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1.
Acta Biomater ; 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32126308

RESUMO

Titanium-based endosseous implants with high antibacterial and osseointegration activities are extremely required in clinics. To achieve this line, herein the doped coatings with three kinds of Zn doses were micro-arc oxidized (MAOed) on Ti. They were examined to reveal a bilayered structure, in which the outer layer consisted completely of the amorphism comprising elements of Ti, O and Zn with Zn doped in the form of weaken Zn-O bonds, and the underlying layer was partially crystallized with nanocrystalline TiO2 and Zn2TiO4 to embed an amorphous matrix. While the Zn doped doses of the surface amorphous layers increased with elevating the MAOed voltages, the weaken Zn-O bonds in the amorphism were identified to act as both the contributor of Zn2+ controllable release and the generator of reactive oxide species (ROS) on the coatings. The enhanced HO• and O2-• formation on the elevated voltage MAOed coatings caused serious break of the cell walls and plasma membranes of S. aureus. In parallel, the enhanced Zn2+ release and extracellular H2O2 formation led to the enhanced intracellular ROS level of S. aureus, further aggravating the damage of plasma membrane, resulting in bacteria death. On contrary to the overdose of Zn doped coating, the moderate doses of Zn doped coatings did not induce additional intracellular ROS and attenuate viability and proliferation of osteoblasts in vitro, and promoted osseointegration in both S. aureus-uninfected and infected rat tibias, which ascribed to the strong antibacterial activity and un-attenuated cell function of the coatings in the infected case. STATEMENT OF SIGNIFICANCE: (1) The Zn-doped coatings revealed a bilayered structure of the surface layer comprising the Ti, O and Zn constructed amorphism with Zn in the form of weaken Zn-O bonds, and the underlying layer comprising nanocrystalline TiO2 and Zn2TiO4 to embed amorphous matrix. (2) The weaken Zn-O bonds in the amorphism were identified to act as both the contributor of Zn2+ controllable release and the generator of ROS on the coatings. (3) The enhanced Zn2+ release and ROS formation on the coatings killed S. aureus by inducing serious break of their cell walls and plasma membranes. This effect in combination of un-attenuated osteoblast proliferation endowed the moderate Zn doped coatings with enhanced osseointegration in S. aureus-infected rat tibias.

2.
J Hazard Mater ; 393: 122423, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32135368

RESUMO

As the environment deterioration is becoming more serious, bacterial pollution is threatening the health of human beings. Hence, it is vital to develop rapid and safe sterilization strategy. Herein, CuS/protonated g-C3N4(CuS/PCN) composites were synthesized by simple hydrothermal method and electrostatic adsorption. This heterostructured system exhibited enhanced photocatalytic properties under visible light compared with CuS or g-C3N4 alone, ascribing to the rapid separation of photogenerated electron-hole pairs. Meanwhile, the obvious photothermal effects of CuS/PCN were achieved and the temperature increased with the increased amount of CuS in the composites due to the more light absorption. However, when the CuS content is more than 10 %, photocurrent density is decreased with increasing the amount of CuS, indicating the increased recombination of photogenerated electron-hole pairs. When the CuS content is 20 %, the composite can perform the optimized synergistic effects of both photothermal action and photocatalysis under light irradiation for 20 min. The corresponding bacteria-killing efficiency against Staphylococcus aureus and Escherichia coli is 98.23 % and 99.16 %, respectively. The underlying mechanism is that the bacterial membrane can be weakened by reactive oxygen species and bacterial activities are inhibited by hyperthermia. This CuS/PCN heterojunction is promising for environmental disinfection including water and public facilities sterilization.

3.
J Hazard Mater ; 390: 122126, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32006853

RESUMO

Some new kinds of antibiotics-free antibacterial agents are required to deal with bacterial infections due to the occurrence of drug-resistance. In this work, Cu-based metal-organic framework (HKUST-1) embedded with CuS NPs were fabricated via a simple in-situ sulfuration process. The synthesized MOFs exhibited an highly effective disinfection efficacy of 99.70 % and 99.80 % against Staphylococcus aureus and Escherichia coli within 20 min irradiation of near-infrared (NIR) light, respectively, which was ascribed to the cooperative effects of photodynamic and photothermal effects of the composites. A certain amount of Cu2+ ions of the MOFs were reacted to form CuS NPs, which endowed this composite with outstanding photocatalytic and photothermal performance during NIR light irradiation. Moreover, HKUST-1 that composed of low toxic organic ligand 1,3,5-benzenetricarboxylic acid (H3BTC) coordinating copper ions could be a controllable carrier that imposed certain constraint on the NPs. Hence, these CuS@HKUST-1 would be a promising bioplatform for rapid bacteria-killing.

