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Paclitaxel-loaded hollow-poly（4-vinylpyridine） nano- particles enhance drug chemotherapeutic efficacy in lung and breast cancer cell lines

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Nano Research 2017年第3期10卷 856-875页

作者： Rafael contreras-caceres Maria c. Leiva Raul Ortiz Amelia Diaz Gloria Perazzoli Miguel A.casado-rodriguez consolacion Melguizo Jose M. Baeyens Juan M. Lopez-Romero Jose Prados Department of Organic chemistry Faculty of Science University of Mdlaga 29071 Malaga Spain Institute of Biopathology and Regenerative Medicine (IBIMER) Center of Biomedical Research (CIBM) University of Granada 18100 Granada Spain Department of Anatomy and Embryology Faculty of Medicine University of Granada 18071 Granada Spain Biosanitary Institute of Granada (IBS. GRANADA) SAS-Universidad de Granada 18014 Granada Spain Department of Health Science University of Jaen 23071 Jadn Spain Department of Pharmacology Institute of Neuroscience Biomedical Research Center (CIBM) University of Granada 18100 Granada Spain

Paclitaxel （PTX）, one of the most effective cytotoxins for the treatment of breast and lung cancer, is limited by its severe side effects and low tumor selectivity. In this work hollow-poly（4-vinylpyridine）（hollow-p4VP） nanoparticles （NPs） have been used for the first time to generate PTX@p4VP NPs, employing a novel technique in which a gold core in the center of the NP is further oxidized to produce the hollow structure into which PTX molecules can be incorporated. The hollow-p4VP NPs exhibit good physicochemical properties and displayed excellent biocompatibility when tested on blood （no hemolysis） and cell cultures （no cytotoxicity）. Interestingly, PTX@p4VP NPs significantly increased PTX cytotoxicity in human lung （A-549） and breast （McF-7） cancer cells with a significant reduction of PTX Ics0 （from 5.9 to 3.6 nM in A-549 and from 13.75 to 4.71 nM in McF-7）. In addition, PTX@p4VP caused a decrease in volume of A-549 and McF-7 multicellular tumor spheroids （MTS）, an in vitro system that mimics in vivo tumors, in comparison to free PTX. This increased antitumoral activity is accompanied by efficient cell internalization and increased apoptosis, especially in lung cancer MTS. Our results offer the first evidence that hollow- p4VP NPs can improve the antitumoral activity of PTX. This system can be used as a new nanoplatform to overcome the limitations of current breast and lung cancer treatments.

关键词： paclitaxel poly(4-vinylpyridine)(p4VP) nanoparticles lung cancer breast cancer cytotoxicity multicellular tumorspheroids

Older candidates for kidney transplantation:Who to refer and what to expect?

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World Journal of Transplantation 2016年第4期6卷 650-657页

作者： Beatrice P concepcion rachel c Forbes Heidi M Schaefer Department of Medicine Division of Nephrology and Hypertension Vanderbilt University Medical Center Division of Kidney and Pancreas Transplantation Vanderbilt University Medical Center

The number of older end-stage renal disease patients being referred for kidney transplantation continues to increase. This rise is occurring alongside the continually increasing prevalence of older end-stage renal disease patients. Although older kidney transplant recipients have decreased patient and graft survival compared to younger patients, transplantation in this patient population is pursued due to the survival advantage that it confers over remaining on the deceased donor waiting list. The upper limit of age and the extent of comorbidity and frailty at which transplantation ceases to be advantageous is not known. Transplant physicians are therefore faced with the challenge of determining who among older patients are appropriate candidates for kidney transplantation. This is usually achieved by means of an organ systemsbased medical evaluation with particular focus given to cardiovascular health. More recently, global measures of health such as functional status and frailty are increasingly being recognized as potential tools in risk stratifying kidney transplant candidates. For those candidates who are deemed eligible, living donor transplantation should be pursued. This may mean accepting a kidney from an older living donor. In the absence of any living donor, the choice to accept lesser quality kidneys should be made while taking into account the organ shortage and expected waiting times on the deceased donor list. Appropriate counseling of patients should be a cornerstone in the evaluation process and includes a discussion regarding expected outcomes, expected waiting times in the setting of the new Kidney Allocation System, benefits of living donor transplantation and the acceptance of lesser quality kidneys.

