Hsuan-Wen Wang, Chih-Hwa Chen, Kuan-Hao Chen, Yu-Hui Zeng, Chun-Li Lin
Metal three-dimensional (3D) printing has become an important manufacturing process in medical implant development. Nevertheless, the metal 3D-printed implant needs to be considered with structural optimization to reduce the stress-shielding effects and to be incorporated with a lattice design to generate better bone ingrowth environment. This study combines topology optimization (TO) and lattice design to acquire an optimal wedge-shaped spacer (OWS) for high tibial osteotomy (HTO) fixation. The OWS was manufactured using titanium alloy 3D printing to conduct biomechanical fatigue testing for mechanical performance validation. A solid wedge-shaped spacer (SWS) with three embedded screws was designed using the HTO model. An OWS was obtained under physiological loads through finite element (FE) analysis and TO. A deformed YM lattice with a porosity of 60% and pore size of 700 μm was filled at the OWS posterior region. The HTO mechanical performance was simulated for SWS, OWS, and commercial T-shaped plate (TP) fixations using FE analysis. The displacement/fracture patterns under OWS and TP fixations were verified using fatigue testing. The manufacturing errors for all 3D-printed OWS features were found to be less than 1%. The FE results revealed that the OWS fixation demonstrated reductions of 56.46%, 11.98%, and 64.31% in displacement, stress in the implant and bone, respectively, compared to the TP fixation. The fatigue test indicated that the OWS fixation exhibited smaller displacement for the HTO, as well as a higher load capacity, minor bone fracture collapse, and a greater number of cycles than the TP system. This study concluded that medical implants can be designed by integrating macro TO and microlattice design to provide enough mechanical strength and an environment for bone ingrowth after surgery. Both FE analysis and biomechanical fatigue tests confirmed that OWS mechanical performance with lattice design was more stable than the HTO TP fixations.
金属三维（3D）打印已成为医疗植入物开发的重要制造工艺。然而，金属三维打印植入物需要考虑结构优化，以减少应力屏蔽效应，并与晶格设计相结合，以产生更好的骨生长环境。本研究将拓扑优化（TO）和晶格设计相结合，以获得用于高胫骨截骨术（HTO）固定的最佳楔形垫片（OWS）。OWS 采用钛合金 3D 打印技术制造，并进行了生物力学疲劳测试，以验证其机械性能。利用 HTO 模型设计了带有三个嵌入螺钉的实心楔形垫片（SWS）。通过有限元（FE）分析和 TO，获得了生理负荷下的 OWS。在 OWS 后部区域填充了孔隙率为 60%、孔径为 700 μm 的变形 YM 晶格。利用有限元分析模拟了 SWS、OWS 和商用 T 型钢板（TP）固定的 HTO 机械性能。通过疲劳测试验证了 OWS 和 TP 固定下的位移/断裂模式。所有 3D 打印 OWS 特征的制造误差均小于 1%。有限元分析结果显示，与 TP 固定相比，OWS 固定的位移、植入体和骨的应力分别减少了 56.46%、11.98% 和 64.31%。疲劳测试表明，与 TP 系统相比，OWS 固定器的 HTO 位移更小，承载能力更高，骨骨折塌陷更小，循环次数更多。这项研究得出结论，医疗植入物可以通过整合宏观 TO 和微格设计来提供足够的机械强度和术后骨生长环境。有限元分析和生物力学疲劳测试均证实，采用晶格设计的 OWS 机械性能比 HTO TP 固定装置更稳定。
{"title":"Designing a 3D-printed medical implant with mechanically macrostructural topology and microbionic lattices: A novel wedge-shaped spacer for high tibial osteotomy and biomechanical study","authors":"Hsuan-Wen Wang, Chih-Hwa Chen, Kuan-Hao Chen, Yu-Hui Zeng, Chun-Li Lin","doi":"10.36922/ijb.1584","DOIUrl":"https://doi.org/10.36922/ijb.1584","url":null,"abstract":"Metal three-dimensional (3D) printing has become an important manufacturing process in medical implant development. Nevertheless, the metal 3D-printed implant needs to be considered with structural optimization to reduce the stress-shielding effects and to be incorporated with a lattice design to generate better bone ingrowth environment. This study combines topology optimization (TO) and lattice design to acquire an optimal wedge-shaped spacer (OWS) for high tibial osteotomy (HTO) fixation. The OWS was manufactured using titanium alloy 3D printing to conduct biomechanical fatigue testing for mechanical performance validation. A solid wedge-shaped spacer (SWS) with three embedded screws was designed using the HTO model. An OWS was obtained under physiological loads through finite element (FE) analysis and TO. A deformed YM lattice with a porosity of 60% and pore size of 700 μm was filled at the OWS posterior region. The HTO mechanical performance was simulated for SWS, OWS, and commercial T-shaped plate (TP) fixations using FE analysis. The displacement/fracture patterns under OWS and TP fixations were verified using fatigue testing. The manufacturing errors for all 3D-printed OWS features were found to be less than 1%. The FE results revealed that the OWS fixation demonstrated reductions of 56.46%, 11.98%, and 64.31% in displacement, stress in the implant and bone, respectively, compared to the TP fixation. The fatigue test indicated that the OWS fixation exhibited smaller displacement for the HTO, as well as a higher load capacity, minor bone fracture collapse, and a greater number of cycles than the TP system. This study concluded that medical implants can be designed by integrating macro TO and microlattice design to provide enough mechanical strength and an environment for bone ingrowth after surgery. Both FE analysis and biomechanical fatigue tests confirmed that OWS mechanical performance with lattice design was more stable than the HTO TP fixations.