is much closer to zero compared to Ru@(10%)NCs and Pt/C(20%), thus Ru cluster@NCs facilitate the HER process.

4.
Inorg Chem ; 62(24): 9687-9694, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37267518

RESUMO

Molybdenum phosphide (MoP) has received increasing attention for the hydrogen evolution reaction (HER) due to its Pt-like electronic structure and high electrical conductivity. In this work, a flake-like Ru-doped MoP with phosphorus vacancy (Ru-MoP-PV) electrocatalyst is synthesized for the first time by a simple and rapid room-temperature microwave approach within 30 s. The created abundant phosphorus vacancies provide rich active sites and favor rapid electron transfer. The introduced Ru also enhances the catalytic activity of the synthesized electrocatalyst efficiently. Then, the designed Ru-MoP-PV possesses low overpotentials for HER with 79, 100, and 161 mV in 1.0 M KOH, 0.5 M H2SO4, and 1.0 M phosphate-buffered saline to obtain 10 mA cm-2. The Ru-MoP-PV and NiFe-layered double hydroxide are used as the cathode and the anode, respectively, to drive water splitting and just need a low cell voltage of 1.6 V to achieve 10 mA cm-2. This work provides a feasible way for the rapid production of metal phosphides for energy conversion and storage applications.

5.
Inorg Chem ; 62(51): 21508-21517, 2023 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-38064289

RESUMO

Transition metal phosphides are ideal inexpensive electrocatalysts for water-splitting, but the catalytic activity still falls behind that of noble metal catalysts. Therefore, developing valid strategies to boost the electrocatalytic activity is urgent to promote large-scale applications. Herein, a microwave combustion strategy (20 s) is applied to synthesize N-doped CoP/Ni2P heterojunctions (N-CoP/Ni2P) with porous structure. The porous structure expands the specific surface area and accelerates the mass transport efficiency. Importantly, the pyrrolic N/pyridinic N content is adjusted by changing the amount of urea during the synthesis process and then optimizing the adsorption/desorption capacity for H*/OH* to enhance the catalyst activity. Then, the synthesized N-CoP/Ni2P exhibits small overpotentials of 111 and 133 mV for HER in acidic and alkaline electrolytes and 290 mV for OER in alkaline electrolytes. This work provides an original and efficient approach to the synthesis of porous metal phosphides.

6.
Angew Chem Int Ed Engl ; 62(14): e202300406, 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-36754865

RESUMO

Oxygen vacancies-enriched black TiO2 is one promising support for enhancing hydrogen evolution reaction (HER). Herein, oxygen vacancies enriched black TiO2 supported sub-nanometer Pt clusters (Pt/TiO2 -OV ) with metal support interactions is designed through solvent-free microwave and following low-temperature electroless approach for the first time. High-temperature and strong reductants are not required and then can avoid the aggregation of decorated Pt species. Experimental and theoretical calculation verify that the created oxygen vacancies and Pt clusters exhibit synergistic effects for optimizing the reaction kinetics. Based on it, Pt/TiO2 -OV presents remarkable electrocatalytic performance with 18 mV to achieve 10 mA cm-2 coupled with small Tafel slope of 12 mV dec-1 . This work provides quick synthetic strategy for preparing black titanium dioxide based nanomaterials.

7.
J Biol Chem ; 289(5): 2776-87, 2014 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-24302723

RESUMO

Magnesium is widely used to control calcium carbonate deposition in the shell of pearl oysters. Matrix proteins in the shell are responsible for nucleation and growth of calcium carbonate crystals. However, there is no direct evidence supporting a connection between matrix proteins and magnesium. Here, we identified a novel acidic matrix protein named PfN44 that affected aragonite formation in the shell of the pearl oyster Pinctada fucata. Using immunogold labeling assays, we found PfN44 in both the nacreous and prismatic layers. In shell repair, PfN44 was repressed, whereas other matrix proteins were up-regulated. Disturbing the function of PfN44 by RNAi led to the deposition of porous nacreous tablets with overgrowth of crystals in the nacreous layer. By in vitro circular dichroism spectra and fluorescence quenching, we found that PfN44 bound to both calcium and magnesium with a stronger affinity for magnesium. During in vitro calcium carbonate crystallization and calcification of amorphous calcium carbonate, PfN44 regulated the magnesium content of crystalline carbonate polymorphs and stabilized magnesium calcite to inhibit aragonite deposition. Taken together, our results suggested that by stabilizing magnesium calcite to inhibit aragonite deposition, PfN44 participated in P. fucata shell formation. These observations extend our understanding of the connections between matrix proteins and magnesium.


