To study the osteogenesis and transformation process of calcium phosphate bioceramic in vivo, biodegradable porous β-tricalcium phosphate ceramics (β-TCP, φ5×8 mm) were implanted in the tibia of rabbits. β-TC...To study the osteogenesis and transformation process of calcium phosphate bioceramic in vivo, biodegradable porous β-tricalcium phosphate ceramics (β-TCP, φ5×8 mm) were implanted in the tibia of rabbits. β-TCP ceramics with surrounding bone tissue were retrieved and observed by SEM, TEM and EPMA every month after implantation. The results showed that osteogenesis was active and β-TCP ceramics bonded to bones directly. The new bones were forming and maturing as materials were continuously degrading, and materials were finally replaced by new bone. Parts of the materials were degraded, absorbed and recrystallized, while the rest were dispersed to the spongy bone and the Haversian lamella in an irregular arrangement, becoming incorporated into bone formation directly by remodeling the structure. Some β-TCP crystals cleaved along its (001) rhombohedral plane and formed lath-like crystals in vivo.展开更多
Porous calcium phosphate ceramics were produced by compression molding using a special mold followed by sintering. The porous calcium phosphate ceramics have three-dimensional and penetrated open pores 380-400μm in...Porous calcium phosphate ceramics were produced by compression molding using a special mold followed by sintering. The porous calcium phosphate ceramics have three-dimensional and penetrated open pores 380-400μm in diacneter spaced at intervals of 200μm. The layers of the linear penetration pores alternately lay perpendicular to pore direction. The porosity was 59%-65% . The Ca/ P molar ratios of the porous calcium phos phate ceramics range from 1.5 to 1.85. A binder cantaining methyl cellulose was most effective for preparing the powder compact among vinyl acetate, polyvinyl alcohol, starch, stearic acid, methyl cellulose and their mixtures . Stainless steel, polystyrene, nylon and bamboo were used as the long columnar dies for the penetrated open pores. When polystyrene, nylon and bamboo were used as the long columnar male dies, the dies were burned oat during the sintering process. Using stainless steel as the male dies with the removal of the dies before heat treatment resulted in a higher level of densification of the calcium phosphate ceramic.展开更多
Calcium phosphate precursory powders containing Na and Mg have been prepared by the citric acid sol-gel combustion method. The elements of Na and Mg were introduced from component of CaO- P2O5 - Na2O- MgO. The effec...Calcium phosphate precursory powders containing Na and Mg have been prepared by the citric acid sol-gel combustion method. The elements of Na and Mg were introduced from component of CaO- P2O5 - Na2O- MgO. The effect of sintering additives on the phase cornposition was characterized by XRD. The effect of sintering additives on sintering of materials was also characterized by linear shrinkage, TEM and SEM. Finally the microstructure of porous calcium phosphate ceramic was determined by SEM.展开更多
To study the transformation process of calcium phosphate bioceramic in vivo,biodegradable porous β-tricalcium phosphate ceramics (β-TCP) were used in this experiment. The materials (5×8mm) were implanted in the...To study the transformation process of calcium phosphate bioceramic in vivo,biodegradable porous β-tricalcium phosphate ceramics (β-TCP) were used in this experiment. The materials (5×8mm) were implanted in the tibia of rabbits. The β-TCP ceramics with bone tissue were retrieved and treated for histology, and then observed by using a scanning electron microscope (SEM) and an electron probe X-ray microanalyzer (EMPA) every month. The results show that β-TCP ceramics bond to bone directly,new bones are forming and maturing with materials continuous degrading,and the materials are nearly replaced by the formed bone finally.Parts of the materials were degraded,absorpted and recrystallized,the others dispersped on the cancellous bone and the Haversian lamella with an irregular arrangement incorporating in bone formation directly by remodeling structure.展开更多
In order to provide valuable information for the design of new calcium phosphate bone repair materials,bone tissue engineering scaffold materials, and other dinical application, the interaction between calcium phospha...In order to provide valuable information for the design of new calcium phosphate bone repair materials,bone tissue engineering scaffold materials, and other dinical application, the interaction between calcium phosphate materials and proteins were investigated. The adsorption of the calcium phosphate ceramic to the protein was investigated by using FT-IR, XPS, SEM, and SDS-PAGE. As the results shown, the proteins were strongly adsorbed adsorbed the CPC, and a shift of the feature peak of the protein and also a chemical shift in the Ca2p and O1s bind energy of CPC was observed. This indicated that the acidic amino-group and alkaline amino- residue on the proteins' surface bonded to the Ca^2+ in the β- TCP crystal by ionic bond and the proteins' alkaline amino groups to the oxygen in PO4^3+ by hydrogen bond and electrostatic attraction. The adsorption mechanism of the protein in the CPC can be described as three adsorption layers : irreversible chemical adsorption layer, physical adsorption layer and biomineralized adsorption layer.展开更多
