Additive manufacturing(AM)has revolutionized the production of metal bone implants,enabling unprecedented levels of customization and functionality.Recent advancements in surface-modification technologies have been cr...Additive manufacturing(AM)has revolutionized the production of metal bone implants,enabling unprecedented levels of customization and functionality.Recent advancements in surface-modification technologies have been crucial in enhancing the performance and biocompatibility of implants.Through leveraging the versatility of AM techniques,particularly powder bed fusion,a range of metallic biomaterials,including stainless steel,titanium,and biodegradable alloys,can be utilized to fabricate implants tailored for craniofacial,trunk,and limb bone reconstructions.However,the potential of AM is contingent on addressing intrinsic defects that may hinder implant performance.Techniques such as sandblasting,chemical treatment,electropolishing,heat treatment,and laser technology effectively remove residual powder and improve the surface roughness of these implants.The development of functional coatings,applied via both dry and wet methods,represents a significant advancement in surface modification research.These coatings not only improve mechanical and biological interactions at the implant-bone interface but also facilitate controlled drug release and enhance antimicrobial properties.Addition-ally,micro-and nanoscale surface modifications using chemical and laser techniques can precisely sculpt implant surfaces to promote the desired cellular responses.This detailed exploration of surface engineering offers a wealth of opportunities for creating next-generation implants that are not only biocompatible but also bioactive,laying the foundation for more effective solutions in bone reconstruction.展开更多
Triply periodic minimal surface(TPMS)-based bone implants are an innovative approach in orthopedic implantology,offering customized solutions for bone defect repair and regeneration.This review comprehensively examine...Triply periodic minimal surface(TPMS)-based bone implants are an innovative approach in orthopedic implantology,offering customized solutions for bone defect repair and regeneration.This review comprehensively examines the current research landscape of TPMS-based bone implants,addressing key challenges and proposing future directions.It explores design strategies aimed at optimizing mechanical strength and enhancing biological integration,with a particular emphasis on TPMS structures.These design strategies include graded,hierarchical,and hybrid designs,each contributing to the overall functionality and performance of the implants.This review also highlights state-of-the-art fabrication technologies,particularly advancements in additive manufacturing(AM)techniques for creating metal-based,polymer-based,and ceramic-based bone implants.The ability to precisely control the architecture of TPMS structures using AM techniques is crucial for tailoring the mechanical and biological properties of such implants.Furthermore,this review critically evaluates the biological performance of TPMS implants,focusing on their potential to promote bone ingrowth and regeneration.Key factors,such as mechanical properties,permeability,and biocompatibility,are examined to determine the effectiveness of these implants in clinical applications.By synthesizing existing knowledge and proposing innovative research directions,this review underscores the transformative potential of TPMS-based bone implants in orthopedic surgery.The objective is to improve clinical outcomes and enhance patient care through advanced implant designs and manufacturing techniques.展开更多
In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessme...In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.展开更多
Porous silicon carbide(SiC)has a specific biomorphous microstructure similar to the trabecular microstructure of human bone.Compared with that of bioactive ceramics,such as calcium phosphate,SiC does not induce sponta...Porous silicon carbide(SiC)has a specific biomorphous microstructure similar to the trabecular microstructure of human bone.Compared with that of bioactive ceramics,such as calcium phosphate,SiC does not induce spontaneous interface bonding to living bone.In this study,bioactive tantalum(Ta)metal deposited on porous SiC scaffolds by chemical vapour deposition was investigated to accelerate osseointegration and improve the bonding to bones.Scanning electron microscopy indicated that the Ta coating evenly covered the entire scaffold structure.Energy-dispersive spectroscopy and X-ray diffraction analysis showed that the coating consisted of Ta phases.The bonding strength between the Ta coating and the SiC substrate is 88.4MPa.The yield strength of porous SiC with a Ta coating(pTa)was 45.862.9MPa,the compressive strength was 61.463.2MPa and the elasticmodulus was4.8GPa.When MG-63 human osteoblasts were co-cultured with pTa,osteoblasts showed good adhesion and spreading on the surface of the pTa and its porous structure,which showed that it has excellent bioactivity and cyto-compatibility.To further study the osseointegration properties of pTa.PTa and porous titanium(pTi)were implanted into the femoral neck of goats for 12weeks,respectively.The Van-Gieson staining of histological sections results that the pTa group had better osseointegration than the pTi group.These results indicate that coating bioactive Ta metal on porous SiC scaffolds could be a potential material for bone substitutes.展开更多
[Objectives] To explore the flexural strength of 3D printed titanium bone bionic dental implants and provide a scientific basis for the clinical application of 3D printed porous bionic bone dental implants. [Methods] ...[Objectives] To explore the flexural strength of 3D printed titanium bone bionic dental implants and provide a scientific basis for the clinical application of 3D printed porous bionic bone dental implants. [Methods] The cone-beam CT( CBCT) image information of 20 premolars extracted by orthodontic requirement was collected,and a new porous bone bionic dental implant was produced using modeling software and 3D printer. The premolars were divided into two groups( A and B). The universal testing machine was used to test the flexural strength of the two groups and the difference in flexural strength between the two groups was compared through statistics. [Results]Twenty 3D printed porous titanium bone bionic implants were accurately produced; the morphology of group A and group B were extremely similar to each other; the average flexural strength of group A was 2 767. 92 N,while the average flexural strength of group B was 778. 77 N,showing that the average flexural strength of group A was significantly higher than that of group B,and the difference was statistically significant( P < 0. 05).[Conclusions]The personalized porous structure root implants produced by 3D printing technology are very similar to the target tooth morphology,and show high accuracy and small error of production. Besides,the flexural strength of 3D printed personalized porous structure root implants can fully meet the requirements of the maximum occlusal force for dental implant restoration. It is expected to provide a scientific basis for clinical application of 3 D printed porous bionic bone tooth implants.展开更多