4.
Colloids Surf B Biointerfaces ; 188: 110781, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31935632

RESUMO

Bacterial infection is seriously threatening human health all over the world, especially with the emergence of increasing drug-fast bacteria. It is urgent to develop a drug-free strategy to kill bacteria rapidly and efficiently. In this work, humic acid (HuA) encapsulated zeolitic imidazole framework-8 (ZIF-8) (HuA@ZIF-8) nanocomposites are synthesized by the in-situ growth of ZIF-8 on the surface of polyvinylpyrrolidone (PVP)-modified HuA. The synthesized nanocomposites possesses good photothermal effects, i.e., the temperature increased to 59.4 °C under the particle concentration of 1000 µg/mL with 10 min NIR irradiation. In addition, NIR irradiation can also control the release of Zn2+ from the composites. The good photothermal effects originate from HuA that can effectively absorb NIR light. The controlled release of Zn2+ is ascribed to the induced-dissociation of ZIF-8 under NIR light irradiation. The synergistic action of photothermal therapy and release of zinc ions contributes to the excellent antibacterial efficiency of HuA@ZIF-8 within a short time, i.e. 99.59 % and 99.37 % against Staphylococcus aureus and Escherichia coli with 20 min NIR irradiation, respectively. This work provides a promising strategy to develop a light-responsive platform with good biodegradability and low cost for rapid and effective sterilization.

5.
ACS Nano ; 14(2): 2077-2089, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31990179

RESUMO

Periprosthetic infection is considered the main cause of implant failure, which is expected to be solved by fabricating an antibacterial coating on the surface of the implant. Nevertheless, systemic antibiotic treatment still represents the mainstream method for preventing infection, and few antibacterial coatings are applied clinically. This is because the externally introduced traditional antibacterial coatings suffer from the risk of invalidation and tissue toxicity induced by the consumption of antibacterial agents, degradation, and shedding. In this work, we proposed a rapid photo-sonotherapy by creating an oxygen deficiency on a titanium (Ti) implant through sulfur (S)-doping (Ti-S-TiO2-x), which endowed the implants with great sonodynamic and photothermal ability. Without introducing an external antibacterial coating, it reached a high antibacterial efficiency of 99.995% against Staphylococcus aureus under 15 min near-infrared light and ultrasound treatments. Furthermore, bone infection was successfully treated after combination treatments, and improved osseointegration was observed. Importantly, the S-doped Ti implant immersed in water for 6 months showed an unchanged structure and properties, suggesting that the Ti implant with intrinsic modification showed stable antibacterial performance under exogenous stimuli with a high antibacterial performance in vivo. This photo-sonotherapy based on sulfur doping is also promising for cancer therapy with biosafety.

6.
Acta Biomater ; 105: 290-303, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31972366

RESUMO

Zinc and its alloys have emerged as a new research direction of biodegradable metals (BMs) due to the significant physiological functions of Zn2+ ions in human body. However, low inhibitory concentration threshold value to cause cytotoxicity by Zn2+ ions during in vitro study and delayed osseointegration in vivo are two key flaws for the bulk Zn-based BMs. To combat these issues, we constructed a barrier layer of ZrO2 nanofilm on the surface of Zn-0.1(wt.%) Li alloy via atomic layer deposition (ALD). A decreased release of Zn2+ ions accompanied with accelerated release of Li+ ions was observed on account of galvanic coupling between the coating compositions and Zn-0.1Li alloy substrate. Cytocompatibility assay reflected that ZrO2 nanofilm coated Zn-0.1Li alloy exhibited improved cell adhesion and viability. Histological analysis also demonstrated better in vivo osseointegration for the ZrO2 nanofilm coated Zn-0.1Li alloy. Hence, the present study elucidated that the ALD of ZrO2 nanofilm on Zn-based BMs can effectively promote osseointegration and control their biodegradation behavior. STATEMENT OF SIGNIFICANCE: Zn-Li binary alloy was reported recently to be the promising biodegradable metals with ultimate tensile strength over 500 MPa, yet the low inhibitory concentration threshold value to cause cytotoxicity by Zn2+ ions is the obstacle needed to be overcome. As a pilot study, a systematic investigation on the ZrO2 nanofilm coated Zn-Li alloy, prepared by atomic layer deposition (ALD) technique, was conducted in the present study, which involved in the formation process, in vitro and in vivo degradation behavior as well as biocompatibility evaluation. We found a controllable corrosion rate and better in vivo osseointegration can be achieved by ZrO2 nanofilm coating on Zn-Li alloy, which provides new insight into the surface modification on biodegradable Zn alloys for usage within bone.

