检索结果-南通市图书馆

Acta Mechanica Sinica 2012年第3期28卷 891-903页

作者： De-Chang Li Bao-Hua Ji Biomechanics and biomaterials Lab Department of Applied MechanicsBeijing Institute of TechnologyKey Laboratory.of Dynamics and Control of Flight VehicleMinistry of Education100081 BeijingChina

Jarzynski＇ identity （JI） method was suggested a promising tool for reconstructing free energy landscape of biomolecular interactions in numerical simulations and ex- periments. However, JI method has not yet been well tested in complex systems such as ligand-receptor molecular pairs. In this paper, we applied a huge number of steered molec- ular dynamics （SMD） simulations to dissociate the protease of human immunodeficiency type I virus （HIV-1 protease） and its inhibitors. We showed that because of intrinsic com- plexity of the ligand-receptor system, the energy barrier pre- dicted by JI method at high pulling rates is much higher than experimental results. However, with a slower pulling rate and fewer switch times of simulations, the predictions of JI method can approach to the experiments. These results sug- gested that the JI method is more appropriate for reconstruct- ing free energy landscape using the data taken from experi- ments, since the pulling rates used in experiments are often much slower than those in SMD simulations. Furthermore, we showed that a higher loading stiffness can produce higher precision of calculation of energy landscape because it yields a lower mean value and narrower bandwidth of work distri- bution in SMD simulations.

关键词： Molecular dynamics simulation. Single molecu-lar interaction ~ Molecular biomechanics ~ Steered moleculardynamics ~ Free energy calculation

Sodium alendronate loaded poly(L-lactideco-glycolide)microparticles immobilized on ceramic scaffolds for local treatment of bone defects

在线全文

学校读者我要写书评

暂无评论

Regenerative biomaterials 2020年第3期7卷 293-302页

作者： Lucja Rumian Cornelia Wolf-Brandstetter Sina Roβler Katarzyna Reczynska Hanna Tiainen Havard J.Haugen Dieter Scharnweber Elzbieta Pamula Faculty of Materials Science and Ceramics Department of Biomaterials and CompositesAGH University of Science and TechnologyAl.A.Mickiewicza 30Krakow 30-059Poland Technische Universitat Dresden Institute of Materials ScienceMax Bergmann Center of BiomaterialsBudapester Str.27Dresden 01-069Germany Department of biomaterials Institute for Clinical DentistryUniversity of OsloGeitmyrsveien 71BlindernP.O.Box 1109Oslo NO-0317Norway

Bone tissue regeneration in critical-size defects is possible after implantation of a 3D scaffold and can be additionally enhanced once the scaffold is enriched with drugs or other factors supporting bone remodelling and *** alendronate(Aln),a widely used anti-osteoporosis drug,exhibits strong inhibitory effect on bone resorption performed by ***,we propose a new approach for the treatment of bone defects in craniofacial region combining biocompatible titanium dioxide scaffolds and poly(L-lactide-co-glycolide)microparticles(MPs)loaded with *** MPs were effectively attached to the surface of the scaffolds’pore walls by human recombinant *** release from the scaffolds was characterized by initial burst(2466% of the drug released within first 24 h)followed by a sustained release phase(on average 5 mg of Aln released per day from Day 3 to Day 18).In vitro tests evidenced that Aln at concentrations of 5 and 2.5 mg/ml was not cytotoxic for MG-63 osteoblast-like cells(viability between 8166% and 9863% of control),but it prevented RANKL-induced formation of osteoclast-like cells from macrophages derived from peripheral blood mononuclear cells,as shown by reduced fusion capability and decreased tartrateresistant acid phosphatase 5b activity(5665% reduction in comparison to control after 8 days of culture).Results show that it is feasible to design the scaffolds providing required doses of Aln inhibiting osteoclastogenesis,reducing osteoclast activity,but not affecting osteoblast functions,which may be beneficial in the treatment of critical-size bone tissue defects.