Screw metal implants (3S, Israel) with rough or smooth polished surface were introduced in a tibial proximal condyle of not purebred rabbits. The condition of surrounding tissues in 2 and 6 months after implantation w...Screw metal implants (3S, Israel) with rough or smooth polished surface were introduced in a tibial proximal condyle of not purebred rabbits. The condition of surrounding tissues in 2 and 6 months after implantation was compared by light microscopy and X-ray methods. Within 6 months after operation the considerable distinctions of radiological and morphological data were revealed not. 2 months later after introduction of implants with a rough surface the effort enclosed for its twisting is, much more, than for removal of the polished product. However, stability of fixing of implants was practically made even at 6 months. On remote rough implants there is a set of tissue scraps whereas on products with a smooth surface the tissue remains were much less. Surrounding tissues strongly join a rough surface, grow into cavities, and during removal of such products there is a considerable trauma of tissues round an implantation place. Smooth implants have the smaller area of contact with organism tissues, they are fixed due to bicortical implantation, during removal easily get out and don’t break off surrounding tissues. The signs of inflammation and formation of merged multinuclear macrophages were not found at all cases, which give evidence to the inertness of material of the mentioned articles for living organism. In some observations however and by implantation of the rough article and by introduction of polished implants, metal particles were found, but after use of the foreign body with grit-blasted treatment of surface metal was found more frequently, and its fragments had larger volume.展开更多
Porous Titanium scaffolds have attracted widespread attention as bone implants for avoiding the stress shielding effect and promoting bone-in-growth.In this study,multi-morphology graded scaffolds hy-bridized by Primi...Porous Titanium scaffolds have attracted widespread attention as bone implants for avoiding the stress shielding effect and promoting bone-in-growth.In this study,multi-morphology graded scaffolds hy-bridized by Primitive and Gyroid structures with porosity of 50,60,and 70%were designed(denoted as PG50,PG60,and PG70,respectively)and fabricated by selective laser melting.The simulation results showed that the maximum von-Mises stress of hybridized scaffolds increased from 504.22 to 884.24 MPa with porosity.The permeability and average pore size of multi-morphology PG50,PG60,and PG70 were in the range of 3.58×10^(-9)-5.50×10^(-9) m^(2) and 568.1-758.4μm,respectively.The microstructure of multi-morphology graded scaffolds consisted of a fully martensiticα′phase.Tested permeabilities of PG50 and PG60 were 3.27×10^(-9) and 4.35×10^(-9) m^(2),respectively,which were within the range of human bone(0.01-12.1×10^(-9) m^(2)).Elastic modulus and compressive yield strength of PG50 and PG60 ranged within 5.93^(-9).86 and 180.06-257.08 MPa,respectively.Therein,the PG50 not only exhibited a similar elastic modulus compared to human cortical bone(10.1 GPa)but also had higher strength(257.08 vs 131 MPa).The results of in vitro biocompatibility assay showed that PG50 and PG60 have better cyto-compatibility than mono-morphology scaffolds with the same porosity.Taken together,PG50 is promising to be used for the restoration of bone defects due to its excellent mechanical properties,appropriate per-meability,and good cytocompatibility.展开更多
As two promising biomaterials for bone implants,biomedical metals have favorable mechanical properties and good machinability but lack of bioactivity;while bioceramics are known for good biocompatibility or even bioac...As two promising biomaterials for bone implants,biomedical metals have favorable mechanical properties and good machinability but lack of bioactivity;while bioceramics are known for good biocompatibility or even bioactivity but limited by their high brittleness.Biocermets,a kind of composites composing of bioceramics and biomedical metals,have been developed as an effective solution by combining their complementary advantages.This paper focused on the recently studied biocermets for bone implant applications.Concretely,biocermets were divided into ceramic-based biocermets and metal-based biocermets according to the phase percentages.Their characteristics were systematically summarized,and the fabrication methods for biocermets were reviewed and compared.Emphases were put on the interactions between bioceramics and biomedical metals,as well as the performance improvement mechanisms.More importantly,the main methods for the interfacial reinforcing were summarized,and the corresponding interfacial reinforcing mechanisms were discussed.In addition,the in vitro and in vivo biological performances of biocermets were also reviewed.Finally,future research directions were proposed on the advancement in component design,interfacial reinforcing and forming mechanisms for the fabrication of high-performance biocermets.展开更多
The major drawback associated with PEEK implants is their biologically inert surface,which caused unsatisfactory cellular response and poor adhesion between the implants and surrounding soft tissues against proper bon...The major drawback associated with PEEK implants is their biologically inert surface,which caused unsatisfactory cellular response and poor adhesion between the implants and surrounding soft tissues against proper bone growth.In this study,polyetheretherketone(PEEK)was incorporated with calcium hydroxyapatite(cHAp)to fabricate a PEEK-cHAp biocomposite,using the fused deposition modeling(FDM)method and a surface treatment strategy to create microporous architectures onto the filaments of PEEK lattice scaffold.Also,nanostructure and morphological tests of the PEEK-cHAp biocomposite were modeled and analyzed on the FDM-printed PEEK-cHAp biocomposite sample to evaluate its mechanical and thermal strengths as well as in vitro cytotoxicity via a scanning electron microscope(SEM).A technique was used innovatively to create and investigate the porous nanostructure of the PEEK with controlled pore size and distribution to promote cell penetration and biological integration of the PEEK-cHAp into the tissue.In vivo tests demonstrated that the surface-treated micropores facilitated the adhesion of newly regenerated soft tissues to form tight implant-tissue interfacial bonding between the cHAp and PEEK.The results of the cell culture depicted that PEEK-cHAp exhibited better cell proliferation attachment spreading and higher alkaline phosphatase activity than PEEK alone.Apatite islands formed on the PEEK-cHAp composite after immersion in simulated body fluid of Dulbecco’s modified Eagle medium(DMEM)for 14 days and grew continuously with more or extended periods.The microstructure treatment of the crystallinity of PEEK was comparatively and significantly different from the PEEK-cHAp sample,indicating a better treatment of PEEK-cHAp.The in vitro results obtained from the PEEK-cHAp biocomposite material showed its biodegradability and performance suitability for bone implants.This study has potential applications in the field of biomedical engineering to strengthen the conceptual knowledge of FDM and medical implants fabricated from PEEK-cHAp biocomposite materials.展开更多