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"41 12","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139441148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Additive manufacturing has enabled the customization of biomedical systems, including transplantable medical devices, to achieve mechanical biocompatibility. For bone implants, patient-specific bone models must be used to evaluate the mechanical properties of implant compression and subsidence. This study proposes a methodology for designing and fabricating bone models to evaluate patient-specific bone implants. The method involves three-dimensional printing of infill-varied structure, with alternating high-low-high infill density regions, which undergo sequential deformation from the surficial region during compression with an implant. Based on this deformation behavior, the relationship between infill density parameters and mechanical properties was confirmed with the tunability of mechanical properties involving stiffness and failure load. The infill-varied design was applied to the inner structures of artificial vertebra models based on computed tomography scans for cadaver specimens. By tailoring the infill density conditions, the stiffness and failure load were approximated to those of the natural vertebrae. Furthermore, this infill-varied artificial vertebra could be used to evaluate additive-manufactured patient-specific implants. The patient-specific implant had greater resistance to subsidence than the commercial implant, suggesting the feasibility of a biomimicking bone model. The bone-mimetic infill-varied structure could be used to evaluate patient-specific manufactured implants and could be applied to other bone engineering structures with optimized biomechanical properties.
{"title":"Additive-manufactured synthetic bone model with biomimicking tunable mechanical properties for evaluation of medical implants","authors":"Ju Chan Yuk, Kyoung Hyup Nam, Suk Hee Park","doi":"10.36922/ijb.1067","DOIUrl":"https://doi.org/10.36922/ijb.1067","url":null,"abstract":"Additive manufacturing has enabled the customization of biomedical systems, including transplantable medical devices, to achieve mechanical biocompatibility. For bone implants, patient-specific bone models must be used to evaluate the mechanical properties of implant compression and subsidence. This study proposes a methodology for designing and fabricating bone models to evaluate patient-specific bone implants. The method involves three-dimensional printing of infill-varied structure, with alternating high-low-high infill density regions, which undergo sequential deformation from the surficial region during compression with an implant. Based on this deformation behavior, the relationship between infill density parameters and mechanical properties was confirmed with the tunability of mechanical properties involving stiffness and failure load. The infill-varied design was applied to the inner structures of artificial vertebra models based on computed tomography scans for cadaver specimens. By tailoring the infill density conditions, the stiffness and failure load were approximated to those of the natural vertebrae. Furthermore, this infill-varied artificial vertebra could be used to evaluate additive-manufactured patient-specific implants. The patient-specific implant had greater resistance to subsidence than the commercial implant, suggesting the feasibility of a biomimicking bone model. The bone-mimetic infill-varied structure could be used to evaluate patient-specific manufactured implants and could be applied to other bone engineering structures with optimized biomechanical properties.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"8 4","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139439510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stem cell differentiation has important implications for biomedical device design and tissue engineering. Recently, inherent material properties, including surface chemistry, stiffness, and topography, have been found to influence stem cell fate. Among these, surface topography is a key regulator of stem cells in contact with materials. The most important aspect of ideal bone tissue engineering is to control the organization of the bone extracellular matrix with fully differentiated osteoblasts. Here, we found that laser powder bed fusion (PBF-LB)-fabricated grooved surface inspired by the microstructure of bone, which induced human mesenchymal stem cell (hMSC) differentiation into the osteogenic lineage without any differentiation supplements. The periodic grooved structure was fabricated by PBF-LB which induced cell elongation facilitated by cytoskeletal tension along the grooves. This resulted in the upregulation of osteogenesis via Runx2 expression. The aligned hMSCs successfully differentiated into osteoblasts and further organized the bone mimetic-oriented extracellular matrix microstructure. Our results indicate that metal additive manufacturing technology has a great advantage in controlling stem cell fate into the osteogenic lineage, and in the construction of bone-mimetic microstructural organization. Our findings on material-induced stem cell differentiation under standard cell culture conditions open new avenues for the development of medical devices that realize the desired tissue regeneration mediated by regulated stem cell functions.
