Objective:To compare the effectiveness,safety,acceptability,and confounding factors of the two-rod levonorgestrel implants between the Indoplant and Sinoplant implant brands.Methods:The study was a double-blind,random...Objective:To compare the effectiveness,safety,acceptability,and confounding factors of the two-rod levonorgestrel implants between the Indoplant and Sinoplant implant brands.Methods:The study was a double-blind,randomized controlled trial at three different centers in Indonesia.A total of 531 participants that met inclusion and exclusion criteria were randomized into two groups,with 264 participants in the Sinoplant group and 267 participants in the Indoplant group.At each center,participants were divided into two groups for Sinoplant and Indoplant.The participants were followed up for 36 months.Four parameters were evaluated:implant effectiveness,safety,acceptability,and confounding factors.Results:A total of 531 eligible participants were enrolled in this study.Both Sinoplant and Indoplant showed 100%efficacy in preventing pregnancy,with no significant differences in side effects.24.22%of the Sinoplant group and 22.18%of the Indoplant group reported weight changes.8.60%of the Sinoplant group and 9.73%of the Indoplant group reported menstrual changes,and 1.17%of the both groups experienced intermenstrual bleeding.Implant acceptability was 96.61%,with 3.39%dropout rates.Confounding factors such as age,parity,and contraceptive history did not significantly differ between the two groups.Conclusions:Sinoplant and Indoplant did not differ significantly in contraceptive effectiveness,safety,acceptability,and confounding factors.展开更多
Currently,there is an essential need for bioresorbable bone implants with antibacterial,anti-inflammatory properties as well as osteoinductivity.Considering this,in presented study for the first time hybrid Mg-ZK coat...Currently,there is an essential need for bioresorbable bone implants with antibacterial,anti-inflammatory properties as well as osteoinductivity.Considering this,in presented study for the first time hybrid Mg-ZK coatings with polydopamine(PDA),menaquinone-7(MK-7),zoledronate(ZA)and vancomycin on the hydroxyapatite(HA)containing layer are formed.Porous coatings were obtained by the plasma electrolytic oxidation(PEO)on an Mg alloy,then MK-7 was impregnated into the pores and PDA film with ZA and vancomycin was polymerized on the samples surface.The presence of HA and organic bioactive compounds was confirmed by EDS,Raman spectroscopy,XRD and XPS.Surface free energy values of hybrid coatings are close to optimal for cell adhesion:75.28±1.35 mJ/m^(2).Viability tests of the medium,in which Mg-ZK implants were soaked,revealed cytotoxic activity on human osteosarcoma cells with no such an effect on fibroblasts.Antibacterial tests showed an inhibition zone on S.aureus with no viable colonies on the hybrid coatings.The growth inhibition zones for the samples with the hybrid coating were 21±1 mm.Data of electrochemical impedance spectroscopy shows increase of corrosion resistance of samples with hybrid coating by 7 times comparing the Mg alloy without a coating.These properties make the hybrid Mg-ZK coating an attractive modification for bone implants.展开更多
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
In this study,in view of the corrosion resistance and bio functionality limitations of medical magnesium alloys,a PCL/MAO@TiO_(2)NPS composite coating was fabricated to enhance biodegradable magnesium alloy orthopedic...In this study,in view of the corrosion resistance and bio functionality limitations of medical magnesium alloys,a PCL/MAO@TiO_(2)NPS composite coating was fabricated to enhance biodegradable magnesium alloy orthopedic implants.This composite coating effectively inhibited pitting corrosion and decreased the degradation rate of the magnesium alloy substrate.Specifically,the corrosion current density of the overall specimen decreased by five orders of magnitude compared to that of the substrate.In vitro cell experiments demonstrated that the composite coating significantly decelerated the degradation of the magnesium alloy.The degradation products and appropriate magnesium ion concentration promoted cell growth and proliferation.After 72-h co-culturing of specimen extracts with cells,cell viability remained at 100%.Antimicrobial test results showed that due to the synergistic effect of ultraviolet treated TiO_(2)nanoparticles and other components,the specimens exhibited excellent antimicrobial properties.Moreover,in vivo animal implantation tests revealed that the PCL/MAO@TiO_(2)NPS composite coated specimens had remarkable bone enhancing capabilities,which were conducive to the healing and functional restoration of bone tissue.Overall,the numerous advantages suggest that the PCL/MAO@TiO_(2)NPS composite coatings hold great promise for improving magnesium alloy implants in clinical applications.展开更多
The rapid corrosion rate and limited biological functionality still pose challenges for magnesium(Mg)-based implants in the treatment of complicated bone-related diseases in clinic.Herein,a multifunctional biodegradab...The rapid corrosion rate and limited biological functionality still pose challenges for magnesium(Mg)-based implants in the treatment of complicated bone-related diseases in clinic.Herein,a multifunctional biodegradable curcumin(herbal medicine)-ferrum(Cur-Fe)nanoflower was self-assembled on plasma electrolytic oxidation(PEO)-treated Mg alloy via a facile immersion process to realize differential biological function for anti-bacteria/tumor and bone regeneration.The results indicated that Cur-Fe nanoflower coating can promote protein adsorption,cell adhesion and proliferation,exhibiting excellent biocompatibility.The Cur-Fe nanoflower coating exhibits unique degradation characteristics,as curcumin gradually decomposes into ferulic acid,aromatic aldehyde and other antibacterial substances,and the coating spontaneously converts into FeOOH nanosheets,ensuring the corrosion resistance of Mg-based implants.Moreover,Cur-Fe coating exhibits remarkable narrow gap semiconductor characteristics,which can generate reactive oxygen species(ROS)and demonstrated excellent antibacterial effect under simulated sunlight(SSL)irradiation.Meanwhile,under NIR irradiation,Cur-Fe coating showed excellent chemotherapy/photodynamic/photothermal synergetic antitumor properties in vitro and in vivo due to the introduction of curcumin,and photocatalysis and photothermal conversion properties of coating.Furthermore,Cur-Fe nanoflower coating demonstrated great osteogenesis activity in vitro and in vivo due to unique micro/nano structure,surface chemical bond,and the release of Mg and Fe ions.展开更多