关键词： ceramic scaffolds sodium alendronate osteoblasts osteoclastogenesis collagen critical-size defect poly(L-lactideco-glycolide) microparticles

Mg-based materials diminish tumor spreading and cancer metastases

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2023年第1期19卷 594-610页

作者： Philipp Globig Roshani Madurawala Regine Willumeit-Römer Fernanda Martini Elisa Mazzoni Bérengère J.C.Luthringer-Feyerabend institute of Metallic biomaterials Helmholtz-Zentrum Hereon GmbH21502GeesthachtGermany Department of Medical Sciences University of Ferrara44121FerraraItaly

Cancer metastases are the most common causes of cancer-related *** formation of secondary tumors at different sites in the human body can impair multiple organ function and dramatically decrease the survival of the *** this stage,it is difficulty to treat tumor growth and spreading due to arising therapy ***,it is important to prevent cancer metastases and to increase subsequent cancer therapy *** metastases are conventionally treated with radiation or ***,these treatments elicit lots of side effects,wherefore novel local treatment approaches are currently *** studies already showed anticancer activity of specially designed degradable magnesium(Mg)alloys by reducing the cancer cell *** this work,we investigated the impact of these Mg-based materials on different steps of the metastatic cascade including cancer cell migration,invasion,and cancer-induced ***,Mg and Mg-6Ag reduced cell migration and invasion of osteosarcoma cells in coculture with ***,the Mg-based materials used in this study diminished the cancer-induced *** cells incubated with conditioned media obtained from these Mg and Mg-6Ag showed a reduced cell layer permeability,a reduced proliferation and inhibited cell *** tube formation as a last step of angiogenesis was stimulated with the presence of Mg under normoxia and diminished under hypoxia.

关键词： Cancer Osteosarcoma Magnesium degradation Cell migration Cell invasion Angiogenesis

Synthesis and performance of Zn–Ni–P thin films

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第3期24卷 259-268页

作者： V.Soare M.Burada I.Constantin M.Ghita V.Constantin F.Miculescu A.M.Popescu New Materials and Technologies Laboratory National Research and Development Institute for Nonferrous and Rare Metals-IMNR institute of Physical Chemistry "Ilie Murgulescu" Laboratory of Molten Salts University Polytehnica of Bucharest Center of Biomaterials (BIOMAT)

The electroplating of Zn–Ni–P thin film alloys from a sulfate bath containing phosphoric and phosphorous acid was investigated. The bath composition and the deposition parameters were optimized through Hull cell experiments, and the optimum experimental conditions were determined（p H = 2, temperature = 298–313 K, zinc sulfate concentration =30 g·L^-1, EDTA concentration = 15 g·L^-1, and current density = 1.0–2.0 A·dm^-2）. The SEM analysis of the coating deposited from the optimum bath revealed fine-grained deposits of the alloy in the presence of EDTA. Optical microscopy analysis indicated an electrodeposited thin film with uniform thickness and good adhesion to the steel substrate. The good adherence of the coatings was also demonstrated by the scratch tests that were performed, with a maximum determined value of 25 N for the critical load. Corrosion resistance tests revealed good protection of the steel substrate by the obtained Zn–Ni–P coatings, with values up to 85.89% for samples with Ni contents higher than 76%. The surface analysis of the thin film samples before and after corrosion was performed by X-ray photoelectron spectroscopy（XPS）.

关键词： thin film corrosion electrochemistry surface

Ultrafast synthesis of gold nanoparticles on cellulose nanocrystals via microwave irradiation and their dyes-degradation catalytic activity

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第6期41卷 168-177页

作者： Madhusudhan Alle Seung-Hwan Lee Jin-Chul Kim institute of Forest Science Kangwon National UniversityChuncheon 24341Republic of Korea Department of Forest biomaterials Engineering Kangwon National UniversityChuncheon 24341Republic of Korea Department of Medical biomaterials Engineering College of Biomedical Science and Institute of Bioscience and BiotechnologyKangwon National University192-1Hyoja 2 dongChuncheonKangwon-do 200-701Republic of Korea

This study represents a well-dispersed gold nanoparticles(AuNPs)synthesis process via cellulose nanocrystals(CNC)which acts as both reducing and supporting *** synthesis process was ultrafast and completed in a few seconds using microwave *** entire synthesis process was cost-effective,sustainable and *** synthesized(AuNPs/CNC)nanocomposite was investigated by transmission electron microscopy,selected area electron diffraction,Fourier transform infrared spectroscopy,energy dispersive X-ray analysis,X-ray diffraction,and UV–vis *** obtained AuNPs were well accumulated on the CNC surface and had a uniform spherical shape with an average diameter of 8±5.3 *** diameter of AuNPs could be altered by tuning the concentration of CNC *** synthesized AuNPs/CNC nanocomposite film exhibited excellent degradation properties against various organic dyes,namely,Allura red,Congo red,Rhodamine B and *** ultrafast degradation reactions followed pseudo first order *** the catalytic degradation reaction,AuNPs/CNC was transmitting electrons from a donor(NaBH4)to an acceptor(a dye).

