In a recent single cell transcriptomic investigation of the peripheral immune responses of the patients with severe COVID-19[1],no substantial expression of pro-inflammatory cytokines has been identified in the periph...In a recent single cell transcriptomic investigation of the peripheral immune responses of the patients with severe COVID-19[1],no substantial expression of pro-inflammatory cytokines has been identified in the peripheral monocytes and lymphocytes,while these peripheral immune cells exhibit phenotypes of heterogeneously expressed interferon-stimulated genes in certain COVID-19 patients.These genes may contribute to the inhibitory response to the viral entry,translation,replication and egress.Questions remain regarding why the peripheral cytokine production is constrained,what additional roles these peripheral immune cells may play in COVID-19 pathophysiology,and which potential targets can be explored for facilitating COVID-19 therapeutics.展开更多
Only a few studies have examined how pore geometry affects the mechanical characteristics, biological behavior, and degradation of additively manufactured biodegradable porous magnesium. In this work, the effects of p...Only a few studies have examined how pore geometry affects the mechanical characteristics, biological behavior, and degradation of additively manufactured biodegradable porous magnesium. In this work, the effects of pore geometry on mechanical qualities, degradation,and biological behavior were investigated using three typical porous architectures with the same porosity. The porous structures were found to satisfy bone tissue engineering requirements because they had sufficient degradation resistance and tunable compressive characteristics. All three types of magnesium alloy scaffolds exhibited good biocompatibility. Additionally, the magnesium alloy porous structures influenced the magnesium scaffold material degradation rate and the surrounding environment, impacting the osteogenic differentiation of bone mesenchymal stem cells and bone tissue regeneration. This work offers conceptual support for optimizing pore geometry to alter the mechanical and degradable characteristics of additively manufactured porous magnesium to meet therapeutic demands.展开更多
The effects of pore size in additively manufactured biodegradable porous magnesium on the mechanical properties and biodegradation of the scaffolds as well as new bone formation have rarely been reported. In this work...The effects of pore size in additively manufactured biodegradable porous magnesium on the mechanical properties and biodegradation of the scaffolds as well as new bone formation have rarely been reported. In this work, we found that high temperature oxidation improves the corrosion resistance of magnesium scaffold. And the effects of pore size on the mechanical characteristics and biodegradation of scaffolds, as well as new bone formation, were investigated using magnesium scaffolds with three different pore sizes, namely, 500, 800, and 1400 μm (P500, P800, and P1400). We discovered that the mechanical characteristics of the P500 group were much better than those of the other two groups. In vitro and in vivo investigations showed that WE43 magnesium alloy scaffolds supported the survival of mesenchymal stem cells and did not cause any local toxicity. Due to their larger specific surface area, the scaffolds in the P500 group released more magnesium ions within reasonable range and improved the osteogenic differentiation of bone mesenchymal stem cells compared with the other two scaffolds. In a rabbit femoral condyle defect model, the P500 group demonstrated unique performance in promoting new bone formation, indicating its great potential for use in bone defect regeneration therapy.展开更多
Reconstruction of subarticular bone defects is an intractable challenge in orthopedics.The simultaneous repair of cancellous defects,fractures,and cartilage damage is an ideal surgical outcome.3D printed porous anatom...Reconstruction of subarticular bone defects is an intractable challenge in orthopedics.The simultaneous repair of cancellous defects,fractures,and cartilage damage is an ideal surgical outcome.3D printed porous anatomical WE43(magnesium with 4 wt%yttrium and 3 wt%rare earths)scaffolds have many advantages for repairing such bone defects,including good biocompatibility,appropriate mechanical strength,customizable shape and structure,and biodegradability.In a previous investigation,we successfully enhanced the corrosion resistance of WE43 samples via high temperature oxidation(HTO).In the present study,we explored the feasibility and effectiveness of HTO-treated 3D printed porous anatomical WE43 scaffolds for repairing the cancellous bone defects accompanied by split fractures via in vitro and in vivo experiments.After HTO treatment,a dense oxidation layer mainly composed of Y2O3 and Nd2O3 formed on the surface of scaffolds.In addition,the majority of the grains were equiaxed,with an average grain size of 7.4μm.Cell and rabbit experiments confirmed the non-cytotoxicity and biocompatibility of the HTO-treated WE43 scaffolds.After the implantation of scaffolds inside bone defects,their porous structures could be maintained for more than 12 weeks without penetration and for more than 6 weeks with penetration.During the postoperative follow-up period for up to 48 weeks,radiographic examinations and histological analysis revealed that abundant bone gradually regenerated along with scaffold degradation,and stable osseointegration formed between new bone and scaffold residues.MRI images further demonstrated no evidence of any obvious damage to the cartilage,ligaments,or menisci,confirming the absence of traumatic osteoarthritis.Moreover,finite element analysis and biomechanical tests further verified that the scaffolds was conducive to a uniform mechanical distribution.In conclusion,applying the HTO-treated 3D printed porous anatomical WE43 scaffolds exhibited favorable repairing effects for subarticular cancellous bone defects,possessing great potential for clinical application.展开更多
基金support received from the Scientific Research Grant of Ningbo University(215-432000282)Ningbo Top Talent Project(215-432094250).
