气道支架:3D打印在医疗领域的潜在应用

<正>到目前为止,3D打印在医疗行业中的应用主要集中于整形外科,近期哈佛大学医学院的研究人员发现了3D打印在医疗领域的另一项潜在突破性应用:气道支架。"我觉得这将是下一场革命,"贝丝以色列迪肯尼斯医疗中心研究人员George Cheng博士说道,"3D打印的气道     

基于水凝胶3D生物打印在组织工程中的应用

3D打印以其个性化定制、快速精准成型的优势,在国家政策的支持下快速发展,3D生物打印作为3D打印的重要组成部分,可以结合细胞进行组织工程支架等的制备,在药物筛选、组织工程再生等方面具有巨大的优势.本文从水凝胶3D生物打印技术、组织工程3D生物打印水凝胶材料及应用方面进行阐述,旨在对科研工作者有一定帮助.     

TPU/β-榄香烯气道支架3D打印制备及药物释放测试

采用熔融沉积3D打印制备热塑性聚氨酯(TPU)气道支架并装载β-榄香烯，研究支架表面孔洞数量和打印挤出率对β-榄香烯释放行为的影响，探究超高效液相色谱法测试β-榄香烯方法。采用安捷伦C18柱，在流动相为乙腈-0.1%磷酸水溶液(93∶7)条件下测试β-榄香烯的分离度大于1.5，理论塔板数≥19 000。打印挤出率不变时，支架表面孔洞越多，药物释放量越大，0孔洞、4孔洞、8孔洞支架的药物累计释放量分别为25.88%,31.02%和34.41%；但前期容易出现爆释，4孔洞和8孔洞支架持续释放时间≤6 d。支架表面0孔洞时，挤出率越大，药物释放速率越低，80%,100%,125%挤出率支架的药物累计释放量分别为67.76%,38.07%和26.08%。采用超高效液相色谱法可准确测试支架中β-榄香烯的释放速率，通过调整3D打印的挤出率可调控支架的药物释放行为，该研究可为载药支架的产品研发和临床应用提供指导。     

3D打印技术在生物骨支架制备中的研究进展

3D打印技术是一种基于计算机设计,逐层叠加的快速成型技术。本文综述了近年来3D打印在制备生物骨支架中的应用,以及如何通过3D打印技术调控生物骨支架的力学性能及生物相容性。当前主要通过光固化立体印刷、选择性激光烧结、熔融沉积成型以及生物3D打印技术制备生物骨支架;通过控制生物骨支架的支架结构和孔隙率对其性能进行调控。迄今为止,3D打印技术在生物骨支架领域已经得到广泛的应用,但是仍存在一些问题有待进一步研究。     

3D打印技术在生物医用高分子材料制备领域的应用进展

3D打印技术因其能够完美地将制造技术和信息技术结合打印获得不同患者所需的个性化生物材料,精准快速,并可以控制材料的内部微观结构在患者体外进行打印等特点在生物医学高分子材料制备应用中成为新的研究热点。本文概括了3D打印技术及其在制备生物支架材料、生物医用水凝胶等高分子材料方面的应用进展情况,并对其在该领域未来应用发展的机遇和挑战做了预测。     

有机硅3D打印的研究进展

有机硅材料具有良好的生物相容性、化学稳定性和力学性能等,在生物医用、包装与交通运输等方面应用广泛。传统工艺生产有机硅制品时间长、成本高,而且无法做到个性化生产。有机硅的3D打印是用3D打印技术加工成型有机硅材料制品,它能够实现有机硅产品的快速、个性化生产。介绍了直接有机硅3D打印中光固化3D打印与基于挤出的3D打印2种技术在材料、打印工艺方面的研究进展。     

3D打印技术在文创产品设计开发中的应用研究——评《3D打印原理、技术与应用》

近年来我国3D打印技术得到了迅速的发展,在文创产品追求个性化的道路上人们将3D打印技术运用在其中,实现了产品的多元化,可以根据自己的需要构建出不同的产品。3D打印技术作为当今较热门的技术门类之一,具有高度的信息化、结构的复杂化、打印精度高等优势,3D打印技术与其说是一种制造技术不如说是运用在设计领域中的设计辅助手段。由吕鉴涛著的《3D打印原理、技术与应用》一书,对于3D打印技术的来源、发展、结构、种类及应用进行了详细的描述,值得相关人士学习与参考。     

3D打印在汽车塑料件设计中的应用与研究进展

阐述了3D打印在汽车塑料件设计中的优势,以及其在汽车行业常用的三种工艺。然后从汽车的内外造型设计、设计验证、复杂结构件、个性化定制等方面分别列举了3D打印的应用实例,并分析其对汽车设计研发的影响。最后介绍了3D打印在汽车塑料件设计中的研究进展和未来趋势。     

3D打印生物陶瓷功能改进的研究进展

临床上骨缺损的治疗方案虽然具有一定的治疗效果,但也存在不可忽视的局限性.生物陶瓷支架作为最有前景的解决方案被广泛研究.传统的生物陶瓷支架能在一定程度上修复骨缺损,但仍有许多不足.本综述简要归纳了制备多孔生物陶瓷支架的3D打印技术的原理及特点,然后重点介绍了3D打印生物陶瓷支架涉及的微量元素掺杂、功能性表面修饰、多孔结构...     