This study examined the biological response of two porous calcium phosphate ceramics, hydroxyapntite ( HA ) and hydroxyapaptite/β-tricalcium phosphate ( HA/β- TCP ) scaffolds. Three different cell types , a huma...This study examined the biological response of two porous calcium phosphate ceramics, hydroxyapntite ( HA ) and hydroxyapaptite/β-tricalcium phosphate ( HA/β- TCP ) scaffolds. Three different cell types , a human osteoblastic cell line ( HOS ) , primary human osteoblasts (HOB) and human mesenehymal stem cells (MSCs), were used to examine biocompatibility and osteoinductive capacity. The experimental results showed both materials were highly biocompatible and proliferation was significantly greater on pure HA ( P 〈 0.01 ), with a peak in proliferation at day 7. Protein levels were significantly higher ( P 〈 0.05) than the control Thermanox( TMX ( tm) ) for both test materials. Osteoinduction of MSCs was observed on both test materials, with cells seeded on HA/ β-TCP showing greater alkaline phosphatase activity compared to HA alone, indicating an enhancement in osteoinductive property. Both materials show good potential for use as tissue engineered scaffolds.展开更多
The bone regenerative scaffold with the tailored degradation rate matching with the growth rate of the new bone is essential for adolescent bone repair.To satisfy these requirement,we proposed bone tissue scaffolds wi...The bone regenerative scaffold with the tailored degradation rate matching with the growth rate of the new bone is essential for adolescent bone repair.To satisfy these requirement,we proposed bone tissue scaffolds with controlled degradation rate using osteoinductive materials(Ca-P bioceramics),which is expected to present a controllable biodegradation rate for patients who need bone regeneration.Physicochemical properties,porosity,compressive strength and degradation properties of the scaffolds were studied.3D printed Ca-P scaffold(3DS),gas foaming Ca-P scaffold(FS)and autogenous bone(AB)were used in vivo for personalized beagle skull defect repair.Histological results indicated that the 3DS was highly vascularized and well combined with surrounding tissues.FS showed obvious newly formed bone tissues.AB showed the best repair effect,but it was found that AB scaffolds were partially absorbed and degraded.This study indicated that the 3D printed Ca-P bioceramics with tailored biodegradation rate is a promising candidate for personalized skull bone tissue reconstruction.展开更多
Porous calcium phosphate ceramics were prepared by slip casting and molding method respectively. By these two different methods, different microstructures can be got. By slip casting method, the pore size was 100- 35...Porous calcium phosphate ceramics were prepared by slip casting and molding method respectively. By these two different methods, different microstructures can be got. By slip casting method, the pore size was 100- 350μm and 20- 80 μm ; pores were opened, interconnected and ball-like ; the grain size was 2-4μm. By molding method, the pore size wus 100-500μm and 1- 10μm ; the grain size was 2- 8μm. By slip casting method regalar and interconnected pores can be gnt. By molding method the porosity and strength can be adjusted easily.展开更多
Titanium alloy has been a successful implant material owing to its excellent ratio of strength to weight, toughness, and bio-inert oxide surface. Significant progress has been made in improving the bioactivity of tita...Titanium alloy has been a successful implant material owing to its excellent ratio of strength to weight, toughness, and bio-inert oxide surface. Significant progress has been made in improving the bioactivity of titanium alloy by coating its oxide surface with calcium phosphates. In the present study, in situ coating was reported on Ti6Al4V(TC4) surface with calcium phosphate (Ca-P) bioceramics synthesized and synchronously cladded by laser beam. This coating was grown by first preplacing directly the raw powders, which contain 80% of CaHPO4 · 2H2O, 20% of CaCO3, and dram of rare earth (RE), on the TC4 surfaces, and then exposing the surfaces to the laser beam with a power density of 12. 73-15.27 MW · m^-2 and a scanning velocity of 10.5 m/s. The resultant coating was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis and Different-thermal Scanning (TG-DSC), and Energy Dispersive X-ray Detection (EDX). The results show that these laser ceramics include hydroxyapatite (HA), tricalcium phosphate (TCP), Ca2 P2 O7, and other Ca-P phases, and the interface between the coating and the TC4 substrate has tighter fixation, in which the chemical bonding is approved. These laser hybrid coatings are useful in enhancing the bioactivity of titanium alloy surfaces.展开更多