TiO2 nanotubes(NT)has been demonstrated its potential in orthopaedic applications due to its enhanced surface wettability and bio-osteointegration.However,the fretting biocorrosion is the main concern that limited its...TiO2 nanotubes(NT)has been demonstrated its potential in orthopaedic applications due to its enhanced surface wettability and bio-osteointegration.However,the fretting biocorrosion is the main concern that limited its successfully application in orthopaedic application.In this study,a structure optimised thin TiO2 nanotube(SONT)layer was successfully created on Ti6Al4V bone screw,and its fretting corrosion performance was investigated and compared to the pristine Ti6Al4V bone screws and NT decorated screw in a bone-screw fretting simulation rig.The results have shown that the debonding TiO2 nanotube from the bone screw reduced significantly,as a result of structure optimisation.The SONT layer also exhibited enhanced bio-corrosion resistance compared pristine bone screw and conventionally NT modified bone screw.It is postulated that interfacial layer between TiO2 nanotube and Ti6Al4V substrate,generated during structure optimisation process,enhanced bonding of TiO2 nanotube layer to the Ti6Al4V bone screws that leading to the improvement in fretting corrosion resistance.The results highlighted the potential SONT in orthopaedic application as bone fracture fixation devices.展开更多
BACKGROUND Bone cement implantation syndrome(BCIS)is characterized by hypotension,arrhythmia,diffuse pulmonary microvascular embolism,shock,cardiac arrest,any combination of these factors,or even death following bone ...BACKGROUND Bone cement implantation syndrome(BCIS)is characterized by hypotension,arrhythmia,diffuse pulmonary microvascular embolism,shock,cardiac arrest,any combination of these factors,or even death following bone cement implantation.CASE SUMMARY An 80-year-old patient with pemphigus and Parkinson’s disease underwent total hip replacement under spinal subarachnoid block and developed acute pulmonary embolism after bone cement implantation.The patient received mask mechanical ventilation with a continuous intravenous infusion of adrenaline(2μg/mL)at a rate of 30 mL/h.Subsequently,the symptoms of BCIS were markedly alleviated,and the infusion rate of adrenaline was gradually reduced until the infusion was completely stopped 45 min later.The patient was then transferred to the Department of Orthopedics,and anticoagulation therapy began at 12 h postoperatively.No other complications were observed.CONCLUSION This is a rare case of BCIS in a high-risk patient with pemphigus and Parkinson’s disease.展开更多
The feasibility of anterior lumbar intervertebral fusion with artificial bone in place of autogenous bone was investigated Porous hydroxyapatite(HA)/ZrO 2 ceramics loading bone morphogenetic protein (BMP) were impl...The feasibility of anterior lumbar intervertebral fusion with artificial bone in place of autogenous bone was investigated Porous hydroxyapatite(HA)/ZrO 2 ceramics loading bone morphogenetic protein (BMP) were implanted after removal of lumbar vertebral disc in rabbits The adjacent intervertebral discs were also removed by the same way and autogenous illic bone was implanted SEM observation and biomechanical test were carried out Compound bone had a bit lower osteoinductive activity than autogenous bone by SEM(Osteoindutive activity of artificial bone in 12 weeks was the same as that of autogenous bone in 9 weeks) Biomechanical test revealed that compound bone had lower anti-pull strength than autogenous bone ( P< 0 001), but there was no significant difference in anti-pull strength between compound bone at 12th week and autogenous bone at 9th week (P>0 05) It was concluded that compound bone could be applied for anterior spinal fusion, especially for those patients who can't use autogenous bone展开更多
The purpose of this study was to find a kind of new artificial bone for anterior spinal fusion.ZrO 2 stabilized by Y 2O 3(Y-PSZ),porous hydroxyapatite(HA) and bone morphogenetic protein (BMP) were used to make arti...The purpose of this study was to find a kind of new artificial bone for anterior spinal fusion.ZrO 2 stabilized by Y 2O 3(Y-PSZ),porous hydroxyapatite(HA) and bone morphogenetic protein (BMP) were used to make artificial compound bone (Y 2O 3) ZrO 2-HA/BMP(Z-H/BMP),whose function was tested,microstructure and mineralogic composition constitution were analysised by SEM and XRD,and the corresponding animal tests were porformed.Osteogenesis of the material was observed by eyes,histology and SEM.Experimental results show that the component and ossific activity of Z-H/BMP were satisfactory.展开更多
Magnesium(Mg)alloys are widely used for temporary bone implants due to their favorable biodegradability,cytocompatibility,hemocompatibility,and close mechanical properties to bone.However,rapid degradation and inadequ...Magnesium(Mg)alloys are widely used for temporary bone implants due to their favorable biodegradability,cytocompatibility,hemocompatibility,and close mechanical properties to bone.However,rapid degradation and inadequate strength limit their applicability.To overcome this,the direct current magnetron sputtering technique is employed for surface coating in Mg-based alloys using various zirconium(Zr)content.This approach presents a promising strategy for simultaneously improving corrosion resistance,maintaining biocompatibility,and enhancing strength without compromising osseointegration.By leveraging Mg’s inherent biodegradability,it has the potential to minimize the need for secondary surgeries,thereby reducing costs and resources.This paper is a systematic study aimed at understanding the corrosion mechanisms of Mg–Zr coatings,denoted Mg-xZr(x=0–5 at.%).Zr-doped coatings exhibited columnar growth leading to denser and refined structures with increasing Zr content.XRD analysis confirmed the presence of the Mg(00.2)basal plane,shifting towards higher angles(1.15°)with 5 at.%Zr doping due to lattice parameter changes(i.e.,decrease and increase of“c”and“a”lattice parameters,respectively).Mg–Zr coatings exhibited“liquidphilic”behavior,while Young’s modulus retained a steady value around 80 GPa across all samples.However,the hardness has significantly improved across all samples’coating,reaching the highest value of(2.2±0.3)GPa for 5 at.%Zr.Electrochemical testing in simulated body fluid(SBF)at 37℃ revealed a significant enhancement in corrosion resistance for Mg–Zr coatings containing 1.0–3.4 at.%Zr.Compared with the 5 at.%Zr coating which exhibited a corrosion rate of 32 mm/year,these coatings displayed lower corrosion rates,ranging from 1 to 12 mm/year.This synergistic enhancement in mechanical properties and corrosion resistance,achieved with 2.0–3.4 at.%Zr,suggests potential ability for reducing stress shielding and controlled degradation performance,and consequently,promising functional biodegradable materials for temporary bone implants.展开更多
<b><span>Background: </span></b><span>In patients with pre-existing pulmonary hypertension undergoing surgery, there is an inherent risk of decompensation and right ventricular failure. C...<b><span>Background: </span></b><span>In patients with pre-existing pulmonary hypertension undergoing surgery, there is an inherent risk of decompensation and right ventricular failure. Cemented hemi-arthroplasty in patients with pre-existing pulmonary hypertension predisposes them even more to morbidity and mortality from bone cement implantation syndrome (BCIS) with worsening of pulmonary hypertension. This risk should be recognized and steps taken for in</span><span>creased awareness, risk counselling and minimization of adverse effects.</span><span> </span><b><span>Case: </span></b><span>We report a case of successful resuscitation of a patient with pre-existing</span><span> pulmonary hypertension who developed 2 episodes of cardiac arrests—Grade 3 BCIS, shortly after cement implantation.</span><span> </span><b><span>Learning Points: </span></b><span>Patients with pre-existing pulmonary hypertension for cemented hemi-arthroplasty are at additional risks and should be identified.</span><span> </span><span>Adequate risk counselling needs to be undertaken prior to surgery.</span><span> </span><span>A multi-disciplinary team effort is required. Discussion should be undertaken with the orthopaedic surgeon about the risks and benefits of using cemented implants.</span><span> </span><span>The anaesthetist needs to be vigilant for signs of BCIS, especially at the time of cement implantation and </span><span>institute immediate resuscitation.</span><span> </span><span>Supportive treatment is the mainstay of </span><span>management.展开更多