关键词： Cellulose nanocrystals Gold nanoparticles Microwave synthesis Catalytic degradation of dyes

Simulation of blood flow in a small-diameter vascular graft model with a swirl (spiral) flow guider

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2008年第10期51卷 913-921页

作者： Robert GUIDOIN Department of Surgery Laval University and Quebec Biomaterials Institute CHUQQuebec G1K7P4

Small-diameter vascular grafts are in large demand for coronary and peripheral bypass procedures, but present products still fail in long-term clinical application. In the present communication, a new type of small-diameter graft with a swirl flow guider was proposed to improve graft patency rate. Flow pattern in the graft was simulated numerically and compared with that in a conventional graft. The numerical results revealed that the swirl flow guider could indeed make the blood flow rotate in the new graft. The swirling flow distal to the flow guider significantly altered the flow pattern in the new graft and the ve- locity profiles were re-distributed. Due to the swirling flow, the blood velocity near the vessel wall and wall shear rate were greatly enhanced. We believe that the increased blood velocity near the wall and the wall shear rate can impede the occurrence of acute thrombus formation and intimal hyperplasia, hence can improve the graft patency rate for long-term clinical use.

关键词： arterial prosthesis acute thrombus formation flow simulation swirling (spiral) flow

Control of the interparticle spacing in superparamagnetic iron oxide nanoparticle clusters by surface ligand engineering

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第7期25卷 427-434页

作者：王丹林兵兵申太鹏吴君豪富华夏春潮龚启勇唐惠儒宋彬艾华 National Engineering Research Center for biomaterials Sichuan University Wuhan institute of Physics and Mathematics Chinese Academy of Sciences Department of Radiology West China Hospital Sichuan University

Polymer-mediated self-assembly of superparamagnetic iron oxide（SPIO） nanoparticles allows modulation of the structure of SPIO nanocrystal cluster and their magnetic properties. In this study, dopamine-functionalized polyesters（DApolyester） were used to directly control the magnetic nanoparticle spacing and its effect on magnetic resonance relaxation properties of these clusters was investigated. Monodisperse SPIO nanocrystals with different surface coating materials（poly（ε-caprolactone）, poly（lactic acid）） of different molecular weights containing dopamine（DA） structure（DA-PCL2k,DA-PCL1k, DA-PLA1k）） were prepared via ligand exchange reaction, and these nanocrystals were encapsulated inside amphiphilic polymer micelles to modulate the SPIO nanocrystal interparticle spacing. Small-angle x-ray scattering（SAXS）was applied to quantify the interparticle spacing of SPIO clusters. The results demonstrated that the tailored magnetic nanoparticle clusters featured controllable interparticle spacing providing directly by the different surface coating of SPIO nanocrystals. Systematic modulation of SPIO nanocrystal interparticle spacing can regulate the saturation magnetization（Ms） and T2 relaxation of the aggregation, and lead to increased magnetic resonance（MR） relaxation properties with decreased interparticle spacing.

关键词： nanoparticle clusters interparticle spacing ligand exchange magnetization

Human osteoclast formation and resorptive function on biomineralized collagen

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2022年第2期7卷 241-252页

作者： Daniel de Melo Pereira Noel Davison Pamela Habibovic Department of Instructive biomaterials Engineering MERLN Institute for Technology-Inspired Regenerative MedicineMaastricht University6229 ERMaastrichtThe Netherlands

Biomineralized collagen composite materials pose an intriguing alternative to current synthetic bone graft substitutes by offering a biomimetic composition that closely resembles native *** hypothesize that this composite can undergo cellular resorption and remodeling similar to natural *** investigate the formation and activity of human osteoclasts cultured on biomineralized collagen and pure collagen membranes in comparison to cortical bone *** monocytes/macrophages from peripheral blood differentiate into multinucleated,tartrate-resistant alkaline phosphatase(TRAP)-positive osteoclast-like cells on all *** cells form clear actin rings on cortical bone,but not on biomineralized collagen or pure collagen *** form resorption pits in cortical bone,resulting in higher calcium ion concentration in cell culture medium;however,osteoclast resorption of biomineralized collagen and collagen membranes does not measurably *** of osteoclast enzymes-TRAP,carbonic anhydrase II(CA-II),and cathepsin-K(CTS-K)-is similar on all substrates,despite phenotypic differences in actin ring formation and *** mesh-like structure,relatively low stiffness,and lack of RGD-containing binding domains are likely the factors responsible for preventing formation of stable actin rings on and resorption of(biomineralized)collagen *** insight helps to guide further research toward the optimized design of biomineralized collagen composites as a more biomimetic bone-graft substitute.

