In the present work,seven Mg-Zn-Ag alloys with the nominal composition of Mg_(96-x)Zn_(x)Ag_(4)(x=17,20,23,26,29,32,35 in at.%)were prepared by induction melting and single-roller melt-spinning.The X-ray diffraction(X...In the present work,seven Mg-Zn-Ag alloys with the nominal composition of Mg_(96-x)Zn_(x)Ag_(4)(x=17,20,23,26,29,32,35 in at.%)were prepared by induction melting and single-roller melt-spinning.The X-ray diffraction(XRD)analyses indicate the metallic glasses with three composition of Mg_(73)Zn_(23)Ag_(4),Mg_(70)Zn_(26)Ag_(4),and Mg_(67)Zn_(29)Ag_(4)were obtained successfully.The differential scanning calorimetry(DSC)measurement was used to obtain the characteristic temperature of Mg-Zn-Ag metallic glasses for the glass-forming ability analysis.The maximum glass transition temperature(Trg)was found to be 0.525 with a composition close to Mg_(67)Zn_(29)Ag_(4),which results in the best glass-forming ability.Moreover,the immersion test in simulated body fluid(SBF)demonstrate the relative homogeneous corrosion behavior of the Mg-Zn-Ag metallic glasses.The corrosion rate of Mg-Zn-Ag metallic glasses in SBF solution decreases with the increase of Zn content.The sample Mg_(67)Zn_(29)Ag_(4)has the lowest corrosion rate of 0.19mm/yr,which could meet the clinical application requirement well.The in vitro cell experiments show that the Madin-Darby canine kidney(MDCK)cells cultured in sample Mg_(67)Zn_(29)Ag_(4)and its extraction medium have higher activity.However,the Mg-Zn-Ag metallic glasses exhibit obvious inhibitory effect on human rhabdomyosarcoma(RD)tumor cells.The present investigations on the glass-forming ability,corrosion behavior,cytocompatibility and tumor inhibition function of the Mg-Zn-Ag based metallic glass could reveal their biomedical application possibility.展开更多
We synthesized photo-responsive carboxymethyl chitosan(CMC-MA)via free radical polymerization and utilized nanoclay laponite(LAP)as an inorganic crosslinking agent to develop an injectable and 3D-printable CMC-MA/LAP ...We synthesized photo-responsive carboxymethyl chitosan(CMC-MA)via free radical polymerization and utilized nanoclay laponite(LAP)as an inorganic crosslinking agent to develop an injectable and 3D-printable CMC-MA/LAP hydrogel.We determined the optimal ratio of 2.5 w/v%CMC-MA/7.5 w/v%LAP based on injection molding,compression modulus,swelling properties,rheological properties,and 3D printing properties of the hydrogel system.In-vitro cytocompatibility experiments showed that both CMC-MA and CMC-MA/LAP hydrogel had no inhibitory effect on cell proliferation and can promote cell growth when cultured on the surface of the hydrogel matrix.Moreover,the hydrogel containing LAP particles significantly facilitated cell adhesion(>60%)compared with the hydrogel without LAP(20%).Our findings demonstrate that the CMC-MA/LAP hydrogel has great potential for tissue repair in neural tissue engineering.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
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 (hyd...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 methiciUin-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
A polymer blends containing thermoplastic polyurethane(TPU) and poly(lactic acid)(PLA) as a biomedical material were prepared by a process of modifying thermally induced phase separation(MTIPS) and melt blendi...A polymer blends containing thermoplastic polyurethane(TPU) and poly(lactic acid)(PLA) as a biomedical material were prepared by a process of modifying thermally induced phase separation(MTIPS) and melt blending.The influences of composition,shear frequency,and temperature on the rheological behaviors of the blends were investigated by small amplitude oscillatory shear rheology.The results revealed that the addition of TPU into PLA significantly decreased the non-Newtonian index of the blends,and increased the sensitivity of the blends on shear rate,suggesting that optimization of the shear rate and temperature could improve the flowability of the blend melts in the extrusion process.In addition,the results of SEM images revealed that TPU distributed well into PLA matrix and showed good compatibility between the TPU and PLA,which made the blends with good toughness.The primary cytocompatibility of the blends was evaluated using C2C12 cells.The results suggested that the TPU/PLA blends did not affect cell growth,showing no cytotoxicity.In short,the TPU/PLA blends with excellent toughness had potential application as biomedical devices.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