The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK implants.Although the porous structure is considered to improve osseointegration of PEEK implants,it is ha...The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK implants.Although the porous structure is considered to improve osseointegration of PEEK implants,it is hardly used due to its mechanical properties.This study investigated the combined influence of the porous structure and in vivo mechanical stimulation on implantation safety and bone growth based on finite element analysis of the biomechanical behavior of the implantation system.The combined control of pore size and screw preloads allows the porous PEEK implant to achieve good osseointegration while maintaining a relatively high safety level.A pore size of 600μm and a preload of 0.05 N·m are the optimal combination for the long-term stability of the implant,with which the safety factor of the implant is>2,and the predicted percentage of effective bone growth area of the bone-implant interface reaches 97%.For further clinical application,PEEK implants were fabricated with fused filament fabrication(FFF)three-dimensional(3D)printing,and clinical outcomes demonstrated better bone repair efficacy and long-term stability of porous PEEK implants compared to solid PEEK implants.Moreover,good osteointegration performance of 3D-printed porous PEEK implants was observed,with an average bone volume fraction>40%three months after implantation.In conclusion,3D-printed porous PEEK implants have great potential for clinical application,with validated implantation safety and good osseointegration.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
Boron nitride(BN),as a nano-reinforcement,offers notable benefits for zinc(Zn)-based implants due to its distinct asymmetric hexagonal structure and high fracture strength.However,the limited interface adhesion betwee...Boron nitride(BN),as a nano-reinforcement,offers notable benefits for zinc(Zn)-based implants due to its distinct asymmetric hexagonal structure and high fracture strength.However,the limited interface adhesion between BN and Zn limits its potential for strengthening and toughening.In this study,copper(Cu)was in situ grown on acidified BN through chemical synthesis and subsequently incorporated into laser additive manufacturing of Zn to enhance interface bonding.During this process,the Cu on BN experienced a displacement reaction with Zn due to thermal reduction induced by the high-energy laser,leading to the replacement of Cu by Zn and the formation of a robust covalent bond between BN and the Zn matrix,thereby improving load transfer.Additionally,the reduced Cu further interacted with Zn to produce the CuZn5 phase,which was evenly dispersed in the Zn matrix under Marangoni vortices,resulting in both dispersion and Orowan strengthening.Consequently,the ultimate tensile strength of the composites achieved(251±7)MPa.The fracture toughness also showed a notable increase from 12.10 to 24.03 MPa·m^(1/2),as the unique structure of BN effectively redistributed stress at the crack tip and absorbed considerable fracture energy.Furthermore,the Cu@BN/Zn implants demonstrated excellent antibacterial properties.展开更多
Biodegradable magnesium(Mg)-based metals can undergo spontaneous corrosion and full degradation in the human body,releasing magnesium ions,hydroxides,and hydrogen.Mg and its alloys have shown preliminary success as an...Biodegradable magnesium(Mg)-based metals can undergo spontaneous corrosion and full degradation in the human body,releasing magnesium ions,hydroxides,and hydrogen.Mg and its alloys have shown preliminary success as an implantable biomaterial.Current research on biodegradable Mg-based metals addresses clinical challenges,including material design and preparation,property enhancement,and exploring relevant biological functions.This review provides a comprehensive overview of the biomedical applications of Mg-based implants across eight fields:cardiovascular,orthopedics,stomatology,general surgery,neurosurgery,fat metabolism,and other potential areas,building upon previously published work.The challenges and prospects of biodegradable Mg-based implants in these application fields are discussed.展开更多
Osteoporotic fractures often exhibit delayed healing and repair difficulties in which the bone immune microenvironment may play a critical role,but direct evidence remains elusive.Recently,magnesium(Mg)-based alloys h...Osteoporotic fractures often exhibit delayed healing and repair difficulties in which the bone immune microenvironment may play a critical role,but direct evidence remains elusive.Recently,magnesium(Mg)-based alloys have emerged as promising biodegradable materials capable of promoting fracture healing.Herein,we performed internal fixation of high-purity Mg implants for osteoporotic fractures and used single-cell studies to investigate and elucidate the cellular heterogeneity and dynamic changes that occurred during osteoporotic fracture repair.We observed an early increase in immature neutrophil numbers,together with anti-inflammatory changes in lymphocytes and macrophages.A cluster of macrophages exhibited pro-angiogenic capabilities activated via the TRPM7/S100A4 pathway.These findings provide new theoretical insights into the biological effects of Mg-based materials on the healing of osteoporotic fractures.展开更多
Thoracic reconstructions are essential surgical techniques used to replace severely damaged tissues and restore protection to internal organs.In recent years,advancements in additive manufacturing have enabled the pro...Thoracic reconstructions are essential surgical techniques used to replace severely damaged tissues and restore protection to internal organs.In recent years,advancements in additive manufacturing have enabled the production of thoracic implants with complex geometries,offering more versatile performance.In this study,we investigated a design based on a spring-like geometry manufactured by laser powder bed fusion(LPBF),as proposed in earlier research.The biomechanical behavior of this design was analyzed using various isolated semi-ring-rib models at different levels of the rib cage.This approach enabled a comprehensive examination,leading to the proposal of several implant configurations that were incorporated into a 3D rib cage model with chest wall defects,to simulate different chest wall reconstruction scenarios.The results revealed that the implant design was too rigid for the second rib level,which therefore was excluded from the proposed implant configurations.In chest wall reconstruction simulations,the maximum stresses observed in all prostheses did not exceed 38%of the implant material's yield stress in the most unfavorable case.Additionally,all the implants showed flexibility compatible with the physiological movements of the human thorax.展开更多
The degradation characteristics of high-purity(HP)magnesium(Mg)orthopedic implants under static and cyclic compressive loads(SCL and CCL)remain inadequately understood.This study developed an in vivo loading device ca...The degradation characteristics of high-purity(HP)magnesium(Mg)orthopedic implants under static and cyclic compressive loads(SCL and CCL)remain inadequately understood.This study developed an in vivo loading device capable of applying single SCL and CCL while shielding against unpredictable host movements.In vitro degradation experiments of HP Mg implants were conducted to verify the experimental protocol,and in vivo experiments in rabbit tibiae to observe the degradation characteristics of the implants.Micro-computed tomography and scanning electron microscope were used for three-dimensional reconstruction and surface morphology analysis,respectively.Compared to in vitro specimens,in vivo specimens exhibited significantly higher corrosion rates and more extensive cracking.Cracks in the in vivo specimens gradually penetrated deeper from the loading surface,eventually leading to a rapid structural deterioration;whereas in vitro specimens exhibited more surface-localized cracking and a relatively uniform corrosion pattern.Compared to SCL,CCL accelerated both corrosion and cracking to some extent.These findings provide new insights into the in vivo degradation behavior of Mg-based implants under compressive loading conditions.展开更多