Objective To investigate the effect of the implant composite of poly lactide-co-glycolide(PLGA)and bone mesenchymal stem cells (BMSCs) modified by basic fibroblast growth factor (bFGF) on injured spinal cord in rats.M...Objective To investigate the effect of the implant composite of poly lactide-co-glycolide(PLGA)and bone mesenchymal stem cells (BMSCs) modified by basic fibroblast growth factor (bFGF) on injured spinal cord in rats.Methods Two hundred and展开更多
Addressing irregular bone defects is a formidable clinical challenge,as traditional scaffolds frequently fail to meet the complex requirements of bone regeneration,resulting in suboptimal healing.This study introduces...Addressing irregular bone defects is a formidable clinical challenge,as traditional scaffolds frequently fail to meet the complex requirements of bone regeneration,resulting in suboptimal healing.This study introduces a novel 3D-printed magnesium scaffold with hierarchical structure(macro-,meso-,and nano-scales)and tempered degradation(microscale),intricately customized at multiple scales to bolster bone regeneration according to patient-specific needs.For the hierarchical structure,at the macroscale,it can feature anatomic geometries for seamless integration with the bone defect;The mesoscale pores are devised with optimized curvature and size,providing an adequate mechanical response as well as promoting cellular proliferation and vascularization,essential for natural bone mimicry;The nanoscale textured surface is enriched with a layered double hydroxide membrane,augmenting bioactivity and osteointegration.Moreover,microscale enhancements involve a duallayer coating of high-temperature oxidized film and hydrotalcite,offering a robust shield against fast degradation.Eventually,this scaffold demonstrates superior geometrical characteristics,load-bearing capacity,and degradation performance,significantly outperforming traditional scaffolds based on in vitro and in vivo assessments,marking a breakthrough in repairing customized bone defects.展开更多
High-porosity,open-cell AZ91 magnesium alloy foams of two pore sizes were fabricated by means of investment casting technology,using PUR foam patterns.Foam casting variables such as pressure,mould temperature and meta...High-porosity,open-cell AZ91 magnesium alloy foams of two pore sizes were fabricated by means of investment casting technology,using PUR foam patterns.Foam casting variables such as pressure,mould temperature and metal pouring temperature were thoroughly investigated to define the most optimal casting conditions.The mechanical properties of the fabricated foams were measured in compression tests.A potential application for the foams considered is temporary bioresorbable bone implants,therefore the mechanical properties of the foams were compared with those of cancellous bone tissue.Foams with smaller pore size and lower porosity(20 PPI and 80%±87%)exhibited mechanical properties in the lower regions of the cancellous bone property range(Young’s modulus 36.5±77.5 MPa),while foams with higher pore size and porosity(10 PPI and~90%)were found to have insufficient compression strength(Young’s modulus 11.65±23.8),but thickening their walls and lowering their porosity below 90%yielded foams with Young’s modulus between 36.5 and 77.5 MPa.Foam fractures were also investigated to determine their collapse mechanism.A series of corrosion tests in stimulated body fluid was carried out to determine their applicability as a biomaterial.The Plasma Electrolytic Oxidation(PEO)process was used in a feasibility study to examine the microstructure and chemical composition of foams with protective coating.展开更多
Regenerative bone implants promote new bone formation and ideally degrade simultaneously to osteogenesis.Although clinically established calcium phosphate bone grafts provide excellent osseointegration and osteoconduc...Regenerative bone implants promote new bone formation and ideally degrade simultaneously to osteogenesis.Although clinically established calcium phosphate bone grafts provide excellent osseointegration and osteoconductive efficacy,they are limited in terms of bioresorption.Magnesium phosphate(MP)based ceramics are a promising alternative,because they are biocompatible,mechanically extremely stable,and degrade much faster than calcium phosphates under physiological conditions.Bioresorption of an implant material can include both chemical dissolution as well as cellular resorption.We investigated the bioresorption of 3D powder printed struvite and newberyite based MP ceramics in vitro by a direct human osteoclast culture approach.The osteoclast response and cellular resorption was evaluated by means of fluorescence and TRAP staining,determination of osteoclast activities(CA II and TRAP),SEM imaging as well as by quantification of the ion release during cell culture.Furthermore,the bioactivity of the materials was investigated via SBF immersion,whereas hydroxyapatite precipitates were analyzed by SEM and EDX measurements.This bioactive coating was resorbed by osteoclasts.In contrast,only chemical dissolution contributed to bioresorption of MP,while no cellular resorption of the materials was observed.Based on our results,we expect an increased bone regeneration effect of MP compared to calcium phosphate based bone grafts and complete chemical degradation within a maximum of 1.5-3.1 years.展开更多
Magnesium(Mg)or its alloys are widely tested as potential orthopedic implants,particularly as biodegradable alloys for fracture fixation due to their mechanical properties are close to those of bone.Currently,availabl...Magnesium(Mg)or its alloys are widely tested as potential orthopedic implants,particularly as biodegradable alloys for fracture fixation due to their mechanical properties are close to those of bone.Currently,available Mg or its alloys are confronted with challenges in passing regulatory biosafety tests prior to clinical trials due to its fast degradation and associated degradation products.The degradation of Mg is accompanied by the release of Mg ions,the rise of pH and osmolality in surrounding environments.According to the standard of ISO 10993 Part 13,the pH value shall be appropriate to the site of intended use maintaining in an appropriate range.Approaches to overcome these challenges include the selection of adequate alloying elements,proper surface treatment techniques and control of the degradation rate of Mg or its alloys developed as orthopedic implants.To date,Mg or its alloy-based bone implants have not yet been widely used in clinical applications as medical implants.This review critically summarized published methods to improve the corrosion resistance of Mg and its alloys.The current progress on in vitro cytotoxicity and in vivo biocompatibility properties of these metals was also reviewed.This review aimed to provide a reference for further research and development(R&D)of biodegradable Mg and its alloys with regard to the evaluation of their corrosion process and biocompatibility and facilitation of their translation to clinical applications.展开更多
基金supported by National Natural Science Foundation of China(Grant No.52275343)Natural Science Foundation of Zhejiang Province(Grant No.LY23E050003)Ningbo Youth Science and Technology Innovation Leading Talent Project(Grant No.2023QL021).