Nano hydroxyapatite (HA) crystals were prepared and dispersed in water to form HA sol by simple methods. The cytotoxicity of the sols were tested by MTT assay and lymphocytotoxicity test. Results show that the average...Nano hydroxyapatite (HA) crystals were prepared and dispersed in water to form HA sol by simple methods. The cytotoxicity of the sols were tested by MTT assay and lymphocytotoxicity test. Results show that the average secondary particle size of the sol containing uncalcined HA crystals is around 750 nm, within micrograde; while the sol of calcined HA contains over 88% nanoparticles with the size between 65~86 nm, in which nano HA crystals are highly dispersed. Both the HA sols have no toxicity on the proliferation of 3T3 cells and lymphocytes. It demonstrates that the nano sol is safe for the application of drug delivery.展开更多
Neural electrodes,the core component of neural prostheses,are usually encapsulated in polydimethylsiloxane(PDMS).However,PDMS can generate a tissue response after implantation.Based on the physicochemical properties...Neural electrodes,the core component of neural prostheses,are usually encapsulated in polydimethylsiloxane(PDMS).However,PDMS can generate a tissue response after implantation.Based on the physicochemical properties and excellent biocompatibility of polyurethane(PU)and poly(vinyl alcohol)(PVA)when used as coating materials,we synthesized PU/PVA hydrogel coatings and coated the surface of PDMS using plasma treatment,and the cytocompatibility to rat pheochromocytoma(PC12)cells was assessed.Protein adsorption tests indicated that the amount of protein adsorption onto the PDMS substrate was reduced by 92%after coating with the hydrogel.Moreover,the PC12 cells on the PU/PVA-coated PDMS showed higher cell density and longer and more numerous neurites than those on the uncoated PDMS.These results indicate that the PU/PVA hydrogel is cytocompatible and a promising coating material for neural electrodes to improve their biocompatibility.展开更多
Neural Stem Cells (NSCs) were incubated with self-assembled hydrogel from IKVAV-containing peptide amphiphile (IKVAV-PA) for one week. The cytocompatibility of hydrogel was evaluated. NSCs were seeded in three-dim...Neural Stem Cells (NSCs) were incubated with self-assembled hydrogel from IKVAV-containing peptide amphiphile (IKVAV-PA) for one week. The cytocompatibility of hydrogel was evaluated. NSCs were seeded in three-dimensional (3D) hydrogels (Experimental Group, EG) or surface of coverslips (Control Group, CG), double-labeled with Calcein-AM and PI. A growth curve of cells was obtained according to CCK-8. TEM study of hydrogel revealed a network of nanofibers. NSCs began to proliferate after 24 h of incubation, and formed bigger neurospheres at 48 h in EG than in CG. Cell proliferation activity was higher in EG than in CG (P〈0.05). The self-assembled Hydrogel had good cytocompatibility and promoted the proliferation of NSCs.展开更多
The porous NiTi(pNiTi)samples were produced by sintering evaporation using Ti−50.8Ni(at.%)gasatomized powders.The samples were analyzed by metallographic microscope and X-ray dispersive spectroscopy(XRD).A comparison ...The porous NiTi(pNiTi)samples were produced by sintering evaporation using Ti−50.8Ni(at.%)gasatomized powders.The samples were analyzed by metallographic microscope and X-ray dispersive spectroscopy(XRD).A comparison of nickel(Ni)release and cytocompatibility between pNiTi and dense NiTi(dNiTi)was made.The results showed that the pNiTi has good mechanical properties.Ni releases from pNiTi in vitro and in vivo are more serious than those form dNiTi.The proliferation and differentiation of cells cultured with the pNiTi extracting liquid are significantly worse,and the rate of early apoptosis is higher.In conclusion,pNiTi is mechanically similar to bone,but pNiTi releases more Ni and interferes with cell proliferation and differentiation.A significantly cautious approach should be adopted when using it as a medical implant.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