{"title":"PBF-LB fabrication of microgrooves for induction of osteogenic differentiation of human mesenchymal stem cells","authors":"Aira Matsugaki, Tadaaki Matsuzaka, Toko Mori, Mitsuka Saito, Kazuma Funaoku, Riku Yamano, O. Gokcekaya, Ryosuke Ozasa, Takayoshi Nakano","doi":"10.36922/ijb.1425","DOIUrl":"https://doi.org/10.36922/ijb.1425","url":null,"abstract":"Stem cell differentiation has important implications for biomedical device design and tissue engineering. Recently, inherent material properties, including surface chemistry, stiffness, and topography, have been found to influence stem cell fate. Among these, surface topography is a key regulator of stem cells in contact with materials. The most important aspect of ideal bone tissue engineering is to control the organization of the bone extracellular matrix with fully differentiated osteoblasts. Here, we found that laser powder bed fusion (PBF-LB)-fabricated grooved surface inspired by the microstructure of bone, which induced human mesenchymal stem cell (hMSC) differentiation into the osteogenic lineage without any differentiation supplements. The periodic grooved structure was fabricated by PBF-LB which induced cell elongation facilitated by cytoskeletal tension along the grooves. This resulted in the upregulation of osteogenesis via Runx2 expression. The aligned hMSCs successfully differentiated into osteoblasts and further organized the bone mimetic-oriented extracellular matrix microstructure. Our results indicate that metal additive manufacturing technology has a great advantage in controlling stem cell fate into the osteogenic lineage, and in the construction of bone-mimetic microstructural organization. Our findings on material-induced stem cell differentiation under standard cell culture conditions open new avenues for the development of medical devices that realize the desired tissue regeneration mediated by regulated stem cell functions.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"34 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139443956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fan Liu, Chaohan Wu, Xinhui Wang, Rong-Zuo Guo, Tianhua Dong, Tao Zhang
The aim of this study was to investigate the use of three-dimensional (3D) printing technology to create a biodegradable scaffold loaded with WNT5A protein and assess its impact on chronic tibial osteomyelitis with bone defects (CTO&BD), focusing on osteoblast differentiation and angiogenesis. We extracted RNA from peripheral blood of healthy individuals and CTO&BD patients for sequencing, followed by differential expression and functional enrichment analysis. Network analysis was performed to identify core genes associated with CTO&BD and construct a protein–protein interaction network. Using Masquelet technique, we fabricated a 3D-printed biodegradable scaffold (G40T60@WNT5A) and conducted various experiments, including rheological testing, printability evaluation, Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy analysis, as well as mechanical and degradation performance assessments. In in vivo experiments, we observed the formation of induced membranes in a CTO&BD rat model implanted with the scaffold. In vitro experiments involved the assessment of scaffold toxicity on rat bone marrow mesenchymal stem cells and umbilical vein endothelial cells, as well as the influence on osteoblast differentiation and angiogenesis. Molecular biology techniques were used to analyze gene and protein expression levels. We discovered for the first time that WNT5A may play a crucial role in CTO&BD. The biodegradable scaffold prepared by 3D printing (G40T60@WNT5A) exhibited excellent biocompatibility in vitro. This scaffold significantly promoted the formation of induced membranes in CTO&BD rats and further enhanced osteoblast differentiation and angiogenesis. In conclusion, this study utilized innovative 3D printing technology to fabricate the G40T60@WNT5A scaffold, confirming its potential application in the treatment of CTO&BD, particularly in promoting osteoblast differentiation and angiogenesis. This research provides new methods and theoretical support for the treatment of bone defects.
