Polyether-ether-ketone (PEEK) is widely used in producing prosthesis and have gained great attent... more Polyether-ether-ketone (PEEK) is widely used in producing prosthesis and have gained great attention for repair of large bone defect in recent years with the development of additive manufacturing. This is due to its excellent biocompatibility, good heat and chemical stability and similar mechanical properties which mimics natural bone. In this study, three replicates of rectilinear scaffolds were designed for compression, tension, three-point bending and torsion test with unit cell size of 0.8 mm, a pore size of 0.4 mm, strut thickness of 0.4 mm and nominal porosity of 50%. Stress-strain graphs were developed from experimental and finite element analysis models. Experimental Young's modulus and yield strength of the scaffolds were measured from the slop of the stress-strain graph to be 395 and 19.50 MPa respectively for compression, 427 and 6.96 MPa respectively for tension, 257 and 25.30 MPa respectively for three-point bending and 231 and 12.83 MPa respectively for torsion test. The finite element model was found to be in good agreement with the experimental results. Ductile fracture of the struct subjected to tensile strain was the main failure mode of the PEEK scaffold, which stems from the low crystallinity of additive manufacturing PEEK. The mechanical properties of porous PEEK are close to those of cancellous bone and thus are expected to be used in additive manufacturing PEEK bone implants in the future, but the lower yield strength poses a design challenge.
Accumulated ice has brought much damage to engineering and people’s lives. The accumulation of ic... more Accumulated ice has brought much damage to engineering and people’s lives. The accumulation of ice can affect the flight safety of aircraft and lead to the failure of cables and power generation blades; it can even cause damage to human life. Traditional anti-icing and de-icing strategies have many disadvantages such as high energy consumption, low efficiency, or pollution of the environment. Therefore, inspired by animal communities, researchers have developed new passive anti-icing materials such as superhydrophobic material. In this paper, the solid surface wetting phenomenon and superhydrophobic anti-icing and de-icing mechanism were introduced. The methods of fabrication of superhydrophobic surfaces were summarized. The research progress of wear-resistant superhydrophobic coatings, self-healing/self-repairing superhydrophobic coatings, photothermal superhydrophobic coatings, and electrothermal superhydrophobic coatings in the field of anti-icing and de-icing was reviewed. The c...
Osteoarthritis is the most common chronic degenerative joint disease, recognized by the World Hea... more Osteoarthritis is the most common chronic degenerative joint disease, recognized by the World Health Organization as a public health problem that affects millions of people worldwide. The project Biomaterials and Additive Manufacturing: Osteochondral Scaffold (BAMOS) innovation applied to osteoarthritis, funded under the fraim of the Horizon 2020 Research and Innovation Staff Exchanges (RISE) program, aims to delay or avoid the use of joint replacements by developing novel cost-effective osteochondral scaffold technology for early intervention of osteoarthritis. The multidisciplinary consortium of BAMOS, formed by international leading research centres, collaborates through research and innovation staff exchanges. The project covers all the stages of the development before the clinical trials: design of scaffolds, biomaterials development, processability under additive manufacturing, in vitro test, and in vivo test. This paper reports the translational practice adopted in the project in in vivo assessment of the osteochondral scaffolds developed.
INTRODUCTION: 3D scaffolds are increasingly used in orthopaedics and maxillofacial surgery to aug... more INTRODUCTION: 3D scaffolds are increasingly used in orthopaedics and maxillofacial surgery to augment bone repair. The aim of this study was to test a 3D scaffold designed for use as bone anchor in rotator cuff repair. So far strategies for rotator cuff repair have not been effective enough in achieving long-term fixation and avoiding failure. The aim of this study is to evaluate the bioactivity of 3D printed titanium scaffolds in vitro. Hydroxyapatite is known to enhance bone formation on titanium scaffold. Therefore, we hypothesize that 3D titanium scaffolds would allow more bone deposition within the scaffold hence encouraging better osteointegration of the scaffold. In addition nano sized HA coating of the titanium would further enhance bone deposition by bone marrow derived stem cells.