9.
Acta Biomater ; 101: 152-167, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31678738

RESUMO

Growing evidence suggests that the physical microenvironment can guide cell fate. However, cells sense cues from the adjacent physical microenvironment over a limited distance. In the present study, murine mesenchymal stem cells (MSCs) and murine preosteoblastic cells (MC3T3-E1) behaviors are regulated by the cell-material interface using ordered-micro and disordered-nano patterned structures on Ti implants. The optimal bone formation structure is a stable wave (horizontal direction: ridge, 2.7 µm; grooves, 5.3 µm; and vertical direction: distance, 700 µm) with the appropriate density of nano-branches (6.0 per µm2). The repeated waves provide cells with directional guidance, and the disordered branches influence cell geometry by providing different spacing and density nanostructure. And micro-nano patterned structure can provide biophysical cues to direct cell phenotype development, including cell size, shape, and orientation, to influence cellular processes including survival, growth, and differentiation. Thus, the overlaid isotropic and anisotropic cues, ordered-micro and disordered-nano patterned structures, could transfer further and alter cell shape and induce nuclear orientation by activating Wnt/ß-catenin signaling to promote integrin α5, integrin ß1, cadherin 2, Runx2, Opn, and Ocn. That canonical Wnt signaling inhibitor dickkopf1 further demonstrates osteogenic differentiation induced by ordered-micro and disordered-nano patterned structures, which is related to Wnt/ß-catenin signaling. Our findings show the role of ordered microstructures and disordered nanostructures in modulating stem cell differentiation with potential medical applications. STATEMENT OF SIGNIFICANCE: It remains a challenge to modify poor osteogenic and osteoconductive properties of titanium alloy bases on the inherent poverty of titanium. We demonstrate that ordered microtopography and disordered nano topography pattern structure could lead to osteogenic differentiation in vitro and bone regeneration in vivo. Furthermore, the pattern structure is created through selective laser melting and alkali heat. And the structure only takes advantage of titanium itself and does not bring in active film, such as hydroxyapatite. On the other hand, we find that cell shape and orientation show angle-orientation tendency due to the polarity, which involves with mechanical signal created via patterned structure. Meanwhile, the Wnt/Ca2+ signaling pathway is activated.

10.
J Hazard Mater ; 383: 121122, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-31518801

RESUMO

Bacterial infection is a serious problem threatening human health. The chitosan (CS)-modified MoS2 coating loaded with silver nanoparticles (Ag NPs) was designed on the surface of titanium (Ti) to kill bacteria rapidly and efficiently under 660 nm visible light. Ag/MoS2 exhibited high photocatalytic activity due to the rapid transfer of photo-inspired electrons from MoS2 to Ag NPs, resulting in higher yields of radical oxygen species (ROS) to kill bacteria. The covering of CS made the composite coating positively charged to further enhance the antibacterial property of the coating. In addition, CS/Ag/MoS2-Ti also showed a certain photothermal effect. in vitro results showed that the antibacterial efficiency of the coating on Staphylococcus aureus and Escherichia coli was 98.66% and 99.77% respectively, when the coating was irradiated by 660 nm visible light for 20 min. Cell culture tests showed that CS/Ag/MoS2-Ti had no adverse effects on cell growth. Hence, this surface system will be a very promising strategy for eliminating bacterial infection on biomedical device and implants safely and effectively within a short time.