Rabbit limbal corneal epithelial cells,corneal endothelial cells and keratocytes were cultured on amniotic membrane. Phase contrast microscope examination was performed daily. Histological and scan electron microscopi...Rabbit limbal corneal epithelial cells,corneal endothelial cells and keratocytes were cultured on amniotic membrane. Phase contrast microscope examination was performed daily. Histological and scan electron microscopic examinations were carried out to observe the growth,arrangement and adhesion of cultivated cells. Results showed that three corneal cell types seeded on amniotic membrane grew well and had normal cell morphology. Cultured cells attached firmly on the surface of amniotic membrane. Corneal epithelial cells showed singular layer or stratification. Cell boundaries were formed and tightly opposed. Corneal endothelial cells showed cobblestone or polygonal morphologic characteristics that appeared uniform in size. The cellular arrangement was compact. Keratocytes elongated and showed triangle or dendritic morphology with many intercellular joints which could form networks. In conclusion,amniotic membrane has good scaffold property,diffusion effect and compatibility with corneal cells. The basement membrane side of amniotic membrane facilitated the growth of corneal epithelial cells and endothelial cells and cell junctions were tightly developed. The spongy layer of amniotic membrane facilitated the growth of keratocytes and intercellular joints were rich. Amniotic membrane is an ideal biomaterial for layering tissue engineered cornea.展开更多
As implanted bone fixation materials,magnesium(Mg)alloys have significant advantages because the density and elastic modulus are closest to those of the human bone and they can bio-degrade in the physiological environ...As implanted bone fixation materials,magnesium(Mg)alloys have significant advantages because the density and elastic modulus are closest to those of the human bone and they can bio-degrade in the physiological environment.However,Mg alloys degrade too rapidly and uncontrollably thus hampering clinical adoption.In this study,a highly corrosion-resistant zinc-phosphate-doped micro-arc oxidation(MAO)coating is prepared on the AZ31B alloy,and the degradation process is assessed in vitro.With increasing zinc phosphate concentrations,both the corrosion potentials and charge transfer resistance of the AZ31B alloy coated with MAO coatings increase gradually,while the corrosion current densities di-minish gradually.Immersion tests in the simulated body fluid(SBF)reveal that the increased zinc phos-phate concentration in MAO coating decreases the degradation rate,consequently reducing the release rates of Mg^(2+)and OH-in the physiological micro-environment,which obtains the lowest weight loss of only 5.22%after immersion for 56 days.Effective regulation of degradation provides a weak alkaline environment that is suitable for long-term cell growth and subsequent promotion of bone proliferation,differentiation,mineralization,and cytocompatibility.In addition,the zinc-phosphate-doped MAO coat-ings show an improved wear resistance as manifested by a wear rate of only 3.81 x 10^(-5) mm^(3) N^(-1) m^(-1).The results reveal a suitable strategy to improve the properties of biodegradable Mg alloys to balance tissue healing with mechanical degradation.展开更多
Silver has been widely used for surface modification to prevent implant-associated infections.However,the inherent cytotoxicity of silver greatly limited the scope of its clinical applications.The construction of surf...Silver has been widely used for surface modification to prevent implant-associated infections.However,the inherent cytotoxicity of silver greatly limited the scope of its clinical applications.The construction of surfaces with both good antibacterial properties and favorable cytocompatibility still remains a challenge.In this study,a structurally homogeneous dopamine-silver(DA/Ag)nanocomposite was fabricated on