文摘In a recent single cell transcriptomic investigation of the peripheral immune responses of the patients with severe COVID-19[1],no substantial expression of pro-inflammatory cytokines has been identified in the peripheral monocytes and lymphocytes,while these peripheral immune cells exhibit phenotypes of heterogeneously expressed interferon-stimulated genes in certain COVID-19 patients.These genes may contribute to the inhibitory response to the viral entry,translation,replication and egress.Questions remain regarding why the peripheral cytokine production is constrained,what additional roles these peripheral immune cells may play in COVID-19 pathophysiology,and which potential targets can be explored for facilitating COVID-19 therapeutics.
基金National Key Research and Development Program of China (2018YFE0104200)Youth Innovation Promotion Association CAS (2019031)National Natural Science Foundation of China (51875310,52175274, 82172065)。
文摘Only a few studies have examined how pore geometry affects the mechanical characteristics, biological behavior, and degradation of additively manufactured biodegradable porous magnesium. In this work, the effects of pore geometry on mechanical qualities, degradation,and biological behavior were investigated using three typical porous architectures with the same porosity. The porous structures were found to satisfy bone tissue engineering requirements because they had sufficient degradation resistance and tunable compressive characteristics. All three types of magnesium alloy scaffolds exhibited good biocompatibility. Additionally, the magnesium alloy porous structures influenced the magnesium scaffold material degradation rate and the surrounding environment, impacting the osteogenic differentiation of bone mesenchymal stem cells and bone tissue regeneration. This work offers conceptual support for optimizing pore geometry to alter the mechanical and degradable characteristics of additively manufactured porous magnesium to meet therapeutic demands.
文摘The effects of pore size in additively manufactured biodegradable porous magnesium on the mechanical properties and biodegradation of the scaffolds as well as new bone formation have rarely been reported. In this work, we found that high temperature oxidation improves the corrosion resistance of magnesium scaffold. And the effects of pore size on the mechanical characteristics and biodegradation of scaffolds, as well as new bone formation, were investigated using magnesium scaffolds with three different pore sizes, namely, 500, 800, and 1400 μm (P500, P800, and P1400). We discovered that the mechanical characteristics of the P500 group were much better than those of the other two groups. In vitro and in vivo investigations showed that WE43 magnesium alloy scaffolds supported the survival of mesenchymal stem cells and did not cause any local toxicity. Due to their larger specific surface area, the scaffolds in the P500 group released more magnesium ions within reasonable range and improved the osteogenic differentiation of bone mesenchymal stem cells compared with the other two scaffolds. In a rabbit femoral condyle defect model, the P500 group demonstrated unique performance in promoting new bone formation, indicating its great potential for use in bone defect regeneration therapy.
基金funded by the National Key Research and Development Program of China(No.2018YFE0104200)National Natural Science Foundation of China(51875310,52175274,82172065)Peking University Medicine Sailing Program for Young Scholars’Scientific&Technological Innovation(BMU2023YFJHPY015).
文摘Reconstruction of subarticular bone defects is an intractable challenge in orthopedics.The simultaneous repair of cancellous defects,fractures,and cartilage damage is an ideal surgical outcome.3D printed porous anatomical WE43(magnesium with 4 wt%yttrium and 3 wt%rare earths)scaffolds have many advantages for repairing such bone defects,including good biocompatibility,appropriate mechanical strength,customizable shape and structure,and biodegradability.In a previous investigation,we successfully enhanced the corrosion resistance of WE43 samples via high temperature oxidation(HTO).In the present study,we explored the feasibility and effectiveness of HTO-treated 3D printed porous anatomical WE43 scaffolds for repairing the cancellous bone defects accompanied by split fractures via in vitro and in vivo experiments.After HTO treatment,a dense oxidation layer mainly composed of Y2O3 and Nd2O3 formed on the surface of scaffolds.In addition,the majority of the grains were equiaxed,with an average grain size of 7.4μm.Cell and rabbit experiments confirmed the non-cytotoxicity and biocompatibility of the HTO-treated WE43 scaffolds.After the implantation of scaffolds inside bone defects,their porous structures could be maintained for more than 12 weeks without penetration and for more than 6 weeks with penetration.During the postoperative follow-up period for up to 48 weeks,radiographic examinations and histological analysis revealed that abundant bone gradually regenerated along with scaffold degradation,and stable osseointegration formed between new bone and scaffold residues.MRI images further demonstrated no evidence of any obvious damage to the cartilage,ligaments,or menisci,confirming the absence of traumatic osteoarthritis.Moreover,finite element analysis and biomechanical tests further verified that the scaffolds was conducive to a uniform mechanical distribution.In conclusion,applying the HTO-treated 3D printed porous anatomical WE43 scaffolds exhibited favorable repairing effects for subarticular cancellous bone defects,possessing great potential for clinical application.