This study aimed at exploring the effect of surface morphology of dense phosphate calcimn (Ca-P) ceramics upon the formation of bone-like apatite in static or dynamic simulated body fluid (SBF). Dense and sandblas...This study aimed at exploring the effect of surface morphology of dense phosphate calcimn (Ca-P) ceramics upon the formation of bone-like apatite in static or dynamic simulated body fluid (SBF). Dense and sandblasted calcium phosphate ceramics were immersed into dynamic SBF flowing at normal physiological speed of body fluid of skeletal muscle. The changes were characterized using SEM, XPS, IR and XRD. Changes can be observed after the sandblasted surface of dense calcium phosphate ceramics had been immersed in SBF for 14 days. XPS analysis results showed that the flake-like structure was composed of Ca, P, C, O; IR analysis result of surface structure of samples showed that there were specific peaks for CO3^2-; XRD results indicated the decrease in crystallinity and the increase in amorphous structure. The rough surface was advantageous for the formation of bone-like apatite. Increasing the Ca^2+, HPO4^2- concentration of SBF could also enhance the bonelike apatite formation. All the results demonstrated that local concentration is a key factor affecting nucleation.展开更多
The discovery of osteoinductivity of calcium phosphate(Ca-P)ceramics has set an enduring paradigm of conferring biological regenerative activity to materials with carefully designed structural characteristics.The uniq...The discovery of osteoinductivity of calcium phosphate(Ca-P)ceramics has set an enduring paradigm of conferring biological regenerative activity to materials with carefully designed structural characteristics.The unique phase composition and porous structural features of osteoinductive Ca-P ceramics allow it to interact with signaling molecules and extracellular matrices in the host system,creating a local environment conducive to new bone formation.Mounting evidence now indicate that the osteoinductive activity of Ca-P ceramics is linked to their physicochemical and three-dimensional structural properties.Inspired by this conceptual breakthrough,many laboratories have shown that other materials can be also enticed to join the rank of tissue-inducing biomaterials,and besides the bones,other tissues such as cartilage,nerves and blood vessels were also regenerated with the assistance of biomaterials.Here,we give a brief historical recount about the discovery of the osteoinductivity of Ca-P ceramics,summarize the underlying material factors and biological characteristics,and discuss the mechanism of osteoinduction concerning protein adsorption,and the interaction with different types of cells,and the involvement of the vascular and immune systems.展开更多
Calcium phosphate(CaP)bioceramics are important for tissue regeneration and immune response,yet how CaP bioceramics influence these biological processes remains unclear.Recently,the role of immune cells in biomaterial...Calcium phosphate(CaP)bioceramics are important for tissue regeneration and immune response,yet how CaP bioceramics influence these biological processes remains unclear.Recently,the role of immune cells in biomaterial-mediated regeneration,especially macrophages,has been well concerned.CD301b^(+)macrophages were a new subset of macrophages we have discovered,which were required for bioceramics-mediated bone regeneration.Nevertheless,the impact of CD301b^(+)macrophages on angiogenesis,which is a vital prerequisite to bone formation is yet indistinct.Herein,we found that CD301b^(+)macrophages were closely correlated to angiogenesis of CaP bioceramics.Additionally,depletion of CD301b^(+)macrophages led to the failure of angiogenesis.We showed that store-operated Ca^(2+)entry and calcineurin signals regulated the VEGF expression of CD301b^(+)macrophages via the NFATc1/VEGF axis.Inhibition of calcineurin effectively impaired angiogenesis via decreasing the infiltration of CD301b^(+)macrophages.These findings provided a potential immunomodulatory strategy to optimize the integration of angiogenesis and bone tissue engineering scaffold materials.展开更多
How to endow bone grafts with long-term antibacterial activity and good bone regenerative ability to achieve the regenerative repair of infected bone defects has been the focus of the clinical treatment of osteomyelit...How to endow bone grafts with long-term antibacterial activity and good bone regenerative ability to achieve the regenerative repair of infected bone defects has been the focus of the clinical treatment of osteomyelitis.The present study introduced a novel one-step route to realizing the co-doping of zinc oxide(ZnO)and zinc ion(Zn^(2+))in biphasic calcium phosphate(BCP)ceramics to utilize their synergistic antibacterial.Compared with the conventional BCP ceramics(BCP-Ca),the ZnO/Zn^(2+)co-doping ones(BCP-Zn)possessed strong antibacterial ability on E.coli and S.aureus as well as stimulated the osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)effectively.The synergistic antibacterial mechanism of ZnO and Zn^(2+)was also investigated.BCP-Zn showed excellent osteoinductivity and angiogenesis at three months postoperatively in the canine intramuscular implantation model.Moreover,BCP-Zn exhibited excellent anti-infective ability and bone regenerative repair compared to BCP-Ca and control groups in the infected bone defect model of rat femur.Collectively,these findings suggest that the simultaneous introduction of ZnO/Zn^(2+)could have immense potential to expand the application of osteoinductive BCP ceramics in the regenerative repair of infected bone defects.展开更多