Assuntos
Carbonato de Cálcio/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Magnésio/metabolismo , Pinctada/metabolismo , Ácidos/metabolismo , Sequência de Aminoácidos , Animais , Cálcio/química , Cálcio/metabolismo , Carbonato de Cálcio/química , Biologia Computacional , Cristalização , Proteínas da Matriz Extracelular/química , Proteínas da Matriz Extracelular/genética , Magnésio/química , Dados de Sequência Molecular , Nácar/química , Nácar/metabolismo , Pinctada/química , Pinctada/genética , Coelhos
8.
BMC Genomics ; 16: 325, 2015 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-25927556

RESUMO

BACKGROUND: The molluscan Pinctada fucata is an important pearl-culturing organism to study biomineralization mechanisms. Several biomineralization-related genes play important roles regulating shell formation, but most previous work has focused only on their functions in adult oysters. Few studies have investigated biomineralization during larval development, when the shell is initially constructed and formed until the juvenile stage in dissoconch shells. Here, we report, for the first time, a global gene analysis during larval development of P. fucata based on a microarray and reveal the relationships between biomineralization-related genes and the shell formation process. RESULTS: Based on the P. fucata mantle transcriptome, 58,940 probes (60 nt), representing 58,623 transcripts, were synthesized. The gene expression profiles of the fertilized egg, trochophore, D-shaped, and umbonal stage larvae, as well as juveniles were analyzed by microarray performance. The expression patterns of the biomineralization-related genes changed corresponding to their regulatory function during shell formation. Matrix proteins chitin synthase and PFMG2 were highly expressed at the D-shaped stage, whereas PFMG6, PFMG8 and PfN23 were significantly up-regulated at the umbonal stage, indicating different roles regulating the formation of either periostracum, Prodissoconch I or Prodissoconch II shells. However, the majority of matrix proteins were expressed at high levels at the juvenile stage, and the shells comprised both an aragonitic nacreous layer and a calcitic prismatic layer as adults. We also identified five new genes that were significantly up-regulated in juveniles. These genes were expressed particularly in the mantle and coded for secreted proteins with tandem-arranged repeat units, as most matrix proteins. RNAi knockdown resulted in disrupted nacreous and prismatic shell layers, indicating their potential roles in shell formation. CONCLUSIONS: Our results add a global perspective on larval expression patterns of P. fucata genes and propose a mechanism of how biomineralization-related genes regulate the larval shell formation process. These results increase knowledge about biomineralization-related genes and highlight new aspects of shell formation mechanisms.


Assuntos
Perfilação da Expressão Gênica/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Pinctada/crescimento & desenvolvimento , Pinctada/genética , Exoesqueleto/metabolismo , Animais , Regulação da Expressão Gênica no Desenvolvimento , Larva/anatomia & histologia , Larva/genética , Larva/crescimento & desenvolvimento , Minerais/metabolismo , Pinctada/anatomia & histologia
9.
Acta Biochim Biophys Sin (Shanghai) ; 46(8): 709-19, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25001481

