Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan(hydro...Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan(hydroxypropyltrimethyl ammonium chloride chitosan, HACC), could effectively inhibit bacterial adherence and biofilm formation in vitro. Therefore, the aim of this study was to further investigate the in vitro cytocompatibility with osteogenic cells and the in vivo anti-infection activity of titanium implants with HACC-loaded nanotubes(NT-H). The titanium implant(Ti), nanotubes without polymer loading(NT), and nanotubes loaded with chitosan(NT-C) were fabricated and served as controls. Firstly, we evaluated the cytocompatibility of these specimens with human bone marrow-derived mesenchymal stem cells in vitro.The observation of cell attachment, proliferation, spreading, and viability in vitro showed that NT-H has improved osteogenic activity compared with Ti and NT-C. A prophylaxis rat model with implantation in the femoral medullary cavity and inoculation with methicillin-resistant Staphylococcus aureus was established and evaluated by radiographical, microbiological, and histopathological assessments. Our in vivo study demonstrated that NT-H coatings exhibited significant anti-infection capability compared with the Ti and NT-C groups. In conclusion, HACC-loaded nanotubes fabricated on a titanium substrate show good compatibility with osteogenic cells and enhanced anti-infection ability in vivo, providing a good foundation for clinical application to combat orthopedic implant-associated infections.展开更多
A micro-nano structure CaF_(2)chemical conversion layer was prepared on fluoride-treated AZ31 alloy,then the composite fluoride conversion film(CaF_(2)/MgF_(2))was modified by stearic acid(SA)and fabricated a superhyd...A micro-nano structure CaF_(2)chemical conversion layer was prepared on fluoride-treated AZ31 alloy,then the composite fluoride conversion film(CaF_(2)/MgF_(2))was modified by stearic acid(SA)and fabricated a superhydrophobic surface.The fluoride-treated magnesium,fluoride conversion film and superhydrophobic coating were characterized by SEM,EDS,XRD and FTIR.The properties of coatings1 adhesion and corrosion resistance were evaluated via tape test and electrochemical measurement.The cytocompatibility of the MgF_(2),CaF_(2)and superhydrophobic CaF_(2)/SA surface was investigated with bone marrow-derived mesenchymal stem cells(BMSCs)by direct culture for 24 h.The results showed that the superhydrophobic fluoride conversion coating composed of inner MgF_(2)layer and the outer CaF_(2)/SA composite layer had an average water contact angle of 152°.SA infiltrated into the micro-nano structure CaF_(2)layer and formed a strong adhesion with CaF_(2)layer.Furthermore,the super-hydrophobic coating showed higher barrier properties and corrosion resistance compared with the fluoride conversion film and fluoride-treated AZ31 alloy.The BMSC adhesion test results demonstrated MgF_(2)CaF_(2)and CaF_(2)/SA coatings were all nontoxic to BMSC.At the condition of in direct contact with cells,MgF_(2)showed higher cell density and enhanced the BMSCs proliferation,while CaF_(2)and CaF_(2)/SA coating showed no statistically difference in cell density compared with glass reference but the CaF_(2)and CaF_(2)/SA coating were not conducive to BMSCs adhesion.展开更多
Polycaprolactone/hydroxyapatite(PCL/HA)composite coating was fabricated by a combination of hydrothermal and dipping methods to delay the degradation of Mg alloy AZ31 as bioresorbable materials.The PCL/HA coating was ...Polycaprolactone/hydroxyapatite(PCL/HA)composite coating was fabricated by a combination of hydrothermal and dipping methods to delay the degradation of Mg alloy AZ31 as bioresorbable materials.The PCL/HA coating was composed of nano rod-shape HA crystals and PCL filled in the space of HA crystals.Compared with the single HA coating,the binding strength between the PCL/HA composite coating and Mg alloy was obviously improved and the PCL/HA coating still adhered to the surface of AZ31 substrate even after 38 days of immersion.The electrochemical corrosion rate of HA coated sample was reduced by ten times after being filled by PCL.The electrochemical impedance spectroscopy(EIS)and immersion test results showed that the PCL/HA composite coating could provide a more effective barrier for Mg substrate than the HA coating alone.The cytocompatibility and the antibacterial property of HA coating and PCL/HA coating were evaluated by culturing with bone marrow-derived mesenchymal stem cells(BMSCs)and methicillin-resistant staphylococcus aureus(MRSA)for 24 h under direct culture conditions,respectively.The PCL/HA composite coating showed better BMSC cell compatibility,more suitable for BMSC adhesion than HA coating alone and showed a potential application prospect as a biological materials.However,from the perspective of clinical applications,the antibacterial property of PCL/HA composite coating needs to be further improved.展开更多
Natural silk from Bombyx mori has been used as medical sutures for several decades,and regenerated silk fibroin( RSF)based biomaterials have been increasingly studied in the past thirty years. However,vascular graft d...Natural silk from Bombyx mori has been used as medical sutures for several decades,and regenerated silk fibroin( RSF)based biomaterials have been increasingly studied in the past thirty years. However,vascular graft derived from silk fibroin fiber has been explored in recent several years with development of textile science and engineering. Moreover,endothelialization of vascular graft has been seen as an ideal strategy for preventing thrombosis and getting higher patency in a long term. Therefore,in the present work silk fibroin fiber vascular graft( SF) was chemically grafted with bioactive molecules such as heparin and RSF to improve the cytocompatibility. 3-aminopropyl-triethoxysilane(APTES),1-ethyl-3-(3-dimethylaminopropyl) carbodiie hydrochlide( EDC · HCl),and N-hydroxysuccinimide( NHS) have been employed as coupling agent and crosslinking agents,respectively. Microscopy and ATRFTIR were used to characterize the surface changes and the structure of the grafts after treatment,respectively. Cell culture in vitro and MTT assay were conducted to determine the improvement of cell affinity to the graft. Furthermore,mechanical properties of the grafts before and after treatment were compared. The results showed that the chemical grafting was an effective method for improving the cytocompatibility of SF without significant loss of mechanical properties.展开更多
The goal of this proof-of-concept study was the fabrication of porous silk fibroin (SF) microspheres which could be used as cell culture carriers under very mild processing conditions. The SF solution was differentiat...The goal of this proof-of-concept study was the fabrication of porous silk fibroin (SF) microspheres which could be used as cell culture carriers under very mild processing conditions. The SF solution was differentiated into droplets which were induced by a syringe needle in the high-voltage electrostatic field. They were collected and frozen in liquid nitrogen and water in droplets formed ice crystals which sublimated during lyophilization and a great quantity of micropores shaped in SF microspheres. Finally, the microspheres were treated in ethanol so as to transfer the molecular conformation into β-sheet and then they were insoluble in water. SF particles were spherical in shape with diameters in the range of 208.4 μm to 727.3 μm, while the pore size on the surface altered from 0.3 μm to 10.7 μm. In vitro, the performances of SF microspheres were assessed by culturing L-929 fibroblasts cells. Cells were observed to be tightly adhered and fully extended;also a large number of connections were established between cells. After 5-day culture, it could be observed under a confocal laser scanning microscope that the porous microenvironment offered by SF particles accelerated proliferation of cells significantly. Furthermore, porous SF particles with smaller diameters (200 - 300 μm) might promote cell growth better. These new porous SF microspheres hold a great potential for cell culture carriers and issue engineering scaffolds.展开更多