β-tricalcium phosphate (β-TCP) powder and Na20-CaO-MgO-P205 glass binder were synthesized and mixed, and then the biodegradable porous calcium phosphate ceramics were successfully prepared by foaming and sintering...β-tricalcium phosphate (β-TCP) powder and Na20-CaO-MgO-P205 glass binder were synthesized and mixed, and then the biodegradable porous calcium phosphate ceramics were successfully prepared by foaming and sintering at 850℃. The as-prepared ceramics possess a high porosity with partial three-dimension interconnected macro- and micro-pores. As in vitro experiment testified, the calcium phosphate ceramics (CPCs) has good degradability.展开更多
Osteoinductivity is a crucial factor to determine the success and efficiency of posterolateral spinal fusion(PLF)by employing calcium phosphate(Ca-P)bioceramics.In this study,three kinds of Ca-P ceramics with microsca...Osteoinductivity is a crucial factor to determine the success and efficiency of posterolateral spinal fusion(PLF)by employing calcium phosphate(Ca-P)bioceramics.In this study,three kinds of Ca-P ceramics with microscale to nanoscale gain size(BCP-control,BCP-micro and BCP-nano)were prepared and their physicochemical properties were characterized.BCP-nano had the spherical shape and nanoscale gain size,BCP-micro had the spherical shape and microscale gain size,and BCP-control(BAM®)had the irregular shape and microscale gain size.The obtained BCP-nano with specific nanotopography could well regulate in vitro protein adsorption and osteogenic differentiation of MC3T3 cells.In vivo rabbit PLF procedures further confirmed that nanotopography of BCP-nano might be responsible for the stronger bone regenerative ability comparing with BCP-micro and BCP-control.Collectedly,due to nanocrystal similarity with natural bone apatite,BCP-nano has excellent efficacy in guiding bone regeneration of PLF,and holds great potentials to become an alternative to standard bone grafts for future clinical applications.展开更多
The custom-tailored medicine requires a developmental strategy that integrates excellent osteogene-sis with mechanical stability to enhance the reconstruction of the critical-size bone defect(CSBD)and the healing proc...The custom-tailored medicine requires a developmental strategy that integrates excellent osteogene-sis with mechanical stability to enhance the reconstruction of the critical-size bone defect(CSBD)and the healing process in weight-bearing bone.We prepared three-dimensional(3D)printed biphasic cal-cium phosphate(BCP)scaffolds composited with nano-graphene oxide(GO).The biological effects of the GO/BCP composite scaffolds could induce the differentiation of rat bone marrow stem cells(BM-SCs)and the migration of human umbilical vein endothelial cells(HUVECs)for bone repair.The proper ratio of GO in the composite scaffold regulated the composites’surface roughness and hydrophilicity to a suitable range for the adhesion and proliferation of BMSCs and HUVECs.Besides,the GO/BCP composite scaffold increased osteogenesis and angiogenesis by activating BMP-2,RUNX-2,Smad1/4,and VEGF.The customized intramedullary nail combined with GO/BCP scaffold was applied to repair CSBD(2.0 cm in length)in a beagle femur model.This fixation strategy was confirmed by finite element analysis.In vivo,the results indicated that the custom-made internal fixation provided sufficient stability in the early stage,ensuring bone healing in a considerable mechanical environment.At 9 months postoperatively,longitudi-nal bony union and blood vessels in osteon were observed in the CSBD area with partial degradation in the 0.3%GO/BCP group.In the three-point bending test,the ultimate load of 0.3%GO/BCP group reached over 50%of the normal femur at 9 months after repair.These results showed a promising application of osteogenic GO/BCP scaffold and custom-made intramedullary nails in repairing CSBD of the beagle femur.This effective strategy could provide an option to treat the clinical CSBD in weight-bearing bones.展开更多
Titanium and its alloys have been widely used as implant materials in bio-medicine.Additionally,surface modification has been utilized to improve the chemical and morphological properties of materials.More specificall...Titanium and its alloys have been widely used as implant materials in bio-medicine.Additionally,surface modification has been utilized to improve the chemical and morphological properties of materials.More specifically,biocoating,especially the calcium-phosphate nano-coating,has been widely used in the research field.In this study,a novel calcium-phosphate nanoflower coating was performed on the titanium surface by a simple approach.This study indicated that the novel calcium-phosphate flower-like coating consisting of calcium-phosphate nanosheets had high surface area,low cytotoxicity as well as promising cell affinity.Hence it could be a potential alternative modification method for titanium.展开更多