RESUMO

The Shematrin family is unique to the organic matrices of pearl oyster shells, containing repetitive, low-complexity domains designated as XGnX (where X is a hydrophobic amino acid). Current studies suggested that Shematrins are framework proteins in the prismatic layer of Pinctada fucata; however, the exact function of Shematrin during shell formation is unclear. In this study, we cloned and characterized Shematrin, a protein highly homologous to Shematrin-2, from the mantle tissue of scallop (Chlamys farreri). Semi-quantitative reverse transcript polymerase chain reaction analysis showed that Shematrin is exclusively expressed in the mantle. Knocking down the expression of Shematrin in adult scallops via double-stranded RNA injection led to an abnormal folia surface. After the shell was notched, the expression level of Shematrin remarkably increased and then gradually decreased, suggesting that Shematrin is critically involved in the shell repair progress. Injection of Shematrin double-stranded RNA reduced the speed of shell regeneration and caused abnormal surface morphology of the regenerated shell. The RNA interference and shell notching experiments indicated that Shematrin plays a key role in the folia formation of C. farreri. Structure prediction showed that Shematrin may be an intrinsically disordered protein, with high flexibility and elasticity of the molecular conformation, which facilitate binding multiple protein partners. Based on the structure features, we hypothesized that Shematrin may participate in framework organization via binding with several specific acidic proteins, functioning as a molecular hub in the protein interaction networks.


Assuntos
Proteínas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Primers do DNA , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Pectinidae , Reação em Cadeia da Polimerase , Proteínas/química , Interferência de RNA , Espectroscopia de Infravermelho com Transformada de Fourier
10.
J Colloid Interface Sci ; 669: 856-863, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38749224

RESUMO

Developing electrocatalysts with high activity and durability for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in both acidic and alkaline electrolytes remains challenging. In this study, we synthesize a self-supported ruthenium-iron oxide on carbon cloth (Ru-Fe-Ox/CC) using solvothermal methods followed by air calcination. The morphology of the nanoparticle exposes numerous active sites vital for electrocatalysis. Additionally, the strong electronic interaction between Ru and Fe enhances electrocatalytic kinetics optimization. The porous structure of the carbon cloth matrix facilitates mass transport, improving electrolyte penetration and bubble release. Consequently, Ru-Fe-Ox/CC demonstrates excellent catalytic performance, achieving low overpotentials of 32 mV and 28 mV for HER and 216 mV and 228 mV for OER in acidic and alkaline electrolytes, respectively. Notably, only 1.48 V and 1.46 V are required to reach 10 mA cm-2 for efficient water-splitting in both mediums, exhibiting remarkable stability. This research offers insights into designing versatile, highly efficient catalysts suitable for varied pH conditions.

11.
Nanoscale ; 16(29): 14057-14065, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-38994556

RESUMO

As a technology for emerging environmental applications, water electrolysis is a significant approach for producing clean hydrogen energy. In this work, we used an efficacious piezoelectric method to significantly improve the catalytic water splitting activity without affecting the morphology as well as the components by altering the bulk charge separation state inside the material. The obtained CuCo2O4 nanorods were treated under a corona polarization apparatus, which significantly enhanced ferroelectricity relative to that before the polarization increasing the physical charge separation and piezoelectric potential energy, enhancing the green hydrogen production. The polarized CuCo2O4 nanorods exhibit excellent water electrolysis performance under alkaline conditions, with hydrogen evolution overpotential of 78.7 mV and oxygen evolution overpotential of 299 mV at 10 mA cm-2, which is much better than that of unpolarized CuCo2O4 nanorods. Moreover, the Tafel slopes of polarized CuCo2O4 nanorods are 86.9 mV dec-1 in the HER process and 73.1 mV dec-1 in the OER process, which are much lower than commercial catalysts of Pt/C (88.0 mV dec-1 for HER) or RuO2 (78.5 mV dec-1 for OER), proving faster kinetic on polarized CuCo2O4 nanorods due to their higher electroconductibility and intrinsic activity. In particular, polarized CuCo2O4 nanorods are identified as promising catalysts for water electrolysis with robust stability, offering outstanding catalytic performance and excellent energy efficiency.

12.
Adv Mater ; 36(13): e2311018, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38101817

RESUMO

Anionic modification engineering is a crucial approach to develop highly efficient electrocatalysts for hydrogen evolution reaction. Herein, halogen elements (X = Cl, Br, and I)-modified Ru-based nanosheets (X-Ru/RuP2) are designed by rapid and eco-friendly microwave-phosphide plasma approach within 60 s. Experimental and density functional theory calculations verify that the introduced halogen element, especially Br, can optimize the surface intermediates adsorption. Specially, the designed Br-Ru/RuP2 favors the water dissociation and following hydrogen adsorption/desorption process. Then, the as-synthesized Br-Ru/RuP2 exhibits low overpotential of 34 mV to reach 10 mA cm-2 coupled with small Tafel slope of 27 mV dec-1 in alkaline electrolyte with excellent long-term stability. Moreover, the electrocatalytic performances in acid and neutral media are also boosted via Br element modification. This work paves a novel way to regulate the electronic structure of Ru-based compounds, and then can boost the electrocatalytic kinetics.