文摘Additive manufacturing(AM)has revolutionized the production of metal bone implants,enabling unprecedented levels of customization and functionality.Recent advancements in surface-modification technologies have been crucial in enhancing the performance and biocompatibility of implants.Through leveraging the versatility of AM techniques,particularly powder bed fusion,a range of metallic biomaterials,including stainless steel,titanium,and biodegradable alloys,can be utilized to fabricate implants tailored for craniofacial,trunk,and limb bone reconstructions.However,the potential of AM is contingent on addressing intrinsic defects that may hinder implant performance.Techniques such as sandblasting,chemical treatment,electropolishing,heat treatment,and laser technology effectively remove residual powder and improve the surface roughness of these implants.The development of functional coatings,applied via both dry and wet methods,represents a significant advancement in surface modification research.These coatings not only improve mechanical and biological interactions at the implant-bone interface but also facilitate controlled drug release and enhance antimicrobial properties.Addition-ally,micro-and nanoscale surface modifications using chemical and laser techniques can precisely sculpt implant surfaces to promote the desired cellular responses.This detailed exploration of surface engineering offers a wealth of opportunities for creating next-generation implants that are not only biocompatible but also bioactive,laying the foundation for more effective solutions in bone reconstruction.
基金funded by the National Natural Science Foundation of China(No.52275343)the Natural Science Foundation of Zhejiang Province(No.LY23E050003)+1 种基金Ningbo Youth Science and Technology Innovation Leading Talent Project(No.2023QL021)Smart Medicine and Engineering Interdisciplinary Innovation Project of Ningbo University(No.ZHYG001).
文摘Triply periodic minimal surface(TPMS)-based bone implants are an innovative approach in orthopedic implantology,offering customized solutions for bone defect repair and regeneration.This review comprehensively examines the current research landscape of TPMS-based bone implants,addressing key challenges and proposing future directions.It explores design strategies aimed at optimizing mechanical strength and enhancing biological integration,with a particular emphasis on TPMS structures.These design strategies include graded,hierarchical,and hybrid designs,each contributing to the overall functionality and performance of the implants.This review also highlights state-of-the-art fabrication technologies,particularly advancements in additive manufacturing(AM)techniques for creating metal-based,polymer-based,and ceramic-based bone implants.The ability to precisely control the architecture of TPMS structures using AM techniques is crucial for tailoring the mechanical and biological properties of such implants.Furthermore,this review critically evaluates the biological performance of TPMS implants,focusing on their potential to promote bone ingrowth and regeneration.Key factors,such as mechanical properties,permeability,and biocompatibility,are examined to determine the effectiveness of these implants in clinical applications.By synthesizing existing knowledge and proposing innovative research directions,this review underscores the transformative potential of TPMS-based bone implants in orthopedic surgery.The objective is to improve clinical outcomes and enhance patient care through advanced implant designs and manufacturing techniques.
文摘In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.
基金supported by the National major research and invention programme of the thirteenth of China(no.2016YFC1102000)the Dalian Science and Technology Innovation Fund Project(no.2018J11CY030).
文摘Porous silicon carbide(SiC)has a specific biomorphous microstructure similar to the trabecular microstructure of human bone.Compared with that of bioactive ceramics,such as calcium phosphate,SiC does not induce spontaneous interface bonding to living bone.In this study,bioactive tantalum(Ta)metal deposited on porous SiC scaffolds by chemical vapour deposition was investigated to accelerate osseointegration and improve the bonding to bones.Scanning electron microscopy indicated that the Ta coating evenly covered the entire scaffold structure.Energy-dispersive spectroscopy and X-ray diffraction analysis showed that the coating consisted of Ta phases.The bonding strength between the Ta coating and the SiC substrate is 88.4MPa.The yield strength of porous SiC with a Ta coating(pTa)was 45.862.9MPa,the compressive strength was 61.463.2MPa and the elasticmodulus was4.8GPa.When MG-63 human osteoblasts were co-cultured with pTa,osteoblasts showed good adhesion and spreading on the surface of the pTa and its porous structure,which showed that it has excellent bioactivity and cyto-compatibility.To further study the osseointegration properties of pTa.PTa and porous titanium(pTi)were implanted into the femoral neck of goats for 12weeks,respectively.The Van-Gieson staining of histological sections results that the pTa group had better osseointegration than the pTi group.These results indicate that coating bioactive Ta metal on porous SiC scaffolds could be a potential material for bone substitutes.
文摘[Objectives] To explore the flexural strength of 3D printed titanium bone bionic dental implants and provide a scientific basis for the clinical application of 3D printed porous bionic bone dental implants. [Methods] The cone-beam CT( CBCT) image information of 20 premolars extracted by orthodontic requirement was collected,and a new porous bone bionic dental implant was produced using modeling software and 3D printer. The premolars were divided into two groups( A and B). The universal testing machine was used to test the flexural strength of the two groups and the difference in flexural strength between the two groups was compared through statistics. [Results]Twenty 3D printed porous titanium bone bionic implants were accurately produced; the morphology of group A and group B were extremely similar to each other; the average flexural strength of group A was 2 767. 92 N,while the average flexural strength of group B was 778. 77 N,showing that the average flexural strength of group A was significantly higher than that of group B,and the difference was statistically significant( P < 0. 05).[Conclusions]The personalized porous structure root implants produced by 3D printing technology are very similar to the target tooth morphology,and show high accuracy and small error of production. Besides,the flexural strength of 3D printed personalized porous structure root implants can fully meet the requirements of the maximum occlusal force for dental implant restoration. It is expected to provide a scientific basis for clinical application of 3 D printed porous bionic bone tooth implants.