Hydrogen peroxide( H_2O_2) is applied for surface modification of polyglycolic acid( PGA) fibers in order to enhance the hydrophilicity and cytocompatibility of PGA fibers effectively,and maintain the breaking strengt...Hydrogen peroxide( H_2O_2) is applied for surface modification of polyglycolic acid( PGA) fibers in order to enhance the hydrophilicity and cytocompatibility of PGA fibers effectively,and maintain the breaking strength as the same time. PGA fibers are dipped in H_2O_2 solution a certain time for modification. Scanning electron microscopy( SEM) was used to observe the surface morphology of PGA fibers before and after modification. The varying of PGA macromolecule was examined with Fourier transform infrared spectroscopy( FTIR) analyses. X-ray diffraction( XRD) and differential scanning calorimetry( DSC) analysis showed that crystallinity slightly decreases. Mechanical performance test showed tensile force of modified PGA fiber was increased. The water contact angle test indicated the improving of hydrophilic. A cell proliferation assay showed that fibroblast cells attach and proliferate well on the fibers, which meant the modified fibers possess good cytocompatibility. These results suggest that H_2O_2 surface modification is easy to operate and a advantageous modification method for PGA fibers.展开更多
There is an increasing demand for crosslinking methods of silk fibroin (SF) scaffolds in biomedical applications that could maintain the biocompatibility, bioactivity as well as improve the water resistance and mechan...There is an increasing demand for crosslinking methods of silk fibroin (SF) scaffolds in biomedical applications that could maintain the biocompatibility, bioactivity as well as improve the water resistance and mechanical properties of SF materials. In this study, SF was crosslinked effectively with genipin which is a naturally occurring iridoid glucoside and the crosslinking mechanism was investigated through FTIR and amino acid analysis. The results showed that genipin could react with the -NH2 groups on the side chains of SF macromolecules and to form inter- and intra-molecular covalent bonds, and improved the stability of SF materials significantly. In vitro, the performances of genipin-crosslinked SF films were assessed by seeding L929 cells and compared with ethanol-processed SF films, glutaraldehyde and polyethylene glycol diglycidyl ether crosslinked ones. The genipin-crosslinked SF films showed a similar affinity to cells as ethanol-processed ones, and a higher bioactivity in promoting cell growth and proliferation, inhibition of cell apoptosis, and maintenance of normal cell cycle compared with glutaraldehyde and polyethylene glycol diglycidyl ether crosslinked SF films. These features, combined with the decrease of brittleness of SF films crosslinked with chemical methods, substantiated genipin as an effective and biocompatible agent for the manufacturing of bioactive SF materials which used as tissue engineering scaffolds and drug delivery carriers.展开更多
Nearly equiatomic nickel–titanium(NiTi) alloy is an ideal implant biomaterial because of its shape memory effect, superelasticity, low elastic modulus as well as other desirable properties.However, it is prone to inf...Nearly equiatomic nickel–titanium(NiTi) alloy is an ideal implant biomaterial because of its shape memory effect, superelasticity, low elastic modulus as well as other desirable properties.However, it is prone to infection because of its poor antibacterial ability.The present work incorporated Cu into Ni–Ti–O nanopores(NP–Cu) anodically grown on the NiTi alloy to enhance its antibacterial ability, which was realized through electrodeposition.Our results show that incorporation of Cu(0.78 at%–2.37 at%)has little influence on the NP diameter, length and morphology.The release level of Cu ions is in line with loadage which may be responsible for the improved antibacterial ability of the NiTi alloy to combat possible bacterial infection in vivo.Meanwhile, the NP–Cu shows better cytocompatibility and even can promote proliferation of bone marrow mesenchymal stem cells(BMSCs),up-regulate collagen secretion and extracellular matrix mineralization when compared with Cu-free sample.Better antibacterial ability and cytocompatibility of the NP–Cu render them to be promising when serving as NiTi implant coatings.展开更多
Basically,Mg–Al layered double hydroxide(LDH)coatings are prepared on the surface of micro-arc oxidation(MAO)coated magnesium(Mg)alloys at a high temperature or a low pH value.This scenario leads to the growth rate o...Basically,Mg–Al layered double hydroxide(LDH)coatings are prepared on the surface of micro-arc oxidation(MAO)coated magnesium(Mg)alloys at a high temperature or a low pH value.This scenario leads to the growth rate of LDH coating inferior to the dissolution rate of the MAO coating.This in turn results in limited corrosion resistance of the composite coating.In this study,a Mg–Al LDH coating on MAO-coated Mg alloy AZ31 is prepared through a water bath with a higher pH(13.76)at a lower temperature(60℃).FE-SEM,EDS,XRD,XPS,and FT-IR are applied to analyze the surface morphology,chemical compositions,and growth process.Electrochemical polarization,electrochemical impedance spectroscopy(EIS)and hydrogen evolution tests are employed to evaluate the corrosion resistance of the samples.The results disclose that the MAO coating is completely covered by the nanosheet-structured LDH coating with a thickness of approximately 3.8μm.The corrosion current density of the MAO-LDH composite coating is decreased four orders of magnitude in comparison to its substrate;the presence of a wide passivation region in anodic polarization branch demonstrates its strong self-healing ability,indicating the hybrid coating possesses excellent corrosion resistance.The formation mechanism of the LDH coating on the MAO-coated Mg alloy is proposed.Furthermore,the cytocompatibility is assessed via an indirect extraction test for MC3T3-E1 pre-osteoblasts,which indicates an acceptable cytocompatibility of osteoblasts for the composite coating.展开更多
Nanorod hydroxyapatite (NRHA)/graphene oxide (GO)composites with weight ratios of 0.4,1.5, and 5have been fabricated by a facile ultrasonic-assisted method at room temperature and atmospheric pressure. The chemical st...Nanorod hydroxyapatite (NRHA)/graphene oxide (GO)composites with weight ratios of 0.4,1.5, and 5have been fabricated by a facile ultrasonic-assisted method at room temperature and atmospheric pressure. The chemical structure properties and morphology of the composites were characterized by field emission source scanning electron microscope,X-ray diffraction,transmission electron microscopy,and high-resolution transmission electron microscopy.The results indicate that the NRHA/ GO composites have an irregular surface with different degree wrinkles and are stable,and NRHA are well combined with GO.In addition,the biomimetic mineralization mechanism of hydroxyapatite on the NRHA/GO composites in simulated body fluid (SBF)is presented.The presence of a bone-like apatite layer on the composite surface indicate that the NRHA/GO composites facilitate the nucleation and growth of hydroxyapatite crystals in SBF for biomimetic mineralization.Moreover,the NRHA-1.5/GO composite and pure GO were cultured with MC3T3-E1cells to investigate the proliferation and adhesion of cells.In vitro cytocompatibility evaluation demonstrated that the NRHA/GO composite can act as a good template for the growth and adhesion of cells. Therefore,the NRHA/GO composite could be applied as a GO-based,free-template,non-toxic,and bioactive composite to substitute for a damaged or defect bone.展开更多
