Infection is a major potential complication in the clinical treatment of bone injuries. Magnesium (Mg)-based composites are biodegradable and antibacterial biomaterials that have been employed to reduce infection foll...Infection is a major potential complication in the clinical treatment of bone injuries. Magnesium (Mg)-based composites are biodegradable and antibacterial biomaterials that have been employed to reduce infection following surgical implants. The aim of present study was to synthesize and in-vitro characterize Mg-based scaffolds containing silver for bone tissue engineering. Porous Mg-based scaffolds with four silver concentrations (i.e., 0, 0.5 wt.%, 1 wt.%, and 2 wt.%), denoted by Mg?Ca?Mn-Zn-xAg (MCMZ?xAg)(where x is the silver concentration), were fabricated by the space holder technique. The effects of silver concentration on pore architecture, mechanical properties, bioactivity, and zone of bacterial inhibition were investigated in-vitro. X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fluorescence microscopy were utilized to characterize the obtained scaffolds. In-vitro corrosion test results indicated that the MCMZ scaffolds with lower silver content were more resistant to corrosion than those enriched with higher amounts of silver. Examination of the antibacterial activity showed that the MCMZ?Ag scaffolds exhibited superb potential with respect to suppressing the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), in the inhibition zone around the MCMZ?Ag scaffolds, with increasing in the amount of incorporated silver;however, higher amounts of silver increased the cytotoxicity. Taken together, the results of this study demonstrate that the porous 0.5 wt.% Ag-containing scaffolds with interconnected pores, adequate mechanical properties, antibacterial activity, and cell adhesion are promising with respect to the repair and substitution of damaged and diseased bones.展开更多
Nowadays,Zinc(Zn)-based biocomposites as biodegradable implant materials have been recognized as a promising approach to overcome the insufficient mechanical performance of Zn matrix and to endow the Zn-based material...Nowadays,Zinc(Zn)-based biocomposites as biodegradable implant materials have been recognized as a promising approach to overcome the insufficient mechanical performance of Zn matrix and to endow the Zn-based materials with biofunctionality.However,the strengthening effect on Zn-based matrix compos-ite remains far from expectation mainly due to the poor interfacial bonding between the reinforcement and Zn matrix,and the relatively coarse grain size of the Zn matrix.Herein,we have developed a novel in situ wetting strategy to ameliorate the interfacial bonding and mechanical performance of Zn-Ag-based composites using cuprous oxide-modified graphene oxide(Cu_(2)O-GO)sheets as reinforcement.The en-hanced interfacial bonding between GO sheets and Zn matrix owing to the in situ generated ZnO inter-layer and the ultrafine microstructure with an average grain size of 360 nm were simultaneously achieved in the hot extruded(HEed)1 wt%Cu_(2)O-GO/Zn-2 wt%Ag biocomposites.Consequently,HEed biocompos-ites possessed excellent tensile properties,including ultimate tensile strength(UTS)of 344.0±2.4 MPa,yield stress(YS)of 314.0±4.8 MPa,and elongation at failure of 15.5%±1.3%.Ultrafine and uniform microstructure of the HEed biocomposites resulted in a relatively uniform corrosion morphology and a degradation rate of 0.195±0.004 mm y^(−1) in simulated body fluid(SBF)solution.The 2-fold diluted extract of the HEed biocomposites exhibited satisfying cytocompatibility with MC3T3-E1 pre-osteoblast comparable to that of Ti-6Al-4 V ELI alloys.More importantly,the synergistic effect of metallic ions,Ag-rich nanoparticles,and GO sheets contributed to the remarkable antibacterial activity of the experimental biocomposites against both S.aureus and E.coli.These results demonstrated that the 1Cu_(2)O-GO/Zn-2Ag biocomposites should be anticipated as a promising biodegradable material for orthopedic applications.展开更多
The adsorption behavior, antibacterial, and corrosion properties of a Ti-3 Cu alloy were studied in a phosphate-buffered saline solution containing 0, 1, 3, and 6 gL^(-1) bovine serum albumin protein at 37℃ and pH = ...The adsorption behavior, antibacterial, and corrosion properties of a Ti-3 Cu alloy were studied in a phosphate-buffered saline solution containing 0, 1, 3, and 6 gL^(-1) bovine serum albumin protein at 37℃ and pH = 7.4(±0.2). The protein adsorption behavior was examined via cyclic voltammetry, secondary ions mass spectroscopy(SIMS), and angle-resolved X-ray photoelectron spectroscopy(ARXPS). The corrosion property was analyzed by the open circuit potential(OCP), potentiodynamic polarization(PD),and electrochemical impedance