{"title":"Building a degradable scaffold with 3D printing using Masquelet technique to promote osteoblast differentiation and angiogenesis in chronic tibial osteomyelitis with bone defects","authors":"Fan Liu, Chaohan Wu, Xinhui Wang, Rong-Zuo Guo, Tianhua Dong, Tao Zhang","doi":"10.36922/ijb.1461","DOIUrl":"https://doi.org/10.36922/ijb.1461","url":null,"abstract":"The aim of this study was to investigate the use of three-dimensional (3D) printing technology to create a biodegradable scaffold loaded with WNT5A protein and assess its impact on chronic tibial osteomyelitis with bone defects (CTO&BD), focusing on osteoblast differentiation and angiogenesis. We extracted RNA from peripheral blood of healthy individuals and CTO&BD patients for sequencing, followed by differential expression and functional enrichment analysis. Network analysis was performed to identify core genes associated with CTO&BD and construct a protein–protein interaction network. Using Masquelet technique, we fabricated a 3D-printed biodegradable scaffold (G40T60@WNT5A) and conducted various experiments, including rheological testing, printability evaluation, Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy analysis, as well as mechanical and degradation performance assessments. In in vivo experiments, we observed the formation of induced membranes in a CTO&BD rat model implanted with the scaffold. In vitro experiments involved the assessment of scaffold toxicity on rat bone marrow mesenchymal stem cells and umbilical vein endothelial cells, as well as the influence on osteoblast differentiation and angiogenesis. Molecular biology techniques were used to analyze gene and protein expression levels. We discovered for the first time that WNT5A may play a crucial role in CTO&BD. The biodegradable scaffold prepared by 3D printing (G40T60@WNT5A) exhibited excellent biocompatibility in vitro. This scaffold significantly promoted the formation of induced membranes in CTO&BD rats and further enhanced osteoblast differentiation and angiogenesis. In conclusion, this study utilized innovative 3D printing technology to fabricate the G40T60@WNT5A scaffold, confirming its potential application in the treatment of CTO&BD, particularly in promoting osteoblast differentiation and angiogenesis. This research provides new methods and theoretical support for the treatment of bone defects.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"21 10","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139444299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, a series of new gradient porous scaffolds were innovatively designed via a dual-unit continuous transition connection strategy based on the minimal surface structures (primitive [P], diamond [D], and gyroid [G]). The scaffolds were successfully prepared through selective laser melting technology. The results showed that the dual-unit continuous transition connection strategy significantly improved the mechanical properties of the connected scaffolds. The compression strength of the scaffolds was found to be (P-G)>(P-D)>(G-P)>(G-D)>(D-G)>(D-P), with the P-G structure exhibiting a compression strength of 167.7 MPa and an elastic modulus of 3.3 GPa. The mechanical properties of the porous scaffolds were primarily influenced by the outer unit type, the connection condition between different units, the unit size, and the porosity. Scaffolds with the outer P unit demonstrated better mechanical properties due to the higher mechanical strength of the P structure. The connection performance between different units varied, with P and G units forming a good continuous transition connection, while the connection performance between P and D units was the weakest. The dual-unit continuous transition connection strategy offers a promising approach to optimize the connection performance of different units, providing new insights into the design of medical porous scaffolds.
本研究基于最小表面结构（原始结构[P]、菱形结构[D]和陀螺结构[G]），通过双单元连续过渡连接策略，创新性地设计了一系列新型梯度多孔支架。通过选择性激光熔融技术成功制备了支架。结果表明，双单元连续过渡连接策略显著提高了连接支架的力学性能。支架的压缩强度依次为（P-G）>（P-D）>（G-P）>（G-D）>（D-G）>（D-P），其中 P-G 结构的压缩强度为 167.7 MPa，弹性模量为 3.3 GPa。多孔支架的力学性能主要受外单元类型、不同单元之间的连接条件、单元尺寸和孔隙率的影响。由于 P 结构的机械强度较高，外层为 P 单元的支架具有更好的机械性能。不同单元之间的连接性能各不相同，P 单元和 G 单元形成了良好的连续过渡连接，而 P 单元和 D 单元之间的连接性能最弱。双单元连续过渡连接策略为优化不同单元的连接性能提供了一种可行的方法，为医用多孔支架的设计提供了新的思路。
{"title":"Design of biomedical gradient porous scaffold via a minimal surface dual-unit continuous transition connection strategy","authors":"Yuting Lv, Zheng Shi, Binghao Wang, Miao Luo, Ouyang Xing, Jia Liu, Hao Dong, Yanlei Sun, Liqiang Wang","doi":"10.36922/ijb.1263","DOIUrl":"https://doi.org/10.36922/ijb.1263","url":null,"abstract":"In this work, a series of new gradient porous scaffolds were innovatively designed via a dual-unit continuous transition connection strategy based on the minimal surface structures (primitive [P], diamond [D], and gyroid [G]). The scaffolds were successfully prepared through selective laser melting technology. The results showed that the dual-unit continuous transition connection strategy significantly improved the mechanical properties of the connected scaffolds. The compression strength of the scaffolds was found to be (P-G)>(P-D)>(G-P)>(G-D)>(D-G)>(D-P), with the P-G structure exhibiting a compression strength of 167.7 MPa and an elastic modulus of 3.3 GPa. The mechanical properties of the porous scaffolds were primarily influenced by the outer unit type, the connection condition between different units, the unit size, and the porosity. Scaffolds with the outer P unit demonstrated better mechanical properties due to the higher mechanical strength of the P structure. The connection performance between different units varied, with P and G units forming a good continuous transition connection, while the connection performance between P and D units was the weakest. The dual-unit continuous transition connection strategy offers a promising approach to optimize the connection performance of different units, providing new insights into the design of medical porous scaffolds.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"42 17","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139448082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Kocich, L. Kuncická, Marek Benč, Adam Weiser, Gergely Németh