the implant surface to balance the antibacterial activity and cytocompatibility of the implant.The results show that the DA/Ag nanocomposites prepared under the acidic conditions(pH=4)on the titanium surface are homogeneous with higher Ag^(+)content,while an obvious core(AgNPs)-shell(PDA)structure is formed under neutral(pH=7)and alkaline conditions(pH=10),and the subsequent heat treatment enhanced the stability of PDA-AgNPs nanocomposite coatings on porous titanium.The antibacterial test,cytotoxicity test,hypodermic implantation and osteogenesis test revealed that the homogeneous PDA-AgNPs nanocomposite coating achieved the balance between the antibacterial ability and cytocompatibility,and had the best outcomes for soft tissue healing and bone formation around the implants.This study provides a facile strategy for preparing silver-loaded surfaces with both good antibacterial effect and favorable cytocompatibility,which is expected to further improve the therapeutic efficacy of silver composite-coated dental implants.展开更多
Injectable bone cements are used in minimally invasive surgical techniques including vertebroplasty and kyphoplasty.This work is devoted to the development of magnesium-calcium phosphate cements(MCPCs)doped with gadol...Injectable bone cements are used in minimally invasive surgical techniques including vertebroplasty and kyphoplasty.This work is devoted to the development of magnesium-calcium phosphate cements(MCPCs)doped with gadolinium ions(Gd^(3+))for bone defect repair.Interaction between cement powders and a cement liquid resulted in the formation of newberyite and brushite phases,which gave mechanical strength up to 17 MPa without a thermal effect.The introduction of Gd3+into the lattice was confirmed by electron paramagnetic resonance spectroscopy;the doping increased injectivity while giving rise to antibacterial properties against Escherichia coli.Assays of the cement samples soaking in Kokubo’s simulated body fluid revealed the formation of calcium phosphate coatings on the cements’surface.The cements manifested biocompatibility with the MG-63 cell line and significantly enhanced contrast when Gd-MCPC was placed into a bone defect and examined by X-ray micro-computed tomography.For the first time,visualization of a Gd-doped cement material was achieved in a model of a bone defect analyzed by MRI.展开更多
In order to develop the Mg-Zn-Ag metallic glasses(MGs)for biodegradable implant applications,the glass formation ability(GFA)and biocompatibility of Mg-Zn-Ag alloys were investigated using a combination of the calcula...In order to develop the Mg-Zn-Ag metallic glasses(MGs)for biodegradable implant applications,the glass formation ability(GFA)and biocompatibility of Mg-Zn-Ag alloys were investigated using a combination of the calculation of phase diagrams(CALPHAD)and experimental measurements.High GFA potentiality of two alloy series,specifically Mg_(96-x)Zn_xAg_(4)and Mg_(94-x)Zn_xAg_6(x=17,20,23,26,29,32,35),was predicted theoretically and then substantiated through experimental testing.X-ray diffraction(XRD)and differential scanning calorimetry(DSC)techniques were used to evaluate the crystallinity,GFA,and crystallization characteristics of these alloys.The results showed that compositions between Mg_(73)Zn_(23)Ag_(4)and Mg_(64)Zn_(32)Ag_(4)for Mg_(96-x)Zn_xAg_4,Mg_(66)Zn_(28)Ag_(6)and Mg_(63)Zn_(31)Ag_(6for)Mg_(94-x)Zn_xAg_(6)displayed a superior GFA.Notably,the GFA of the Mg_(96-x)Zn_xAg_(4)series was better than that of the Mg_(94-x)Zn_xAg_(6)series.Furthermore,the Mg_(70)Zn_(26)Ag_4,Mg_(74)Zn_(20)Ag_6,and Mg_(71)Zn_(23)Ag_(6)alloys showed acceptable corrosion rates,good cytocompatibility,and positive effects on cell proliferation.These characteristics make them suitable for applications in medical settings,potentially materials as biodegradable implants.展开更多
基金National Key Research and Development Program of China(2018YFC1106702)Guangdong Basic and Applied Basic Research Foundation(2020A1515011301,2019A1515110067 and 2020A1515110055)+1 种基金Shenzhen Basic Research Project(JCYJ20210324120001003,JCYJ20200109144608205 and JCYJ20200109144604020)IER Foundation(HT-JDCXY-201902 and HT-JD-CXY-201907)for financial support.