spectroscopy(EIS) examinations. The antibacterial test was conducted according to the GB/T 21510 China Standard. It was observed that the surface charge density(QA DS) was directly proportional to the amount of the adsorbed BSA protein, signifying that the protein adsorption was accompanied by the charge transfer, pointing to chemisorptions phenomena. BSA amino groups and other organic species were observed in the surface analysis examinations. It was shown that the formation of barrier complexes between the TiO_(2) oxide-layer and PBS solution resulted in decreasing the release of Cu-ions, which consequently reduced the antibacterial activity. On the other hand, these barrier complexes improved the corrosion resistance by increasing the charge transfer resistance and double-layer capacitance of the Ti-3 Cu alloy.展开更多
Biomaterial-associated infection(BAI)is a kind of serious post-operative complication in orthopaedic surgery.Antibiotic-loaded bone cement shines a light on BAI prevention for convenient manipulation and complex filli...Biomaterial-associated infection(BAI)is a kind of serious post-operative complication in orthopaedic surgery.Antibiotic-loaded bone cement shines a light on BAI prevention for convenient manipulation and complex filling.To this aim,we designed an antibacterial bone cement based on Nano-hydroxyapatite/Polyurethane(PUHA)loading with antibiotic Enoxacin(EN).The distinct shear-thinning behavior of the prepolymers was observed,indicating a good injectability.The PUHA bone cement possessed a suitable curing speed,and the addition of EN might slightly expedite the curing process and enhance the mechanical properties.The EN release profile indicated that the EN-loaded bone cement could reach the minimum inhibitory concentration in 2 h,and sustainedly released EN for almost 8 days,exhibiting an antibacterial delivery potential.Antibacterial test further confirmed the antibacterial ability of EN-loaded bone cement is in a dose-dependent manner.However,the osteogenic performance of drug-loaded bone cement with high dosage is not as good as antibacterial activity.When the EN concentration of antibacterial cement was lower than 32μg·mL^(-1),the proliferation and osteogenic differentiation of rat mesenchymal stem cells could be significantly promoted.Overall,this study verified the potential of the EN-loaded PUHA bone cement in anti-infection and osteogenesis for bone repairing.展开更多
基金partial financial support to this research from the Saskatchewan Health Research Foundation (SHRF)
文摘Infection is a major potential complication in the clinical treatment of bone injuries. Magnesium (Mg)-based composites are biodegradable and antibacterial biomaterials that have been employed to reduce infection following surgical implants. The aim of present study was to synthesize and in-vitro characterize Mg-based scaffolds containing silver for bone tissue engineering. Porous Mg-based scaffolds with four silver concentrations (i.e., 0, 0.5 wt.%, 1 wt.%, and 2 wt.%), denoted by Mg?Ca?Mn-Zn-xAg (MCMZ?xAg)(where x is the silver concentration), were fabricated by the space holder technique. The effects of silver concentration on pore architecture, mechanical properties, bioactivity, and zone of bacterial inhibition were investigated in-vitro. X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fluorescence microscopy were utilized to characterize the obtained scaffolds. In-vitro corrosion test results indicated that the MCMZ scaffolds with lower silver content were more resistant to corrosion than those enriched with higher amounts of silver. Examination of the antibacterial activity showed that the MCMZ?Ag scaffolds exhibited superb potential with respect to suppressing the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), in the inhibition zone around the MCMZ?Ag scaffolds, with increasing in the amount of incorporated silver;however, higher amounts of silver increased the cytotoxicity. Taken together, the results of this study demonstrate that the porous 0.5 wt.% Ag-containing scaffolds with interconnected pores, adequate mechanical properties, antibacterial activity, and cell adhesion are promising with respect to the repair and substitution of damaged and diseased bones.
基金National Natural Science Foundation of China(No.51801164)the Fundamental Research Funds for the Central Universities,China(No.XDJK2020C005)+1 种基金Chongqing Key Laboratory Fund of Soft-matter Material Chemistry and Function Manufacturing,China(No.20200006)Chongqing College Student Innovation and Entrepreneurship Program of Southwest University,China(No.202010635076).
基金This work was financially supported by the Tianjin Natural Sci-ence Foundation(Nos.20JCQNJC00610 and 20JCYBJC00620)the National Natural Science Foundation of China(Nos.51871166 and U1764254).