磷酸钙陶瓷植入体内后其表面类骨磷灰石层的形成是诱导成骨的先决条件.本实验在模拟体液(simulated body fluid, SBF)以人体骨骼肌组织内体液的正常生理流率(2mL/100mL.min)和偏离正常生理流率流动的动态条件下,研究在动态SBF中影响致...磷酸钙陶瓷植入体内后其表面类骨磷灰石层的形成是诱导成骨的先决条件.本实验在模拟体液(simulated body fluid, SBF)以人体骨骼肌组织内体液的正常生理流率(2mL/100mL.min)和偏离正常生理流率流动的动态条件下,研究在动态SBF中影响致密磷酸钙陶瓷表面类骨磷灰石层形成的因素.结果表明:在生理流率条件下,材料的粗糙表面有利于类骨磷灰石的形成,加大SBF中Ca2+、HPO2-4离子浓度,类骨磷灰石层的形成速度加快.比起通常使用的静态浸泡试验,SBF以生理流率流动的动态试验能够更好地模拟类骨磷灰石生长的体内环境.动态SBF对了解类骨磷灰石形成,进而了解磷酸钙陶瓷在体内诱导成骨机理是十分有用的.展开更多
基金supported by the“973”Chinese National Key Fundamental Research and Development Program(G1999064701)
文摘To study the osteogenesis and transformation process of calcium phosphate bioceramic in vivo, biodegradable porous β-tricalcium phosphate ceramics (β-TCP, φ5×8 mm) were implanted in the tibia of rabbits. β-TCP ceramics with surrounding bone tissue were retrieved and observed by SEM, TEM and EPMA every month after implantation. The results showed that osteogenesis was active and β-TCP ceramics bonded to bones directly. The new bones were forming and maturing as materials were continuously degrading, and materials were finally replaced by new bone. Parts of the materials were degraded, absorbed and recrystallized, while the rest were dispersed to the spongy bone and the Haversian lamella in an irregular arrangement, becoming incorporated into bone formation directly by remodeling the structure. Some β-TCP crystals cleaved along its (001) rhombohedral plane and formed lath-like crystals in vivo.
文摘Porous calcium phosphate ceramics were produced by compression molding using a special mold followed by sintering. The porous calcium phosphate ceramics have three-dimensional and penetrated open pores 380-400μm in diacneter spaced at intervals of 200μm. The layers of the linear penetration pores alternately lay perpendicular to pore direction. The porosity was 59%-65% . The Ca/ P molar ratios of the porous calcium phos phate ceramics range from 1.5 to 1.85. A binder cantaining methyl cellulose was most effective for preparing the powder compact among vinyl acetate, polyvinyl alcohol, starch, stearic acid, methyl cellulose and their mixtures . Stainless steel, polystyrene, nylon and bamboo were used as the long columnar dies for the penetrated open pores. When polystyrene, nylon and bamboo were used as the long columnar male dies, the dies were burned oat during the sintering process. Using stainless steel as the male dies with the removal of the dies before heat treatment resulted in a higher level of densification of the calcium phosphate ceramic.
文摘Calcium phosphate precursory powders containing Na and Mg have been prepared by the citric acid sol-gel combustion method. The elements of Na and Mg were introduced from component of CaO- P2O5 - Na2O- MgO. The effect of sintering additives on the phase cornposition was characterized by XRD. The effect of sintering additives on sintering of materials was also characterized by linear shrinkage, TEM and SEM. Finally the microstructure of porous calcium phosphate ceramic was determined by SEM.
文摘To study the transformation process of calcium phosphate bioceramic in vivo,biodegradable porous β-tricalcium phosphate ceramics (β-TCP) were used in this experiment. The materials (5×8mm) were implanted in the tibia of rabbits. The β-TCP ceramics with bone tissue were retrieved and treated for histology, and then observed by using a scanning electron microscope (SEM) and an electron probe X-ray microanalyzer (EMPA) every month. The results show that β-TCP ceramics bond to bone directly,new bones are forming and maturing with materials continuous degrading,and the materials are nearly replaced by the formed bone finally.Parts of the materials were degraded,absorpted and recrystallized,the others dispersped on the cancellous bone and the Haversian lamella with an irregular arrangement incorporating in bone formation directly by remodeling structure.
文摘In order to provide valuable information for the design of new calcium phosphate bone repair materials,bone tissue engineering scaffold materials, and other dinical application, the interaction between calcium phosphate materials and proteins were investigated. The adsorption of the calcium phosphate ceramic to the protein was investigated by using FT-IR, XPS, SEM, and SDS-PAGE. As the results shown, the proteins were strongly adsorbed adsorbed the CPC, and a shift of the feature peak of the protein and also a chemical shift in the Ca2p and O1s bind energy of CPC was observed. This indicated that the acidic amino-group and alkaline amino- residue on the proteins' surface bonded to the Ca^2+ in the β- TCP crystal by ionic bond and the proteins' alkaline amino groups to the oxygen in PO4^3+ by hydrogen bond and electrostatic attraction. The adsorption mechanism of the protein in the CPC can be described as three adsorption layers : irreversible chemical adsorption layer, physical adsorption layer and biomineralized adsorption layer.