关键词： Kidney transplant outcomes Frailty Elderly Expanded criteria donor Quality of life

Design of active orthoses for a robotic gait rehabilitation system

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Frontiers of Mechanical Engineering 2015年第3期10卷 242-254页

作者： A. c. VILLA-PARRA L. BROcHE D. DELISLE-rodriguez R. SAGARO Y. BASTOS A. FRIZERA-NETO Post-Graduate Program in Electrical Engineering Universidade Federaldo Espirito Santo Vit6ria 29075-910 Brazil Grupo de Investigacion en Ingenieria Biomodica GIIB UniversidadPolitdcnica Salesiana Cuenca 010105 Ecuador Mechanical and Design Engineering Department Universidad deOriente Santiago de Cuba 90500 Cuba center of Medical Biophysics Universidad de Oriente Santiago deCuba 90500 Cuba

An active orthosis （AO） is a robotic device that assists both human gait and rehabilitation therapy. This work proposes portable AOs, one for the knee joint and another for the ankle joint. Both AOs will be used to complete a robotic system that improves gait rehabilitation. The requirements for actuator selection, the biomechanical considerations during the AO design, the finite element method, and a control approach based on electroencepha-lographic and surface electromyographic signals are reviewed. This work contributes to the design of AOs for users with foot drop and knee flexion impairment. However, the potential of the proposed AOs to be part of a robotic gait rehabilitation system that improves the quality of life of stroke survivors requires further investigation.

关键词： active orthosis gait rehabilitation,electroencephalography surface electromyography

A new spallation mechanism of thermal barrier coatings on aero-engine turbine blades

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Theoretical & Applied Mechanics Letters 2018年第1期8卷 7-11页

作者： Bo Yuan christopher M.Harvey rachel c.Thomson Gary W.critchlow Simon Wang Department of Aeronautical and Automotive Engineering Loughborough University Department of Materials Engineering Loughborough University School of Mechanical and Equipment Engineering Hebei University of Engineering

Laboratory experiments were conducted to study the spallation behaviour of thermal barrier coatings(TBcs) on aero-engine turbine blades manufactured by the electron-beam physical vapour deposition technique(EB-PVD). Intact blades were heated at temperature 1135℃ in a furnace for certain time and then cooled to the room temperature in the laboratory condition. It was found that no spallation occurred during cooling, but spallation happened at constant room temperature after cooling. The spallation mechanism is studied by using the mechanical model developed(Harvey 2017 and Wang 2017), which are based on the hypothesis of pockets of energy concentration(PEcs). Some observations of the spallation behaviour are well predicted by the model.

关键词： Thermal barrier coating Interface fracture Spallation Pockets of energy concentration Buckling

Mesoporous fibrous silicon nitride by catalytic nitridation of silicon

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Progress in Natural Science:Materials International 2019年第2期29卷 190-197页

作者： Tatevik Minasyan Le Liu Marina Aghayan Miguel A.rodriguez Sofiya Aydinyan Irina Hussainova Tallinn University of Technology Functional Advanced composite Technology Industries 3. Instituto de cerámica y Vidrio IcV-cSIc ITMO University Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign

The catalytic effect of metal oxide/alumina whiskers（ceO;, Mn;O;, NiO, co;O;, Fe;O;, cr;O;/AW） was evaluated on their ability to drive the nitridation of silicon and to generate mesoporous fibrous silicon *** powder with different particles size along with the catalyst was nitridized at 1300 °c for 5 h in nitrogen and nitrogen diluted with 10 vol% ammonia atmospheres. Nitridation degree of silicon up to 99% was recorded using 1.5 wt% ceO;and Fe;O;catalysts in nitrogen-ammonia atmosphere. The catalyzed samples contain submicronic silicon nitride fibres with a diameter of 400–500 nm and a length of up to few micrometers. The compressive strength of 46 ± 1 MPa was measured for silicon samples catalyzed with nickel oxide/alumina whiskers and nitridized in N;/10 vol%NH;atmosphere. Porous silicon nitride networks were produced with 45–52% porosity, pore sizes in the range of 370–1200 nm and median pore in the range of 495–1655 nm.