The effect of structure,elastic modulus and thickness of lower modulus layer in porous titanium implants on the stress distribution at the implant-bone interface was investigated.Three-dimensional finite element model...The effect of structure,elastic modulus and thickness of lower modulus layer in porous titanium implants on the stress distribution at the implant-bone interface was investigated.Three-dimensional finite element models of different titanium implants were constructed.The structures of the implants included the whole lower modulus style （No.1）,bio-mimetic style （No.2）,the whole lower modulus style in cancellous bone （No.3） and the whole dense style No.4.The stress distributions at bone-implant interface under static loading were analyzed using Ansys Workbench 10.0 software.The results indicated that the distribution of interface stress is strongly depended on the structure of the implants.The maximum stresses in cancellous bone and root region of implant No.2 are lower than those in the other three implants.A decrease in the modulus of the low modulus layer facilitates the interface stress transferring.Increasing the thickness of the low modulus layer can reduce the stress and induce a more uniform stress distribution at the interface.Among the four implants,biomimetic style implant No.2 is superior in transferring implant-bone interface stress to surrounding bones.展开更多
AIM:To compare the visual outcomes between bilateral implantation of Tecnis ZXR00 extended depth-of-focus(EDOF)intraocular lenses(IOLs)and mixed implantation of Tecnis ZXR00(EDOF)with Tecnis ZMB00(bifocal)IOLs.METHODS...AIM:To compare the visual outcomes between bilateral implantation of Tecnis ZXR00 extended depth-of-focus(EDOF)intraocular lenses(IOLs)and mixed implantation of Tecnis ZXR00(EDOF)with Tecnis ZMB00(bifocal)IOLs.METHODS:This postoperative cross-sectional study enrolled patients who underwent phacoemulsification combined with IOL implantation.Patients were divided into two groups:the bilateral ZXR00 group(ZXR00-only group)and the mixed IOL group(ZXR00+ZMB00 group).Primary outcome measures included uncorrected and corrected distance visual acuity(UDVA,CDVA),uncorrected and distance-corrected near visual acuity(UNVA,DCNVA),uncorrected and distance-corrected intermediate visual acuity(UIVA,DCIVA),and defocus curves.Secondary outcome measures were visual quality,spectacle independence,patient satisfaction,photic phenomena,and stereopsis.RESULTS:A total of 47 patients(94 eyes)were included,with 26 patients(11 males,15 females)in the ZXR00-only group(mean age:62.73±7.24y)and 21 patients(7 males,14 females)in the mixed group(mean age:65.71±9.16y).There was no statistically significant difference in age between the two groups(P=0.218).The mixed group showed significantly better binocular DCNVA compared to the ZXR00-only group(P=0.002).Defocus curve analysis revealed that the mixed group exhibited superior performance at−2.5 to−4.0 D but inferior performance at−0.5 and−1.5 D.Near stereoacuity was significantly poorer in the mixed group(Randot:5.589±0.744 vs 6.240±0.394 ln arcsec;Contour:4.966±0.973 vs 5.740±0.833 ln arcsec;both P<0.01).Both groups achieved high levels of spectacle independence and patient satisfaction,with no significant differences in photic phenomena or questionnaire scores.CONCLUSION:Mixed implantation of EDOF and bifocal IOLs improve near visual acuity but may compromise near stereopsis.This approach provides a viable option for patients prioritizing near vision;however,caution is recommended for individuals requiring fine stereoscopic vision for daily or professional tasks.展开更多
The last decade has seen a significant growth in the market for alloys used for implants,especially for those intended for orthopedic implants.Research into biodegradable magnesium-based alloys has made great strides ...The last decade has seen a significant growth in the market for alloys used for implants,especially for those intended for orthopedic implants.Research into biodegradable magnesium-based alloys has made great strides in this period,so huge progress has been made in their use in the medical industry.The important factors that led to the intensification of research in this regard,were social but also economic,wanting to improve the quality of life,by reducing the use of conventionally permanent metallic implants(stainless steel,cobalt-based alloys,and titanium alloys)which involve the second implant removal surgery and other undesirable effects(stress shielding and metal ion releases),with a negative impact on the emotional and physical condition of patients,and by significantly reducing the costs for both the patient and the health system in the field of orthopedics.This paper refers to the impact and importance of biodegradable Mg alloys,reviewing the beginning of their development,the significant characteristics that make them so desirable for such applications(orthopedic implants)but also the characteristics that must be modulated(corrosion rate and mechanical properties)to arrive at the ideal product for the targeted application.It highlights,in detail,the mechanism and aspects related to the corrosion behaviour of Mg alloys,electrochemical characterization techniques/methods,as well as strategies to improve the corrosion behaviour and mechanical properties of these types of biodegradable alloys.The means of optimization,the category and the effect of the alloying elements,the design criteria,the requirements that the implants of biodegradable alloys Mg-based must meet and the aspects related to their efficiency are also presented.Finally,the potential applications in the specialized clinics,as well as the final products currently used and made by important prestigious companies in the world are approached.展开更多
Mg and its alloys are drawing huge attention since the last two decades as a viable option for temporary implants applications.A commendable progress has already been made in the development of these alloys.The biodeg...Mg and its alloys are drawing huge attention since the last two decades as a viable option for temporary implants applications.A commendable progress has already been made in the development of these alloys.The biodegradable nature of Mg,appreciable biocompatibility of elemental Mg,and its close resemblance to natural bone in terms of density and elastic modulus make them highly preferable option amongst other available alternatives in this field.This review article presents an overview covering the recent advancements made in the field of Mg-based biodegradable implants for orthopaedic implant applications.The paper focuses on alloy development and fabrication techniques,the state of the art of important Mg-based alloy systems in terms of their mechanical properties,in-vitro and in-vivo degradation behaviour and cytotoxicity.Further,the paper reviews the current progress achieved in the clinical transition of Mg-based alloys for orthopaedic fixtures.The review also includes the degradation mechanisms of the alloys in physiological environment and highlights the mismatch existing between the rate of bone healing and alloy degradation due to rapid corrosion of the alloys in such environment,which has still restricted their widespread application.Finally,the surface coating techniques available for the alloys as an effective way to reduce the degradation rate are reviewed,followed by a discussion on the future research prospects.展开更多
Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading ...Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading is still lacking. For this randomized split-mouth study, six mongrel dogs randomly received one of four treatment protocols at 36 implant-recipient sites over 16 weeks （third maxillary incisor, third and fourth mandibular premolar）： immediate implant placement and immediate loading （liP＋ IL）; delayed implant placement and delayed loading （DIP＋DL）; delayed implant placement and immediate loading （DIP＋IL）; and natural extraction socket healing （control）. Histomorphometry was performed in the peri-implant bone and soft tissues within 300 pm around the implants. Immunocytochemistry and transmission electron microscopy were used to confirm the presence of neural structures and to reveal their ultrastructural characteristics, respectively. Myelinated nerve fibres densely populated the peri-implant crestal gingival and apical regions, although they were also identified in the woven bone and in the osteons near the implant threads. Compared with the control group in the mandible, the group that received IIP＋IL showed a higher innervation （in N.mm^-2, 5.94±1.12 vs. 3.15±0.63, P〈0.001） and smaller fibre diameter （in pm, 1.37±0.05 vs. 1.64±0.13, P=0.016）, smaller axon diameter （in pm, 0.89±0.05 vs. 1.24±0,10, P=0.009） and g-ratio （0.64±0.04 vs. 0.76±0.05, P〈0.001） in the middle region around the implants. Compared with DIP＋IL in the mandible, IIP＋IL had a higher nerve density （in N.mm^-2, 13.23±2.54 vs. 9.64±1.86, P=0.027）, greater fibre diameter （in pm, 1.32±0.02 vs. 1.20±0.04, P=0.021）, greater axon diameter （in μm, 0.92±0.01 vs. 0.89±0.03, P=-0.035） and lower g-ratio （0.69±0.01 vs. 0.74±0.01, P=-0.033） in the apical region around the implants. It may be assumed that the treatment protocol with liP＋ IL is the preferred method to allow optimized peri-implant re-innervation, but further functional measurements are still required.展开更多
Synthetic grafting needs improvements to eliminate secondary surgeries for the removal of implants after healing of the defected tissues.Tissue scaffolds are engineered to serve as temporary templates,which support th...Synthetic grafting needs improvements to eliminate secondary surgeries for the removal of implants after healing of the defected tissues.Tissue scaffolds are engineered to serve as temporary templates,which support the affected tissue and gradually degrade through the healing period.Beside mechanical function to withstand the anatomic loading conditions,scaffolds should also provide a decent biological function for the diffusion of nutrients and oxygen to the cells,and excretion of the wastes from the cells to promote the new tissue growth and vascularization.Moreover,the degradation byproducts of the scaffolds should be safe to the human body.Development of such multifunctional scaffolds requires selection of the right material,design,and manufacturing method.Mg has been recognized as the prominent biodegradable metal with regards to its mechanical properties matching to that of human bone,degradability in the body fluid,and its ability to stimulate new tissue growth.Scaffolds with intricate porous structures can be designed according to the patient-specific anatomic data using computer aided designs.Additive manufacturing(AM)is the right method to materialize these models rapidly with reasonably acceptable range of dimensional accuracy.Thus,the recent research trend is to develop ideal scaffolds using biodegradable Mg through AM methods.This review compiles and discusses the available literature on the AM of biodegradable Mg parts from the viewpoints of material compositions,process conditions,formation quality,dimensional accuracy,microstructure,biodegradation,and mechanical properties.The current achievements are summarized together,and future research directions are identified to promote clinical applications of biodegradable Mg through the advancement of AM.展开更多
Objective: To evaluate the efficacy and the indication of basic fibroblast growth factor (bFGF) in the treatment of exposure of orbital implants. Design: Retrospective and observational case series. Methods: We review...Objective: To evaluate the efficacy and the indication of basic fibroblast growth factor (bFGF) in the treatment of exposure of orbital implants. Design: Retrospective and observational case series. Methods: We reviewed 41 patients (41 eyes) suffering exposure of orbital implants from Jan. 2000 to June 2006. The study group patients with mild exposure received com-bined treatment with bFGF and antibiotic drops, and while the control group patients with mild exposure were treated with anti-biotic drops only. The study group patients with moderate and severe exposure received combined treatment with bFGF and antibiotic drops, and after 2 months they were subjected to amniotic membrane transplantation, while the control group patients with moderate and severe exposure underwent amniotic membrane transplantation after using antibiotic drops. Observation of the growth of conjunctival epithelium and comparison of the healing rate of the two groups. Results: The healing rates of the mild, moderate and severe exposure study group were 100% and 92.3%. The healing rates of the mild, moderate and severe exposure control group were 55.6% and 66.7% respectively. The difference of the healing rates of the mild exposure study group and the control group was significant (P=0.033). And the difference of the healing rates of the moderate and severe exposure study group and the control group was not significant (P=0.167). Conclusion: bFGF may promote obviously the healing of orbital implant exposure, particularly it can be the first choice for the treatment of mild degree exposure. For the moderate and severe cases, it can be administered before surgical repair to enhance neovascularization and will tend to increase the success rate of surgical repair.展开更多
The effects of surface-modified porous titanium implants with different porosities and pore sizes on osseointegration were investigated in vivo.Three porous titanium implants(A30,A40 and A50 containing volume fraction...The effects of surface-modified porous titanium implants with different porosities and pore sizes on osseointegration were investigated in vivo.Three porous titanium implants(A30,A40 and A50 containing volume fractions of space-holder NaCl being 30%,40%and 50%,respectively)were manufactured by metal injection moulding(MIM).The surface-modified implants were implanted into muscles and femurs of hybrid male dogs.Interface osteogenic activity and histological bone ingrowth of porous titanium implants were evaluated at 28,56 and 84 d.The results showed that when additive space-holder amount of NaCl increased from 30%to 50%(volume fraction),the general porosity and mass fraction of macropores of porous titanium rose from 42.4%to 62.0%and from 8.3%to 69.3%,respectively.Histologic sections and fluorescent labeling showed that the A50 implant demonstrated a significantly higher osteogenic capacity at 28 d than other implants.Bone ingrowth into the A30 implant was lower than that into other implants at 84 d.Therefore,the pore structure of A50 implant was suitable for new bone tissue to grow into porous implant.展开更多
基金supported by PT.Catur Dakwah Crane Pharmacy,an Indonesian pharmaceutical company.The funding was granted through a mutual agreement between the research team and the company,under the coordination of the National Population and Family Planning Board(BKKBN Indonesia).The funder provided financial support only and had no role in the study design,data collection,analysis,interpretation of data,or the decision to submit the manuscript for publication.
