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
This paper describes a formation of hybrid coatings on a Ti-2Ta-3Zr-36Nb surface.This is accomplished by plasma electrolytic oxidation and a dip-coating technique with poly(adipic anhydride)((C6H8O3)n)that is loaded w...This paper describes a formation of hybrid coatings on a Ti-2Ta-3Zr-36Nb surface.This is accomplished by plasma electrolytic oxidation and a dip-coating technique with poly(adipic anhydride)((C6H8O3)n)that is loaded with drugs:amoxicillin(C16H19N3O5S),cefazolin(C14H14N8O4S3)or vancomycin(C66H75Cl2N9O24·xHCl).The characteristic microstructure of the polymer was evaluated using scanning electron microscopy and confocal microscopy.Depending on the surface treatment,the surface roughness varied(between 1.53μm and 2.06μm),and the wettability was change with the over of time.X-ray photoelectron spectroscopy analysis showed that the oxide layer did not affect the polymer layer or loaded drugs.However,the drugs lose their stability in a phosphate-buffered saline solution after 6.5 h of exposure,and its decrease was greater than 7%(HPLC analysis).The stability,drug release and concentration of the drug loaded into the material were precisely analyzed by high-performance liquid chromatography.The results correlated with the degradation of the polymer in which the addition of drugs caused the percent of degraded polymer to be between 35.5%and 49.4%after 1 h of material immersion,depending on the mass of the loaded drug and various biological responses that were obtained.However,all of the coatings were cytocompatible with MG-63 osteoblast-like cells.The drug concentrations released from the coatings were sufficient to inhibit adhesion of reference and clinical bacterial strains(S.aureus).The coatings with amoxicillin showed the best results in the bacterial inhibition zone,whereas coatings with cefazolin inhibited adhesion of the above bacteria on the surface.展开更多
Magnetostrictive Fe-Ga alloys have captivated substantial focus in biomedical applications because of their exceptional transition efficiency and favorable cytocompatibility.Nevertheless,Fe-Ga alloys always exhibit fr...Magnetostrictive Fe-Ga alloys have captivated substantial focus in biomedical applications because of their exceptional transition efficiency and favorable cytocompatibility.Nevertheless,Fe-Ga alloys always exhibit frustrating magnetostriction coefficients when presented in bulk dimensions.It is well-established that the magnetostrictive performance of Fe-Ga alloys is intimately linked to their phase and crystal structures.In this study,various concentrations of boron(B)were doped into Fe_(81)Ga_(19) alloys via the laser-beam powder bed fusion(LPBF)technique to tailor the crystal and phase structures,thereby improving the magnetostrictive performance.The results revealed the capacity for quick solidification of the LPBF process in expediting the solid solution of B element,which increased both lattice distortion and dislocations within the Fe-Ga matrix.These factors contributed to an elevation in the density of the modified-D0_(3) phase structure.Moreover,the prepared Fe-Ga-B alloys also exhibited a(001)preferred grain orientation caused by the high thermal gradients during the LPBF process.As a result,a maximum magnetostriction coefficient of 105 ppm was achieved in the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy.In alternating magnetic fields,all the LPBF-prepared alloys showed good dynamic magnetostriction response without visible hysteresis,while the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy presented a notable enhancement of~30%in magnetostriction coefficient when compared with the Fe_(81)Ga_(19) alloy.Moreover.the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy exhibited favorable biocompatibility and osteogenesis,as confirmed by increased alkaline phosphatase(ALP)activity and the formation of mineralized nodules.These findings suggest that the B-doped Fe-Ga alloys combined with the LPBF technique hold promise for the development of bulk magnetostrictive alloys that are applicable for bone repair applications.展开更多
Photoinitiators(PIs), as the key substances for photopolymerized antibacterial film(PAF), affect the cure rate and color of PAF. Herein, two enone dyes were designed and synthesized by a facile approach. Among the can...Photoinitiators(PIs), as the key substances for photopolymerized antibacterial film(PAF), affect the cure rate and color of PAF. Herein, two enone dyes were designed and synthesized by a facile approach. Among the candidates, BDO1 has demonstrated the ability to initiate polymerization of acrylate monomers as single-component PI with the advantages of low mobility, outstanding photobleaching, excellent cytocompatibility, and suitability for light emitting diode(LED) light sources above 365 nm. Taking BDOs as examples, a novel method based on theoretical calculations aiming to assess the potential of enone molecules as single-component PIs was proposed. Finally, under the initiation of BDO1, tannic acid was photopolymerized to a colorless and transparent antibacterial film with high antibacterial ability, which indicated that BDO1 was expected to be used in environmentally friendly PAF.展开更多