3D打印技术用于不规则骨缺损的重建与修复

为研究3D打印技术对不规则形状骨缺损模型的重建程度及3D打印的可降解生物材料对脊椎骨缺损在12周内的修复效果,随机选取1名病人,用电子计算机断层扫描(CT)数据构建出不规则的三维脊柱缺损模型,选用聚己内酯(PCL)作为支架材料,运用3D打印技术打印出高度符合该病人骨缺损部位的人工骨支架。同时建立1个简单的兔子脊椎缺损模型,以聚乳酸-羟基乙酸共聚物(PLGA)为支架材料,运用3D打印技术打印缺损尺寸的支架移植兔子体内,术后观察3个月,将兔子处死取出缺损部位,制作切片进行苏木素和伊红(HE)染色,染色结果表明缺损部位修复良好。     

连续玻璃纤维增强PLA复合材料3D打印技术研究

以聚乳酸(PLA)为基体,连续玻璃纤维为增强体,采用熔融浸渍工艺制备连续玻璃纤维预浸丝,将制得的预浸丝作为3D打印耗材用于熔融沉积(FDM)的3D技术来制备连续玻璃纤维增强PLA复合材料试样,并研究了打印温度、层厚和打印速度对复合材料力学性能的影响。结果表明,当打印层厚为0. 5 mm,打印温度为230℃,打印速度为2 mm/s时,连续玻璃纤维增强PLA复合材料的弯曲性能最佳,弯曲强度和弯曲模量分别为327. 84 MPa和20. 293 GPa。综合考虑复合材料的力学性能、表面质量和尺寸稳定性,连续玻璃纤维增强PLA复合材料的最佳打印层厚为0. 5 mm,适宜的打印温度范围为200~220℃,打印速度范围为2~4 mm/s。     

耐碱玻璃纤维掺量对3D打印砂浆性能的影响研究

耐碱玻璃纤维作为一种性能优良的无机非金属纤维材料,在土木工程领域有很好的研究价值和应用潜力。而3D打印作为新兴技术,在土木工程领域有较高匹配度和广阔应用前景。本文通过在3D打印砂浆中掺入不同掺量的耐碱玻璃纤维并调节减水剂用量,制备一系列打印性能良好的砂浆,探究耐碱玻璃纤维掺量对砂浆力学性能的影响。试验结果表明:要获得良好的打印性能,跳桌试验流动度建议在180~220 mm之间;砂浆抗折强度随耐碱玻璃纤维掺量增加而提高,强度增幅最多可达99.2%;砂浆抗压强度随耐碱玻璃纤维掺量增加先提升后降低,纤维最优掺量为0.25%(质量分数)。     

Silicon carbide whiskers reinforced SiOC ceramics through digital light processing 3D printing technology

Polymer derived silicon oxycarbide ceramic materials and silicon carbide whiskers reinforced ceramic composite are prepared through digital light processing (DLP) 3D printing technology in the present work. A new type of UV-curable preceramic polymer is firstly synthesized and then two types of photopolymer resins with and without SiC whiskers as reinforcement are prepared. Due to the high curing rate and good fluidity of the resins, they are applied in DLP 3D printing and various 3D objects with complicated structures and high printing resolution have been printed. The derived ceramic materials show amorphous microstructure and there is no apparent porosity and cracking throughout the whole sample surface of the ceramic materials and the SiC whiskers are uniformly embedded in the ceramic matrix and remain intact and unaffected during the pyrolysis process. The SiC whiskers reduced the shrinkage and mass loss. More importantly, it significantly improves the mechanical performance of the derived ceramic materials in which the compressive strength increases from 77.5 ± 10.2 MPa to 98.4 ± 12.3 MPa. Benefiting from the easiness of the fabrication, high printing resolution and excellent mechanical performance, the derived ceramic materials have great potential applications in various areas.     