The influences of Mo contents on mechanical properties,biocorrosion and cytocompatibility of as-cast Mg-6Zn-8.16Y-2.02Mn-xMo(x=0.0,0.1,0.3,0.5,0.7 wt%) alloys were firstly investigated.Appropriate amount of Mo was con...The influences of Mo contents on mechanical properties,biocorrosion and cytocompatibility of as-cast Mg-6Zn-8.16Y-2.02Mn-xMo(x=0.0,0.1,0.3,0.5,0.7 wt%) alloys were firstly investigated.Appropriate amount of Mo was conducive to grain refinement and the formation of long-period stacking ordered structure with continuous distribution,which was advantageous to mechanical properties and corrosion resistance.Mg-6Zn-8.16Y-2.02Mn-0.3Mo exhibited the ultimate tensile strength of 265.0 MPa,elongation of 13.5% and the lowest weight loss rate in Hank’s solution.Moreover,the cell toxicity cultured in 25% extract was evaluated and the alloy with 0.3 wt% Mo exhibited the best cytocompatibility.Thus,the alloy was expected to become a novel biodegradable implant material.展开更多
Gelatin(G)is a commonly used natural biomaterial owing to its good biocompatibility and easy availability.However,using pure gelatin as a bioink can barely achieve an ideal shape fidelity in 3D printing.In this study,...Gelatin(G)is a commonly used natural biomaterial owing to its good biocompatibility and easy availability.However,using pure gelatin as a bioink can barely achieve an ideal shape fidelity in 3D printing.In this study,Antheraea pernyi silk fibroin nanofibers(ASFNFs)with arginine-glycine-aspartic acid(RGD)peptide and partial natural silk structure are extracted and combined with pure gelatin bioink to simultaneously improve the shape fidelity and cytocompatibility of corresponding 3D printed scaffold.Results show that the optimum printing temperature is 30℃ for these bioinks.The printed filaments using 16G/4ASFNFs bioink(16wt%gelatin and 4wt%ASFNFs)demonstrate better morphology and larger pore size than those printed by pure gelatin bioink(20G,20wt%gelatin),thus successfully improve the shape fidelity and porosity of the 3D printed scaffold.The 16G/4ASFNFs scaffold also demonstrate higher swelling ratio and faster degradation rate than the pure gelatin scaffold.Moreover,the cell viability and proliferation ability of Schwann cells cultured on the 16G/4ASFNFs scaffold are significantly superior than those cultured on the pure 20G scaffold.The ASFNFs enhanced 16G/4ASFNFs scaffold reported here are expected to be a candidate with excellent potential for biomedical applications.展开更多
Citrate based polymer poly(octamethylene citrate)(POC)has shown promise when formulated into composite material containing up to 65 wt%hydroxylapatite(HA)for orthopedic applications.Despite significant research into P...Citrate based polymer poly(octamethylene citrate)(POC)has shown promise when formulated into composite material containing up to 65 wt%hydroxylapatite(HA)for orthopedic applications.Despite significant research into POC,insufficient information about the biocompatibility of the monomers 1,8-Octanediol and Citrate used in its synthesis is available.Herein,we investigated the acute cytotoxicity,immune response,and long-term functionality of both monomers.Our results showed a cell-type dependent cytotoxicity of the two monomers:1,8-Octanediol induced less acute toxicity to 3T3 fibroblasts than Citrate while presenting comparable cytotoxicity to MG63 osteoblast-like cells;however,Citrate demonstrated enhanced compatibility with hMSCs compared to 1,8-Octanediol.The critical cytotoxic concentration values EC30 and EC50,standard for comparing cytotoxicity of chemicals,were also provided.Additionally,Citrate showed slower and less inhibitory effects on long-term hMSC cell proliferation compared with 1,8-Octanediol.Furthermore,osteogenic differentiation of hMSCs exposure to Citrate resulted in less inhibitory effect on alkaline phosphatase(ALP)production.Neither monomer triggered undesired pro-inflammatory responses.In combination with diffusion model analysis of monomer release from cylindrical implants,based on which the maximum concentration of monomers in contact with bone tissue was estimated to be 2.2104 mmol/L,far lower than the critical cytotoxic concentrations as well as the 1,8-Octanediol concentration(0.4 mg/mL or 2.7 mmol/L)affecting hMSCs differentiation,we provide strong evidence for the cytocompatibility of the two monomers degraded from citrate-based composites in the orthopedic setting.展开更多
Fluoride-incorporated plasma electrolytic oxidation(PEO)coating was fabricated on biodegradable AZ31 alloy.The surface morphologies and phases were investigated by scanning electron microscopy and X-ray diffraction.Th...Fluoride-incorporated plasma electrolytic oxidation(PEO)coating was fabricated on biodegradable AZ31 alloy.The surface morphologies and phases were investigated by scanning electron microscopy and X-ray diffraction.The effect of fluoride incorporation in coatings on corrosion behaviour was investigated in simulated body fluid and in vitro cytocompatibility of the coatings was also studied by evaluating cytotoxicity,adhesion,proliferation and live-dead stain of osteoblast cells(MC3T3-E1).Furthermore,the corrosion morphologies in vivo were examined.The results showed that the fluoride could be incorporated into the coating to form MgF2 phase.In vitro and in vivo degradation tests revealed that the corrosion resistance of the coating could be improved by the incorporation of fluoride,which may attribute to the chemical stability of MgF2 phase.Moreover,good cytocompatibility of fluoride-incorporated coating was confirmed with no obvious cytotoxicity,enhanced cell adhesion and proliferation.However,when the fluoride content was high,a slight inhibition of cell growth was observed.The results indicate that although fluoride incorporation can enhance the corrosion resistance of the coatings,thus resulting a more suitable environment for cells,the high content of fluoride in the coating also kill cells ascribed to the high released of fluorine.If the content of fluoride is well controlled,the PEO coating with MgF2 phase is a promising surface modification of Mg alloys.展开更多
Biogenic synthesis of silver nanoparticles(b-AgNPs)utilising plant extract has gained the interest of researchers due to the environmentally friendly and cost-effective technique.However,the extent of its application ...Biogenic synthesis of silver nanoparticles(b-AgNPs)utilising plant extract has gained the interest of researchers due to the environmentally friendly and cost-effective technique.However,the extent of its application in the biomedical field remains scarce.This study evaluates the antibacterial,cytocompatibility,and wound healing activities of synthesised AgNPs using Persicaria odorata leaves extract(PO-AgNPs).The formation of PO-AgNPs was observed by visual colour changes and verified by ultraviolet-visible(UV–vis)spectrophotometer,which revealed a surface plasmon resonance(SPR)at around 440 nm,and further confirmed by X-ray diffraction(XRD).Characterisation using Fourier transform infrared(FTIR)spectroscopy showed biomolecules from the leaves extract presented together on PO-AgNPs.Field emission scanning electron microscope(FESEM)and high-resolution transmission electron microscopy(HR-TEM)images revealed PO-AgNPs nanospheres with diameters of 11±3 nm.Disc diffusion test(DDT)and minimum inhibitory concentration(MIC)analysis resulted in a dose-dependent inhibition of PO-AgNPs against tested Staphylococcus epidermidis and Methicillin-resistant Staphylococcus aureus(MRSA).These results were further corroborated by time-kill kinetic assay which revealed that PO-AgNPs were bactericidal against both strains 24 h post-treatment.Cytocompatibility and in vitro wound healing evaluation against normal human fibroblast cells,HSF 1184 inferred that PO-AgNPs are non-toxic to normal cells and able to enhance cell migration as compared to the non-treated cells.Therefore,PO-AgNPs are biocompatible and possess antibacterial and wound healing capabilities that are useful in biomedical applications.展开更多