文摘This study examined the biological response of two porous calcium phosphate ceramics, hydroxyapntite ( HA ) and hydroxyapaptite/β-tricalcium phosphate ( HA/β- TCP ) scaffolds. Three different cell types , a human osteoblastic cell line ( HOS ) , primary human osteoblasts (HOB) and human mesenehymal stem cells (MSCs), were used to examine biocompatibility and osteoinductive capacity. The experimental results showed both materials were highly biocompatible and proliferation was significantly greater on pure HA ( P 〈 0.01 ), with a peak in proliferation at day 7. Protein levels were significantly higher ( P 〈 0.05) than the control Thermanox( TMX ( tm) ) for both test materials. Osteoinduction of MSCs was observed on both test materials, with cells seeded on HA/ β-TCP showing greater alkaline phosphatase activity compared to HA alone, indicating an enhancement in osteoinductive property. Both materials show good potential for use as tissue engineered scaffolds.
基金This work was supported by the National Key Research and Development Program of China(No.18YFB1105600,2018YFC1106800)National Natural Science Foundation of China(51875518)+1 种基金Sichuan Province Science&Technology Department Projects(2016CZYD0004,2017SZ0001,2018GZ0142,2019YFH0079)Research Foundation for Young Teachers of Sichuan University(2018SCUH0017)and The“111”Project(No.B16033).
文摘The bone regenerative scaffold with the tailored degradation rate matching with the growth rate of the new bone is essential for adolescent bone repair.To satisfy these requirement,we proposed bone tissue scaffolds with controlled degradation rate using osteoinductive materials(Ca-P bioceramics),which is expected to present a controllable biodegradation rate for patients who need bone regeneration.Physicochemical properties,porosity,compressive strength and degradation properties of the scaffolds were studied.3D printed Ca-P scaffold(3DS),gas foaming Ca-P scaffold(FS)and autogenous bone(AB)were used in vivo for personalized beagle skull defect repair.Histological results indicated that the 3DS was highly vascularized and well combined with surrounding tissues.FS showed obvious newly formed bone tissues.AB showed the best repair effect,but it was found that AB scaffolds were partially absorbed and degraded.This study indicated that the 3D printed Ca-P bioceramics with tailored biodegradation rate is a promising candidate for personalized skull bone tissue reconstruction.
文摘Porous calcium phosphate ceramics were prepared by slip casting and molding method respectively. By these two different methods, different microstructures can be got. By slip casting method, the pore size was 100- 350μm and 20- 80 μm ; pores were opened, interconnected and ball-like ; the grain size was 2-4μm. By molding method, the pore size wus 100-500μm and 1- 10μm ; the grain size was 2- 8μm. By slip casting method regalar and interconnected pores can be gnt. By molding method the porosity and strength can be adjusted easily.
基金Item Sponsored by National Natural Science Foundation of China(59571045)
文摘Titanium alloy has been a successful implant material owing to its excellent ratio of strength to weight, toughness, and bio-inert oxide surface. Significant progress has been made in improving the bioactivity of titanium alloy by coating its oxide surface with calcium phosphates. In the present study, in situ coating was reported on Ti6Al4V(TC4) surface with calcium phosphate (Ca-P) bioceramics synthesized and synchronously cladded by laser beam. This coating was grown by first preplacing directly the raw powders, which contain 80% of CaHPO4 · 2H2O, 20% of CaCO3, and dram of rare earth (RE), on the TC4 surfaces, and then exposing the surfaces to the laser beam with a power density of 12. 73-15.27 MW · m^-2 and a scanning velocity of 10.5 m/s. The resultant coating was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis and Different-thermal Scanning (TG-DSC), and Energy Dispersive X-ray Detection (EDX). The results show that these laser ceramics include hydroxyapatite (HA), tricalcium phosphate (TCP), Ca2 P2 O7, and other Ca-P phases, and the interface between the coating and the TC4 substrate has tighter fixation, in which the chemical bonding is approved. These laser hybrid coatings are useful in enhancing the bioactivity of titanium alloy surfaces.
文摘This study aimed at exploring the effect of surface morphology of dense phosphate calcimn (Ca-P) ceramics upon the formation of bone-like apatite in static or dynamic simulated body fluid (SBF). Dense and sandblasted calcium phosphate ceramics were immersed into dynamic SBF flowing at normal physiological speed of body fluid of skeletal muscle. The changes were characterized using SEM, XPS, IR and XRD. Changes can be observed after the sandblasted surface of dense calcium phosphate ceramics had been immersed in SBF for 14 days. XPS analysis results showed that the flake-like structure was composed of Ca, P, C, O; IR analysis result of surface structure of samples showed that there were specific peaks for CO3^2-; XRD results indicated the decrease in crystallinity and the increase in amorphous structure. The rough surface was advantageous for the formation of bone-like apatite. Increasing the Ca^2+, HPO4^2- concentration of SBF could also enhance the bonelike apatite formation. All the results demonstrated that local concentration is a key factor affecting nucleation.