Surface modification is found to be an effective way to control the initial degradation of Mg based biomedical alloys.The present study focuses on the modulation of in vitro and in vivo degradation behavior of Mg-Ce a...Surface modification is found to be an effective way to control the initial degradation of Mg based biomedical alloys.The present study focuses on the modulation of in vitro and in vivo degradation behavior of Mg-Ce alloy through a stearic acid-treated polypyrrole coating,which developed superhydrophobic surface(contact angle∼153°)that drastically enhanced the corrosion resistance(more than 85%efficacy).Cerium addition to Mg alloy results basal texture strengthening and grain refinement,resulting in improved mechanical properties.All the specimens exhibited excellent antibacterial performance against gram-negative E.Coli(DH5α)and gram positive S.aureus bacteria.The oligodynamic effect of polypyrrole coating leads to complete bacterial mitigation.Non-toxic nature of the specimens was studied by MC3T3-E1 cell proliferation and differentiation in indirect cell culture method.Improved corrosion resistance of the coated specimen leads to enhanced cell proliferation and osteogenic differentiation.Hard tissue histology and micro-CT analysis exhibited higher fraction of newly formed callus tissues and highest bone-implant integration across the coated specimen,when implanted in rabbit femur.Efficacy of the material in fracture healing was evaluated by implanting bone plate and screw in a clinically fractured goat tibia.At 3 months,complete fracture healed with no vital organ toxicity was observed for the coated specimen.The present results suggest that Ce addition and polypyrrole coating are effective ways to modulate the corrosion and biocompatibility behavior making it a potential candidate for fracture fixation applications.展开更多
There have been many studies on the perspective Zn alloys for bone implants,but few for intestinal applications.Zn-0.4Mn-x Ca(x=0,0.05 and 0.1 wt.%)alloys are developed in this work for intestinal applications,in orde...There have been many studies on the perspective Zn alloys for bone implants,but few for intestinal applications.Zn-0.4Mn-x Ca(x=0,0.05 and 0.1 wt.%)alloys are developed in this work for intestinal applications,in order to make use of proliferation effects of Mn and Ca elements on intestinal probiotics and epithelial cells.Rat small intestinal crypt epithelial(IEC-6)cells can grow healthily on surfaces of all the alloys.Among them,the number of healthy cells on Zn-0.4Mn-0.1Ca is the largest.IEC-6 cell vi-ability is over 160%(much higher than the benchmark of 75%)in 20%-100%extracts of Zn-0.4Mn-0.1Ca for 5 d.All the alloys can promote proliferation of L.acidophilus(intestinal probiotic)and inhibit growth of Escherichia coli(intestinal pathogen).Among them,Zn-0.4Mn-0.1Ca alloy possesses the greatest effect.With the increase of Ca content,the strength of the alloy increases.Zn-0.4Mn-0.1Ca alloy has the highest strength and good plasticity among the three alloys.It exhibits a yield strength of 252 MPa,an ultimate tensile strength of 288 MPa,and a elongation to failure of 41%.Since CaZn_(13)-MnZn_(13)-Zn micro-cell con-trols corrosion rate,Zn-0.4Mn-0.1Ca with the highest volume fractions of MnZn_(13)and CaZn_(13)has the highest corrosion rate of 17.64μm/year when immersed in simulated intestinal fluid for 28 d.Overall,the Zn-Mn-Ca alloys are promising candidates for intestinal implants.展开更多
Zinc(Zn)and its alloys are considered promising biodegradable metallic materials for biomedical implants.However,the correlation between the dynamic degradation evolution of Zn and its biocompatibility remains unclear...Zinc(Zn)and its alloys are considered promising biodegradable metallic materials for biomedical implants.However,the correlation between the dynamic degradation evolution of Zn and its biocompatibility remains unclear.This study evaluates the long-term degradation/corrosion behavior of pure Zn under dynamic immersion in Hank’s solution containing bovine serum albumin(BSA),and investigates the impact of its dynamic degradation evolution on cytocompatibilities of the representative human umbilical vein endothelial cells(HUVECs)and bone marrow mesenchymal stem cells(BMSCs).Degradation behavior results demonstrate that the dynamic fluidic medium led to speeding-up of the corrosion rate of Zn and exacerbation of the localized corrosion,with this phenomenon being more pronounced under influence of BSA.Correspondingly,the cells’viability increased with prolonged immersion time under both static and dynamic conditions,alleviating a certain level of cytotoxicity initiated at an earlier stage.Nonetheless,as compared to the static cases the dynamic fluidic environments induced a poorer cell viability,although the BSA helped to offset this impact.Our findings provide not only new insights into better-understanding Zn-based biodegradable metals but also clarify the critical concern in their clinical translations,offering therefore important guidance for development of new biodegradable metallic medical implants.展开更多
Calcium phosphate coated Mg alloy was prepared. The phase constitute and surface morphology were identified and observed by X-ray diffractometer （XRD） and SEM. The results show that the coating is composed of flake-...Calcium phosphate coated Mg alloy was prepared. The phase constitute and surface morphology were identified and observed by X-ray diffractometer （XRD） and SEM. The results show that the coating is composed of flake-like CaHPO4-2H2O crystals. The corrosion resistance of the coated Mg alloy was measured by electrochemical polarization and immersion test in comparison with uncoated Mg alloy. Cytocompatibility was designed by observing the attachment, growth and proliferation of L929 cell on both coated and uncoated Mg alloy samples. The results display that the corrosion resistance of the coated Mg alloy is better than that of uncoated one. The immersion test also shows that the calcium phosphate coating can mitigate the corrosion of Mg alloy substrate, and tends to transform into hydroxyapatite （HA）. Compared with uncoated Mg alloy, L929 cells exhibit good adherence, growth and proliferation characteristics on the coated Mg alloy, indicating that the cytocompatibility is significantly improved with the calcium phosphate coating.展开更多