The washout resistance of injectable calcium phosphate cement(CPC) is highly requisite for more widely clinical applications. In this work, locust bean gum(LBG) was used as the anti-washout agent to improve the washou...The washout resistance of injectable calcium phosphate cement(CPC) is highly requisite for more widely clinical applications. In this work, locust bean gum(LBG) was used as the anti-washout agent to improve the washout resistance of CPC. The results indicated that the washout resistance was greatly improved,and meanwhile the injectability, setting time and compressive strength slightly decreased when the content of LBG was no more than 1.0%. Additionally, the CPC with 1.0% LBG exhibited good cell compatibility of the mouse bone mesenchymal stem cells(mBMSCs). Therefore, the 1.0% LBG content was proposed to serve as a useful additive in CPC as a result of its ability to promote washout resistance, which may play an important role in clinical applications.展开更多
Extracellular supplement of Ca and Si accelerates osteogenisis and angiogenisis during bone repair.CaSi-based ceramics are biodegradable and can release Ca and Si ions efficiently.However,locally high alkalinity induc...Extracellular supplement of Ca and Si accelerates osteogenisis and angiogenisis during bone repair.CaSi-based ceramics are biodegradable and can release Ca and Si ions efficiently.However,locally high alkalinity induced by excessively rapid degradation limits their application.In this paper,NaCa_(2)HSi_(3)O_(9)(NCS)nanorods were fabricated on Ti by micro-arc oxidation and hydrothermal treatment;protein layers consisted of different rations of bovine serum albumin(BSA)and lysozyme(LYS)were prepared on NCS nanorods by spinning coating and thermal stabilization.The microstructure,ion releasing and wettability of coatings were observed;osteoblast and endotheliocyte behaviors,as well as bacteria response in vitro,were evaluated.The protein layer did not change microstructure and phase composition of nanorods but acted as a barrier isolating nanorods from contacting medium,and it results in slowing down the degradation of nanorods.The reduced increase of pH value,released Ca and Si ions and incorporation of LYS in BSA protein layer gave NCS nanorods improved MC3 T3-E1 and HUVECs response,compared with Ti.Meanwhile,the protein layers except pure LYS endowed nanorods with a highly antibacterial effect against staphylococcus aureus and escherichia coli simultaneously,indicating the key role of BSA in resisting antibacterial adhesion.NCS nanorods with BSA and LYS composited protein layers should be a potential coating applied on Ti implants for increasing osseointegration.展开更多
The work is dedicated to develop a one-step eco-friendly method to prepare antibacterial polyethylene terephthalate(PET).We report a one-step eco-friendly method to manufacture antibacterial PET via on-line amination ...The work is dedicated to develop a one-step eco-friendly method to prepare antibacterial polyethylene terephthalate(PET).We report a one-step eco-friendly method to manufacture antibacterial PET via on-line amination reaction by melt coextrusion.Beside evenly mixing of poly(hexamethylene guanidine)(PHMG)and PET in the melt coextrusion procedure,the amination reaction also occurred between PHMG and PET under high temperature(230-270℃).The antibacterial ability of composite PET showed obvious PHMG concentration dependence,and antibacterial activity reached more than 99%when PHMG content was 2.5 wt%.Moreover,LIVE/DEAD fluorescence test further confirmed that the composite PET could kill bacteria quickly and efiectively(within 30 min);while negligible cytotoxicity was observed to HSF and HUVEC cells.Onestep eco-friendly fabrication of composite antibacterial PET was accomplished by on-line melt coextrusion.The composite antibacterial PET has potential use in multiple fields to combat with pathogenic including textiles,packaging materials,decoration materials and biomedical devices,etc.展开更多
Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN...Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN/Cu nanocomposite coatings with various N_(2) partial pressures were deposited on 304 stainless steels(SS)using an arc ion plating(AIP)system,named TiN/Cu-x(x=0.5,1.0,1.5 Pa).The results of X-ray diffraction analysis,energy-dispersive X-ray spectroscopy,and scanning electron microscopy showed that the N_(2) partial pressures determined the Cu contents,surface defects,and crystallite sizes of TiN/Cu nanocomposite coatings,which further influenced the comprehensive abilities.And the hardness and wear resistances of TiN/Cu coatings were enhanced with increase of the crystallite sizes.Under the co-actions of surface defects,crystallite sizes,and Cu content,TiN/Cu-1.0 and TiN/Cu-1.5 coatings possessed excellent corrosion resistance.Besides,the biological tests proved that all the TiN/Cu coatings showed no cytotoxicity with strong antibacterial ability.Among them,TiN/Cu-1.5 coating significantly promoted the cell proliferation,which is expected to be a novel antibacterial,corrosion-resistant,and wear-resistant coating on the surfaces of medical implants.展开更多
The mechanical properties and bio-corrosion behaviors of as-extruded Mg-4Zn alloys after Sn addition were investigated,systemati-cally.A small amount of Sn addition to Mg-4Zn alloy slightly improved the mechanical pro...The mechanical properties and bio-corrosion behaviors of as-extruded Mg-4Zn alloys after Sn addition were investigated,systemati-cally.A small amount of Sn addition to Mg-4Zn alloy slightly improved the mechanical properties for solid solution strengthening,and significantly controlled the bio-corrosion rates.Sn participating in the outer layer film formation as SnO/SnO_(2)resisted the bio-corrosion proceeding.Especially,Mg-4Zn-1.5Sn alloy,with a weight loss rate of 0.45 mm/y and hydrogen evolution rate of 0.099 mL/cm^(2)/day,showed cytotoxicity grade of 0 to MC3T3-E1 cells.The perfect alliance of cytocompatibility,suitable mechanical properties and low bio-corrosion rate demonstrates that this Mg-4Zn-1.5Sn alloy is a promising biodegradable magnesium alloy for orthopedic implants.展开更多
基金financially supported by the National Natural Science Foundation of China (No.31271015,81501856)National Key R&D Program (2016YFC1102100)+1 种基金Shanghai Science and Technology Development Fund (13JC1403900,13DZ2294000)Medical Engineering Collaborative Project of Shanghai Jiao Tong University (YG2014ZD01)
文摘Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan(hydroxypropyltrimethyl ammonium chloride chitosan, HACC), could effectively inhibit bacterial adherence and biofilm formation in vitro. Therefore, the aim of this study was to further investigate the in vitro cytocompatibility with osteogenic cells and the in vivo anti-infection activity of titanium implants with HACC-loaded nanotubes(NT-H). The titanium implant(Ti), nanotubes without polymer loading(NT), and nanotubes loaded with chitosan(NT-C) were fabricated and served as controls. Firstly, we evaluated the cytocompatibility of these specimens with human bone marrow-derived mesenchymal stem cells in vitro.The observation of cell attachment, proliferation, spreading, and viability in vitro showed that NT-H has improved osteogenic activity compared with Ti and NT-C. A prophylaxis rat model with implantation in the femoral medullary cavity and inoculation with methicillin-resistant Staphylococcus aureus was established and evaluated by radiographical, microbiological, and histopathological assessments. Our in vivo study demonstrated that NT-H coatings exhibited significant anti-infection capability compared with the Ti and NT-C groups. In conclusion, HACC-loaded nanotubes fabricated on a titanium substrate show good compatibility with osteogenic cells and enhanced anti-infection ability in vivo, providing a good foundation for clinical application to combat orthopedic implant-associated infections.