Additive manufacturing (AM) is gaining increasing popularity in various fields, including biomedical engineering. Although AM enables fabrication of tailored components with complex geometries, the manufactured parts typically feature several internal issues, such as unpredictable distribution of residual stress and printing defects. However, these issues can be reduced or eliminated by post-processing via thermomechanical treatment. The study investigated the effects of combinations of AM and post-processing by the intensive plastic deformation method of rotary swaging (variable swaging ratios) on microstructures, residual stress, and corrosion behaviors of AISI 316L stainless steel workpieces; the corrosion tests were performed in an ionized simulated body fluid. The results showed that the gradual swaging process favorably refined the grains and homogenized the grain size. The imposed swaging ratio also directly influenced the development of substructure and dislocations density. A high density of dislocations positively affected the corrosion resistance, whereas annihilation of dislocations and formation of subgrains had a negative effect on the corrosion behavior. The first few swaging passes homogenized the distribution of residual stress within the workpiece and acted toward imparting a predominantly compressive stress state, which also favorably influenced the corrosion behavior. Lastly, the presence of the {111}||swaging direction texture fiber (of a high intensity) increased the resistance to pitting corrosion. Overall, the most favorable corrosion behavior was acquired for the AM sample subjected to the swaging ratio of 0.8, exhibiting a strong fiber texture and a high density of dislocations.
快速成型制造（AM）在包括生物医学工程在内的各个领域越来越受欢迎。虽然增材制造可以制造出具有复杂几何形状的定制部件，但制造出的部件通常会出现一些内部问题，如不可预知的残余应力分布和打印缺陷。不过，这些问题可以通过热机械处理的后处理方法来减少或消除。该研究调查了 AM 与旋转锻造（可变锻造比）强化塑性变形方法后处理的组合对 AISI 316L 不锈钢工件的微观结构、残余应力和腐蚀行为的影响；腐蚀测试在离子化模拟体液中进行。结果表明，渐进式锻造过程有利于细化晶粒和均匀晶粒尺寸。所施加的锻造比率也直接影响了亚结构和位错密度的发展。位错密度高会对耐腐蚀性产生积极影响，而位错湮灭和亚晶粒的形成则会对腐蚀行为产生消极影响。前几道锻造工序使工件内部的残余应力分布均匀化，并形成了以压应力为主的应力状态，这也对腐蚀行为产生了有利影响。最后，{111}|||浇铸方向纹理纤维（高强度）的存在提高了抗点蚀能力。总体而言，采用 0.8 拉伸比的 AM 样品具有最理想的腐蚀性能，表现出较强的纤维纹理和较高的位错密度。
{"title":"Corrosion behavior of selective laser melting-manufactured bio-applicable 316L stainless steel in ionized simulated body fluid","authors":"R. Kocich, L. Kuncická, Marek Benč, Adam Weiser, Gergely Németh","doi":"10.36922/ijb.1416","DOIUrl":"https://doi.org/10.36922/ijb.1416","url":null,"abstract":"Additive manufacturing (AM) is gaining increasing popularity in various fields, including biomedical engineering. Although AM enables fabrication of tailored components with complex geometries, the manufactured parts typically feature several internal issues, such as unpredictable distribution of residual stress and printing defects. However, these issues can be reduced or eliminated by post-processing via thermomechanical treatment. The study investigated the effects of combinations of AM and post-processing by the intensive plastic deformation method of rotary swaging (variable swaging ratios) on microstructures, residual stress, and corrosion behaviors of AISI 316L stainless steel workpieces; the corrosion tests were performed in an ionized simulated body fluid. The results showed that the gradual swaging process favorably refined the grains and homogenized the grain size. The imposed swaging ratio also directly influenced the development of substructure and dislocations density. A high density of dislocations positively affected the corrosion resistance, whereas annihilation of dislocations and formation of subgrains had a negative effect on the corrosion behavior. The first few swaging passes homogenized the distribution of residual stress within the workpiece and acted toward imparting a predominantly compressive stress state, which also favorably influenced the corrosion behavior. Lastly, the presence of the {111}||swaging direction texture fiber (of a high intensity) increased the resistance to pitting corrosion. Overall, the most favorable corrosion behavior was acquired for the AM sample subjected to the swaging ratio of 0.8, exhibiting a strong fiber texture and a high density of dislocations.