基金This work was supported by the National Natural Science Foundation of China(No.81190131)the National Basic Research Program of China(‘973’Program No.2011CB606201).
文摘The discovery of osteoinductivity of calcium phosphate(Ca-P)ceramics has set an enduring paradigm of conferring biological regenerative activity to materials with carefully designed structural characteristics.The unique phase composition and porous structural features of osteoinductive Ca-P ceramics allow it to interact with signaling molecules and extracellular matrices in the host system,creating a local environment conducive to new bone formation.Mounting evidence now indicate that the osteoinductive activity of Ca-P ceramics is linked to their physicochemical and three-dimensional structural properties.Inspired by this conceptual breakthrough,many laboratories have shown that other materials can be also enticed to join the rank of tissue-inducing biomaterials,and besides the bones,other tissues such as cartilage,nerves and blood vessels were also regenerated with the assistance of biomaterials.Here,we give a brief historical recount about the discovery of the osteoinductivity of Ca-P ceramics,summarize the underlying material factors and biological characteristics,and discuss the mechanism of osteoinduction concerning protein adsorption,and the interaction with different types of cells,and the involvement of the vascular and immune systems.
基金supported by the National Natural Science Foundation of China(82025011 and 82100975)the China National Postdoctoral Program for Innovative Talents(BX2021227)+1 种基金the Young Elite Scientist Support Program by CSA(2020PYRC001)the Fundamental Research Funds for the Central Universities(2042021kf0181 and 2042020kf0204).
文摘Calcium phosphate(CaP)bioceramics are important for tissue regeneration and immune response,yet how CaP bioceramics influence these biological processes remains unclear.Recently,the role of immune cells in biomaterial-mediated regeneration,especially macrophages,has been well concerned.CD301b^(+)macrophages were a new subset of macrophages we have discovered,which were required for bioceramics-mediated bone regeneration.Nevertheless,the impact of CD301b^(+)macrophages on angiogenesis,which is a vital prerequisite to bone formation is yet indistinct.Herein,we found that CD301b^(+)macrophages were closely correlated to angiogenesis of CaP bioceramics.Additionally,depletion of CD301b^(+)macrophages led to the failure of angiogenesis.We showed that store-operated Ca^(2+)entry and calcineurin signals regulated the VEGF expression of CD301b^(+)macrophages via the NFATc1/VEGF axis.Inhibition of calcineurin effectively impaired angiogenesis via decreasing the infiltration of CD301b^(+)macrophages.These findings provided a potential immunomodulatory strategy to optimize the integration of angiogenesis and bone tissue engineering scaffold materials.
基金the National Key Research and Development Program of China(Grant No.2022YFC2401801)National Science Foundation of China(Grant No.52002256)+1 种基金Major Project of Sichuan Science and Technology Department(Grant Nos.2022ZDZX0029 and 2021YFS0032)Sichuan University“Zero to one”Innovation Research Project(Grant No.2022SCUH0044).
文摘How to endow bone grafts with long-term antibacterial activity and good bone regenerative ability to achieve the regenerative repair of infected bone defects has been the focus of the clinical treatment of osteomyelitis.The present study introduced a novel one-step route to realizing the co-doping of zinc oxide(ZnO)and zinc ion(Zn^(2+))in biphasic calcium phosphate(BCP)ceramics to utilize their synergistic antibacterial.Compared with the conventional BCP ceramics(BCP-Ca),the ZnO/Zn^(2+)co-doping ones(BCP-Zn)possessed strong antibacterial ability on E.coli and S.aureus as well as stimulated the osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)effectively.The synergistic antibacterial mechanism of ZnO and Zn^(2+)was also investigated.BCP-Zn showed excellent osteoinductivity and angiogenesis at three months postoperatively in the canine intramuscular implantation model.Moreover,BCP-Zn exhibited excellent anti-infective ability and bone regenerative repair compared to BCP-Ca and control groups in the infected bone defect model of rat femur.Collectively,these findings suggest that the simultaneous introduction of ZnO/Zn^(2+)could have immense potential to expand the application of osteoinductive BCP ceramics in the regenerative repair of infected bone defects.
基金supported by the National Basic Research Program of China under grant No. 1999064701the National Natural Science Foundation of China undergrant No. 50472041
文摘β-tricalcium phosphate (β-TCP) powder and Na20-CaO-MgO-P205 glass binder were synthesized and mixed, and then the biodegradable porous calcium phosphate ceramics were successfully prepared by foaming and sintering at 850℃. The as-prepared ceramics possess a high porosity with partial three-dimension interconnected macro- and micro-pores. As in vitro experiment testified, the calcium phosphate ceramics (CPCs) has good degradability.