11.
ACS Nano ; 13(11): 13581-13594, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31697055

RESUMO

Using noninvasive stimulation of cells to control cell fate and improve bone regeneration by optical stimulation can achieve the aim of precisely orchestrating biological activities. In this study, we create a fast and repeatable photoelectric-responsive microenvironment around an implant using a bismuth sulfide/hydroxyapatite (BS/HAp) film. The unexpected increase of photocurrent on the BS/HAp film under near-infrared (NIR) light is mainly due to the depletion of holes through PO43- from HAp and interfacial charge transfer by HAp compared with BS. The electrons activate the Na+ channel of mesenchymal stem cells (MSCs) and change the cell adhesion in the intermediate environment. The behavior of MSCs is tuned by changing the photoelectronic microenvironment. RNA sequencing reveals that when photoelectrons transfer to the cell membrane, sodium ions flux and the membrane potential depolarizes to change the cell shape. Meanwhile, calcium ions fluxed and FDE1 was upregulated. Furthermore, the TCF/LEF in the cell nucleus began transcription to regulate the downstream genes involved in osteogenic differentiation, which is performed through the Wnt/Ca2+ signaling pathway. This research has created a biological therapeutic strategy, which can achieve in vitro remotely, precisely, and noninvasively controlling cell differentiation behaviors by tuning the in vivo photoelectric microenvironment using NIR light.

12.
ACS Appl Mater Interfaces ; 11(44): 41758-41769, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31610117

RESUMO

Bone repair and regeneration are greatly influenced by the local immune microenvironment. In this regard, the immunomodulatory capability of biomaterials should be considered when evaluating their osteogenic effects. In this study, we investigated the modulatory effects of gold nanoparticle (AuNP)-loaded mesoporous silica nanoparticles (Au-MSNs) on macrophages and the subsequent effects on the behavior of osteoblastic lineage cells. The results demonstrate that Au-MSNs could generate a favorable immune microenvironment by stimulating an anti-inflammatory response and promoting the secretion of osteogenic cytokines by macrophages. As a result, there is an enhancement of osteogenic differentiation in preosteoblastic MC3T3 cells as assessed by the increased expression of osteogenic markers, alkaline phosphatase (ALP) production, and calcium deposition. The immunomodulatory effects and direct osteogenic stimulation by Au-MSNs synergistically increased the osteogenic differentiation capability of MC3T3 cells as a result of crosstalk between Au-MSN-conditioned macrophages and Au-MSN-treated osteoblasts in a coculture system. An in vivo study further revealed that Au-MSNs could accelerate new bone formation in a critical-sized cranial defect site in rats based on computed tomography analysis and histological examination. Together, this novel Au-MSNs could significantly promote osteogenic activity by modulating the immune microenvironment, showing its therapeutic potential for bone tissue repair and regeneration.

13.
Nat Commun ; 10(1): 4490, 2019 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-31582736

RESUMO

The application of photothermal therapy to treat bacterial infections remains a challenge, as the high temperatures required for bacterial elimination can damage healthy tissues. Here, we develop an exogenous antibacterial agent consisting of zinc-doped Prussian blue (ZnPB) that kills methicillin-resistant Staphylococcus aureus in vitro and in a rat model of cutaneous wound infection. Local heat triggered by the photothermal effect accelerates the release and penetration of ions into the bacteria, resulting in alteration of intracellular metabolic pathways and bacterial killing without systemic toxicity. ZnPB treatment leads to the upregulation of genes involved in tissue remodeling, promotes collagen deposition and enhances wound repair. The efficient photothermal conversion of ZnPB allows the use of relatively few doses and low laser flux, making the platform a potential alternative to current antibiotic therapies against bacterial wound infections.