文摘In the present work,seven Mg-Zn-Ag alloys with the nominal composition of Mg_(96-x)Zn_(x)Ag_(4)(x=17,20,23,26,29,32,35 in at.%)were prepared by induction melting and single-roller melt-spinning.The X-ray diffraction(XRD)analyses indicate the metallic glasses with three composition of Mg_(73)Zn_(23)Ag_(4),Mg_(70)Zn_(26)Ag_(4),and Mg_(67)Zn_(29)Ag_(4)were obtained successfully.The differential scanning calorimetry(DSC)measurement was used to obtain the characteristic temperature of Mg-Zn-Ag metallic glasses for the glass-forming ability analysis.The maximum glass transition temperature(Trg)was found to be 0.525 with a composition close to Mg_(67)Zn_(29)Ag_(4),which results in the best glass-forming ability.Moreover,the immersion test in simulated body fluid(SBF)demonstrate the relative homogeneous corrosion behavior of the Mg-Zn-Ag metallic glasses.The corrosion rate of Mg-Zn-Ag metallic glasses in SBF solution decreases with the increase of Zn content.The sample Mg_(67)Zn_(29)Ag_(4)has the lowest corrosion rate of 0.19mm/yr,which could meet the clinical application requirement well.The in vitro cell experiments show that the Madin-Darby canine kidney(MDCK)cells cultured in sample Mg_(67)Zn_(29)Ag_(4)and its extraction medium have higher activity.However,the Mg-Zn-Ag metallic glasses exhibit obvious inhibitory effect on human rhabdomyosarcoma(RD)tumor cells.The present investigations on the glass-forming ability,corrosion behavior,cytocompatibility and tumor inhibition function of the Mg-Zn-Ag based metallic glass could reveal their biomedical application possibility.
基金Funded by the Natural Science Foundation of Hubei Province(No.2022CFB386)。
文摘We synthesized photo-responsive carboxymethyl chitosan(CMC-MA)via free radical polymerization and utilized nanoclay laponite(LAP)as an inorganic crosslinking agent to develop an injectable and 3D-printable CMC-MA/LAP hydrogel.We determined the optimal ratio of 2.5 w/v%CMC-MA/7.5 w/v%LAP based on injection molding,compression modulus,swelling properties,rheological properties,and 3D printing properties of the hydrogel system.In-vitro cytocompatibility experiments showed that both CMC-MA and CMC-MA/LAP hydrogel had no inhibitory effect on cell proliferation and can promote cell growth when cultured on the surface of the hydrogel matrix.Moreover,the hydrogel containing LAP particles significantly facilitated cell adhesion(>60%)compared with the hydrogel without LAP(20%).Our findings demonstrate that the CMC-MA/LAP hydrogel has great potential for tissue repair in neural tissue engineering.
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 methiciUin-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.
基金Funded by the Major State Basic Research Development Program of China(973 Program)(No.2012CB933600)the National Natural Science Foundation of China(Nos.81271705 and 83171383)the Major Program of Natural Science Foundation of Shanghai,China(No.12JC1416302)
文摘A polymer blends containing thermoplastic polyurethane(TPU) and poly(lactic acid)(PLA) as a biomedical material were prepared by a process of modifying thermally induced phase separation(MTIPS) and melt blending.The influences of composition,shear frequency,and temperature on the rheological behaviors of the blends were investigated by small amplitude oscillatory shear rheology.The results revealed that the addition of TPU into PLA significantly decreased the non-Newtonian index of the blends,and increased the sensitivity of the blends on shear rate,suggesting that optimization of the shear rate and temperature could improve the flowability of the blend melts in the extrusion process.In addition,the results of SEM images revealed that TPU distributed well into PLA matrix and showed good compatibility between the TPU and PLA,which made the blends with good toughness.The primary cytocompatibility of the blends was evaluated using C2C12 cells.The results suggested that the TPU/PLA blends did not affect cell growth,showing no cytotoxicity.In short,the TPU/PLA blends with excellent toughness had potential application as biomedical devices.