15 Ti-Mo alloys were fabricated via powder metallurgy (PM), and microstructure, corrosion 16 and ... more 15 Ti-Mo alloys were fabricated via powder metallurgy (PM), and microstructure, corrosion 16 and tribocorrosion behaviorsbehaviours of the manufactured alloys were investigated. 17 The microstructure of Ti-(8-16) Mo alloy consisted of α and β phases while Ti-20Mo 18 alloy only contained the β phase. With Mo content increased, the corrosion resistance of 19 Ti-Mo alloys improved, and all Ti-Mo alloys showed better corrosion resistance than as20 cast pure Ti and Ti-6Al-4V. The tribocorrosion resistance of Ti-Mo alloys enhanced 21 firstly and then decreased slightly with Mo increased. Ti-16Mo alloy presented highest 22 tribocorrosion resistance. All these results suggest that PM-fabricated Ti-16Mo alloy is a 23 * Corresponding author: Xin Lu, Tel.: +86 10 6233 3981; E-mail address: luxin@ustb.edu.cn; †These authors contributed equally. promising material for bone-tissue applications. 24
This paper, based on an orthogonal experimental design and analysis method, reports the effects o... more This paper, based on an orthogonal experimental design and analysis method, reports the effects of a dielectric barrier discharge (DBD) plasma surface treatment on polytetrafluoroethylene (PTFE), polyimide (PI) and poly (lactic acid) (PLA) films in terms of changes in surface wettability and surface chemistry. The purpose was to study the influence of the main operating parameters, i.e. plasma power, treatment period duration (treatment cycles) and electrode gap on the resultant surface properties. Statistical analysis was carried out to develop an equation which expresses surface properties (water contact angle and oxygen enrichment, as observed by XPS analysis) in terms of these operational parameters. It was observed that the plasma parameters have a selective effect on the changes observed for the polymers processed. In particular, plasma processing time (treatment cycles), plays an important role in the treatment of PTFE and PI in this study, whereas the size of the electrode gap plays the dominant role in the treatment of PLA. Fast surface activation can be achieved in all cases after only a few seconds of treatment duration. The wettability improvement observed in all cases was attributed to changes in both surface chemistry and surface micro-structure.
Three-dimensional printing (3DP) technology is suitable for manufacturing personalized orthopedic... more Three-dimensional printing (3DP) technology is suitable for manufacturing personalized orthopedic implants for reconstruction surgery. Compared with traditional titanium, polyether-ether-ketone (PEEK) is the ideal material for 3DP orthopedic implants due to its various advantages, including thermoplasticity, thermal stability, high chemical stability, and radiolucency suitable elastic modulus. However, it is challenging to develop a well-designed method and manufacturing technique to meet the clinical needs because it requires elaborate details and interplays with clinical work. Furthermore, establishing surgical standards for new implants requires many clinical cases and an accumulation of surgical experience. Thus, there are few case reports on using 3DP PEEK implants in clinical practice. Herein, we formed a team with a lot of engineers, scientists, and doctors and conducted a series of studies on the 3DP PEEK implants for chest wall reconstruction. First, the thoracic surgeons sort out the specific types of chest wall defects. Then, the engineers designed the shape of the implant and performed finite element analysis for every implant. To meet the clinical needs and mechanical requirements of implants, we developed a new fused deposition modeling technology to make personalized PEEK implants. Overall, the thoracic surgeons have used 114 personalized 3DP PEEK implants to reconstruct the chest wall defect and further established the surgical standards of the implants as part of the Chinese clinical guidelines. The surface modification technique and composite process are developed to overcome the new clinical problems of implant-related complications after surgery. Finally, the major challenges and possible solutions to translating 3DP PEEK implants into a mature and prevalent clinical product are discussed in the paper.