Assuntos
Antibacterianos/administração & dosagem , Terapia a Laser , Estruturas Metalorgânicas/administração & dosagem , Infecções Estafilocócicas/terapia , Infecção dos Ferimentos/terapia , Administração Cutânea , Animais , Antibacterianos/química , Terapia Combinada/métodos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ferrocianetos/administração & dosagem , Ferrocianetos/química , Humanos , Raios Infravermelhos/uso terapêutico , Masculino , Estruturas Metalorgânicas/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Nanopartículas/administração & dosagem , Nanopartículas/química , Ratos , Infecções Estafilocócicas/microbiologia , Resultado do Tratamento , Cicatrização/efeitos dos fármacos , Cicatrização/efeitos da radiação , Infecção dos Ferimentos/microbiologia , Zinco/administração & dosagem , Zinco/química
14.
ACS Cent Sci ; 5(9): 1591-1601, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31572786

RESUMO

Herein, a core-shell dual metal-organic framework (MOF) heterointerface is synthesized. The Prussian blue (PB) MOF acts as a core for the growth of a porphyrin-doped MOF which is named PB@MOF. Porphyrins can significantly enhance the transfer of photoinspired electrons from PB and suppress the recombination of electrons and holes, thus enhancing the photocatalytic properties and consequently promoting the yields of singlet oxygen rapidly under 660 nm illumination. PB@MOF can exhibit a better photothermal conversion efficiency up to 29.9% under 808 nm near-infrared irradiation (NIR). The PB@MOF heterointerface can possess excellent antibacterial efficacies of 99.31% and 98.68% opposed to Staphylococcus aureus and Escherichia coli, separately, under the dual light illumination of 808 nm NIR and 660 nm red light for 10 min. Furthermore, the trace amount of Fe and Zr ions can trigger the immune system to favor wound healing, promising that PB@MOF achieves the rapid therapy of bacterial infected wounds and environmental disinfection.

15.
Biomater Sci ; 7(12): 5383-5387, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31626246

RESUMO

Xerogels usually possess a stable structure and have a low swelling rate due to their inferior dynamics. Herein, a xerogel was synthesized by "imitative" click chemistry based on lipoic acid for picking up bacteria from wound sites, and thus accelerating tissue repair. The cross-linking structure of disulfide and thioether inside the xerogel not only exhibited good ductility and intrinsic self-healing performance, but also showed superior biocompatibility. The xerogel captured more than 60% of the bacteria Staphylococcus aureus via strong electrostatic adsorption in the colonies with a bacteria count of 106. In addition, this xerogel can stick to the skin in the form of patches in the wounds during therapy for wound healing and can be easily stripped from the skin after treatment, which makes it appropriate for the portable therapy of bacteria-infected wounds in emergency circumstances.

16.
Acta Biomater ; 99: 495-513, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31518705

RESUMO

Magnesium biometals exhibit great potentials for orthopeadic applications owing to their biodegradability, bioactive effects and satisfactory mechanical properties. However, rapid corrosion of Mg implants in vivo combined with large amount of hydrogen gas evolution is harmful to bone healing process which seriously confines their clinical applications. Enlightened by the superior biocompatibility and corrosion resistance of passive titanium oxide layer automatically formed on titanium alloy, we employ the Ti and O dual plasma ion immersion implantation (PIII) technique to construct a multifunctional TiO2 based nano-layer on ZK60 magnesium substrates for enhanced corrosion resistance, osteoconductivity and antimicrobial activity. The constructed nano-layer (TiO2/MgO) can effectively suppress degradation rate of ZK60 substrates in vitro and still maintain 94% implant volume after post-surgery eight weeks. In animal study, a large amount of bony tissue with increased bone mineral density and trabecular thickness is formed around the PIII treated group in post-operation eight weeks. Moreover, the newly formed bone in the PIII treated group is well mineralized and its mechanical property almost restores to the level of that of surrounding mature bone. Surprisingly, a remarkable killing ratio of 99.31% against S. aureus can be found on the PIII treated sample under ultra-violet (UV) irradiation which mainly attributes to the oxidative stress induced by the reactive oxygen species (ROS). We believe that this multifunctional TiO2 based nano-layer not only controls the degradation of magnesium implant, but also regulates its implant-to-bone integration effectively. STATEMENT OF SIGNIFICANCE: Rapid corrosion of magnesium implants is the major issue for orthopaedic applications. Inspired by the biocompatibility and corrosion resistance of passive titanium oxide layer automatically formed on titanium alloy, we construct a multifunctional TiO2/MgO nanolayer on magnesium substrates to simultaneously achieve superior corrosion resistance, satisfactory osteoconductivity in rat intramedullary bone defect model and excellent antimicrobial activity against S. aureus under UV irradiation. The current findings suggest that the specific TiO2/MgO nano-layer on magnesium surface can achieve the three objectives aforementioned and we believe this study can demonstrate the potential of biodegradable metals for future clinical applications.