文摘Objective:To compare the effectiveness,safety,acceptability,and confounding factors of the two-rod levonorgestrel implants between the Indoplant and Sinoplant implant brands.Methods:The study was a double-blind,randomized controlled trial at three different centers in Indonesia.A total of 531 participants that met inclusion and exclusion criteria were randomized into two groups,with 264 participants in the Sinoplant group and 267 participants in the Indoplant group.At each center,participants were divided into two groups for Sinoplant and Indoplant.The participants were followed up for 36 months.Four parameters were evaluated:implant effectiveness,safety,acceptability,and confounding factors.Results:A total of 531 eligible participants were enrolled in this study.Both Sinoplant and Indoplant showed 100%efficacy in preventing pregnancy,with no significant differences in side effects.24.22%of the Sinoplant group and 22.18%of the Indoplant group reported weight changes.8.60%of the Sinoplant group and 9.73%of the Indoplant group reported menstrual changes,and 1.17%of the both groups experienced intermenstrual bleeding.Implant acceptability was 96.61%,with 3.39%dropout rates.Confounding factors such as age,parity,and contraceptive history did not significantly differ between the two groups.Conclusions:Sinoplant and Indoplant did not differ significantly in contraceptive effectiveness,safety,acceptability,and confounding factors.
基金The formation of coatingsas well as SEM,EDS,FIB,Raman spectroscopy,XRD,XPS,EIS,IR spectra,release studies and antibacterial studies were supported by Russian Science Foundation Grant No 22-73-10149,https://rscf.ru/project/22-73-10149/The wettability studies,all viability tests,alizarin red assay,evaluation of inflammatory activity and adhesion tests were supported by Russian Science Foundation Grant No 23-13-00329,https://rscf.ru/project/23-13-00329/。
文摘Currently,there is an essential need for bioresorbable bone implants with antibacterial,anti-inflammatory properties as well as osteoinductivity.Considering this,in presented study for the first time hybrid Mg-ZK coatings with polydopamine(PDA),menaquinone-7(MK-7),zoledronate(ZA)and vancomycin on the hydroxyapatite(HA)containing layer are formed.Porous coatings were obtained by the plasma electrolytic oxidation(PEO)on an Mg alloy,then MK-7 was impregnated into the pores and PDA film with ZA and vancomycin was polymerized on the samples surface.The presence of HA and organic bioactive compounds was confirmed by EDS,Raman spectroscopy,XRD and XPS.Surface free energy values of hybrid coatings are close to optimal for cell adhesion:75.28±1.35 mJ/m^(2).Viability tests of the medium,in which Mg-ZK implants were soaked,revealed cytotoxic activity on human osteosarcoma cells with no such an effect on fibroblasts.Antibacterial tests showed an inhibition zone on S.aureus with no viable colonies on the hybrid coatings.The growth inhibition zones for the samples with the hybrid coating were 21±1 mm.Data of electrochemical impedance spectroscopy shows increase of corrosion resistance of samples with hybrid coating by 7 times comparing the Mg alloy without a coating.These properties make the hybrid Mg-ZK coating an attractive modification for bone implants.
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supported by National Natural Science Foundation of China(Grant no 52371070 and 52271249)Key Research and Development Program of Shaanxi(2023-YBGY-488)+1 种基金State Key Laboratory of Solidification Processing in NPU(Grant no SKLSP202415)Xi’an Talent Plan(XAYC240016).
文摘In this study,in view of the corrosion resistance and bio functionality limitations of medical magnesium alloys,a PCL/MAO@TiO_(2)NPS composite coating was fabricated to enhance biodegradable magnesium alloy orthopedic implants.This composite coating effectively inhibited pitting corrosion and decreased the degradation rate of the magnesium alloy substrate.Specifically,the corrosion current density of the overall specimen decreased by five orders of magnitude compared to that of the substrate.In vitro cell experiments demonstrated that the composite coating significantly decelerated the degradation of the magnesium alloy.The degradation products and appropriate magnesium ion concentration promoted cell growth and proliferation.After 72-h co-culturing of specimen extracts with cells,cell viability remained at 100%.Antimicrobial test results showed that due to the synergistic effect of ultraviolet treated TiO_(2)nanoparticles and other components,the specimens exhibited excellent antimicrobial properties.Moreover,in vivo animal implantation tests revealed that the PCL/MAO@TiO_(2)NPS composite coated specimens had remarkable bone enhancing capabilities,which were conducive to the healing and functional restoration of bone tissue.Overall,the numerous advantages suggest that the PCL/MAO@TiO_(2)NPS composite coatings hold great promise for improving magnesium alloy implants in clinical applications.
基金supported by the National Key R&D Program of China(2021YFC2400500)Shanghai Committee of Science and Technology,China(20S31901200)+2 种基金the Fundamental Research Funds for the Central Universities(2022ZYGXZR042)Postdoctoral Science Foundation of China(2022M723288)GDPH Supporting Fund for Talent Program(KY0120220137).
文摘The rapid corrosion rate and limited biological functionality still pose challenges for magnesium(Mg)-based implants in the treatment of complicated bone-related diseases in clinic.Herein,a multifunctional biodegradable curcumin(herbal medicine)-ferrum(Cur-Fe)nanoflower was self-assembled on plasma electrolytic oxidation(PEO)-treated Mg alloy via a facile immersion process to realize differential biological function for anti-bacteria/tumor and bone regeneration.The results indicated that Cur-Fe nanoflower coating can promote protein adsorption,cell adhesion and proliferation,exhibiting excellent biocompatibility.The Cur-Fe nanoflower coating exhibits unique degradation characteristics,as curcumin gradually decomposes into ferulic acid,aromatic aldehyde and other antibacterial substances,and the coating spontaneously converts into FeOOH nanosheets,ensuring the corrosion resistance of Mg-based implants.Moreover,Cur-Fe coating exhibits remarkable narrow gap semiconductor characteristics,which can generate reactive oxygen species(ROS)and demonstrated excellent antibacterial effect under simulated sunlight(SSL)irradiation.Meanwhile,under NIR irradiation,Cur-Fe coating showed excellent chemotherapy/photodynamic/photothermal synergetic antitumor properties in vitro and in vivo due to the introduction of curcumin,and photocatalysis and photothermal conversion properties of coating.Furthermore,Cur-Fe nanoflower coating demonstrated great osteogenesis activity in vitro and in vivo due to unique micro/nano structure,surface chemical bond,and the release of Mg and Fe ions.
基金supported by the National Key R&D Program of China(No.2023YFB4603500)the Program for Innovation Team of Shaanxi Province(No.2023-CX-TD-17)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Shaanxi Province Qinchuangyuan“Scientist+Engineer”Team Construction Project(No.2022KXJ-106).