A synthetic diblock copolymer poly（2-ethyl-2-oxazoline）-poly（D,L-lactide） （PEOz-PLA） can self-assemble into micelles with an increased efficiency of drug delivery. However, the interactions of blood-micelles and...A synthetic diblock copolymer poly（2-ethyl-2-oxazoline）-poly（D,L-lactide） （PEOz-PLA） can self-assemble into micelles with an increased efficiency of drug delivery. However, the interactions of blood-micelles and cell-micelles remain unclear. In the present study, we aimed to assess the hemocompatibility and cytocompatibility of PEOz-PLA micelles in order to clarify its potentials as carriers for drug delivery. Blood compatibility of the micelles was evaluated by hemolysis analysis, coagulation test, platelet activation investigation and assessment of their interaction with protein. The results revealed that PEOz-PLA micelles had a favorable blood compatibility. In addition, PEOz-PLA micelles showed a good cytocompatibility through SRB assay, presenting only negligible cytotoxicity when incubated with KBv cells. Taken together, PEOz-PLA micelles could be used as a hemocompatible and cytocompatible drug carrier for intravenous administration.展开更多
Magnesium(Mg) alloys possess comparable physical and mechanical properties to bone, making them an outstanding candidate of implant materials for bone fracture treatment. In addition to the excellent biocompatibility,...Magnesium(Mg) alloys possess comparable physical and mechanical properties to bone, making them an outstanding candidate of implant materials for bone fracture treatment. In addition to the excellent biocompatibility, and bioactivity, the engagement of Mg alloys is key for a number of biological functionalities in the human body. The unique biodegradation nature of Mg alloy implants implies that it may not require a secondary removal procedure when the expected supporting tasks accomplish, as they may simply and safely "disappear" over time. Nonetheless, the demonstrated drawback of potentially rapid degradation, is an issue that must be addressed appropriately for Mg implants and is consequently given unique attention in this review article. Herein, the critical criteria and the state-of-the-art strategies for controlling the degradation process of Mg alloys are reported. Furthermore, future developments of biodegradable Mg and its alloys systems with satisfactory specifications for clinical trials and deployment,are discussed. This review aims to provide information to materials scientists and clinical practitioners in the context of developing practical biodegradable Mg alloys.展开更多
Magnesium （Mg） alloys are receiving increasing attention for body implants owing to their good bio- compatibility and biodegradability. However, they often suffer from bacterial infections on account of their insuff...Magnesium （Mg） alloys are receiving increasing attention for body implants owing to their good bio- compatibility and biodegradability. However, they often suffer from bacterial infections on account of their insufficient antibacterial ability. In this study, ZK60-xCu （x = O, 0.2, 0.4, 0.6 and 0.8 wt%） alloys were prepared by selective laser melting （SLM） with alloying copper （Cu） to enhance their antibacterial ability. Results showed that ZK60-Cu alloys exhibited strong antibacterial ability due to combination of release of Cu ions and alkaline environment which could kill bacteria by destroying cellular membrane structure, denaturing enzymes and inhibiting deoxyribonucleic acid （DNA） replication. In addition, their compres- sive strength increased due to grain refinement and uniformly dispersing of short-bar shaped MgZnCu phases. Moreover, ZK60-Cu alloys also exhibited good cytocompatibility. In summary, ZK60-Cu alloys with antibacterial ability may be Dromising implants for biomedical anDlications.展开更多
Objective： To explore the feasibility of using regenerated silk fibroin membrane to construct artificial skin substitutes for wound healing, it is necessary to evaluate its cytocompatibility. Methods： The effects of...Objective： To explore the feasibility of using regenerated silk fibroin membrane to construct artificial skin substitutes for wound healing, it is necessary to evaluate its cytocompatibility. Methods： The effects of regenerated silk fibroin film on cytotoxicity, adhesion, cell cycle, and apoptosis of L929 cells, growth and vascular endothelial growth factor （VEGF） expression of ECV304 cells, and VEGF, angiopoietin-1 （Ang-1）, platelet-derived growth factor （PDGF） and fibroblast growth factor 2 （FGF2） expression of WI-38 cells were assessed by 3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-di-phenytetrazoliumromide （MTT） assay, viable cell counting, flow cytometry （FCM）, and enzyme-linked immunosorbant assay （ELISA）. Results： We showed that the regenerated silk fibroin film was not cytotoxic to L929 cells and had no adverse influence on their adhesion, cell cycle or apoptosis; it had no adverse influence on the growth and VEGF secretion of ECV304 cells and no effect on the secretion of VEGF, Ang-1, PDGF and FGF2 by WI-38 cells. Conclusion： The regenerated silk fibroin film should be an excellent biomaterial with good cytocompatibility, providing a framework for reparation after trauma in clinical applications.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
This study aims to investigate the addition of Zn on the corrosion property and cytocompatibility of Mg- 2Gd-xZn (x = 0, 3, 4 and 5;wt%) alloys, which were prepared by gravity permanent mold casting and solution treat...This study aims to investigate the addition of Zn on the corrosion property and cytocompatibility of Mg- 2Gd-xZn (x = 0, 3, 4 and 5;wt%) alloys, which were prepared by gravity permanent mold casting and solution treatment, respectively. The results show that the intermetallic phases of these ternary alloys are mainly composed of Mg12GdZn and Mg3GdZn3. The content of secondary phases as well as the grain size is greatly dependent on the Zn addition. Compared to the binary Mg- 2Gd alloy, the corrosion resistance of the most ternary alloys is significantly improved. Furthermore, the in vitro cell culture study demonstrates the potential cytocompatibility of the developed ternary alloys. It indicates that a series of Mg-2Gd-xZn (x = 0, 3, 4 and 5;wt%) with medically acceptable corrosion rate are developed and show great potential use as a new type of biodegradable implants.展开更多