文摘Screw metal implants (3S, Israel) with rough or smooth polished surface were introduced in a tibial proximal condyle of not purebred rabbits. The condition of surrounding tissues in 2 and 6 months after implantation was compared by light microscopy and X-ray methods. Within 6 months after operation the considerable distinctions of radiological and morphological data were revealed not. 2 months later after introduction of implants with a rough surface the effort enclosed for its twisting is, much more, than for removal of the polished product. However, stability of fixing of implants was practically made even at 6 months. On remote rough implants there is a set of tissue scraps whereas on products with a smooth surface the tissue remains were much less. Surrounding tissues strongly join a rough surface, grow into cavities, and during removal of such products there is a considerable trauma of tissues round an implantation place. Smooth implants have the smaller area of contact with organism tissues, they are fixed due to bicortical implantation, during removal easily get out and don’t break off surrounding tissues. The signs of inflammation and formation of merged multinuclear macrophages were not found at all cases, which give evidence to the inertness of material of the mentioned articles for living organism. In some observations however and by implantation of the rough article and by introduction of polished implants, metal particles were found, but after use of the foreign body with grit-blasted treatment of surface metal was found more frequently, and its fragments had larger volume.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51922004 and 51874037)the State Key Lab of Advanced Metals and Materials,University of Sci-ence and Technology Beijing(Nos.2020Z-04,2021Z-03,and 2022Z-12)+5 种基金the Fundamental Research Funds for the Central Universi-ties(Nos.FRF-TP-19005C1Z and 06500236)the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Re-search Funds for the Central Universities,No.FRF-IDRY-20-023)the Postdoctor Research Foundation of Shunde Graduate School of University of Science and Technology Beijing(No.2022BH001)the China Postdoctoral Science Foundation(No.2021M700377)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110548)the State Key Laboratory of Powder Metallurgy,Central South University and the Beijing Natural Science Founda-tion(No.2212035)。
文摘Porous Titanium scaffolds have attracted widespread attention as bone implants for avoiding the stress shielding effect and promoting bone-in-growth.In this study,multi-morphology graded scaffolds hy-bridized by Primitive and Gyroid structures with porosity of 50,60,and 70%were designed(denoted as PG50,PG60,and PG70,respectively)and fabricated by selective laser melting.The simulation results showed that the maximum von-Mises stress of hybridized scaffolds increased from 504.22 to 884.24 MPa with porosity.The permeability and average pore size of multi-morphology PG50,PG60,and PG70 were in the range of 3.58×10^(-9)-5.50×10^(-9) m^(2) and 568.1-758.4μm,respectively.The microstructure of multi-morphology graded scaffolds consisted of a fully martensiticα′phase.Tested permeabilities of PG50 and PG60 were 3.27×10^(-9) and 4.35×10^(-9) m^(2),respectively,which were within the range of human bone(0.01-12.1×10^(-9) m^(2)).Elastic modulus and compressive yield strength of PG50 and PG60 ranged within 5.93^(-9).86 and 180.06-257.08 MPa,respectively.Therein,the PG50 not only exhibited a similar elastic modulus compared to human cortical bone(10.1 GPa)but also had higher strength(257.08 vs 131 MPa).The results of in vitro biocompatibility assay showed that PG50 and PG60 have better cyto-compatibility than mono-morphology scaffolds with the same porosity.Taken together,PG50 is promising to be used for the restoration of bone defects due to its excellent mechanical properties,appropriate per-meability,and good cytocompatibility.
基金This study was supported by the following funds:The Natural Science Foundation of China(51705540,51935014,51905553,81871494,81871498)Hunan Provincial Natural Science Foundation of China(2020JJ3047,2018JJ3671,2019JJ50774,2019JJ50588)+6 种基金The Provincial Key R&D Projects of Jiangxi(20201BBE51012)JiangXi Provincial Natural Science Foundation of China(20192ACB20005)Guangdong Province Higher Vocational Colleges&Schools Pearl River Scholar Funded Scheme(2018)The Project of Hunan Provincial Science and Technology Plan(2017RS3008)Shenzhen Science and Technology Plan Project(JCYJ20170817112445033)Innovation Team Project on University of Guangdong Province(2018GKCXTD001)Technology Innovation Platform Project of Shenzhen Institute of Information Technology 2020(PT2020E002).
文摘As two promising biomaterials for bone implants,biomedical metals have favorable mechanical properties and good machinability but lack of bioactivity;while bioceramics are known for good biocompatibility or even bioactivity but limited by their high brittleness.Biocermets,a kind of composites composing of bioceramics and biomedical metals,have been developed as an effective solution by combining their complementary advantages.This paper focused on the recently studied biocermets for bone implant applications.Concretely,biocermets were divided into ceramic-based biocermets and metal-based biocermets according to the phase percentages.Their characteristics were systematically summarized,and the fabrication methods for biocermets were reviewed and compared.Emphases were put on the interactions between bioceramics and biomedical metals,as well as the performance improvement mechanisms.More importantly,the main methods for the interfacial reinforcing were summarized,and the corresponding interfacial reinforcing mechanisms were discussed.In addition,the in vitro and in vivo biological performances of biocermets were also reviewed.Finally,future research directions were proposed on the advancement in component design,interfacial reinforcing and forming mechanisms for the fabrication of high-performance biocermets.
基金We appreciate the funding/financial support received from the Higher Education Innovation Fund(HEIF)of De Montfort University,Leicester,UK,under Research Project No.0043.06.
文摘The major drawback associated with PEEK implants is their biologically inert surface,which caused unsatisfactory cellular response and poor adhesion between the implants and surrounding soft tissues against proper bone growth.In this study,polyetheretherketone(PEEK)was incorporated with calcium hydroxyapatite(cHAp)to fabricate a PEEK-cHAp biocomposite,using the fused deposition modeling(FDM)method and a surface treatment strategy to create microporous architectures onto the filaments of PEEK lattice scaffold.Also,nanostructure and morphological tests of the PEEK-cHAp biocomposite were modeled and analyzed on the FDM-printed PEEK-cHAp biocomposite sample to evaluate its mechanical and thermal strengths as well as in vitro cytotoxicity via a scanning electron microscope(SEM).A technique was used innovatively to create and investigate the porous nanostructure of the PEEK with controlled pore size and distribution to promote cell penetration and biological integration of the PEEK-cHAp into the tissue.In vivo tests demonstrated that the surface-treated micropores facilitated the adhesion of newly regenerated soft tissues to form tight implant-tissue interfacial bonding between the cHAp and PEEK.The results of the cell culture depicted that PEEK-cHAp exhibited better cell proliferation attachment spreading and higher alkaline phosphatase activity than PEEK alone.Apatite islands formed on the PEEK-cHAp composite after immersion in simulated body fluid of Dulbecco’s modified Eagle medium(DMEM)for 14 days and grew continuously with more or extended periods.The microstructure treatment of the crystallinity of PEEK was comparatively and significantly different from the PEEK-cHAp sample,indicating a better treatment of PEEK-cHAp.The in vitro results obtained from the PEEK-cHAp biocomposite material showed its biodegradability and performance suitability for bone implants.This study has potential applications in the field of biomedical engineering to strengthen the conceptual knowledge of FDM and medical implants fabricated from PEEK-cHAp biocomposite materials.