基金sponsored by the National Natural Science Foundation of China(52002256)Sichuan Science and Technology Innovation Team of China(2019JDTD0008)+2 种基金China Postdoctoral Innovation Talent Support program(BX20180204)China Postdoctoral Science Foundation(2018M643483)Sichuan University Postdoctoral Interdisciplinary Innovation Fund(0900904153024).
文摘Osteoinductivity is a crucial factor to determine the success and efficiency of posterolateral spinal fusion(PLF)by employing calcium phosphate(Ca-P)bioceramics.In this study,three kinds of Ca-P ceramics with microscale to nanoscale gain size(BCP-control,BCP-micro and BCP-nano)were prepared and their physicochemical properties were characterized.BCP-nano had the spherical shape and nanoscale gain size,BCP-micro had the spherical shape and microscale gain size,and BCP-control(BAM®)had the irregular shape and microscale gain size.The obtained BCP-nano with specific nanotopography could well regulate in vitro protein adsorption and osteogenic differentiation of MC3T3 cells.In vivo rabbit PLF procedures further confirmed that nanotopography of BCP-nano might be responsible for the stronger bone regenerative ability comparing with BCP-micro and BCP-control.Collectedly,due to nanocrystal similarity with natural bone apatite,BCP-nano has excellent efficacy in guiding bone regeneration of PLF,and holds great potentials to become an alternative to standard bone grafts for future clinical applications.
基金This work was financially supported,in part,by the Sci-ence and Technology Research Program of Sichuan Province(No.2020YFS0036,Dr.Tu)the 1·3·5 project for disciplines of excel-lence,West China Hospital,Sichuan University(No.ZYJC18036,Dr.Tu).
文摘The custom-tailored medicine requires a developmental strategy that integrates excellent osteogene-sis with mechanical stability to enhance the reconstruction of the critical-size bone defect(CSBD)and the healing process in weight-bearing bone.We prepared three-dimensional(3D)printed biphasic cal-cium phosphate(BCP)scaffolds composited with nano-graphene oxide(GO).The biological effects of the GO/BCP composite scaffolds could induce the differentiation of rat bone marrow stem cells(BM-SCs)and the migration of human umbilical vein endothelial cells(HUVECs)for bone repair.The proper ratio of GO in the composite scaffold regulated the composites’surface roughness and hydrophilicity to a suitable range for the adhesion and proliferation of BMSCs and HUVECs.Besides,the GO/BCP composite scaffold increased osteogenesis and angiogenesis by activating BMP-2,RUNX-2,Smad1/4,and VEGF.The customized intramedullary nail combined with GO/BCP scaffold was applied to repair CSBD(2.0 cm in length)in a beagle femur model.This fixation strategy was confirmed by finite element analysis.In vivo,the results indicated that the custom-made internal fixation provided sufficient stability in the early stage,ensuring bone healing in a considerable mechanical environment.At 9 months postoperatively,longitudi-nal bony union and blood vessels in osteon were observed in the CSBD area with partial degradation in the 0.3%GO/BCP group.In the three-point bending test,the ultimate load of 0.3%GO/BCP group reached over 50%of the normal femur at 9 months after repair.These results showed a promising application of osteogenic GO/BCP scaffold and custom-made intramedullary nails in repairing CSBD of the beagle femur.This effective strategy could provide an option to treat the clinical CSBD in weight-bearing bones.
基金supported by the National Natural Science Foundation of China(No.81471803)Sichuan Province Youth Science and Technology Innovation Team(No.2014TD0001)
文摘Titanium and its alloys have been widely used as implant materials in bio-medicine.Additionally,surface modification has been utilized to improve the chemical and morphological properties of materials.More specifically,biocoating,especially the calcium-phosphate nano-coating,has been widely used in the research field.In this study,a novel calcium-phosphate nanoflower coating was performed on the titanium surface by a simple approach.This study indicated that the novel calcium-phosphate flower-like coating consisting of calcium-phosphate nanosheets had high surface area,low cytotoxicity as well as promising cell affinity.Hence it could be a potential alternative modification method for titanium.
文摘磷酸钙陶瓷植入体内后其表面类骨磷灰石层的形成是诱导成骨的先决条件.本实验在模拟体液(simulated body fluid, SBF)以人体骨骼肌组织内体液的正常生理流率(2mL/100mL.min)和偏离正常生理流率流动的动态条件下,研究在动态SBF中影响致密磷酸钙陶瓷表面类骨磷灰石层形成的因素.结果表明:在生理流率条件下,材料的粗糙表面有利于类骨磷灰石的形成,加大SBF中Ca2+、HPO2-4离子浓度,类骨磷灰石层的形成速度加快.比起通常使用的静态浸泡试验,SBF以生理流率流动的动态试验能够更好地模拟类骨磷灰石生长的体内环境.动态SBF对了解类骨磷灰石形成,进而了解磷酸钙陶瓷在体内诱导成骨机理是十分有用的.