基金supported by the National Natural Science Foundation of China[Grant No.51201192]Natural Science Foundation of Chongqing[Grant No.cstc2018jcyj A2285]。
文摘A micro-nano structure CaF_(2)chemical conversion layer was prepared on fluoride-treated AZ31 alloy,then the composite fluoride conversion film(CaF_(2)/MgF_(2))was modified by stearic acid(SA)and fabricated a superhydrophobic surface.The fluoride-treated magnesium,fluoride conversion film and superhydrophobic coating were characterized by SEM,EDS,XRD and FTIR.The properties of coatings1 adhesion and corrosion resistance were evaluated via tape test and electrochemical measurement.The cytocompatibility of the MgF_(2),CaF_(2)and superhydrophobic CaF_(2)/SA surface was investigated with bone marrow-derived mesenchymal stem cells(BMSCs)by direct culture for 24 h.The results showed that the superhydrophobic fluoride conversion coating composed of inner MgF_(2)layer and the outer CaF_(2)/SA composite layer had an average water contact angle of 152°.SA infiltrated into the micro-nano structure CaF_(2)layer and formed a strong adhesion with CaF_(2)layer.Furthermore,the super-hydrophobic coating showed higher barrier properties and corrosion resistance compared with the fluoride conversion film and fluoride-treated AZ31 alloy.The BMSC adhesion test results demonstrated MgF_(2)CaF_(2)and CaF_(2)/SA coatings were all nontoxic to BMSC.At the condition of in direct contact with cells,MgF_(2)showed higher cell density and enhanced the BMSCs proliferation,while CaF_(2)and CaF_(2)/SA coating showed no statistically difference in cell density compared with glass reference but the CaF_(2)and CaF_(2)/SA coating were not conducive to BMSCs adhesion.
基金supported by the National Natural Science Foundation of China[Grant No.51201192]Natural Science Foundation of Chongqing[Grant No.cstc2018jcyj A2285cstc2018jcyjA 2285]。
文摘Polycaprolactone/hydroxyapatite(PCL/HA)composite coating was fabricated by a combination of hydrothermal and dipping methods to delay the degradation of Mg alloy AZ31 as bioresorbable materials.The PCL/HA coating was composed of nano rod-shape HA crystals and PCL filled in the space of HA crystals.Compared with the single HA coating,the binding strength between the PCL/HA composite coating and Mg alloy was obviously improved and the PCL/HA coating still adhered to the surface of AZ31 substrate even after 38 days of immersion.The electrochemical corrosion rate of HA coated sample was reduced by ten times after being filled by PCL.The electrochemical impedance spectroscopy(EIS)and immersion test results showed that the PCL/HA composite coating could provide a more effective barrier for Mg substrate than the HA coating alone.The cytocompatibility and the antibacterial property of HA coating and PCL/HA coating were evaluated by culturing with bone marrow-derived mesenchymal stem cells(BMSCs)and methicillin-resistant staphylococcus aureus(MRSA)for 24 h under direct culture conditions,respectively.The PCL/HA composite coating showed better BMSC cell compatibility,more suitable for BMSC adhesion than HA coating alone and showed a potential application prospect as a biological materials.However,from the perspective of clinical applications,the antibacterial property of PCL/HA composite coating needs to be further improved.
基金National Natural Science Foundations of China(No.51003014,No.31100682)"111 Project" Biomedical Textile Materials Science and Technology of China(No.B07024)
文摘Natural silk from Bombyx mori has been used as medical sutures for several decades,and regenerated silk fibroin( RSF)based biomaterials have been increasingly studied in the past thirty years. However,vascular graft derived from silk fibroin fiber has been explored in recent several years with development of textile science and engineering. Moreover,endothelialization of vascular graft has been seen as an ideal strategy for preventing thrombosis and getting higher patency in a long term. Therefore,in the present work silk fibroin fiber vascular graft( SF) was chemically grafted with bioactive molecules such as heparin and RSF to improve the cytocompatibility. 3-aminopropyl-triethoxysilane(APTES),1-ethyl-3-(3-dimethylaminopropyl) carbodiie hydrochlide( EDC · HCl),and N-hydroxysuccinimide( NHS) have been employed as coupling agent and crosslinking agents,respectively. Microscopy and ATRFTIR were used to characterize the surface changes and the structure of the grafts after treatment,respectively. Cell culture in vitro and MTT assay were conducted to determine the improvement of cell affinity to the graft. Furthermore,mechanical properties of the grafts before and after treatment were compared. The results showed that the chemical grafting was an effective method for improving the cytocompatibility of SF without significant loss of mechanical properties.
文摘The goal of this proof-of-concept study was the fabrication of porous silk fibroin (SF) microspheres which could be used as cell culture carriers under very mild processing conditions. The SF solution was differentiated into droplets which were induced by a syringe needle in the high-voltage electrostatic field. They were collected and frozen in liquid nitrogen and water in droplets formed ice crystals which sublimated during lyophilization and a great quantity of micropores shaped in SF microspheres. Finally, the microspheres were treated in ethanol so as to transfer the molecular conformation into β-sheet and then they were insoluble in water. SF particles were spherical in shape with diameters in the range of 208.4 μm to 727.3 μm, while the pore size on the surface altered from 0.3 μm to 10.7 μm. In vitro, the performances of SF microspheres were assessed by culturing L-929 fibroblasts cells. Cells were observed to be tightly adhered and fully extended;also a large number of connections were established between cells. After 5-day culture, it could be observed under a confocal laser scanning microscope that the porous microenvironment offered by SF particles accelerated proliferation of cells significantly. Furthermore, porous SF particles with smaller diameters (200 - 300 μm) might promote cell growth better. These new porous SF microspheres hold a great potential for cell culture carriers and issue engineering scaffolds.