13.
Small Methods ; 7(1): e2201225, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36549895

RESUMO

The electrocatalytic nitrogen reduction reaction (NRR) is emerging as a great promise for ambient and sustainable NH3 production while it still suffers from the high adsorption energy of N2 , the difficulty of *NN protonation, and inevitable hydrogen evolution, leading to a great challenge for efficient NRR. Herein, we synthesized a series of amorphous trimetal Pd-based (PdCoM (M = Cu, Ag, Fe, Mo)) nanosheets (NSs) with an ultrathin 2D structure, which shows high efficiency and robust electrocatalytic nitrogen fixation. Among them, amorphous PdCoCu NSs exhibit excellent NRR activity at low overpotentials with an NH3 yield of 60.68 µg h-1 mgcat -1 and a corresponding Faraday efficiency of 42.93% at -0.05 V versus reversible hydrogen electrode as well as outstanding stability with only 5% decrease after a long test period of 40 h at room temperature. The superior NRR activity and robust stability should be attributed to the large specific surface area, abundant active sites as well as structural engineering and electronic effect that boosts up the Pd 4d band center, which further efficiently restrains the hydrogen evolution. This work offers an opportunity for more energy conversion devices through the novel strategy for designing active and stable catalysts.


Assuntos
Amônia , Eletrônica , Adsorção , Eletrodos , Hidrogênio , Nitrogênio
14.
J Colloid Interface Sci ; 646: 391-398, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37207421

RESUMO

Developing a facile and time-saving method for preparing hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalysts can accelerate the practical applications of hydrogen energy. In this study, halogen (X = F, Cl, Br and I) doped Ru-RuO2 on carbon cloth (CC) (X-Ru-RuO2/MCC) was synthesized via an ultrafast microwave-assisted method for 30 s. Particularly, the doped Br (Br-Ru-RuO2/MCC) significantly improved the electrocatalytic performances of the catalyst through the regulation of electronic structures. Then, the Br-Ru-RuO2/MCC catalyst featured HER overpotentials of 44 mV and 77 mV in 1.0 M KOH and 0.5 M H2SO4, and the OER overpotential of 300 mV at 10 mA cm-2 in 1.0 M KOH. This study provides a novel method for developing of halogen-doped catalysts.

15.
Drug Deliv ; 27(1): 1360-1368, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32985911

RESUMO

Food protein and polysaccharide complex emulsions are safe carriers of hydrophobic drugs and nutrients. To improve oral bioavailability and therapeutic/healthy efficacy of hydrophobic drugs and nutrients, herein, protamine (PRO), a cationic cell-penetrating peptide, was introduced into protein and polysaccharide complex emulsion. The electrostatic complex of PRO and BSA-dextran conjugate (BD) produced by Maillard reaction was used as emulsifier to produce oil-in-water emulsion (@BD/PRO). The BSA molecules were crosslinked at the oil-water interface by a heat treatment and the PRO chains were simultaneously anchored in the interface. BD emulsion (@BD) without PRO was produced for comparation. Paclitaxel (PTX), a hydrophobic antineoplastic drug, was encapsulated in the emulsions with 99% loading efficiency and 6.4% loading capacity. The emulsions had long-term stability. The bioavailability and H22 tumor inhibition efficacy of PTX@BD/PRO were 40% and 70% higher than those of PTX@BD, respectively, after oral administration in the mice. More importantly, orally administrated PTX@BD/PRO had the same anti-tumor efficacy as intravenously injected commercial PTX injection. No abnormality was observed in the main organs of the mice after consecutive oral administration of PTX@BD/PRO. This study indicates that @BD/PRO is an excellent carrier of hydrophobic drugs/nutrients and is suitable for long-term oral administration.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Dextranos/administração & dosagem , Trato Gastrointestinal/efeitos dos fármacos , Paclitaxel/administração & dosagem , Protaminas/administração & dosagem , Soroalbumina Bovina/administração & dosagem , Administração Oral , Animais , Antineoplásicos Fitogênicos/metabolismo , Disponibilidade Biológica , Dextranos/metabolismo , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/metabolismo , Trato Gastrointestinal/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Paclitaxel/metabolismo , Protaminas/metabolismo , Soroalbumina Bovina/metabolismo , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
16.
Nanoscale ; 12(21): 11526-11535, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32432270