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"73 5","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139381583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bone fractures are recognized as a global health problem. A common strategy to tackle this issue is to employ a tissue engineering scaffold to accelerate tissue healing. However, one of the main challenges that can result in delaying the recovery is the risk of bacterial infections. This study aims to assess the impact of the geometry and the porosity of tissue scaffolds on the Staphylococcus aureus biofilm formation. Three triply periodic minimal surface designs of Schwarz primitive (SP), gyroid (GY), and Schwarz diamond (SD) and re-entrant auxetic (RE) design were examined and compared to a reference design (RD) considering two different porosity levels of 75% and 45%. The amount of biofilm was quantified using crystal violet assay and was visualized using scanning electron microscopy. The SP scaffold, with low porosity, exhibited a significantly less amount of bacterial biofilm formation and was regarded as having the best design among the others, while the SD with low porosity showed the greatest amount of biofilm. The morphological analysis was also in line with the crystal violet assay results. On the other hand, the surface roughness was affected by the complexity, geometrical variations, and limitations of fused filament fabrication three-dimensional printing. For the RD, SP, GY, and SD designs, an increase in surface roughness was demonstrated to increase the production of bacterial biofilms. Without statistical significance, the RE design showed the opposite trend. Contrary to other designs, the increase in pore size of the SP and GY designs was associated with the development of bacterial biofilms. This study suggests that it is possible to minimize the likelihood of bacterial biofilm formation by optimizing the scaffold geometry and its manufacturing.
{"title":"The effect of 3D-printed bone tissue scaffolds geometrical designs on bacterial biofilm formation","authors":"A. Al-Tamimi, Esraa Aldawood","doi":"10.36922/ijb.1768","DOIUrl":"https://doi.org/10.36922/ijb.1768","url":null,"abstract":"Bone fractures are recognized as a global health problem. A common strategy to tackle this issue is to employ a tissue engineering scaffold to accelerate tissue healing. However, one of the main challenges that can result in delaying the recovery is the risk of bacterial infections. This study aims to assess the impact of the geometry and the porosity of tissue scaffolds on the Staphylococcus aureus biofilm formation. Three triply periodic minimal surface designs of Schwarz primitive (SP), gyroid (GY), and Schwarz diamond (SD) and re-entrant auxetic (RE) design were examined and compared to a reference design (RD) considering two different porosity levels of 75% and 45%. The amount of biofilm was quantified using crystal violet assay and was visualized using scanning electron microscopy. The SP scaffold, with low porosity, exhibited a significantly less amount of bacterial biofilm formation and was regarded as having the best design among the others, while the SD with low porosity showed the greatest amount of biofilm. The morphological analysis was also in line with the crystal violet assay results. On the other hand, the surface roughness was affected by the complexity, geometrical variations, and limitations of fused filament fabrication three-dimensional printing. For the RD, SP, GY, and SD designs, an increase in surface roughness was demonstrated to increase the production of bacterial biofilms. Without statistical significance, the RE design showed the opposite trend. Contrary to other designs, the increase in pore size of the SP and GY designs was associated with the development of bacterial biofilms. This study suggests that it is possible to minimize the likelihood of bacterial biofilm formation by optimizing the scaffold geometry and its manufacturing.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"34 45","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139382669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liusheng Wu, Huansong Li, Yangsui Liu, Zhengyang Fan, Jingyi Xu, Ning Li, Xinye Qian, Zewei Lin, Xiaoqiang Li, Jun Yan
With the rapid development of three-dimensional (3D) bioprinting technology, the research revolving around in vitro functional pancreas and tumor models has become the focus of attention in the field of life sciences. This review aims to summarize and deeply discuss the research progress and prospects of 3D-bioprinted functional pancreas and in vitro tumor models. The efforts in improving 3D printing technology to increase its accuracy and reliability in the biomedical applications have been ramped up over the past few years. Researchers are now able to create highly complex 3D structures through precise layering of biological materials at the micron scale. For instance, a functional pancreas can be printed in vitro by combining cells, biomaterials, and growth factors. The introduction of new technologies allows researchers to more accurately simulate the growth and spread of tumors, providing a more realistic platform for cancer treatment research. This not only helps accelerate the process of drug screening, but also lays the foundation for personalized medicine. As multiple disciplines, such as materials science, cell biology, and engineering, continue to converge with 3D bioprinting, emergence of more innovative applications is anticipated. However, despite significant progress, many technical and ethical challenges still need to be overcome before practical clinical applications can be implemented. In summary, the application of bioprinting technology is of great significance to the study of functional pancreas and in vitro tumor models, which could lead to new breakthroughs in the development of clinical treatment and personalized medicine.