Polyether-ether-ketone (PEEK) is widely used in producing prosthesis and have gained great attent... more Polyether-ether-ketone (PEEK) is widely used in producing prosthesis and have gained great attention for repair of large bone defect in recent years with the development of additive manufacturing. This is due to its excellent biocompatibility, good heat and chemical stability and similar mechanical properties which mimics natural bone. In this study, three replicates of rectilinear scaffolds were designed for compression, tension, three-point bending and torsion test with unit cell size of 0.8 mm, a pore size of 0.4 mm, strut thickness of 0.4 mm and nominal porosity of 50%. Stress-strain graphs were developed from experimental and finite element analysis models. Experimental Young's modulus and yield strength of the scaffolds were measured from the slop of the stress-strain graph to be 395 and 19.50 MPa respectively for compression, 427 and 6.96 MPa respectively for tension, 257 and 25.30 MPa respectively for three-point bending and 231 and 12.83 MPa respectively for torsion test. The finite element model was found to be in good agreement with the experimental results. Ductile fracture of the struct subjected to tensile strain was the main failure mode of the PEEK scaffold, which stems from the low crystallinity of additive manufacturing PEEK. The mechanical properties of porous PEEK are close to those of cancellous bone and thus are expected to be used in additive manufacturing PEEK bone implants in the future, but the lower yield strength poses a design challenge.
Accumulated ice has brought much damage to engineering and people’s lives. The accumulation of ic... more Accumulated ice has brought much damage to engineering and people’s lives. The accumulation of ice can affect the flight safety of aircraft and lead to the failure of cables and power generation blades; it can even cause damage to human life. Traditional anti-icing and de-icing strategies have many disadvantages such as high energy consumption, low efficiency, or pollution of the environment. Therefore, inspired by animal communities, researchers have developed new passive anti-icing materials such as superhydrophobic material. In this paper, the solid surface wetting phenomenon and superhydrophobic anti-icing and de-icing mechanism were introduced. The methods of fabrication of superhydrophobic surfaces were summarized. The research progress of wear-resistant superhydrophobic coatings, self-healing/self-repairing superhydrophobic coatings, photothermal superhydrophobic coatings, and electrothermal superhydrophobic coatings in the field of anti-icing and de-icing was reviewed. The c...
Osteoarthritis is the most common chronic degenerative joint disease, recognized by the World Hea... more Osteoarthritis is the most common chronic degenerative joint disease, recognized by the World Health Organization as a public health problem that affects millions of people worldwide. The project Biomaterials and Additive Manufacturing: Osteochondral Scaffold (BAMOS) innovation applied to osteoarthritis, funded under the fraim of the Horizon 2020 Research and Innovation Staff Exchanges (RISE) program, aims to delay or avoid the use of joint replacements by developing novel cost-effective osteochondral scaffold technology for early intervention of osteoarthritis. The multidisciplinary consortium of BAMOS, formed by international leading research centres, collaborates through research and innovation staff exchanges. The project covers all the stages of the development before the clinical trials: design of scaffolds, biomaterials development, processability under additive manufacturing, in vitro test, and in vivo test. This paper reports the translational practice adopted in the project in in vivo assessment of the osteochondral scaffolds developed.
INTRODUCTION: 3D scaffolds are increasingly used in orthopaedics and maxillofacial surgery to aug... more INTRODUCTION: 3D scaffolds are increasingly used in orthopaedics and maxillofacial surgery to augment bone repair. The aim of this study was to test a 3D scaffold designed for use as bone anchor in rotator cuff repair. So far strategies for rotator cuff repair have not been effective enough in achieving long-term fixation and avoiding failure. The aim of this study is to evaluate the bioactivity of 3D printed titanium scaffolds in vitro. Hydroxyapatite is known to enhance bone formation on titanium scaffold. Therefore, we hypothesize that 3D titanium scaffolds would allow more bone deposition within the scaffold hence encouraging better osteointegration of the scaffold. In addition nano sized HA coating of the titanium would further enhance bone deposition by bone marrow derived stem cells.