In the present work, the biodegradable behavior, cytocompatibility and osteogenesis activity of a Mg69Zn27Ca4 metal glass were investigated. Electrochemical test, immersion test, cytotoxicity test and histopathologica...In the present work, the biodegradable behavior, cytocompatibility and osteogenesis activity of a Mg69Zn27Ca4 metal glass were investigated. Electrochemical test, immersion test, cytotoxicity test and histopathological evaluation were carried out. The results showed that there was a dense protective layer formed on the surface of Mg69Zn27Ca4 metal glass which could inhibit the degradation process in the Hank’s solution. In vitro cytotoxicity test showed that Mg69Zn27Ca4 metal glass had good biocompatibility. Histopathological evaluation showed that the degradation of Mg69Zn27Ca4 metal glass could promote the new bone formation with no obvious inflammatory reactions. After 2 months implantation, the diameter of the bone defect was reduced from the original φ6 mm to φ3.35 ± 0.40 mm with the degradation of Mg69Zn27Ca4 metal glass. Therefore, it can be concluded that Mg69Zn27Ca4 glass has great potential to be used as bone substitutes.展开更多
Different graphene oxide(GO)contents were chosen as the addition to prepare ZK30-xGO composites by selective laser melting(SLM).The microstructure and biodegradation of the SLMed ZK30-xGO composites were investigated....Different graphene oxide(GO)contents were chosen as the addition to prepare ZK30-xGO composites by selective laser melting(SLM).The microstructure and biodegradation of the SLMed ZK30-xGO composites were investigated.The results indicated that(i)SLM effectively produced a small grain size,(ii)the incorporation of GO into ZK30 caused a further decrease in grain size,and(iii)GO has a strong effect on the formation of the MgZn2 precipitates.The SLMed ZK30-0.6GO had the lowest biodegradation rate,which is attributed to the fact that the effect of the increased grain refinement and decreased amount of the MgZn?precipitates counteracted the effect of the increased GO content on the biodegradation rate.Furthermore,the SLMed ZK30-xGO composites had good cytocompatibility.This work provided a novel approach to the composition design and fabrication of novel biodegradable GO reinforced Mg-based biomedical implants.展开更多
For high corrosion resistance and extensively modified biodegradable Mg-based alloys and composites for bone implants,a new Mgbased matrix model prepared by powder metallurgy is discussed and developed.In this researc...For high corrosion resistance and extensively modified biodegradable Mg-based alloys and composites for bone implants,a new Mgbased matrix model prepared by powder metallurgy is discussed and developed.In this research,Mg-5 wt.%Zn alloys were selected as a case.And they were impacted by hot extrusion and aging treatments to construct microstructure with different characteristics.Their selfforming corrosion product layer in Ringer’s solution,biodegradable behavior and corrosion mechanism were minutely investigated by in vitro degradation,electrochemical corrosion and cytocompatibility.The results demonstrated the extruded Mg-5 wt.%Zn alloy aged for 96 h showed high corrosion resistance,good biocompatibility for L929 and excellent ability of maintaining sample integrity during the immersion.Significantly,the alloy showed fine-grain microstructure and uniform distributed hundred nano-sized second phases,which promoted the formation of the uniform and smooth corrosion product layer at the beginning of immersion.The corrosion product layer was more stable in chloride containing aqueous solution and could be directly formed and repaired quickly,which effectively protected the matrix from further corrosion.In addition,an ideal model of Mg-based matrix for bone tissue engineering was tried to presume and propose by discussing the causal relationship between microstructure and bio-corrosion process.展开更多
In the present study, a Si-containing coating was fabricated on AZ31B Mg alloy. Cytocompatibility of the coated alloy was evaluated by both indirect and direct contact methods, respectively. Effects of a number of inc...In the present study, a Si-containing coating was fabricated on AZ31B Mg alloy. Cytocompatibility of the coated alloy was evaluated by both indirect and direct contact methods, respectively. Effects of a number of incubation variables on the sensitivity and reproducibility of the hemolysis test were also examined by using positively and negatively responding biomaterials. Cytocompatibility testing results indicated that cell condition, cell adherence, cell proliferation and extracellular matrix secretion of the coated alloy were improved compared with those of the uncoated alloy for different extraction and co-culture time. The hemolysis test suggested that hemolysis testing conditions were critical to determine the hemolysis of the alloy. It was also found that 1 day in vitro degradation of the uncoated AZ31B alloy had no destructive effect on erythrocyte. As for the coated AZ31B alloy at any time point, the hemolysis rate was much lower than 5%, the safe value for biomaterials. These in vitro experimental results indicate that the Si-containing coating is effective to improve the cytocompatibility and hemolysis behaviors of AZ31B alloy during its degradation.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
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
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.
基金supported by the National Science Centre,Poland(UMO-2016/21/D/ST5/01652)supported by Rector's Grant in the field of research and development(Silesian University of Technology,Poland,04/010/RGJ19/0095).