基金Shanghai Science and Technical Committee,China(No.10411953300)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,China(No.LZ0902)Minhang District Industry-Study-Research Cooperation,China(No.2012MH202)
文摘Hydrogen peroxide( H_2O_2) is applied for surface modification of polyglycolic acid( PGA) fibers in order to enhance the hydrophilicity and cytocompatibility of PGA fibers effectively,and maintain the breaking strength as the same time. PGA fibers are dipped in H_2O_2 solution a certain time for modification. Scanning electron microscopy( SEM) was used to observe the surface morphology of PGA fibers before and after modification. The varying of PGA macromolecule was examined with Fourier transform infrared spectroscopy( FTIR) analyses. X-ray diffraction( XRD) and differential scanning calorimetry( DSC) analysis showed that crystallinity slightly decreases. Mechanical performance test showed tensile force of modified PGA fiber was increased. The water contact angle test indicated the improving of hydrophilic. A cell proliferation assay showed that fibroblast cells attach and proliferate well on the fibers, which meant the modified fibers possess good cytocompatibility. These results suggest that H_2O_2 surface modification is easy to operate and a advantageous modification method for PGA fibers.
文摘There is an increasing demand for crosslinking methods of silk fibroin (SF) scaffolds in biomedical applications that could maintain the biocompatibility, bioactivity as well as improve the water resistance and mechanical properties of SF materials. In this study, SF was crosslinked effectively with genipin which is a naturally occurring iridoid glucoside and the crosslinking mechanism was investigated through FTIR and amino acid analysis. The results showed that genipin could react with the -NH2 groups on the side chains of SF macromolecules and to form inter- and intra-molecular covalent bonds, and improved the stability of SF materials significantly. In vitro, the performances of genipin-crosslinked SF films were assessed by seeding L929 cells and compared with ethanol-processed SF films, glutaraldehyde and polyethylene glycol diglycidyl ether crosslinked ones. The genipin-crosslinked SF films showed a similar affinity to cells as ethanol-processed ones, and a higher bioactivity in promoting cell growth and proliferation, inhibition of cell apoptosis, and maintenance of normal cell cycle compared with glutaraldehyde and polyethylene glycol diglycidyl ether crosslinked SF films. These features, combined with the decrease of brittleness of SF films crosslinked with chemical methods, substantiated genipin as an effective and biocompatible agent for the manufacturing of bioactive SF materials which used as tissue engineering scaffolds and drug delivery carriers.
基金financially supported by the Fund for Shanxi ‘‘1331 Project’’ Key Innovative Research Team (No.1331KIRT)the Natural Science Foundation of Shanxi Province (No.201801D121093)the Key Innovative Research Team in Science and Technology of Shanxi Province (No.201805D131001)
文摘Nearly equiatomic nickel–titanium(NiTi) alloy is an ideal implant biomaterial because of its shape memory effect, superelasticity, low elastic modulus as well as other desirable properties.However, it is prone to infection because of its poor antibacterial ability.The present work incorporated Cu into Ni–Ti–O nanopores(NP–Cu) anodically grown on the NiTi alloy to enhance its antibacterial ability, which was realized through electrodeposition.Our results show that incorporation of Cu(0.78 at%–2.37 at%)has little influence on the NP diameter, length and morphology.The release level of Cu ions is in line with loadage which may be responsible for the improved antibacterial ability of the NiTi alloy to combat possible bacterial infection in vivo.Meanwhile, the NP–Cu shows better cytocompatibility and even can promote proliferation of bone marrow mesenchymal stem cells(BMSCs),up-regulate collagen secretion and extracellular matrix mineralization when compared with Cu-free sample.Better antibacterial ability and cytocompatibility of the NP–Cu render them to be promising when serving as NiTi implant coatings.
基金supported by the National Natural Science Foundation of China(No.51571134)the SDUST Research Fund(No.2014TDJH104).
文摘Basically,Mg–Al layered double hydroxide(LDH)coatings are prepared on the surface of micro-arc oxidation(MAO)coated magnesium(Mg)alloys at a high temperature or a low pH value.This scenario leads to the growth rate of LDH coating inferior to the dissolution rate of the MAO coating.This in turn results in limited corrosion resistance of the composite coating.In this study,a Mg–Al LDH coating on MAO-coated Mg alloy AZ31 is prepared through a water bath with a higher pH(13.76)at a lower temperature(60℃).FE-SEM,EDS,XRD,XPS,and FT-IR are applied to analyze the surface morphology,chemical compositions,and growth process.Electrochemical polarization,electrochemical impedance spectroscopy(EIS)and hydrogen evolution tests are employed to evaluate the corrosion resistance of the samples.The results disclose that the MAO coating is completely covered by the nanosheet-structured LDH coating with a thickness of approximately 3.8μm.The corrosion current density of the MAO-LDH composite coating is decreased four orders of magnitude in comparison to its substrate;the presence of a wide passivation region in anodic polarization branch demonstrates its strong self-healing ability,indicating the hybrid coating possesses excellent corrosion resistance.The formation mechanism of the LDH coating on the MAO-coated Mg alloy is proposed.Furthermore,the cytocompatibility is assessed via an indirect extraction test for MC3T3-E1 pre-osteoblasts,which indicates an acceptable cytocompatibility of osteoblasts for the composite coating.
基金the National Natural Science Foundation of China (Grant Nos.21201142and 11502158)Southwest University of Science and Technology Researching Project (Grant No.14tdsc03).
文摘Nanorod hydroxyapatite (NRHA)/graphene oxide (GO)composites with weight ratios of 0.4,1.5, and 5have been fabricated by a facile ultrasonic-assisted method at room temperature and atmospheric pressure. The chemical structure properties and morphology of the composites were characterized by field emission source scanning electron microscope,X-ray diffraction,transmission electron microscopy,and high-resolution transmission electron microscopy.The results indicate that the NRHA/ GO composites have an irregular surface with different degree wrinkles and are stable,and NRHA are well combined with GO.In addition,the biomimetic mineralization mechanism of hydroxyapatite on the NRHA/GO composites in simulated body fluid (SBF)is presented.The presence of a bone-like apatite layer on the composite surface indicate that the NRHA/GO composites facilitate the nucleation and growth of hydroxyapatite crystals in SBF for biomimetic mineralization.Moreover,the NRHA-1.5/GO composite and pure GO were cultured with MC3T3-E1cells to investigate the proliferation and adhesion of cells.In vitro cytocompatibility evaluation demonstrated that the NRHA/GO composite can act as a good template for the growth and adhesion of cells. Therefore,the NRHA/GO composite could be applied as a GO-based,free-template,non-toxic,and bioactive composite to substitute for a damaged or defect bone.
基金This research was financially supported by the National Natural Science Foundation of China(Nos.51474153 and 51574175).