RESUMO

Water electrolysis is an environmentally friendly and sustainable technique for ultra-pure hydrogen production, while expensive electrode materials and high driving voltage have seriously hindered its commercialization process. Here, Earth-abundant bifunctional porous Ni2P hollow nanotubes on nickel foam (Ni2P-HNTs/NF) electrocatalysts are synthesized through a facile self-template method and a phosphating process, which are perfectly combined with the hydrazine electrooxidation reaction (HzOR) boosted water electrolysis. Benefiting from the unique structural characteristic of open-framework and abundant step atoms, Ni2P-HNTs/NF achieves 10 mA cm-2 at 91 mV (vs. RHE) for the cathodic hydrogen evolution reaction and 18 mV (vs. RHE) for the anodic HzOR in a three electrode system, respectively. The corresponding two-electrode hydrazine electrolyzer produces 10 mA cm-2 with a total voltage of only 152 mV for ultra-pure hydrogen production, highlighting a cost-effective and energy-saving water electrolysis mode.

17.
Nanoscale ; 11(28): 13477-13483, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31287477

RESUMO

Direct ethanol fuel cells (DEFCs) with a high conversion efficiency are quite promising candidates for energy conversion devices. Herein, we have successfully synthesized PdCo alloy nanocubes supported on carbon nanobowl (denoted as Pd2Co1/CNB) nanohybrids by using the cyanogel auto-reduction method at high temperature. The morphology, composition and structure of Pd2Co1/CNB nanohybrids are characterized in detail, revealing that PdCo nanocubes have a high alloying degree and special {110} facets. In cyclic voltammetry measurements, Pd2Co1/CNB nanohybrids show a mass activity of 1089.0 A g Pd-1 and a specific activity of 40.03 mA cm-2 for ethanol electrooxidation at peak potential, which are much higher than that of the commercial Pd/C electrocatalyst (278.2 A gPd-1 and 8.22 mA cm-2). Additionally, chronoamperometry measurements show that Pd2Co1/CNB nanohybrids have excellent durability for ethanol electrooxidation. A high alloying degree, special {110} facets and the CNB supporting material contribute to the high activity and durability of Pd2Co1/CNB nanohybrids, making them a highly promising Pt-alternative electrocatalyst for ethanol electrooxidation in DEFCs.

18.
Drug Deliv ; 25(1): 1224-1233, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29791242

RESUMO

Liver is the primary acting site of insulin. In this study, we developed innovative nanoparticles for oral and liver-targeted delivery of insulin by using enterohepatic circulation of bile acids. The nanoparticles were produced from cholic acid and quaternary ammonium modified chitosan derivative and hydroxypropyl methylcellulose phthalate (HPMCP). The nanoparticles had a diameter of 239 nm, an insulin loading efficiency of 90.9%, and a loading capacity of 18.2%. Cell culture studies revealed that the cholic acid groups effectively enhanced the transport of the nanoparticles through Caco-2 cell monolayer and greatly increased the absorption of the nanoparticles in HepG-2 cells via bile acid transporter mechanism. Ex vivo fluorescence images of ileum section, gastrointestinal tract, and liver demonstrated that the HPMCP increased the mucoadhesion of the nanoparticles in ileum, and the cholic acid groups facilitated the absorptions of the nanoparticles in both ileum and liver by use of bile acid transporters via enterohepatic circulation of bile acids. The therapy for diabetic mice displayed that the oral nanoparticle group could maintain hypoglycemic effect for more than 24 h and its pharmacological availability was about 30% compared with the insulin injection group. For the first time, this study demonstrates that using enterohepatic circulation of bile acids is an effective strategy for oral delivery of insulin.