文摘Nowadays,Zinc(Zn)-based biocomposites as biodegradable implant materials have been recognized as a promising approach to overcome the insufficient mechanical performance of Zn matrix and to endow the Zn-based materials with biofunctionality.However,the strengthening effect on Zn-based matrix compos-ite remains far from expectation mainly due to the poor interfacial bonding between the reinforcement and Zn matrix,and the relatively coarse grain size of the Zn matrix.Herein,we have developed a novel in situ wetting strategy to ameliorate the interfacial bonding and mechanical performance of Zn-Ag-based composites using cuprous oxide-modified graphene oxide(Cu_(2)O-GO)sheets as reinforcement.The en-hanced interfacial bonding between GO sheets and Zn matrix owing to the in situ generated ZnO inter-layer and the ultrafine microstructure with an average grain size of 360 nm were simultaneously achieved in the hot extruded(HEed)1 wt%Cu_(2)O-GO/Zn-2 wt%Ag biocomposites.Consequently,HEed biocompos-ites possessed excellent tensile properties,including ultimate tensile strength(UTS)of 344.0±2.4 MPa,yield stress(YS)of 314.0±4.8 MPa,and elongation at failure of 15.5%±1.3%.Ultrafine and uniform microstructure of the HEed biocomposites resulted in a relatively uniform corrosion morphology and a degradation rate of 0.195±0.004 mm y^(−1) in simulated body fluid(SBF)solution.The 2-fold diluted extract of the HEed biocomposites exhibited satisfying cytocompatibility with MC3T3-E1 pre-osteoblast comparable to that of Ti-6Al-4 V ELI alloys.More importantly,the synergistic effect of metallic ions,Ag-rich nanoparticles,and GO sheets contributed to the remarkable antibacterial activity of the experimental biocomposites against both S.aureus and E.coli.These results demonstrated that the 1Cu_(2)O-GO/Zn-2Ag biocomposites should be anticipated as a promising biodegradable material for orthopedic applications.
基金financially supported by the National Key Research and Development Program of China(2018YFC1106601)Liaoning Revitalization Talents Program(XLYC1807069)+1 种基金National Natural Science Foundation(No.51631009,31870954)support of the CSC scholarship。
文摘The adsorption behavior, antibacterial, and corrosion properties of a Ti-3 Cu alloy were studied in a phosphate-buffered saline solution containing 0, 1, 3, and 6 gL^(-1) bovine serum albumin protein at 37℃ and pH = 7.4(±0.2). The protein adsorption behavior was examined via cyclic voltammetry, secondary ions mass spectroscopy(SIMS), and angle-resolved X-ray photoelectron spectroscopy(ARXPS). The corrosion property was analyzed by the open circuit potential(OCP), potentiodynamic polarization(PD),and electrochemical impedance spectroscopy(EIS) examinations. The antibacterial test was conducted according to the GB/T 21510 China Standard. It was observed that the surface charge density(QA DS) was directly proportional to the amount of the adsorbed BSA protein, signifying that the protein adsorption was accompanied by the charge transfer, pointing to chemisorptions phenomena. BSA amino groups and other organic species were observed in the surface analysis examinations. It was shown that the formation of barrier complexes between the TiO_(2) oxide-layer and PBS solution resulted in decreasing the release of Cu-ions, which consequently reduced the antibacterial activity. On the other hand, these barrier complexes improved the corrosion resistance by increasing the charge transfer resistance and double-layer capacitance of the Ti-3 Cu alloy.
基金funded by the Sichuan International Science and Technology Innovation Cooperation Project[Grant Numbers2021YFH0122]the Fundamental Research Funds for the Central Universities。
文摘Biomaterial-associated infection(BAI)is a kind of serious post-operative complication in orthopaedic surgery.Antibiotic-loaded bone cement shines a light on BAI prevention for convenient manipulation and complex filling.To this aim,we designed an antibacterial bone cement based on Nano-hydroxyapatite/Polyurethane(PUHA)loading with antibiotic Enoxacin(EN).The distinct shear-thinning behavior of the prepolymers was observed,indicating a good injectability.The PUHA bone cement possessed a suitable curing speed,and the addition of EN might slightly expedite the curing process and enhance the mechanical properties.The EN release profile indicated that the EN-loaded bone cement could reach the minimum inhibitory concentration in 2 h,and sustainedly released EN for almost 8 days,exhibiting an antibacterial delivery potential.Antibacterial test further confirmed the antibacterial ability of EN-loaded bone cement is in a dose-dependent manner.However,the osteogenic performance of drug-loaded bone cement with high dosage is not as good as antibacterial activity.When the EN concentration of antibacterial cement was lower than 32μg·mL^(-1),the proliferation and osteogenic differentiation of rat mesenchymal stem cells could be significantly promoted.Overall,this study verified the potential of the EN-loaded PUHA bone cement in anti-infection and osteogenesis for bone repairing.