文摘The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK implants.Although the porous structure is considered to improve osseointegration of PEEK implants,it is hardly used due to its mechanical properties.This study investigated the combined influence of the porous structure and in vivo mechanical stimulation on implantation safety and bone growth based on finite element analysis of the biomechanical behavior of the implantation system.The combined control of pore size and screw preloads allows the porous PEEK implant to achieve good osseointegration while maintaining a relatively high safety level.A pore size of 600μm and a preload of 0.05 N·m are the optimal combination for the long-term stability of the implant,with which the safety factor of the implant is>2,and the predicted percentage of effective bone growth area of the bone-implant interface reaches 97%.For further clinical application,PEEK implants were fabricated with fused filament fabrication(FFF)three-dimensional(3D)printing,and clinical outcomes demonstrated better bone repair efficacy and long-term stability of porous PEEK implants compared to solid PEEK implants.Moreover,good osteointegration performance of 3D-printed porous PEEK implants was observed,with an average bone volume fraction>40%three months after implantation.In conclusion,3D-printed porous PEEK implants have great potential for clinical application,with validated implantation safety and good osseointegration.
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.
基金supported by the National Key Research and Development Program of China(No.2023YFB4605800)the Natural Science Foundation of China(Nos.51935014,52165043 and 82072084)+4 种基金Jiangxi Provincial Cultivation Program for Academic and Technical Leaders of Major Subjects(No.20225BCJ23008)Jiangxi Provincial Natural Science Foundation of China(Nos.20224ACB204013 and 20224ACB214008)the Technology Innovation Platform Project of Shenzhen Institute of Information Technology 2020(No.PT2020E002)the Shccig-Qinling Program(No.2022360702014891)Jiangxi University of Science and Technology Graduate Innovation Special Fund Project(No.XY2023-S677).
文摘Boron nitride(BN),as a nano-reinforcement,offers notable benefits for zinc(Zn)-based implants due to its distinct asymmetric hexagonal structure and high fracture strength.However,the limited interface adhesion between BN and Zn limits its potential for strengthening and toughening.In this study,copper(Cu)was in situ grown on acidified BN through chemical synthesis and subsequently incorporated into laser additive manufacturing of Zn to enhance interface bonding.During this process,the Cu on BN experienced a displacement reaction with Zn due to thermal reduction induced by the high-energy laser,leading to the replacement of Cu by Zn and the formation of a robust covalent bond between BN and the Zn matrix,thereby improving load transfer.Additionally,the reduced Cu further interacted with Zn to produce the CuZn5 phase,which was evenly dispersed in the Zn matrix under Marangoni vortices,resulting in both dispersion and Orowan strengthening.Consequently,the ultimate tensile strength of the composites achieved(251±7)MPa.The fracture toughness also showed a notable increase from 12.10 to 24.03 MPa·m^(1/2),as the unique structure of BN effectively redistributed stress at the crack tip and absorbed considerable fracture energy.Furthermore,the Cu@BN/Zn implants demonstrated excellent antibacterial properties.
基金supported by grants from the Fundamental Research Funds for the Central Universities(No.2232024D-34 and No 2232023A-10)the National Natural Science Foundation of China(No.52201300)+4 种基金the National Key R&D Program of China(No.2023YFC2416800)the Shanghai Pujiang Program(No.23PJ1400500 and No 23PJ1400600)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Major/key program(No.23M1060280)the Science and Technology Project of Jiangsu Province(No.BE2022758)the Medicine-Engineering Interdisciplinary Project of Shanghai Xuhui District Dental Center(No.SHXYFYG202305).
文摘Biodegradable magnesium(Mg)-based metals can undergo spontaneous corrosion and full degradation in the human body,releasing magnesium ions,hydroxides,and hydrogen.Mg and its alloys have shown preliminary success as an implantable biomaterial.Current research on biodegradable Mg-based metals addresses clinical challenges,including material design and preparation,property enhancement,and exploring relevant biological functions.This review provides a comprehensive overview of the biomedical applications of Mg-based implants across eight fields:cardiovascular,orthopedics,stomatology,general surgery,neurosurgery,fat metabolism,and other potential areas,building upon previously published work.The challenges and prospects of biodegradable Mg-based implants in these application fields are discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.81871742 and 82102538)Shanghai Sailing Program(No.21YF1405800)+2 种基金Shanghai Pudong Science and Technology Development Funding(No.PKJ2020-Y44)the Featured Clinical Discipline Project of Shanghai Pudong New District(No.Pwyts2021-03)the support of the National Engineering Research Center of Light Alloy Net Forming,Shanghai Jiao Tong University
文摘Osteoporotic fractures often exhibit delayed healing and repair difficulties in which the bone immune microenvironment may play a critical role,but direct evidence remains elusive.Recently,magnesium(Mg)-based alloys have emerged as promising biodegradable materials capable of promoting fracture healing.Herein,we performed internal fixation of high-purity Mg implants for osteoporotic fractures and used single-cell studies to investigate and elucidate the cellular heterogeneity and dynamic changes that occurred during osteoporotic fracture repair.We observed an early increase in immature neutrophil numbers,together with anti-inflammatory changes in lymphocytes and macrophages.A cluster of macrophages exhibited pro-angiogenic capabilities activated via the TRPM7/S100A4 pathway.These findings provide new theoretical insights into the biological effects of Mg-based materials on the healing of osteoporotic fractures.
文摘Thoracic reconstructions are essential surgical techniques used to replace severely damaged tissues and restore protection to internal organs.In recent years,advancements in additive manufacturing have enabled the production of thoracic implants with complex geometries,offering more versatile performance.In this study,we investigated a design based on a spring-like geometry manufactured by laser powder bed fusion(LPBF),as proposed in earlier research.The biomechanical behavior of this design was analyzed using various isolated semi-ring-rib models at different levels of the rib cage.This approach enabled a comprehensive examination,leading to the proposal of several implant configurations that were incorporated into a 3D rib cage model with chest wall defects,to simulate different chest wall reconstruction scenarios.The results revealed that the implant design was too rigid for the second rib level,which therefore was excluded from the proposed implant configurations.In chest wall reconstruction simulations,the maximum stresses observed in all prostheses did not exceed 38%of the implant material's yield stress in the most unfavorable case.Additionally,all the implants showed flexibility compatible with the physiological movements of the human thorax.
基金supported by National Natural Science Foundation of China[51975317].