基金financially supported by the European Union via the H2020-MSCA-RISE-2016 program(BAMOS Project,734156)Royal Society via the International Exchange Program(IE161349)+2 种基金Key Research Project from the National Key Research and Development Program of China(2016YFC1100401)National Natural Science Foundation of China(51705507)Young Elite Scientists Sponsorship Program by CAST(2017QNRC0181)。
文摘TiO2 nanotubes(NT)has been demonstrated its potential in orthopaedic applications due to its enhanced surface wettability and bio-osteointegration.However,the fretting biocorrosion is the main concern that limited its successfully application in orthopaedic application.In this study,a structure optimised thin TiO2 nanotube(SONT)layer was successfully created on Ti6Al4V bone screw,and its fretting corrosion performance was investigated and compared to the pristine Ti6Al4V bone screws and NT decorated screw in a bone-screw fretting simulation rig.The results have shown that the debonding TiO2 nanotube from the bone screw reduced significantly,as a result of structure optimisation.The SONT layer also exhibited enhanced bio-corrosion resistance compared pristine bone screw and conventionally NT modified bone screw.It is postulated that interfacial layer between TiO2 nanotube and Ti6Al4V substrate,generated during structure optimisation process,enhanced bonding of TiO2 nanotube layer to the Ti6Al4V bone screws that leading to the improvement in fretting corrosion resistance.The results highlighted the potential SONT in orthopaedic application as bone fracture fixation devices.
文摘BACKGROUND Bone cement implantation syndrome(BCIS)is characterized by hypotension,arrhythmia,diffuse pulmonary microvascular embolism,shock,cardiac arrest,any combination of these factors,or even death following bone cement implantation.CASE SUMMARY An 80-year-old patient with pemphigus and Parkinson’s disease underwent total hip replacement under spinal subarachnoid block and developed acute pulmonary embolism after bone cement implantation.The patient received mask mechanical ventilation with a continuous intravenous infusion of adrenaline(2μg/mL)at a rate of 30 mL/h.Subsequently,the symptoms of BCIS were markedly alleviated,and the infusion rate of adrenaline was gradually reduced until the infusion was completely stopped 45 min later.The patient was then transferred to the Department of Orthopedics,and anticoagulation therapy began at 12 h postoperatively.No other complications were observed.CONCLUSION This is a rare case of BCIS in a high-risk patient with pemphigus and Parkinson’s disease.
文摘The feasibility of anterior lumbar intervertebral fusion with artificial bone in place of autogenous bone was investigated Porous hydroxyapatite(HA)/ZrO 2 ceramics loading bone morphogenetic protein (BMP) were implanted after removal of lumbar vertebral disc in rabbits The adjacent intervertebral discs were also removed by the same way and autogenous illic bone was implanted SEM observation and biomechanical test were carried out Compound bone had a bit lower osteoinductive activity than autogenous bone by SEM(Osteoindutive activity of artificial bone in 12 weeks was the same as that of autogenous bone in 9 weeks) Biomechanical test revealed that compound bone had lower anti-pull strength than autogenous bone ( P< 0 001), but there was no significant difference in anti-pull strength between compound bone at 12th week and autogenous bone at 9th week (P>0 05) It was concluded that compound bone could be applied for anterior spinal fusion, especially for those patients who can't use autogenous bone
文摘The purpose of this study was to find a kind of new artificial bone for anterior spinal fusion.ZrO 2 stabilized by Y 2O 3(Y-PSZ),porous hydroxyapatite(HA) and bone morphogenetic protein (BMP) were used to make artificial compound bone (Y 2O 3) ZrO 2-HA/BMP(Z-H/BMP),whose function was tested,microstructure and mineralogic composition constitution were analysised by SEM and XRD,and the corresponding animal tests were porformed.Osteogenesis of the material was observed by eyes,histology and SEM.Experimental results show that the component and ossific activity of Z-H/BMP were satisfactory.
基金support by the project n°7225-ILLIANCE High Performing EnergyPro-jeto apoiado pelo PRR-Plano de Recuperação e Resiliência e pelos Fundos Europeus Next Generation EU,no sequência do AVISO N.°02/C05-i01/2022,Componente 5-Capital-ização e Inovação Empresarial-Agendas Mobilizadores para a Inovação Empresarialsupport by national funds through FCT-Fundação para a Ciência e a Tecnologia,under the project UID/EMS/00285/2020,ARISE-LA/P/0112/2020.
文摘Magnesium(Mg)alloys are widely used for temporary bone implants due to their favorable biodegradability,cytocompatibility,hemocompatibility,and close mechanical properties to bone.However,rapid degradation and inadequate strength limit their applicability.To overcome this,the direct current magnetron sputtering technique is employed for surface coating in Mg-based alloys using various zirconium(Zr)content.This approach presents a promising strategy for simultaneously improving corrosion resistance,maintaining biocompatibility,and enhancing strength without compromising osseointegration.By leveraging Mg’s inherent biodegradability,it has the potential to minimize the need for secondary surgeries,thereby reducing costs and resources.This paper is a systematic study aimed at understanding the corrosion mechanisms of Mg–Zr coatings,denoted Mg-xZr(x=0–5 at.%).Zr-doped coatings exhibited columnar growth leading to denser and refined structures with increasing Zr content.XRD analysis confirmed the presence of the Mg(00.2)basal plane,shifting towards higher angles(1.15°)with 5 at.%Zr doping due to lattice parameter changes(i.e.,decrease and increase of“c”and“a”lattice parameters,respectively).Mg–Zr coatings exhibited“liquidphilic”behavior,while Young’s modulus retained a steady value around 80 GPa across all samples.However,the hardness has significantly improved across all samples’coating,reaching the highest value of(2.2±0.3)GPa for 5 at.%Zr.Electrochemical testing in simulated body fluid(SBF)at 37℃ revealed a significant enhancement in corrosion resistance for Mg–Zr coatings containing 1.0–3.4 at.%Zr.Compared with the 5 at.%Zr coating which exhibited a corrosion rate of 32 mm/year,these coatings displayed lower corrosion rates,ranging from 1 to 12 mm/year.This synergistic enhancement in mechanical properties and corrosion resistance,achieved with 2.0–3.4 at.%Zr,suggests potential ability for reducing stress shielding and controlled degradation performance,and consequently,promising functional biodegradable materials for temporary bone implants.
文摘<b><span>Background: </span></b><span>In patients with pre-existing pulmonary hypertension undergoing surgery, there is an inherent risk of decompensation and right ventricular failure. Cemented hemi-arthroplasty in patients with pre-existing pulmonary hypertension predisposes them even more to morbidity and mortality from bone cement implantation syndrome (BCIS) with worsening of pulmonary hypertension. This risk should be recognized and steps taken for in</span><span>creased awareness, risk counselling and minimization of adverse effects.</span><span> </span><b><span>Case: </span></b><span>We report a case of successful resuscitation of a patient with pre-existing</span><span> pulmonary hypertension who developed 2 episodes of cardiac arrests—Grade 3 BCIS, shortly after cement implantation.</span><span> </span><b><span>Learning Points: </span></b><span>Patients with pre-existing pulmonary hypertension for cemented hemi-arthroplasty are at additional risks and should be identified.</span><span> </span><span>Adequate risk counselling needs to be undertaken prior to surgery.</span><span> </span><span>A multi-disciplinary team effort is required. Discussion should be undertaken with the orthopaedic surgeon about the risks and benefits of using cemented implants.</span><span> </span><span>The anaesthetist needs to be vigilant for signs of BCIS, especially at the time of cement implantation and </span><span>institute immediate resuscitation.</span><span> </span><span>Supportive treatment is the mainstay of </span><span>management.