关键词： Osteoclastogenesis Osteoclast resorption Biomineralized collagen Intrafibrillar mineral Bone graft substitute

Bioactivation of titanium dioxide scaffolds by ALP-functionalization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bioactive Materials 2017年第2期2卷 108-115页

作者： A.Sengottuvelan P.Balasubramanian J.Will A.R.Boccaccini Department of Materials Science and Engineering Institute of BiomaterialsUniversity of Erlangen-NurembergCauerstraße 691058 ErlangenGermany

Three dimensional TiO2 scaffolds are receiving renewed attention for bone tissue engineering (TE) due totheir biocompatibility and attractive mechanical properties. However the bioactivity of these scaffolds iscomparatively lower than that of bioactive glass or hydroxyapatite (HA) scaffolds. One strategy toimprove bioactivity is to functionalize the surface of the scaffolds using biomolecules. Alkaline phosphatase(ALP) was chosen in this study due to its important role in the bone mineralization process. Thecurrent study investigated the ALP functionalization of 3D titanium dioxide scaffolds using selfpolymerizationof dopamine. Robust titanium scaffolds (compressive strength^2.7 ± 0.3 MPa) wereproduced via foam replica method. Enzyme grafting was performed by dip-coating in polydopamine/ALPsolution. The presence of ALP was indirectly confirmed by contact angle measurements and enzymaticactivity study. The influence of the enzyme on the bioactivity, e.g. hydroxyapatite formation on thescaffold surface, was measured in simulated body fluid (SBF). After 28 days in SBF, 5 mg ALP coatedtitania scaffolds exhibited increased hydroxyapatite formation. It was thus confirmed that ALP enhancesthe bioactivity of titania scaffolds, converting an inert bioceramic in an attractive bioactive system forbone TE.

关键词： Alkaline phosphatase Titanium dioxide Scaffolds Polydopamine Surface modification Bioactivity

Micropatterned composite membrane guides oriented cell growth and vascularization for accelerating wound healing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Regenerative biomaterials 2023年第1期10卷 344-353页

作者： Jiaqi Li Xulong Liu Weiyong Tao Yan Li Yingying Du Shengmin Zhang Advanced biomaterials and Tissue Engineering Center Huazhong University of Science and TechnologyWuhan 430074China NMPA Research Base of Regulatory Science for Medical Devices&institute of Regulatory Science for Medical Devices Huazhong University of Science and TechnologyWuhan 430074China institute of biomaterials and Medical Devices Wuhan Institute of Industrial Innovation and DevelopmentWuhan 430074China Department of Biomedical Engineering Huazhong University of Science and TechnologyWuhan 430074China

Skin defect is common in daily life,but repairing large skin defects remains a *** biomaterials to deliver biochemical or physical factors to promote skin tissue regeneration is of great significance for accelerating wound *** surface micropatterns on biomaterials could affect cell behavior and tissue ***,few studies have focused on the construction of wound healing biomaterials with surface micropatterns and their role in skin tissue *** the present study,gelatin-polycaprolactone/silk fibroin composite membranes with different micropatterns were fabricated by photolithography,including line,grid and plane *** vitro cell experiments demonstrated that the line micropattern on the composite membrane could guide cell-oriented growth,and more importantly,promote the expression of angiogenesis-related markers andα-smooth muscle actin(α-SMA)at both gene level and protein *** the rat full-thickness skin defect model,the composite membrane with line micropatterns increasedα-SMA production and neovascularization in wounds,leading to accelerated wound contraction and *** current study not only suggests that composite membranes with specific micropatterns can be promising wound repair materials but also provides new insights into the importance of biomaterial surface topology for tissue regeneration.

关键词： topology cell behavior wound healing gelatin polymer biomaterials