文摘The degradation characteristics of high-purity(HP)magnesium(Mg)orthopedic implants under static and cyclic compressive loads(SCL and CCL)remain inadequately understood.This study developed an in vivo loading device capable of applying single SCL and CCL while shielding against unpredictable host movements.In vitro degradation experiments of HP Mg implants were conducted to verify the experimental protocol,and in vivo experiments in rabbit tibiae to observe the degradation characteristics of the implants.Micro-computed tomography and scanning electron microscope were used for three-dimensional reconstruction and surface morphology analysis,respectively.Compared to in vitro specimens,in vivo specimens exhibited significantly higher corrosion rates and more extensive cracking.Cracks in the in vivo specimens gradually penetrated deeper from the loading surface,eventually leading to a rapid structural deterioration;whereas in vitro specimens exhibited more surface-localized cracking and a relatively uniform corrosion pattern.Compared to SCL,CCL accelerated both corrosion and cracking to some extent.These findings provide new insights into the in vivo degradation behavior of Mg-based implants under compressive loading conditions.
基金Project(30770576) supported by the National Natural Science Foundation of ChinaProject(2007AA03Z114) supported by Hi-tech Research and Development Program of ChinaProject supported by State Key Laboratory of Powder Metallurgy,China
文摘The effect of structure,elastic modulus and thickness of lower modulus layer in porous titanium implants on the stress distribution at the implant-bone interface was investigated.Three-dimensional finite element models of different titanium implants were constructed.The structures of the implants included the whole lower modulus style （No.1）,bio-mimetic style （No.2）,the whole lower modulus style in cancellous bone （No.3） and the whole dense style No.4.The stress distributions at bone-implant interface under static loading were analyzed using Ansys Workbench 10.0 software.The results indicated that the distribution of interface stress is strongly depended on the structure of the implants.The maximum stresses in cancellous bone and root region of implant No.2 are lower than those in the other three implants.A decrease in the modulus of the low modulus layer facilitates the interface stress transferring.Increasing the thickness of the low modulus layer can reduce the stress and induce a more uniform stress distribution at the interface.Among the four implants,biomimetic style implant No.2 is superior in transferring implant-bone interface stress to surrounding bones.
文摘AIM:To compare the visual outcomes between bilateral implantation of Tecnis ZXR00 extended depth-of-focus(EDOF)intraocular lenses(IOLs)and mixed implantation of Tecnis ZXR00(EDOF)with Tecnis ZMB00(bifocal)IOLs.METHODS:This postoperative cross-sectional study enrolled patients who underwent phacoemulsification combined with IOL implantation.Patients were divided into two groups:the bilateral ZXR00 group(ZXR00-only group)and the mixed IOL group(ZXR00+ZMB00 group).Primary outcome measures included uncorrected and corrected distance visual acuity(UDVA,CDVA),uncorrected and distance-corrected near visual acuity(UNVA,DCNVA),uncorrected and distance-corrected intermediate visual acuity(UIVA,DCIVA),and defocus curves.Secondary outcome measures were visual quality,spectacle independence,patient satisfaction,photic phenomena,and stereopsis.RESULTS:A total of 47 patients(94 eyes)were included,with 26 patients(11 males,15 females)in the ZXR00-only group(mean age:62.73±7.24y)and 21 patients(7 males,14 females)in the mixed group(mean age:65.71±9.16y).There was no statistically significant difference in age between the two groups(P=0.218).The mixed group showed significantly better binocular DCNVA compared to the ZXR00-only group(P=0.002).Defocus curve analysis revealed that the mixed group exhibited superior performance at−2.5 to−4.0 D but inferior performance at−0.5 and−1.5 D.Near stereoacuity was significantly poorer in the mixed group(Randot:5.589±0.744 vs 6.240±0.394 ln arcsec;Contour:4.966±0.973 vs 5.740±0.833 ln arcsec;both P<0.01).Both groups achieved high levels of spectacle independence and patient satisfaction,with no significant differences in photic phenomena or questionnaire scores.CONCLUSION:Mixed implantation of EDOF and bifocal IOLs improve near visual acuity but may compromise near stereopsis.This approach provides a viable option for patients prioritizing near vision;however,caution is recommended for individuals requiring fine stereoscopic vision for daily or professional tasks.
基金performed under contracts no.46N/2019-project no.PN19310102/2019 and 30PFE/2018 between the National Institute for Research and Development in Electrical Engineering ICPE-CA and the Romanian Ministry of Research and Innovation
文摘The last decade has seen a significant growth in the market for alloys used for implants,especially for those intended for orthopedic implants.Research into biodegradable magnesium-based alloys has made great strides in this period,so huge progress has been made in their use in the medical industry.The important factors that led to the intensification of research in this regard,were social but also economic,wanting to improve the quality of life,by reducing the use of conventionally permanent metallic implants(stainless steel,cobalt-based alloys,and titanium alloys)which involve the second implant removal surgery and other undesirable effects(stress shielding and metal ion releases),with a negative impact on the emotional and physical condition of patients,and by significantly reducing the costs for both the patient and the health system in the field of orthopedics.This paper refers to the impact and importance of biodegradable Mg alloys,reviewing the beginning of their development,the significant characteristics that make them so desirable for such applications(orthopedic implants)but also the characteristics that must be modulated(corrosion rate and mechanical properties)to arrive at the ideal product for the targeted application.It highlights,in detail,the mechanism and aspects related to the corrosion behaviour of Mg alloys,electrochemical characterization techniques/methods,as well as strategies to improve the corrosion behaviour and mechanical properties of these types of biodegradable alloys.The means of optimization,the category and the effect of the alloying elements,the design criteria,the requirements that the implants of biodegradable alloys Mg-based must meet and the aspects related to their efficiency are also presented.Finally,the potential applications in the specialized clinics,as well as the final products currently used and made by important prestigious companies in the world are approached.
文摘Mg and its alloys are drawing huge attention since the last two decades as a viable option for temporary implants applications.A commendable progress has already been made in the development of these alloys.The biodegradable nature of Mg,appreciable biocompatibility of elemental Mg,and its close resemblance to natural bone in terms of density and elastic modulus make them highly preferable option amongst other available alternatives in this field.This review article presents an overview covering the recent advancements made in the field of Mg-based biodegradable implants for orthopaedic implant applications.The paper focuses on alloy development and fabrication techniques,the state of the art of important Mg-based alloy systems in terms of their mechanical properties,in-vitro and in-vivo degradation behaviour and cytotoxicity.Further,the paper reviews the current progress achieved in the clinical transition of Mg-based alloys for orthopaedic fixtures.The review also includes the degradation mechanisms of the alloys in physiological environment and highlights the mismatch existing between the rate of bone healing and alloy degradation due to rapid corrosion of the alloys in such environment,which has still restricted their widespread application.Finally,the surface coating techniques available for the alloys as an effective way to reduce the degradation rate are reviewed,followed by a discussion on the future research prospects.