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This work is supported by Guangdong Natural Science Foundation Grant (0 2 1180 ) and the National 86 3 Project(2 0 0 1AA2 180 31)
文摘Nano hydroxyapatite (HA) crystals were prepared and dispersed in water to form HA sol by simple methods. The cytotoxicity of the sols were tested by MTT assay and lymphocytotoxicity test. Results show that the average secondary particle size of the sol containing uncalcined HA crystals is around 750 nm, within micrograde; while the sol of calcined HA contains over 88% nanoparticles with the size between 65~86 nm, in which nano HA crystals are highly dispersed. Both the HA sols have no toxicity on the proliferation of 3T3 cells and lymphocytes. It demonstrates that the nano sol is safe for the application of drug delivery.
基金supported by the National Natural Science Foundation of China,No.81170768grant from the Fundamental Research Project of Shanxi Province of China,No.2015021079
文摘Neural electrodes,the core component of neural prostheses,are usually encapsulated in polydimethylsiloxane(PDMS).However,PDMS can generate a tissue response after implantation.Based on the physicochemical properties and excellent biocompatibility of polyurethane(PU)and poly(vinyl alcohol)(PVA)when used as coating materials,we synthesized PU/PVA hydrogel coatings and coated the surface of PDMS using plasma treatment,and the cytocompatibility to rat pheochromocytoma(PC12)cells was assessed.Protein adsorption tests indicated that the amount of protein adsorption onto the PDMS substrate was reduced by 92%after coating with the hydrogel.Moreover,the PC12 cells on the PU/PVA-coated PDMS showed higher cell density and longer and more numerous neurites than those on the uncoated PDMS.These results indicate that the PU/PVA hydrogel is cytocompatible and a promising coating material for neural electrodes to improve their biocompatibility.
文摘Neural Stem Cells (NSCs) were incubated with self-assembled hydrogel from IKVAV-containing peptide amphiphile (IKVAV-PA) for one week. The cytocompatibility of hydrogel was evaluated. NSCs were seeded in three-dimensional (3D) hydrogels (Experimental Group, EG) or surface of coverslips (Control Group, CG), double-labeled with Calcein-AM and PI. A growth curve of cells was obtained according to CCK-8. TEM study of hydrogel revealed a network of nanofibers. NSCs began to proliferate after 24 h of incubation, and formed bigger neurospheres at 48 h in EG than in CG. Cell proliferation activity was higher in EG than in CG (P〈0.05). The self-assembled Hydrogel had good cytocompatibility and promoted the proliferation of NSCs.
文摘The porous NiTi(pNiTi)samples were produced by sintering evaporation using Ti−50.8Ni(at.%)gasatomized powders.The samples were analyzed by metallographic microscope and X-ray dispersive spectroscopy(XRD).A comparison of nickel(Ni)release and cytocompatibility between pNiTi and dense NiTi(dNiTi)was made.The results showed that the pNiTi has good mechanical properties.Ni releases from pNiTi in vitro and in vivo are more serious than those form dNiTi.The proliferation and differentiation of cells cultured with the pNiTi extracting liquid are significantly worse,and the rate of early apoptosis is higher.In conclusion,pNiTi is mechanically similar to bone,but pNiTi releases more Ni and interferes with cell proliferation and differentiation.A significantly cautious approach should be adopted when using it as a medical implant.
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This work was funded by majorspecial item ofScienceandTechnology Office of Guangdong ( No. 2 0 0 1A30 2 0 2 0 10 2 ),NationalNatural Scientific Fund of China ( No. 30 371519) and Natural Scientific Fund ofJinanUniversity
文摘Rabbit limbal corneal epithelial cells,corneal endothelial cells and keratocytes were cultured on amniotic membrane. Phase contrast microscope examination was performed daily. Histological and scan electron microscopic examinations were carried out to observe the growth,arrangement and adhesion of cultivated cells. Results showed that three corneal cell types seeded on amniotic membrane grew well and had normal cell morphology. Cultured cells attached firmly on the surface of amniotic membrane. Corneal epithelial cells showed singular layer or stratification. Cell boundaries were formed and tightly opposed. Corneal endothelial cells showed cobblestone or polygonal morphologic characteristics that appeared uniform in size. The cellular arrangement was compact. Keratocytes elongated and showed triangle or dendritic morphology with many intercellular joints which could form networks. In conclusion,amniotic membrane has good scaffold property,diffusion effect and compatibility with corneal cells. The basement membrane side of amniotic membrane facilitated the growth of corneal epithelial cells and endothelial cells and cell junctions were tightly developed. The spongy layer of amniotic membrane facilitated the growth of keratocytes and intercellular joints were rich. Amniotic membrane is an ideal biomaterial for layering tissue engineered cornea.