{"title":"Research progress of 3D-bioprinted functional pancreas and in vitro tumor models","authors":"Liusheng Wu, Huansong Li, Yangsui Liu, Zhengyang Fan, Jingyi Xu, Ning Li, Xinye Qian, Zewei Lin, Xiaoqiang Li, Jun Yan","doi":"10.36922/ijb.1256","DOIUrl":"https://doi.org/10.36922/ijb.1256","url":null,"abstract":"With the rapid development of three-dimensional (3D) bioprinting technology, the research revolving around in vitro functional pancreas and tumor models has become the focus of attention in the field of life sciences. This review aims to summarize and deeply discuss the research progress and prospects of 3D-bioprinted functional pancreas and in vitro tumor models. The efforts in improving 3D printing technology to increase its accuracy and reliability in the biomedical applications have been ramped up over the past few years. Researchers are now able to create highly complex 3D structures through precise layering of biological materials at the micron scale. For instance, a functional pancreas can be printed in vitro by combining cells, biomaterials, and growth factors. The introduction of new technologies allows researchers to more accurately simulate the growth and spread of tumors, providing a more realistic platform for cancer treatment research. This not only helps accelerate the process of drug screening, but also lays the foundation for personalized medicine. As multiple disciplines, such as materials science, cell biology, and engineering, continue to converge with 3D bioprinting, emergence of more innovative applications is anticipated. However, despite significant progress, many technical and ethical challenges still need to be overcome before practical clinical applications can be implemented. In summary, the application of bioprinting technology is of great significance to the study of functional pancreas and in vitro tumor models, which could lead to new breakthroughs in the development of clinical treatment and personalized medicine.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"134 7","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139387666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cancer is now one of the leading causes of mortality worldwide, and the cancer treatment development is still slow due to the lack of efficient in vitro tumor models for studying tumorigenesis and facilitating drug development. Multicellular tumor spheroids can recapitulate the critical properties of tumors in vivo, including spatial organization, physiological responses, and metabolism, and are considered powerful platform for disease study and drug screening. Although several spheroid fabrication methods have been developed, most of them result in uncontrolled cell aggregations, yielding spheroids of variable size and function. Droplet-based bioprinting is capable of depositing cells in spatiotemporal manner so as to control the composition and distribution of printed biological constructs, thereby facilitating high-throughput fabrication of complicated and reproducible tumor spheroids. In this review, we introduce the progress of droplet-based bioprinting technology for the fabrication of tumor spheroids. First, different droplet-based bioprinting technologies are compared in terms of their strengths and shortcomings, which should be taken into account while fabricating tumor spheroids. Second, the latest advances in modeling distinct types of cancers and the enabled applications with tumor spheroids are summarized. Finally, we discuss the challenges and potentials revolving around the advances of bioprinting technology, improvement of spheroid quality, and integration of different technologies.