关键词： Mesoporous substrate Silicon nitride Nanofibers Wet-combustion catalytic nitridation

Powder metallurgy with space holder for porous titanium implants:A review

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Journal of Materials Science & Technology 2021年第17期76卷 129-149页

作者： Alejandra rodriguez-contreras Miquel Punset JoséA.calero Francisco Javier Gil Elisa Ruperez JoséMaría Manero Biomaterials Biomechanics and Tissue Engineering Group(BBT)Department of Materials Science and EngineeringUniversitat Politecnica de Catalunya(UPC)Av.Edurad Maristany 1608019BarcelonaSpain Barcelona Research centre in Multiscale Science and Engineering Technical University of Catalonia(UPC)Av.Eduard Maristany 10-1408019BarcelonaSpain UPc Innovation and Technology center(cIT-UPc).Technical University of catalonia(UPc) C.Jordi Girona 3-108034Barcelona.Spain AMES GROUP SA.carretera Nacional 340 Pol.Ind."Les Fallulles"08620Sant Vicenc dels HortsBarcelonaSpain Bioengineering Institute for Technology Universitat Intemacional de Catalunyac/Josep Trueta s/n08195BarcelonaSpain

One of the biggest challenges in the biocompatibility of implantable metals is the prevention of the stress shielding effect,which is related to the coupling of the bone-metal mechanical *** stress shielding phenomenon provokes bone resorption and the consequent adverse effects on prosthesis ***,it can be inhibited by adapting the stiffness of the implant *** the use of titanium(Ti)porous structures is a great alternative not only to inhibit this effect but also to improve the osteointegration of orthopedic and dental implants,a brief description of the techniques used for their manufacturing and a review of the current commercialized implants produced from porous Ti assemblies are compiled in this *** powder metallurgy(PM)with space holder(SH)is a powerful technology used to produce porous Ti structures,it is here discussed its potential for the fabrication of medical devices from the perspectives of both design and *** most important parameters of the technique such as the size and shape of the initial metallic particles,the SH and binder type of materials,the compaction pressure of the green form,and in the sintering stage,the temperature,atmosphere,and time are reviewed according to the bibliography ***,the importance of the porosity and its types together with the influence of the mentioned parameters in the final porosity and,consequently,in the ultimate mechanical properties of the structure are ***,a few examples of the PM-SH application for the manufacturing of orthopedic implants are presented.

关键词： Powder metallurgy Space holder method Porous titanium structures Medical devices Stress shielding effect Porous materials permeability Interconnected porosity Porous bone substitute materials Open-cell titanium foams Sintering-dissolution technique

P. fluorescens and B. megaterium Effect on the Lifespan of Mutant-Type dpy-11 and Wild-Type of c. elegans

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cellBio 2022年第1期11卷 1-9页

作者： rachel Ross Biotechnoloy High School Freehold NJ USA

The research question being studied in this paper is how do different types of bacteria as food (Pseudomonas fluorescens and Bacillus megaterium) affect the lifespan of caenorhabditis elegans in dpy-11 mutant-type and wild-type? P. fluorescens and B. megaterium will be the two pathogens that will be tested on two different types of c. elegans: mutant-type dpy-11 and wild-type. From the analysis of primary articles studying these pathogens, it can be concluded that P. fluorescens and B. megaterium are decent contenders for allowing c. elegans to grow and possibly extend the lifespan of it. P. fluorescens will allow the lifespan of the two types of nematodes to be longer. Additionally, the mu-tant-type dpy-11 of c. elegans will have a much longer lifespan, even double, compared to that of the wild-type. The results showed P. fluorescens had a longer lifespan than B. megaterium but not as long as c. elegans’ main food source, E. coli. c. elegans mutant dpy-11 had a longer lifespan than the wild-type. Furthermore, there were no c. elegans present in the B. megaterium wild-type plates.