17.
ACS Appl Mater Interfaces ; 11(39): 35513-35524, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31507175

RESUMO

Surface topography has been reported to play a key role in modulating cell behaviors, yet the mechanism through which it modulates these behaviors is not fully understood, especially in the case of three-dimensional (3D) topographies. In this study, a series of novel hemispherical 3D imprints ranging from the nanoscale to the microscale were prepared on titanium (Ti) surfaces using a customized interfacial lithography method. Mouse embryo osteoblast precursor cells (MC3T3-E1) were selected to investigate the solitary effect of specific hemispherical 3D imprints on cellular behaviors. The results indicated that varied hemispherical 3D imprints can affect the formation of filopodia and the arrangement of the cytoskeleton in different ways. Specifically, they can alter the spreading morphologies of cells and lead to deformation of the nucleus, which eventually affects cell proliferation and osteogenic differentiation. Cells cultured on different hemispherical 3D imprints exhibited promoted proliferation and osteogenic differentiation to different degrees; for example, cells cultured on 90 and 500 nm hemispherical imprints formed abundant filopodia and exhibited the highest alkaline phosphatase activity and osteogenic gene expression, respectively. Four-week tibia implantation also confirmed that 90 nm hemispherical imprints improved the osteogenic ability in vivo compared with an unpatterned Ti substrate. In addition to promoted proliferation, colonization of more cells on the surface of implants and induction of rapid osteogenic differentiation can occur. Our work provides a rational way to balance cell proliferation and differentiation, which can accelerate bone integration of an implant and host tissue.


Assuntos
Calcificação Fisiológica , Diferenciação Celular , Osteoblastos/metabolismo , Osteogênese , Impressão Tridimensional , Tecidos Suporte/química , Animais , Linhagem Celular , Camundongos , Osteoblastos/citologia
18.
Adv Sci (Weinh) ; 6(17): 1900599, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31508278

RESUMO

Biofilms have been related to the persistence of infections on medical implants, and these cannot be eradicated because of the resistance of biofilm structures. Therefore, a biocompatible phototherapeutic system is developed composed of MoS2, IR780 photosensitizer, and arginine-glycine-aspartic acid-cysteine (RGDC) to safely eradicate biofilms on titanium implants within 20 min. The magnetron-sputtered MoS2 film possesses excellent photothermal properties, and IR780 can produce reactive oxygen species (ROS) with the irradiation of near-infrared (NIR, λ = 700-1100 nm) light. Consequently, the combination of photothermal therapy (PTT) and photodynamic therapy (PDT), assisted by glutathione oxidation accelerated by NIR light, can provide synergistic and rapid killing of bacteria, i.e., 98.99 ± 0.42% eradication ratio against a Staphylococcus aureus biofilm in vivo within 20 min, which is much greater than that of PTT or PDT alone. With the assistance of ROS, the permeability of damaged bacterial membranes increases, and the damaged bacterial membranes become more sensitive to heat, thus accelerating the leakage of proteins from the bacteria. In addition, RGDC can provide excellent biosafety and osteoconductivity, which is confirmed by in vivo animal experiments.

19.
20.
Front Chem ; 7: 521, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31396507

RESUMO

The controlled synthesis of highly ordered mesoporous structure has attracted considerable attention in the field of electrochemistry because of its high specific surface area which can contribute the transportation of ions. Herein, a general nano-casting approach is proposed for synthesizing highly ordered mesoporous NiCo2O4 microspheres. The as-synthesized mesoporous NiCo2O4 microsphere materials with high Brunner-Emmett-Teller (BET) surface area (~97.77 m2g-1) and uniform pore size distribution around 4 nm exhibited a high initial discharge capacity of ~1,467 mAhg-1, a good rate capability as well as cycling stability. The superior electrochemical performance was mainly because of the highly porous nature of NiCo2O4, which rendered volume expansion during the process of cycling and shortened lithium-ions transport pathways. These properties showcase the inherent potential for use of highly ordered mesoporous NiCo2O4 microspheres as a potential anode material for lithium-ion batteries in the future.

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