{"title":"Droplet-based bioprinting for fabrication of tumor spheroids","authors":"Congying Liu, Yuhe Chen, Huawei Chen, Pengfei Zhang","doi":"10.36922/ijb.1214","DOIUrl":"https://doi.org/10.36922/ijb.1214","url":null,"abstract":"Cancer is now one of the leading causes of mortality worldwide, and the cancer treatment development is still slow due to the lack of efficient in vitro tumor models for studying tumorigenesis and facilitating drug development. Multicellular tumor spheroids can recapitulate the critical properties of tumors in vivo, including spatial organization, physiological responses, and metabolism, and are considered powerful platform for disease study and drug screening. Although several spheroid fabrication methods have been developed, most of them result in uncontrolled cell aggregations, yielding spheroids of variable size and function. Droplet-based bioprinting is capable of depositing cells in spatiotemporal manner so as to control the composition and distribution of printed biological constructs, thereby facilitating high-throughput fabrication of complicated and reproducible tumor spheroids. In this review, we introduce the progress of droplet-based bioprinting technology for the fabrication of tumor spheroids. First, different droplet-based bioprinting technologies are compared in terms of their strengths and shortcomings, which should be taken into account while fabricating tumor spheroids. Second, the latest advances in modeling distinct types of cancers and the enabled applications with tumor spheroids are summarized. Finally, we discuss the challenges and potentials revolving around the advances of bioprinting technology, improvement of spheroid quality, and integration of different technologies.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"35 10","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139389718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Federico Serpe, C. Casciola, Giancarlo Ruocco, Gianluca Cidonio, C. Scognamiglio
Microfluidics is rapidly revolutionizing the scientific panorama, providing unmatched high-throughput platforms that find application in numerous areas of physics, chemistry, biology, and materials science. Recently, microfluidic chips have been proposed, in combination with bioactive materials, as promising tools for spinning cell-laden fibers with on-demand characteristics. However, cells encapsulated in filaments produced via microfluidic spinning technology are confined in a quasi-three-dimensional (3D) environment that fails to replicate the intricate 3D architecture of biological tissues. Thanks to the recent synergistic combination of microfluidic devices with 3D bioprinting technologies that enable the production of sophisticated microfibers serving as the backbone of 3D structures, a new age of tissue engineering is emerging. This review looks at how combining microfluidics with 3D printing is contributing to the biofabrication of relevant human substitutes and implants. This paper also describes the whole manufacturing process from the production of the microfluidic tool to the printing of tissue models, focusing on cutting-edge fabrication technologies and emphasizing the most noticeable achievements for microfluidic spinning technology. A theoretical insight for thixotropic hydrogels is also proposed to predict the fiber size and shear stress developing within microfluidic channels. The potential of using microfluidic chips as bio-printheads for multi-material and multi-cellular bioprinting is discussed, highlighting the challenges that microfluidic bioprinting still faces in advancing the field of biofabrication for tissue engineering and regenerative medicine purposes.
{"title":"Microfluidic fiber spinning for 3D bioprinting: Harnessing microchannels to build macrotissues","authors":"Federico Serpe, C. Casciola, Giancarlo Ruocco, Gianluca Cidonio, C. Scognamiglio","doi":"10.36922/ijb.1404","DOIUrl":"https://doi.org/10.36922/ijb.1404","url":null,"abstract":"Microfluidics is rapidly revolutionizing the scientific panorama, providing unmatched high-throughput platforms that find application in numerous areas of physics, chemistry, biology, and materials science. Recently, microfluidic chips have been proposed, in combination with bioactive materials, as promising tools for spinning cell-laden fibers with on-demand characteristics. However, cells encapsulated in filaments produced via microfluidic spinning technology are confined in a quasi-three-dimensional (3D) environment that fails to replicate the intricate 3D architecture of biological tissues. Thanks to the recent synergistic combination of microfluidic devices with 3D bioprinting technologies that enable the production of sophisticated microfibers serving as the backbone of 3D structures, a new age of tissue engineering is emerging. This review looks at how combining microfluidics with 3D printing is contributing to the biofabrication of relevant human substitutes and implants. This paper also describes the whole manufacturing process from the production of the microfluidic tool to the printing of tissue models, focusing on cutting-edge fabrication technologies and emphasizing the most noticeable achievements for microfluidic spinning technology. A theoretical insight for thixotropic hydrogels is also proposed to predict the fiber size and shear stress developing within microfluidic channels. The potential of using microfluidic chips as bio-printheads for multi-material and multi-cellular bioprinting is discussed, highlighting the challenges that microfluidic bioprinting still faces in advancing the field of biofabrication for tissue engineering and regenerative medicine purposes.","PeriodicalId":48522,"journal":{"name":"International Journal of Bioprinting","volume":"109 23","pages":""},"PeriodicalIF":8.4,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139391277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：