文摘The influences of Mo contents on mechanical properties,biocorrosion and cytocompatibility of as-cast Mg-6Zn-8.16Y-2.02Mn-xMo(x=0.0,0.1,0.3,0.5,0.7 wt%) alloys were firstly investigated.Appropriate amount of Mo was conducive to grain refinement and the formation of long-period stacking ordered structure with continuous distribution,which was advantageous to mechanical properties and corrosion resistance.Mg-6Zn-8.16Y-2.02Mn-0.3Mo exhibited the ultimate tensile strength of 265.0 MPa,elongation of 13.5% and the lowest weight loss rate in Hank’s solution.Moreover,the cell toxicity cultured in 25% extract was evaluated and the alloy with 0.3 wt% Mo exhibited the best cytocompatibility.Thus,the alloy was expected to become a novel biodegradable implant material.
基金This work was supported by the Natural Science Foundation of Shanghai(20ZR1402400)the National Natural Science Foundation of China(52173031,51903045,51703033)+4 种基金the Program of Shanghai Academic/Technology Research Leader(20XD1400100)the National Key Research and Development Program of China(2020YFC1910303,2018YFC1105800)the Basic Research Project of the Science and Technology Commission of Shanghai Municipality(21JC1400100)the Fundamental Research Funds for the Central Universities(2232020D-04,2232019A3-06,2232019D3-02)the Science and Technology Commission of Shanghai Municipality(20DZ2254900).
文摘Gelatin(G)is a commonly used natural biomaterial owing to its good biocompatibility and easy availability.However,using pure gelatin as a bioink can barely achieve an ideal shape fidelity in 3D printing.In this study,Antheraea pernyi silk fibroin nanofibers(ASFNFs)with arginine-glycine-aspartic acid(RGD)peptide and partial natural silk structure are extracted and combined with pure gelatin bioink to simultaneously improve the shape fidelity and cytocompatibility of corresponding 3D printed scaffold.Results show that the optimum printing temperature is 30℃ for these bioinks.The printed filaments using 16G/4ASFNFs bioink(16wt%gelatin and 4wt%ASFNFs)demonstrate better morphology and larger pore size than those printed by pure gelatin bioink(20G,20wt%gelatin),thus successfully improve the shape fidelity and porosity of the 3D printed scaffold.The 16G/4ASFNFs scaffold also demonstrate higher swelling ratio and faster degradation rate than the pure gelatin scaffold.Moreover,the cell viability and proliferation ability of Schwann cells cultured on the 16G/4ASFNFs scaffold are significantly superior than those cultured on the pure 20G scaffold.The ASFNFs enhanced 16G/4ASFNFs scaffold reported here are expected to be a candidate with excellent potential for biomedical applications.
文摘Citrate based polymer poly(octamethylene citrate)(POC)has shown promise when formulated into composite material containing up to 65 wt%hydroxylapatite(HA)for orthopedic applications.Despite significant research into POC,insufficient information about the biocompatibility of the monomers 1,8-Octanediol and Citrate used in its synthesis is available.Herein,we investigated the acute cytotoxicity,immune response,and long-term functionality of both monomers.Our results showed a cell-type dependent cytotoxicity of the two monomers:1,8-Octanediol induced less acute toxicity to 3T3 fibroblasts than Citrate while presenting comparable cytotoxicity to MG63 osteoblast-like cells;however,Citrate demonstrated enhanced compatibility with hMSCs compared to 1,8-Octanediol.The critical cytotoxic concentration values EC30 and EC50,standard for comparing cytotoxicity of chemicals,were also provided.Additionally,Citrate showed slower and less inhibitory effects on long-term hMSC cell proliferation compared with 1,8-Octanediol.Furthermore,osteogenic differentiation of hMSCs exposure to Citrate resulted in less inhibitory effect on alkaline phosphatase(ALP)production.Neither monomer triggered undesired pro-inflammatory responses.In combination with diffusion model analysis of monomer release from cylindrical implants,based on which the maximum concentration of monomers in contact with bone tissue was estimated to be 2.2104 mmol/L,far lower than the critical cytotoxic concentrations as well as the 1,8-Octanediol concentration(0.4 mg/mL or 2.7 mmol/L)affecting hMSCs differentiation,we provide strong evidence for the cytocompatibility of the two monomers degraded from citrate-based composites in the orthopedic setting.
基金Financial support from the National Science Foundation for Distinguished Young Scholars of China(51525207)National Natural Science Foundation of China(31570973)Shanghai Committee of Science and Technology,China(14XD1403900,15441904900)are acknowledged.
文摘Fluoride-incorporated plasma electrolytic oxidation(PEO)coating was fabricated on biodegradable AZ31 alloy.The surface morphologies and phases were investigated by scanning electron microscopy and X-ray diffraction.The effect of fluoride incorporation in coatings on corrosion behaviour was investigated in simulated body fluid and in vitro cytocompatibility of the coatings was also studied by evaluating cytotoxicity,adhesion,proliferation and live-dead stain of osteoblast cells(MC3T3-E1).Furthermore,the corrosion morphologies in vivo were examined.The results showed that the fluoride could be incorporated into the coating to form MgF2 phase.In vitro and in vivo degradation tests revealed that the corrosion resistance of the coating could be improved by the incorporation of fluoride,which may attribute to the chemical stability of MgF2 phase.Moreover,good cytocompatibility of fluoride-incorporated coating was confirmed with no obvious cytotoxicity,enhanced cell adhesion and proliferation.However,when the fluoride content was high,a slight inhibition of cell growth was observed.The results indicate that although fluoride incorporation can enhance the corrosion resistance of the coatings,thus resulting a more suitable environment for cells,the high content of fluoride in the coating also kill cells ascribed to the high released of fluorine.If the content of fluoride is well controlled,the PEO coating with MgF2 phase is a promising surface modification of Mg alloys.
基金This work was supported by the Universiti Teknologi Malaysia(UTM)-Transdisciplinary Research Grant(Q.J130000.3554.06G86).
文摘Biogenic synthesis of silver nanoparticles(b-AgNPs)utilising plant extract has gained the interest of researchers due to the environmentally friendly and cost-effective technique.However,the extent of its application in the biomedical field remains scarce.This study evaluates the antibacterial,cytocompatibility,and wound healing activities of synthesised AgNPs using Persicaria odorata leaves extract(PO-AgNPs).The formation of PO-AgNPs was observed by visual colour changes and verified by ultraviolet-visible(UV–vis)spectrophotometer,which revealed a surface plasmon resonance(SPR)at around 440 nm,and further confirmed by X-ray diffraction(XRD).Characterisation using Fourier transform infrared(FTIR)spectroscopy showed biomolecules from the leaves extract presented together on PO-AgNPs.Field emission scanning electron microscope(FESEM)and high-resolution transmission electron microscopy(HR-TEM)images revealed PO-AgNPs nanospheres with diameters of 11±3 nm.Disc diffusion test(DDT)and minimum inhibitory concentration(MIC)analysis resulted in a dose-dependent inhibition of PO-AgNPs against tested Staphylococcus epidermidis and Methicillin-resistant Staphylococcus aureus(MRSA).These results were further corroborated by time-kill kinetic assay which revealed that PO-AgNPs were bactericidal against both strains 24 h post-treatment.Cytocompatibility and in vitro wound healing evaluation against normal human fibroblast cells,HSF 1184 inferred that PO-AgNPs are non-toxic to normal cells and able to enhance cell migration as compared to the non-treated cells.Therefore,PO-AgNPs are biocompatible and possess antibacterial and wound healing capabilities that are useful in biomedical applications.