文摘This paper describes a formation of hybrid coatings on a Ti-2Ta-3Zr-36Nb surface.This is accomplished by plasma electrolytic oxidation and a dip-coating technique with poly(adipic anhydride)((C6H8O3)n)that is loaded with drugs:amoxicillin(C16H19N3O5S),cefazolin(C14H14N8O4S3)or vancomycin(C66H75Cl2N9O24·xHCl).The characteristic microstructure of the polymer was evaluated using scanning electron microscopy and confocal microscopy.Depending on the surface treatment,the surface roughness varied(between 1.53μm and 2.06μm),and the wettability was change with the over of time.X-ray photoelectron spectroscopy analysis showed that the oxide layer did not affect the polymer layer or loaded drugs.However,the drugs lose their stability in a phosphate-buffered saline solution after 6.5 h of exposure,and its decrease was greater than 7%(HPLC analysis).The stability,drug release and concentration of the drug loaded into the material were precisely analyzed by high-performance liquid chromatography.The results correlated with the degradation of the polymer in which the addition of drugs caused the percent of degraded polymer to be between 35.5%and 49.4%after 1 h of material immersion,depending on the mass of the loaded drug and various biological responses that were obtained.However,all of the coatings were cytocompatible with MG-63 osteoblast-like cells.The drug concentrations released from the coatings were sufficient to inhibit adhesion of reference and clinical bacterial strains(S.aureus).The coatings with amoxicillin showed the best results in the bacterial inhibition zone,whereas coatings with cefazolin inhibited adhesion of the above bacteria on the surface.
基金supported by the National Natural Science Foundation of China(Nos.52275395,51935014,and 82072084)the Science and Technology Innovation Program of Hunan Province(No.2023RC3046)+4 种基金the Young Elite Scientists Sponsorship Program byCAST(No.2020QNRC002)the NationalKeyResearchand Development Program of China(No.2023YFB4605800)the Central South University Innovation-Driven Research Programme(No.2023CXQD023)the Jiangxi Provincial Natural Science Foundation of China(No.20224ACB204013)the Project of State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University.
文摘Magnetostrictive Fe-Ga alloys have captivated substantial focus in biomedical applications because of their exceptional transition efficiency and favorable cytocompatibility.Nevertheless,Fe-Ga alloys always exhibit frustrating magnetostriction coefficients when presented in bulk dimensions.It is well-established that the magnetostrictive performance of Fe-Ga alloys is intimately linked to their phase and crystal structures.In this study,various concentrations of boron(B)were doped into Fe_(81)Ga_(19) alloys via the laser-beam powder bed fusion(LPBF)technique to tailor the crystal and phase structures,thereby improving the magnetostrictive performance.The results revealed the capacity for quick solidification of the LPBF process in expediting the solid solution of B element,which increased both lattice distortion and dislocations within the Fe-Ga matrix.These factors contributed to an elevation in the density of the modified-D0_(3) phase structure.Moreover,the prepared Fe-Ga-B alloys also exhibited a(001)preferred grain orientation caused by the high thermal gradients during the LPBF process.As a result,a maximum magnetostriction coefficient of 105 ppm was achieved in the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy.In alternating magnetic fields,all the LPBF-prepared alloys showed good dynamic magnetostriction response without visible hysteresis,while the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy presented a notable enhancement of~30%in magnetostriction coefficient when compared with the Fe_(81)Ga_(19) alloy.Moreover.the(Fe_(81)Ga_(19))_(98.5)B_(1.5) alloy exhibited favorable biocompatibility and osteogenesis,as confirmed by increased alkaline phosphatase(ALP)activity and the formation of mineralized nodules.These findings suggest that the B-doped Fe-Ga alloys combined with the LPBF technique hold promise for the development of bulk magnetostrictive alloys that are applicable for bone repair applications.
基金financially supported by National Natural Science Foundation of China (Nos. 21925802, 22338005)Liaoning Binhai Laboratory (No. LBLB-2023–03)the Fundamental Research Funds for the Central Universities (No. DUT22LAB601)。
文摘Photoinitiators(PIs), as the key substances for photopolymerized antibacterial film(PAF), affect the cure rate and color of PAF. Herein, two enone dyes were designed and synthesized by a facile approach. Among the candidates, BDO1 has demonstrated the ability to initiate polymerization of acrylate monomers as single-component PI with the advantages of low mobility, outstanding photobleaching, excellent cytocompatibility, and suitability for light emitting diode(LED) light sources above 365 nm. Taking BDOs as examples, a novel method based on theoretical calculations aiming to assess the potential of enone molecules as single-component PIs was proposed. Finally, under the initiation of BDO1, tannic acid was photopolymerized to a colorless and transparent antibacterial film with high antibacterial ability, which indicated that BDO1 was expected to be used in environmentally friendly PAF.
基金the financial assistance from Science and Engineering Research Board(SERBCRG/2020/002818/MMM).
文摘Surface modification is found to be an effective way to control the initial degradation of Mg based biomedical alloys.The present study focuses on the modulation of in vitro and in vivo degradation behavior of Mg-Ce alloy through a stearic acid-treated polypyrrole coating,which developed superhydrophobic surface(contact angle∼153°)that drastically enhanced the corrosion resistance(more than 85%efficacy).Cerium addition to Mg alloy results basal texture strengthening and grain refinement,resulting in improved mechanical properties.All the specimens exhibited excellent antibacterial performance against gram-negative E.Coli(DH5α)and gram positive S.aureus bacteria.The oligodynamic effect of polypyrrole coating leads to complete bacterial mitigation.Non-toxic nature of the specimens was studied by MC3T3-E1 cell proliferation and differentiation in indirect cell culture method.Improved corrosion resistance of the coated specimen leads to enhanced cell proliferation and osteogenic differentiation.Hard tissue histology and micro-CT analysis exhibited higher fraction of newly formed callus tissues and highest bone-implant integration across the coated specimen,when implanted in rabbit femur.Efficacy of the material in fracture healing was evaluated by implanting bone plate and screw in a clinically fractured goat tibia.At 3 months,complete fracture healed with no vital organ toxicity was observed for the coated specimen.The present results suggest that Ce addition and polypyrrole coating are effective ways to modulate the corrosion and biocompatibility behavior making it a potential candidate for fracture fixation applications.