基金supported by the Natural Science Foundation of China (81000459)the Chinese Scholarship Council
文摘Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading is still lacking. For this randomized split-mouth study, six mongrel dogs randomly received one of four treatment protocols at 36 implant-recipient sites over 16 weeks （third maxillary incisor, third and fourth mandibular premolar）： immediate implant placement and immediate loading （liP＋ IL）; delayed implant placement and delayed loading （DIP＋DL）; delayed implant placement and immediate loading （DIP＋IL）; and natural extraction socket healing （control）. Histomorphometry was performed in the peri-implant bone and soft tissues within 300 pm around the implants. Immunocytochemistry and transmission electron microscopy were used to confirm the presence of neural structures and to reveal their ultrastructural characteristics, respectively. Myelinated nerve fibres densely populated the peri-implant crestal gingival and apical regions, although they were also identified in the woven bone and in the osteons near the implant threads. Compared with the control group in the mandible, the group that received IIP＋IL showed a higher innervation （in N.mm^-2, 5.94±1.12 vs. 3.15±0.63, P〈0.001） and smaller fibre diameter （in pm, 1.37±0.05 vs. 1.64±0.13, P=0.016）, smaller axon diameter （in pm, 0.89±0.05 vs. 1.24±0,10, P=0.009） and g-ratio （0.64±0.04 vs. 0.76±0.05, P〈0.001） in the middle region around the implants. Compared with DIP＋IL in the mandible, IIP＋IL had a higher nerve density （in N.mm^-2, 13.23±2.54 vs. 9.64±1.86, P=0.027）, greater fibre diameter （in pm, 1.32±0.02 vs. 1.20±0.04, P=0.021）, greater axon diameter （in μm, 0.92±0.01 vs. 0.89±0.03, P=-0.035） and lower g-ratio （0.69±0.01 vs. 0.74±0.01, P=-0.033） in the apical region around the implants. It may be assumed that the treatment protocol with liP＋ IL is the preferred method to allow optimized peri-implant re-innervation, but further functional measurements are still required.
文摘Synthetic grafting needs improvements to eliminate secondary surgeries for the removal of implants after healing of the defected tissues.Tissue scaffolds are engineered to serve as temporary templates,which support the affected tissue and gradually degrade through the healing period.Beside mechanical function to withstand the anatomic loading conditions,scaffolds should also provide a decent biological function for the diffusion of nutrients and oxygen to the cells,and excretion of the wastes from the cells to promote the new tissue growth and vascularization.Moreover,the degradation byproducts of the scaffolds should be safe to the human body.Development of such multifunctional scaffolds requires selection of the right material,design,and manufacturing method.Mg has been recognized as the prominent biodegradable metal with regards to its mechanical properties matching to that of human bone,degradability in the body fluid,and its ability to stimulate new tissue growth.Scaffolds with intricate porous structures can be designed according to the patient-specific anatomic data using computer aided designs.Additive manufacturing(AM)is the right method to materialize these models rapidly with reasonably acceptable range of dimensional accuracy.Thus,the recent research trend is to develop ideal scaffolds using biodegradable Mg through AM methods.This review compiles and discusses the available literature on the AM of biodegradable Mg parts from the viewpoints of material compositions,process conditions,formation quality,dimensional accuracy,microstructure,biodegradation,and mechanical properties.The current achievements are summarized together,and future research directions are identified to promote clinical applications of biodegradable Mg through the advancement of AM.
文摘Objective: To evaluate the efficacy and the indication of basic fibroblast growth factor (bFGF) in the treatment of exposure of orbital implants. Design: Retrospective and observational case series. Methods: We reviewed 41 patients (41 eyes) suffering exposure of orbital implants from Jan. 2000 to June 2006. The study group patients with mild exposure received com-bined treatment with bFGF and antibiotic drops, and while the control group patients with mild exposure were treated with anti-biotic drops only. The study group patients with moderate and severe exposure received combined treatment with bFGF and antibiotic drops, and after 2 months they were subjected to amniotic membrane transplantation, while the control group patients with moderate and severe exposure underwent amniotic membrane transplantation after using antibiotic drops. Observation of the growth of conjunctival epithelium and comparison of the healing rate of the two groups. Results: The healing rates of the mild, moderate and severe exposure study group were 100% and 92.3%. The healing rates of the mild, moderate and severe exposure control group were 55.6% and 66.7% respectively. The difference of the healing rates of the mild exposure study group and the control group was significant (P=0.033). And the difference of the healing rates of the moderate and severe exposure study group and the control group was not significant (P=0.167). Conclusion: bFGF may promote obviously the healing of orbital implant exposure, particularly it can be the first choice for the treatment of mild degree exposure. For the moderate and severe cases, it can be administered before surgical repair to enhance neovascularization and will tend to increase the success rate of surgical repair.
基金Project(81571021) supported by the National Natural Science Foundation of ChinaProjects(2015WK3012,2018SK2017) supported by the Hunan Provincial Science and Technology Department Project,ChinaProject(20160301) supported by New Talent Project of the Third Xiangya Hospital of Central South University,China
文摘The effects of surface-modified porous titanium implants with different porosities and pore sizes on osseointegration were investigated in vivo.Three porous titanium implants(A30,A40 and A50 containing volume fractions of space-holder NaCl being 30%,40%and 50%,respectively)were manufactured by metal injection moulding(MIM).The surface-modified implants were implanted into muscles and femurs of hybrid male dogs.Interface osteogenic activity and histological bone ingrowth of porous titanium implants were evaluated at 28,56 and 84 d.The results showed that when additive space-holder amount of NaCl increased from 30%to 50%(volume fraction),the general porosity and mass fraction of macropores of porous titanium rose from 42.4%to 62.0%and from 8.3%to 69.3%,respectively.Histologic sections and fluorescent labeling showed that the A50 implant demonstrated a significantly higher osteogenic capacity at 28 d than other implants.Bone ingrowth into the A30 implant was lower than that into other implants at 84 d.Therefore,the pore structure of A50 implant was suitable for new bone tissue to grow into porous implant.