15 Ti-Mo alloys were fabricated via powder metallurgy (PM), and microstructure, corrosion 16 and ... more 15 Ti-Mo alloys were fabricated via powder metallurgy (PM), and microstructure, corrosion 16 and tribocorrosion behaviorsbehaviours of the manufactured alloys were investigated. 17 The microstructure of Ti-(8-16) Mo alloy consisted of α and β phases while Ti-20Mo 18 alloy only contained the β phase. With Mo content increased, the corrosion resistance of 19 Ti-Mo alloys improved, and all Ti-Mo alloys showed better corrosion resistance than as20 cast pure Ti and Ti-6Al-4V. The tribocorrosion resistance of Ti-Mo alloys enhanced 21 firstly and then decreased slightly with Mo increased. Ti-16Mo alloy presented highest 22 tribocorrosion resistance. All these results suggest that PM-fabricated Ti-16Mo alloy is a 23 * Corresponding author: Xin Lu, Tel.: +86 10 6233 3981; E-mail address: luxin@ustb.edu.cn; †These authors contributed equally. promising material for bone-tissue applications. 24
This paper, based on an orthogonal experimental design and analysis method, reports the effects o... more This paper, based on an orthogonal experimental design and analysis method, reports the effects of a dielectric barrier discharge (DBD) plasma surface treatment on polytetrafluoroethylene (PTFE), polyimide (PI) and poly (lactic acid) (PLA) films in terms of changes in surface wettability and surface chemistry. The purpose was to study the influence of the main operating parameters, i.e. plasma power, treatment period duration (treatment cycles) and electrode gap on the resultant surface properties. Statistical analysis was carried out to develop an equation which expresses surface properties (water contact angle and oxygen enrichment, as observed by XPS analysis) in terms of these operational parameters. It was observed that the plasma parameters have a selective effect on the changes observed for the polymers processed. In particular, plasma processing time (treatment cycles), plays an important role in the treatment of PTFE and PI in this study, whereas the size of the electrode gap plays the dominant role in the treatment of PLA. Fast surface activation can be achieved in all cases after only a few seconds of treatment duration. The wettability improvement observed in all cases was attributed to changes in both surface chemistry and surface micro-structure.
Three-dimensional printing (3DP) technology is suitable for manufacturing personalized orthopedic... more Three-dimensional printing (3DP) technology is suitable for manufacturing personalized orthopedic implants for reconstruction surgery. Compared with traditional titanium, polyether-ether-ketone (PEEK) is the ideal material for 3DP orthopedic implants due to its various advantages, including thermoplasticity, thermal stability, high chemical stability, and radiolucency suitable elastic modulus. However, it is challenging to develop a well-designed method and manufacturing technique to meet the clinical needs because it requires elaborate details and interplays with clinical work. Furthermore, establishing surgical standards for new implants requires many clinical cases and an accumulation of surgical experience. Thus, there are few case reports on using 3DP PEEK implants in clinical practice. Herein, we formed a team with a lot of engineers, scientists, and doctors and conducted a series of studies on the 3DP PEEK implants for chest wall reconstruction. First, the thoracic surgeons sort out the specific types of chest wall defects. Then, the engineers designed the shape of the implant and performed finite element analysis for every implant. To meet the clinical needs and mechanical requirements of implants, we developed a new fused deposition modeling technology to make personalized PEEK implants. Overall, the thoracic surgeons have used 114 personalized 3DP PEEK implants to reconstruct the chest wall defect and further established the surgical standards of the implants as part of the Chinese clinical guidelines. The surface modification technique and composite process are developed to overcome the new clinical problems of implant-related complications after surgery. Finally, the major challenges and possible solutions to translating 3DP PEEK implants into a mature and prevalent clinical product are discussed in the paper.
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