基金supported by the National Natural Science Foundation of China(Nos.52231010 and 52071028)Beijing Nova Program(2022 Beijing Nova Program Cross Cooperation Program,No.20220484178).
文摘There have been many studies on the perspective Zn alloys for bone implants,but few for intestinal applications.Zn-0.4Mn-x Ca(x=0,0.05 and 0.1 wt.%)alloys are developed in this work for intestinal applications,in order to make use of proliferation effects of Mn and Ca elements on intestinal probiotics and epithelial cells.Rat small intestinal crypt epithelial(IEC-6)cells can grow healthily on surfaces of all the alloys.Among them,the number of healthy cells on Zn-0.4Mn-0.1Ca is the largest.IEC-6 cell vi-ability is over 160%(much higher than the benchmark of 75%)in 20%-100%extracts of Zn-0.4Mn-0.1Ca for 5 d.All the alloys can promote proliferation of L.acidophilus(intestinal probiotic)and inhibit growth of Escherichia coli(intestinal pathogen).Among them,Zn-0.4Mn-0.1Ca alloy possesses the greatest effect.With the increase of Ca content,the strength of the alloy increases.Zn-0.4Mn-0.1Ca alloy has the highest strength and good plasticity among the three alloys.It exhibits a yield strength of 252 MPa,an ultimate tensile strength of 288 MPa,and a elongation to failure of 41%.Since CaZn_(13)-MnZn_(13)-Zn micro-cell con-trols corrosion rate,Zn-0.4Mn-0.1Ca with the highest volume fractions of MnZn_(13)and CaZn_(13)has the highest corrosion rate of 17.64μm/year when immersed in simulated intestinal fluid for 28 d.Overall,the Zn-Mn-Ca alloys are promising candidates for intestinal implants.
基金financially supported by the Sichuan Science and Technology Program(No.2024YFHZ0310)the China Postdoctoral Science Foundation(No.2024M752092)+1 种基金the Shenzhen Medical Research Fund(No.A2402040)the Shenzhen Science and Technology Program(No.JCYJ20240813180905008).
文摘Zinc(Zn)and its alloys are considered promising biodegradable metallic materials for biomedical implants.However,the correlation between the dynamic degradation evolution of Zn and its biocompatibility remains unclear.This study evaluates the long-term degradation/corrosion behavior of pure Zn under dynamic immersion in Hank’s solution containing bovine serum albumin(BSA),and investigates the impact of its dynamic degradation evolution on cytocompatibilities of the representative human umbilical vein endothelial cells(HUVECs)and bone marrow mesenchymal stem cells(BMSCs).Degradation behavior results demonstrate that the dynamic fluidic medium led to speeding-up of the corrosion rate of Zn and exacerbation of the localized corrosion,with this phenomenon being more pronounced under influence of BSA.Correspondingly,the cells’viability increased with prolonged immersion time under both static and dynamic conditions,alleviating a certain level of cytotoxicity initiated at an earlier stage.Nonetheless,as compared to the static cases the dynamic fluidic environments induced a poorer cell viability,although the BSA helped to offset this impact.Our findings provide not only new insights into better-understanding Zn-based biodegradable metals but also clarify the critical concern in their clinical translations,offering therefore important guidance for development of new biodegradable metallic medical implants.
文摘Calcium phosphate coated Mg alloy was prepared. The phase constitute and surface morphology were identified and observed by X-ray diffractometer （XRD） and SEM. The results show that the coating is composed of flake-like CaHPO4-2H2O crystals. The corrosion resistance of the coated Mg alloy was measured by electrochemical polarization and immersion test in comparison with uncoated Mg alloy. Cytocompatibility was designed by observing the attachment, growth and proliferation of L929 cell on both coated and uncoated Mg alloy samples. The results display that the corrosion resistance of the coated Mg alloy is better than that of uncoated one. The immersion test also shows that the calcium phosphate coating can mitigate the corrosion of Mg alloy substrate, and tends to transform into hydroxyapatite （HA）. Compared with uncoated Mg alloy, L929 cells exhibit good adherence, growth and proliferation characteristics on the coated Mg alloy, indicating that the cytocompatibility is significantly improved with the calcium phosphate coating.
基金National Natural Science Foundation of China(Grant No.81172990)the National Key Science Research Program of China(Grant No.973 Program,2009CB930300)+1 种基金Innovation Team of Ministry of Education(Grant No.BMU20110263)the Open Project Program of State Key Laboratory of Drug Delivery Technology and Pharmacokinetics,Tianjin Institute of Pharmaceutical Research
文摘A synthetic diblock copolymer poly（2-ethyl-2-oxazoline）-poly（D,L-lactide） （PEOz-PLA） can self-assemble into micelles with an increased efficiency of drug delivery. However, the interactions of blood-micelles and cell-micelles remain unclear. In the present study, we aimed to assess the hemocompatibility and cytocompatibility of PEOz-PLA micelles in order to clarify its potentials as carriers for drug delivery. Blood compatibility of the micelles was evaluated by hemolysis analysis, coagulation test, platelet activation investigation and assessment of their interaction with protein. The results revealed that PEOz-PLA micelles had a favorable blood compatibility. In addition, PEOz-PLA micelles showed a good cytocompatibility through SRB assay, presenting only negligible cytotoxicity when incubated with KBv cells. Taken together, PEOz-PLA micelles could be used as a hemocompatible and cytocompatible drug carrier for intravenous administration.