基金supported by the National Natural Science Foundation of China (Grant No.51172074)the National High Technology Research and Development Program of China (Grant No.2015AA033601)+1 种基金the Science and Technology Program of Guangzhou City of China (Grant No.201508020017)the Research Foundation for the Author of the Excellent Doctoral Dissertation of Guangdong Province (Grant No.sybzzxm 201024)
文摘The washout resistance of injectable calcium phosphate cement(CPC) is highly requisite for more widely clinical applications. In this work, locust bean gum(LBG) was used as the anti-washout agent to improve the washout resistance of CPC. The results indicated that the washout resistance was greatly improved,and meanwhile the injectability, setting time and compressive strength slightly decreased when the content of LBG was no more than 1.0%. Additionally, the CPC with 1.0% LBG exhibited good cell compatibility of the mouse bone mesenchymal stem cells(mBMSCs). Therefore, the 1.0% LBG content was proposed to serve as a useful additive in CPC as a result of its ability to promote washout resistance, which may play an important role in clinical applications.
基金financially supported by the National Natural Science Foundation of China(Nos.51771142,51631007 and 51971171)the National Key Research and Development Programof China No.2016YFC1100600(sub-project 2016YFC1100604)the Natural Science Basic Research Program of Shaanxi Province(No.2020JM-024)。
文摘Extracellular supplement of Ca and Si accelerates osteogenisis and angiogenisis during bone repair.CaSi-based ceramics are biodegradable and can release Ca and Si ions efficiently.However,locally high alkalinity induced by excessively rapid degradation limits their application.In this paper,NaCa_(2)HSi_(3)O_(9)(NCS)nanorods were fabricated on Ti by micro-arc oxidation and hydrothermal treatment;protein layers consisted of different rations of bovine serum albumin(BSA)and lysozyme(LYS)were prepared on NCS nanorods by spinning coating and thermal stabilization.The microstructure,ion releasing and wettability of coatings were observed;osteoblast and endotheliocyte behaviors,as well as bacteria response in vitro,were evaluated.The protein layer did not change microstructure and phase composition of nanorods but acted as a barrier isolating nanorods from contacting medium,and it results in slowing down the degradation of nanorods.The reduced increase of pH value,released Ca and Si ions and incorporation of LYS in BSA protein layer gave NCS nanorods improved MC3 T3-E1 and HUVECs response,compared with Ti.Meanwhile,the protein layers except pure LYS endowed nanorods with a highly antibacterial effect against staphylococcus aureus and escherichia coli simultaneously,indicating the key role of BSA in resisting antibacterial adhesion.NCS nanorods with BSA and LYS composited protein layers should be a potential coating applied on Ti implants for increasing osseointegration.
基金Funded by the National Natural Science Foundation of China(No.51703169)Key Program of Science and Technology of Jieyang City(No.2019016)Key Research and Development Program of Shandong Province of China(No.2019JZZY010338)。
文摘The work is dedicated to develop a one-step eco-friendly method to prepare antibacterial polyethylene terephthalate(PET).We report a one-step eco-friendly method to manufacture antibacterial PET via on-line amination reaction by melt coextrusion.Beside evenly mixing of poly(hexamethylene guanidine)(PHMG)and PET in the melt coextrusion procedure,the amination reaction also occurred between PHMG and PET under high temperature(230-270℃).The antibacterial ability of composite PET showed obvious PHMG concentration dependence,and antibacterial activity reached more than 99%when PHMG content was 2.5 wt%.Moreover,LIVE/DEAD fluorescence test further confirmed that the composite PET could kill bacteria quickly and efiectively(within 30 min);while negligible cytotoxicity was observed to HSF and HUVEC cells.Onestep eco-friendly fabrication of composite antibacterial PET was accomplished by on-line melt coextrusion.The composite antibacterial PET has potential use in multiple fields to combat with pathogenic including textiles,packaging materials,decoration materials and biomedical devices,etc.
基金financially supported by National Key Research and Development Program of China (Nos. 2018YFC1106601 and 2016YFC1100601)Liaoning Revitalization Talents Program (No. XLYC1807069)+1 种基金National Natural Science Foundation of China (Nos. 51631009 and 31870954)Key Projects for Foreign Cooperation of Bureau of International Cooperation Chinese Academy of Sciences (No. 174321KYSB20180006)
文摘Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN/Cu nanocomposite coatings with various N_(2) partial pressures were deposited on 304 stainless steels(SS)using an arc ion plating(AIP)system,named TiN/Cu-x(x=0.5,1.0,1.5 Pa).The results of X-ray diffraction analysis,energy-dispersive X-ray spectroscopy,and scanning electron microscopy showed that the N_(2) partial pressures determined the Cu contents,surface defects,and crystallite sizes of TiN/Cu nanocomposite coatings,which further influenced the comprehensive abilities.And the hardness and wear resistances of TiN/Cu coatings were enhanced with increase of the crystallite sizes.Under the co-actions of surface defects,crystallite sizes,and Cu content,TiN/Cu-1.0 and TiN/Cu-1.5 coatings possessed excellent corrosion resistance.Besides,the biological tests proved that all the TiN/Cu coatings showed no cytotoxicity with strong antibacterial ability.Among them,TiN/Cu-1.5 coating significantly promoted the cell proliferation,which is expected to be a novel antibacterial,corrosion-resistant,and wear-resistant coating on the surfaces of medical implants.
基金The authors are grateful for the financial support from the National Key Research and Development Program of China(No.2016YFB0301100)the National Natural Science Foundation of China(Grant Nos.51571044,51671162 and 51874062)the Fundamental Research Funds for the Cen-tral Universities(No.2018CDGFCL0005).
文摘The mechanical properties and bio-corrosion behaviors of as-extruded Mg-4Zn alloys after Sn addition were investigated,systemati-cally.A small amount of Sn addition to Mg-4Zn alloy slightly improved the mechanical properties for solid solution strengthening,and significantly controlled the bio-corrosion rates.Sn participating in the outer layer film formation as SnO/SnO_(2)resisted the bio-corrosion proceeding.Especially,Mg-4Zn-1.5Sn alloy,with a weight loss rate of 0.45 mm/y and hydrogen evolution rate of 0.099 mL/cm^(2)/day,showed cytotoxicity grade of 0 to MC3T3-E1 cells.The perfect alliance of cytocompatibility,suitable mechanical properties and low bio-corrosion rate demonstrates that this Mg-4Zn-1.5Sn alloy is a promising biodegradable magnesium alloy for orthopedic implants.