基金Shenzhen-Hong Kong Research and Development Fund(No.SGDX20201103095406024)2022 Shenzhen Sustainable Supporting Funds for Colleges and Universities(No.20220810143642004)+9 种基金Shenzhen Basic Research Project(Nos.JCYJ20200109144608205 and JCYJ20210324120001003)Guangdong Basic and Applied Basic Research Foundation(Nos.2020A1515011301 and 2021A1515012246)Peking University Shenzhen Graduate School Research Start-up Fund of Introducing Talent(No.1270110273)Shenzhen Postdoctoral Research Fund Project after Outbound(No.2129933651)China Postdoctoral Science Foundation(No.2023M730032)City University of Hong Kong Strategic Research Grants(SRG)(7005505)City University of Hong Kong Donation Research Grants(No.9220061 and DON-RMG No.9229021)Guangdong-Hong Kong Technology Cooperation Funding Scheme(TCFS)(No.GHP/085/18SZ)Shenzhen-Hong Kong Technology Cooperation Funding Scheme(TCFS)(No.GHP/149/20SZ and CityU 9440296)IER Foundation(Nos.IERF2020001 and IERF202102).
文摘As implanted bone fixation materials,magnesium(Mg)alloys have significant advantages because the density and elastic modulus are closest to those of the human bone and they can bio-degrade in the physiological environment.However,Mg alloys degrade too rapidly and uncontrollably thus hampering clinical adoption.In this study,a highly corrosion-resistant zinc-phosphate-doped micro-arc oxidation(MAO)coating is prepared on the AZ31B alloy,and the degradation process is assessed in vitro.With increasing zinc phosphate concentrations,both the corrosion potentials and charge transfer resistance of the AZ31B alloy coated with MAO coatings increase gradually,while the corrosion current densities di-minish gradually.Immersion tests in the simulated body fluid(SBF)reveal that the increased zinc phos-phate concentration in MAO coating decreases the degradation rate,consequently reducing the release rates of Mg^(2+)and OH-in the physiological micro-environment,which obtains the lowest weight loss of only 5.22%after immersion for 56 days.Effective regulation of degradation provides a weak alkaline environment that is suitable for long-term cell growth and subsequent promotion of bone proliferation,differentiation,mineralization,and cytocompatibility.In addition,the zinc-phosphate-doped MAO coat-ings show an improved wear resistance as manifested by a wear rate of only 3.81 x 10^(-5) mm^(3) N^(-1) m^(-1).The results reveal a suitable strategy to improve the properties of biodegradable Mg alloys to balance tissue healing with mechanical degradation.
基金supported by the National Natural Science Foundation of China(No.31670967,32000932 and 82061160492)the Key Research and Development Projects in Anhui Province(No.202104j07020039 and 2022e07020051)+4 种基金the Scientific Research Foundation of the Institute for Translational Medicine of Anhui Province(No.2021zhyx-C51 and No.2021zhyx-C68)2020 Disciplinary Construction Project in School of Dentistry,Anhui Medical University(No.2020kqkyT01,2020kqkyT03 and 2020kqsy09)2021 Disciplinary Construction Project in School of Dentistry,Anhui Medical University(No.2021kqxkFY13 and 2021kqxkFY16)Key Project of Natural Science Research of the Anhui Provincial Department of Education(No.KJ2019A0251 and KJ2021A0270)Anhui Provincial Natural Science Foundation(No.2208085QE136 and 2008085QH374).