Assuntos
Ácidos e Sais Biliares/metabolismo , Circulação Êntero-Hepática/efeitos dos fármacos , Insulina/farmacologia , Fígado/efeitos dos fármacos , Nanopartículas/química , Animais , Glicemia/efeitos dos fármacos , Células CACO-2 , Linhagem Celular Tumoral , Quitosana/química , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Feminino , Células Hep G2 , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Insulina/química , Fígado/metabolismo , Masculino , Metilcelulose/análogos & derivados , Metilcelulose/química , Camundongos Endogâmicos ICR
19.
Sci Rep ; 8(1): 3563, 2018 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-29476076

RESUMO

Kinase-family with sequence similarity 20, member C (Fam20C) is a protein kinase, which can phosphorylate biomineralization related proteins in vertebrate animals. However, the function of Fam20C in invertebrate animals especially the role in biomineralization is still unknown. Herein, we cloned the cDNA of fam20C from the pearl oyster, Pinctada fucata. It is showed that the expression of fam20C in the mantle edge was much higher than other tissues. In situ hybridization showed that fam20C was expressed mostly in the outer epithelial cells of the middle fold, indicating it may play important roles in the shell formation. Besides, fam20C expression increased greatly in the D-shape stage of pearl oyster development, when the shell was first formed. During the shell repair process, the expression level of fam20C increased 1.5 times at 6 h after shell notching. Knockdown of fam20C in vivo by RNA interference resulted in abnormally stacking of calcium carbonate crystals at the edges of nacre tablets, showing direct evidence that fam20C participates in the shell formation. This study provides an insight into the role of kinase protein in the shell formation in mollusk and broaden our understanding of biomineralization mechanism.


Assuntos
Exoesqueleto/crescimento & desenvolvimento , Calcificação Fisiológica/genética , Caseína Quinase I/genética , Pinctada/genética , Animais , Biomineralização/genética , Proteínas de Ligação ao Cálcio/genética , Clonagem Molecular , DNA Complementar/genética , Proteínas da Matriz Extracelular/genética , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Hibridização In Situ , Pinctada/crescimento & desenvolvimento , Transporte Proteico/genética , Interferência de RNA
20.
Colloids Surf B Biointerfaces ; 170: 136-143, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29894834

RESUMO

Liver is the major organ where insulin performs its physiological function. In this study, lauric acid and oleic acid were respectively conjugated to quaternized chitosan, and the fatty acid modified chitosan derivatives were used as the carriers to deliver the loaded insulin to liver. The nanoparticles with sizes of about 280 nm were fabricated via the electrostatic and hydrophobic interactions between insulin and the chitosan derivative. Both of insulin loading efficiency and loading capacity of the chitosan derivatives were higher than 98%. The surface hydrophobicity of the nanoparticles increased with the increases of fatty acid hydrophobicity and also fatty acid substitution degree of the chitosan derivative. The nanoparticles with higher surface hydrophobicity displayed higher hepatocyte absorption, more accumulation in the liver and better antidiabetic efficacy. Compared with free insulin treatment group, the relative pharmacological availabilities were 233% and 311% for the groups treated with the nanoparticles having lauric acid and oleic acid, respectively, after subcutaneous injection into diabetic mice. This study demonstrates that the nanoparticles fabricated from fatty acid modified polymer are an effective liver-targeted delivery system of insulin.


Assuntos
Quitosana/química , Diabetes Mellitus Experimental/tratamento farmacológico , Portadores de Fármacos/química , Ácidos Graxos/química , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Compostos de Amônio Quaternário/química , Absorção Fisiológica/efeitos dos fármacos , Administração Oral , Animais , Sistemas de Liberação de Medicamentos , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/química , Insulina/administração & dosagem , Insulina/química , Masculino , Camundongos , Camundongos Endogâmicos ICR , Nanopartículas/química , Tamanho da Partícula , Propriedades de Superfície
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