基金financial support through VC Fellowships and Enabling Capability Platform for Advanced Manufacturing and FabricationFinancial support from the Australian Research Council through DECRA (DE130100090) and Linkage Schemes (LP150100343) is also gratefully acknowledged+2 种基金 support by the National Natural Science Foundation of China (51571134)Shandong University of Science and Technology Research Fund (2014TDJH104)supported by the Natural Science Foundation of the Higher Education Institute of Jiangsu Province (17KJB430003)
文摘Magnesium(Mg) alloys possess comparable physical and mechanical properties to bone, making them an outstanding candidate of implant materials for bone fracture treatment. In addition to the excellent biocompatibility, and bioactivity, the engagement of Mg alloys is key for a number of biological functionalities in the human body. The unique biodegradation nature of Mg alloy implants implies that it may not require a secondary removal procedure when the expected supporting tasks accomplish, as they may simply and safely "disappear" over time. Nonetheless, the demonstrated drawback of potentially rapid degradation, is an issue that must be addressed appropriately for Mg implants and is consequently given unique attention in this review article. Herein, the critical criteria and the state-of-the-art strategies for controlling the degradation process of Mg alloys are reported. Furthermore, future developments of biodegradable Mg and its alloys systems with satisfactory specifications for clinical trials and deployment,are discussed. This review aims to provide information to materials scientists and clinical practitioners in the context of developing practical biodegradable Mg alloys.
基金supported financially by the National Natural Science Foundation of China(Nos.51575537,81572577 and51705540)the Hunan Provincial Natural Science Foundation of China(No.2016JJ1027)+5 种基金the Project of Innovation-driven Plan of Central South University(No.2016CX023)the Open-End Fund for the Valuable and Precision Instruments of Central South Universitythe Fund of the State Key Laboratory of Solidification Processing at NWPU(No.SKLSP201605)the Project of State Key Laboratoryof High Performance Complex Manufacturing,Central South Universitythe National Postdoctoral Program for Innovative Talents(No.BX201700291)the Project of Hunan Provincial Science and Technology Plan(No.2017RS3008)
文摘Magnesium （Mg） alloys are receiving increasing attention for body implants owing to their good bio- compatibility and biodegradability. However, they often suffer from bacterial infections on account of their insufficient antibacterial ability. In this study, ZK60-xCu （x = O, 0.2, 0.4, 0.6 and 0.8 wt%） alloys were prepared by selective laser melting （SLM） with alloying copper （Cu） to enhance their antibacterial ability. Results showed that ZK60-Cu alloys exhibited strong antibacterial ability due to combination of release of Cu ions and alkaline environment which could kill bacteria by destroying cellular membrane structure, denaturing enzymes and inhibiting deoxyribonucleic acid （DNA） replication. In addition, their compres- sive strength increased due to grain refinement and uniformly dispersing of short-bar shaped MgZnCu phases. Moreover, ZK60-Cu alloys also exhibited good cytocompatibility. In summary, ZK60-Cu alloys with antibacterial ability may be Dromising implants for biomedical anDlications.
基金supported by the National Basic Research Program (973) of China (No.2005CB623906)the Medical Development Foundation of Soochow University (No.EE134702),China
文摘Objective： To explore the feasibility of using regenerated silk fibroin membrane to construct artificial skin substitutes for wound healing, it is necessary to evaluate its cytocompatibility. Methods： The effects of regenerated silk fibroin film on cytotoxicity, adhesion, cell cycle, and apoptosis of L929 cells, growth and vascular endothelial growth factor （VEGF） expression of ECV304 cells, and VEGF, angiopoietin-1 （Ang-1）, platelet-derived growth factor （PDGF） and fibroblast growth factor 2 （FGF2） expression of WI-38 cells were assessed by 3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-di-phenytetrazoliumromide （MTT） assay, viable cell counting, flow cytometry （FCM）, and enzyme-linked immunosorbant assay （ELISA）. Results： We showed that the regenerated silk fibroin film was not cytotoxic to L929 cells and had no adverse influence on their adhesion, cell cycle or apoptosis; it had no adverse influence on the growth and VEGF secretion of ECV304 cells and no effect on the secretion of VEGF, Ang-1, PDGF and FGF2 by WI-38 cells. Conclusion： The regenerated silk fibroin film should be an excellent biomaterial with good cytocompatibility, providing a framework for reparation after trauma in clinical applications.