文摘Silver has been widely used for surface modification to prevent implant-associated infections.However,the inherent cytotoxicity of silver greatly limited the scope of its clinical applications.The construction of surfaces with both good antibacterial properties and favorable cytocompatibility still remains a challenge.In this study,a structurally homogeneous dopamine-silver(DA/Ag)nanocomposite was fabricated on the implant surface to balance the antibacterial activity and cytocompatibility of the implant.The results show that the DA/Ag nanocomposites prepared under the acidic conditions(pH=4)on the titanium surface are homogeneous with higher Ag^(+)content,while an obvious core(AgNPs)-shell(PDA)structure is formed under neutral(pH=7)and alkaline conditions(pH=10),and the subsequent heat treatment enhanced the stability of PDA-AgNPs nanocomposite coatings on porous titanium.The antibacterial test,cytotoxicity test,hypodermic implantation and osteogenesis test revealed that the homogeneous PDA-AgNPs nanocomposite coating achieved the balance between the antibacterial ability and cytocompatibility,and had the best outcomes for soft tissue healing and bone formation around the implants.This study provides a facile strategy for preparing silver-loaded surfaces with both good antibacterial effect and favorable cytocompatibility,which is expected to further improve the therapeutic efficacy of silver composite-coated dental implants.
基金supported by the Russian Science Foundation,grant No.23-63-10056.
文摘Injectable bone cements are used in minimally invasive surgical techniques including vertebroplasty and kyphoplasty.This work is devoted to the development of magnesium-calcium phosphate cements(MCPCs)doped with gadolinium ions(Gd^(3+))for bone defect repair.Interaction between cement powders and a cement liquid resulted in the formation of newberyite and brushite phases,which gave mechanical strength up to 17 MPa without a thermal effect.The introduction of Gd3+into the lattice was confirmed by electron paramagnetic resonance spectroscopy;the doping increased injectivity while giving rise to antibacterial properties against Escherichia coli.Assays of the cement samples soaking in Kokubo’s simulated body fluid revealed the formation of calcium phosphate coatings on the cements’surface.The cements manifested biocompatibility with the MG-63 cell line and significantly enhanced contrast when Gd-MCPC was placed into a bone defect and examined by X-ray micro-computed tomography.For the first time,visualization of a Gd-doped cement material was achieved in a model of a bone defect analyzed by MRI.
基金the financial supports from the Shenzhen Basic Research Project,China(No.JCYJ20170815153210359)the National Natural Science Foundation of China(No.12174210)。
文摘In order to develop the Mg-Zn-Ag metallic glasses(MGs)for biodegradable implant applications,the glass formation ability(GFA)and biocompatibility of Mg-Zn-Ag alloys were investigated using a combination of the calculation of phase diagrams(CALPHAD)and experimental measurements.High GFA potentiality of two alloy series,specifically Mg_(96-x)Zn_xAg_(4)and Mg_(94-x)Zn_xAg_6(x=17,20,23,26,29,32,35),was predicted theoretically and then substantiated through experimental testing.X-ray diffraction(XRD)and differential scanning calorimetry(DSC)techniques were used to evaluate the crystallinity,GFA,and crystallization characteristics of these alloys.The results showed that compositions between Mg_(73)Zn_(23)Ag_(4)and Mg_(64)Zn_(32)Ag_(4)for Mg_(96-x)Zn_xAg_4,Mg_(66)Zn_(28)Ag_(6)and Mg_(63)Zn_(31)Ag_(6for)Mg_(94-x)Zn_xAg_(6)displayed a superior GFA.Notably,the GFA of the Mg_(96-x)Zn_xAg_(4)series was better than that of the Mg_(94-x)Zn_xAg_(6)series.Furthermore,the Mg_(70)Zn_(26)Ag_4,Mg_(74)Zn_(20)Ag_6,and Mg_(71)Zn_(23)Ag_(6)alloys showed acceptable corrosion rates,good cytocompatibility,and positive effects on cell proliferation.These characteristics make them suitable for applications in medical settings,potentially materials as biodegradable implants.