关键词： c. elegans P. fluorescens B. megaterium E. coli

Prediabetes and type 2 diabetes implication in central proliferation and neurogenesis

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Neural Regeneration Research 2015年第1期10卷 28-29页

作者： carmen Infante-Garcia Juan Jose Ramos-rodriguez Monica Garcia-Alloza Division of Physiology School of MedicineUniversidad de CádizCádiz 11003Spain

Type 2 diabetes （T2D） is an important risk factor for developing dementias, including Alzheimer＇s disease （AD）. Hyperinsulin- emia and glucose intolerance, as features of T2D, might increase the neurodegeneration process, synaptic loss and brain atrophy, leading to cognitive impairment observed in AD. Also, adult neurogenesis seems to be impaired in AD models. Therefore, we have studied morphological alterations, cell proliferation and neurogenesis in the central nervous system （cNS） from a classical model of T2D, the db/db mouse, and in a prediabetes insulin-resistant model, obtained after long-term high fat diet （HFD） administration to c57B1/6 mice. Db/db mice showed an age-dependent cortical and hippocampal atrophy, whereas in HFD mice cortex and hippocampus were preserved. Neurogen- esis and cell proliferation were increased in young db/db mice, when compared with control mice, whereas no differences were detected in the prediabetic model. We also detected significant correlations between metabolic parameters and central atrophy, altered proliferation and neurogenesis in the central nervous system. Altogether these data support that glycaemia control in elderly patients, could help to control central alterations and improve dementia prognosis.

关键词： Prediabetes and type 2 diabetes implication in central proliferation and neurogenesis

All carbon non-covalent exohedral hybrids:c60 aggregates on nanotube networks

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Journal of Energy chemistry 2018年第4期27卷 957-961页

作者： Evgenee Yekymov celine Bounioux racheli Itzhak-cohen Leila Zeiri Emil Shahnazaryan Eugene A.Katz rachel Yerushalmi-Rozen Department of chemical Engineering the Ben-Curion University of the NegevBeer-ShevaIsrael The Ilse Katz Institute for Nanoscience and Technology the Ben-Gurion University of the NegevBeer-ShevaIsrael Department of Solar Energy and Envirornental Physics Jacob Blaustein Institute of Desert ResearchBen-Garion University of the NegevSde-Boker CampusMidreshet Ben-GurionIsrael

Exohedral van der Waals （vdW） hybrids comprising pristine carbon nanotubes （cNTs） and c60 fullerenes are expected to enable the engineering of carbonaceous materials with tunable physical and chemical properties due to the unperturbed sp2 hybridization of the comprising allotropes. In spite of theoretical predictions, experimental realization of exohedral non-covalent hybridization of unmodified c60 fullerenes and cNTs was not reported before, probably due to the relatively strong inter-fullerene and inter-tube interactions that drive the system toward phase separation and the formation of fullerene crystals and cNTs bundles. Here we describe a two-step process for preparation of c60-cNTs hybrids. The first step is based on solution-assembly of random, 3D-networks of individual, pristine cNTs followed by fast solvent-quenching. In the second step sublimated fullerenes are deposited onto the pre-assembled networks where structural defects serve as nucleation points for fullerite nanocrystals. Annealing at low temperature （80 ℃） results in re-organization of the c6o nanocrystals into nanometric layers, forming a cNT-c6o core-shell like cylindrical hybrids. Raman characterization and the observed high mobility of the fullerenes at the cNT surface support the assumption that the exohedral hybrids are of vdW type. The approach presented here offers a pathway for preparation of exohedral hybrids with controlled nano- morphology： cNTs-networks decorated by nanometric c60 crystals and cNTs-3D-networks coated by a shell of non-covalently bonded mono- or multi-layers of c60 molecules that may serve to shape the nanomorphology of the active layer in polymer-fullerene bulk-heterojunction solar cells.

关键词： Fullerenes Exohedral hybrids carbon-nanotubes