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financially supported by the National Natural Science Foundation of China (Nos. 31300808 and 31400815)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (No. 201417)the Natural Science Foundation of Shanxi Province (No. 2013021011-1)
文摘This study aims to investigate the addition of Zn on the corrosion property and cytocompatibility of Mg- 2Gd-xZn (x = 0, 3, 4 and 5;wt%) alloys, which were prepared by gravity permanent mold casting and solution treatment, respectively. The results show that the intermetallic phases of these ternary alloys are mainly composed of Mg12GdZn and Mg3GdZn3. The content of secondary phases as well as the grain size is greatly dependent on the Zn addition. Compared to the binary Mg- 2Gd alloy, the corrosion resistance of the most ternary alloys is significantly improved. Furthermore, the in vitro cell culture study demonstrates the potential cytocompatibility of the developed ternary alloys. It indicates that a series of Mg-2Gd-xZn (x = 0, 3, 4 and 5;wt%) with medically acceptable corrosion rate are developed and show great potential use as a new type of biodegradable implants.
基金financially supported by the Key Program of China on Biomedical Materials Research and Tissue and Organ Replacement (Nos. 2016YFC1101804 and 2016YFC1100604)the Shenyang Key Research & Development and Technology Transfer Program (No. Z18-0-027)
文摘In the present work, the biodegradable behavior, cytocompatibility and osteogenesis activity of a Mg69Zn27Ca4 metal glass were investigated. Electrochemical test, immersion test, cytotoxicity test and histopathological evaluation were carried out. The results showed that there was a dense protective layer formed on the surface of Mg69Zn27Ca4 metal glass which could inhibit the degradation process in the Hank’s solution. In vitro cytotoxicity test showed that Mg69Zn27Ca4 metal glass had good biocompatibility. Histopathological evaluation showed that the degradation of Mg69Zn27Ca4 metal glass could promote the new bone formation with no obvious inflammatory reactions. After 2 months implantation, the diameter of the bone defect was reduced from the original φ6 mm to φ3.35 ± 0.40 mm with the degradation of Mg69Zn27Ca4 metal glass. Therefore, it can be concluded that Mg69Zn27Ca4 glass has great potential to be used as bone substitutes.
基金Natural Science Foundation of China(No.51874368).
文摘Different graphene oxide(GO)contents were chosen as the addition to prepare ZK30-xGO composites by selective laser melting(SLM).The microstructure and biodegradation of the SLMed ZK30-xGO composites were investigated.The results indicated that(i)SLM effectively produced a small grain size,(ii)the incorporation of GO into ZK30 caused a further decrease in grain size,and(iii)GO has a strong effect on the formation of the MgZn2 precipitates.The SLMed ZK30-0.6GO had the lowest biodegradation rate,which is attributed to the fact that the effect of the increased grain refinement and decreased amount of the MgZn?precipitates counteracted the effect of the increased GO content on the biodegradation rate.Furthermore,the SLMed ZK30-xGO composites had good cytocompatibility.This work provided a novel approach to the composition design and fabrication of novel biodegradable GO reinforced Mg-based biomedical implants.
基金The authors acknowledge the Project(81472058)sup-ported by the National Natural Science Foundation of Chinathe financial support of the 2015 ShanDong province project of outstanding subject talent group.the project(LSD-KB1806)+2 种基金supported by the foundation of National Key labo-ratory of Shock Wave and Detonation Physics and the project(11802284)supported by the National Natural Science Foun-dation of China.The project(2017GK2120)supported by the Key Research and Development Program of Hunan Province and the Natural Science Foundation of Hunan Province of China(2018JJ2506).
文摘For high corrosion resistance and extensively modified biodegradable Mg-based alloys and composites for bone implants,a new Mgbased matrix model prepared by powder metallurgy is discussed and developed.In this research,Mg-5 wt.%Zn alloys were selected as a case.And they were impacted by hot extrusion and aging treatments to construct microstructure with different characteristics.Their selfforming corrosion product layer in Ringer’s solution,biodegradable behavior and corrosion mechanism were minutely investigated by in vitro degradation,electrochemical corrosion and cytocompatibility.The results demonstrated the extruded Mg-5 wt.%Zn alloy aged for 96 h showed high corrosion resistance,good biocompatibility for L929 and excellent ability of maintaining sample integrity during the immersion.Significantly,the alloy showed fine-grain microstructure and uniform distributed hundred nano-sized second phases,which promoted the formation of the uniform and smooth corrosion product layer at the beginning of immersion.The corrosion product layer was more stable in chloride containing aqueous solution and could be directly formed and repaired quickly,which effectively protected the matrix from further corrosion.In addition,an ideal model of Mg-based matrix for bone tissue engineering was tried to presume and propose by discussing the causal relationship between microstructure and bio-corrosion process.
基金the financial support of the project from the National Basic Research Program(No.2012CB619101)the National Natural Science Foundation of China(No.30970715)
文摘In the present study, a Si-containing coating was fabricated on AZ31B Mg alloy. Cytocompatibility of the coated alloy was evaluated by both indirect and direct contact methods, respectively. Effects of a number of incubation variables on the sensitivity and reproducibility of the hemolysis test were also examined by using positively and negatively responding biomaterials. Cytocompatibility testing results indicated that cell condition, cell adherence, cell proliferation and extracellular matrix secretion of the coated alloy were improved compared with those of the uncoated alloy for different extraction and co-culture time. The hemolysis test suggested that hemolysis testing conditions were critical to determine the hemolysis of the alloy. It was also found that 1 day in vitro degradation of the uncoated AZ31B alloy had no destructive effect on erythrocyte. As for the coated AZ31B alloy at any time point, the hemolysis rate was much lower than 5%, the safe value for biomaterials. These in vitro experimental results indicate that the Si-containing coating is effective to improve the cytocompatibility and hemolysis behaviors of AZ31B alloy during its degradation.
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.