文摘Objective To investigate the effect of the implant composite of poly lactide-co-glycolide(PLGA)and bone mesenchymal stem cells (BMSCs) modified by basic fibroblast growth factor (bFGF) on injured spinal cord in rats.Methods Two hundred and
基金funded by Tsinghua-Toyota Joint Research Fund,National Natural Science Foundation of China(52175274)Tsinghua Precision Medicine Foundation.X.W.thanks the funding support from the National Natural Science Foundation of China(Grant ID:81630064)Beijing Natural Science Foundation(Grant ID:7232129).
文摘Addressing irregular bone defects is a formidable clinical challenge,as traditional scaffolds frequently fail to meet the complex requirements of bone regeneration,resulting in suboptimal healing.This study introduces a novel 3D-printed magnesium scaffold with hierarchical structure(macro-,meso-,and nano-scales)and tempered degradation(microscale),intricately customized at multiple scales to bolster bone regeneration according to patient-specific needs.For the hierarchical structure,at the macroscale,it can feature anatomic geometries for seamless integration with the bone defect;The mesoscale pores are devised with optimized curvature and size,providing an adequate mechanical response as well as promoting cellular proliferation and vascularization,essential for natural bone mimicry;The nanoscale textured surface is enriched with a layered double hydroxide membrane,augmenting bioactivity and osteointegration.Moreover,microscale enhancements involve a duallayer coating of high-temperature oxidized film and hydrotalcite,offering a robust shield against fast degradation.Eventually,this scaffold demonstrates superior geometrical characteristics,load-bearing capacity,and degradation performance,significantly outperforming traditional scaffolds based on in vitro and in vivo assessments,marking a breakthrough in repairing customized bone defects.
文摘High-porosity,open-cell AZ91 magnesium alloy foams of two pore sizes were fabricated by means of investment casting technology,using PUR foam patterns.Foam casting variables such as pressure,mould temperature and metal pouring temperature were thoroughly investigated to define the most optimal casting conditions.The mechanical properties of the fabricated foams were measured in compression tests.A potential application for the foams considered is temporary bioresorbable bone implants,therefore the mechanical properties of the foams were compared with those of cancellous bone tissue.Foams with smaller pore size and lower porosity(20 PPI and 80%±87%)exhibited mechanical properties in the lower regions of the cancellous bone property range(Young’s modulus 36.5±77.5 MPa),while foams with higher pore size and porosity(10 PPI and~90%)were found to have insufficient compression strength(Young’s modulus 11.65±23.8),but thickening their walls and lowering their porosity below 90%yielded foams with Young’s modulus between 36.5 and 77.5 MPa.Foam fractures were also investigated to determine their collapse mechanism.A series of corrosion tests in stimulated body fluid was carried out to determine their applicability as a biomaterial.The Plasma Electrolytic Oxidation(PEO)process was used in a feasibility study to examine the microstructure and chemical composition of foams with protective coating.
基金funded by the Deutsche Forschungsgemeinschaft,grant number 417069397,as a collaboration project between the Ludwig Maximilians University Munich and the University Clinic of Würzburgthe DFG for funding the crossbeam scanning electron microscope Zeiss CB 340(INST 105022/58-1 FUGG)within the DFG State Major Instrumentation Programme。
文摘Regenerative bone implants promote new bone formation and ideally degrade simultaneously to osteogenesis.Although clinically established calcium phosphate bone grafts provide excellent osseointegration and osteoconductive efficacy,they are limited in terms of bioresorption.Magnesium phosphate(MP)based ceramics are a promising alternative,because they are biocompatible,mechanically extremely stable,and degrade much faster than calcium phosphates under physiological conditions.Bioresorption of an implant material can include both chemical dissolution as well as cellular resorption.We investigated the bioresorption of 3D powder printed struvite and newberyite based MP ceramics in vitro by a direct human osteoclast culture approach.The osteoclast response and cellular resorption was evaluated by means of fluorescence and TRAP staining,determination of osteoclast activities(CA II and TRAP),SEM imaging as well as by quantification of the ion release during cell culture.Furthermore,the bioactivity of the materials was investigated via SBF immersion,whereas hydroxyapatite precipitates were analyzed by SEM and EDX measurements.This bioactive coating was resorbed by osteoclasts.In contrast,only chemical dissolution contributed to bioresorption of MP,while no cellular resorption of the materials was observed.Based on our results,we expect an increased bone regeneration effect of MP compared to calcium phosphate based bone grafts and complete chemical degradation within a maximum of 1.5-3.1 years.
基金This work was supported by the National High Technology Research and Development Program of China(Youth 863 Program,Project No.2015AA020935)National Natural Science Foundation of China grant(Project No.51573206)+1 种基金Shenzhen Fundamental Research Foundation(Project No.JCYJ20150731154850925,JCYJ20150521144321001,JSGG20151030140325149,CXZZ20150529144128031)Hong Kong GRF(CUHK No.14140816).
文摘Magnesium(Mg)or its alloys are widely tested as potential orthopedic implants,particularly as biodegradable alloys for fracture fixation due to their mechanical properties are close to those of bone.Currently,available Mg or its alloys are confronted with challenges in passing regulatory biosafety tests prior to clinical trials due to its fast degradation and associated degradation products.The degradation of Mg is accompanied by the release of Mg ions,the rise of pH and osmolality in surrounding environments.According to the standard of ISO 10993 Part 13,the pH value shall be appropriate to the site of intended use maintaining in an appropriate range.Approaches to overcome these challenges include the selection of adequate alloying elements,proper surface treatment techniques and control of the degradation rate of Mg or its alloys developed as orthopedic implants.To date,Mg or its alloy-based bone implants have not yet been widely used in clinical applications as medical implants.This review critically summarized published methods to improve the corrosion resistance of Mg and its alloys.The current progress on in vitro cytotoxicity and in vivo biocompatibility properties of these metals was also reviewed.This review aimed to provide a reference for further research and development(R&D)of biodegradable Mg and its alloys with regard to the evaluation of their corrosion process and biocompatibility and facilitation of their translation to clinical applications.