固废基硫铝酸盐胶凝材料用于建筑3D打印的特性与过程仿真

为了解决建筑3D打印材料的性能、成本及技术应用等问题,通过以工业固体废弃物为原料制备了硫铝酸盐胶凝基质材料,配以促凝剂、缓凝剂等形成的建筑3D打印粉体,并应用多物理场耦合软件对同一喷嘴结构不同水灰比（W/C）下喷出浆体速度及质量的影响规律进行仿真计算。结果表明：以工业固体废弃物为原料能成功制备达到GB-2007-R525的硫铝酸盐胶凝材料,且经过外加剂改性后凝结时间可控制在10～30 min,2 h抗压强度15～20 MPa,后期强度稳定;水灰比高于0.6,打印浆体出现堆叠、坍塌的现象,影响打印精度及打印构件质量;水灰比低于0.4,喷射浆体会出现拖尾,影响打印速度,最终确定水灰比在0.5附近较适合相应尺寸喷嘴的3D打印应用。     

大壁厚3D打印SiO2陶瓷快速制备技术研究

选用复合分散剂制备低粘度陶瓷料浆,采用自主研发的陶瓷3D打印机,以DLP(digital light processing)工艺制备出了大壁厚(>3 mm)SiO₂空心内六角陶瓷部件,坯体精度均在50 μm内。分析了3D打印陶瓷素坯在空气气氛和氩气气氛下的热分解过程,研究了气氛对大壁厚(>3 mm)SiO₂陶瓷部件脱脂与烧结的影响。结合扫描电子显微镜(SEM)分析了大壁厚(>3 mm)3D打印SiO₂陶瓷坯体快速脱脂烧结的工艺,氩气气氛有利于大壁厚SiO₂陶瓷快速脱脂烧结。氩气气氛下,控制气流量,进行了大壁厚(>3 mm)SiO₂陶瓷部件的快速制备,脱脂烧结周期大大缩短,为21.8 h,较自国外某公司进口的料浆及其工艺的制备周期(以进口的该公司料浆及工艺制备的相同产品制备周期为283 h)缩短92.3%,较公开报道的3D打印相同工艺制备的SiO₂陶瓷空心叶片制备周期缩短82%以上。     

The study of near-net shape lithium aluminosilicate glass-ceramics by direct ink writing

3D printing, a competitive manufacturing technology, has opened up new possibilities for fabricating complex structure ceramic components, but near-net forming is still difficult. This work presented a kind of near-net forming lithium aluminosilicate (LAS) glass-ceramics using direct ink writing (DIW) method by controlling thermal shrinkage. To achieve this goal, a high solid-loading ink was prepared using low thermal expansion LAS glass-ceramic powder containing β-spodumene as raw material. And we comprehensively evaluated the effects of the rheological properties of the slurry and sintering process on the thermal and mechanical performances. Attributed to the restricted sintering activity and thermal deformation of LAS glass-ceramic particles, the 3D-printed samples sintered at 1300 ^◦C for 2 h showed an average linear shrinkage of 0.84% with a flexural strength of 45.59 ± 2.82 MPa and a compressive strength of 65.58 ± 3.99 MPa, respectively. The results suggested that LAS glass-ceramics were excellent candidate materials for near-net forming 3D printing.     

Fabrication of alumina ceramics with functional gradient structures by digital light processing 3D printing technology

Alumina ceramics with different unit numbers and gradient modes were prepared by digital light processing (DLP) 3D printing technology. The side length of each functional gradient structure was 10 mm, the porosity ratio was controlled to 70%, and the number of units were (1 × 1 × 1 unit) and (2 × 2 × 2 unit) respectively. The different gradient modes were named FCC, GFCC-1, GFCC-2 and GFCC-3. SEM, XRD, and other characterization methods proved that these gradient structures of alumina ceramics had only α-Al2O3 phase and good surface morphology. The mechanical properties and energy absorption properties of alumina ceramics with different functional gradient structures were studied by compression test. The results show that the gradient structure with 1 × 1 × 1 unit has better mechanical properties and energy absorption properties when the number of units is different. When the number of units is the same, GFCC-2 and GFCC-3 gradient structures have better compressive performance and energy absorption potential than FCC structures. The GFCC-2 gradient structure with 1 × 1 × 1 unit has a maximum compressive strength of 19.62 MPa and a maximum energy absorption value of 2.72 × 105 J/m3. The good performance of such functional gradient structures can provide new ideas for the design of lightweight and compressive energy absorption structures in the future.     

基于计算机辅助的聚乳酸3D打印工艺研究

以聚乳酸骨钉为例,利用计算机辅助技术对其加工温度、打印速率和冷却速率进行了优化,通过对制件尺寸精度和力学强度的模拟,得到了最佳加工工艺为供料段、压缩段和均化段温度分别为230,250,260℃;打印速率为70 mm/s,冷却速率为30℃/s。在该工艺下制得的骨钉制件尺寸精度和力学强度高。另外,还通过实际实验对模拟结果进行了验证,所得制件的尺寸误差和标准差均较小,力学强度为54.7–56.9 MPa,与模拟结果相近。将计算机辅助技术应用到3D打印工艺优化中,可使优化参数周期缩短,大幅提升工作效率。     

DLP 3D printing porous β-tricalcium phosphate scaffold by the use of acrylate/ceramic composite slurry

Digital light processing (DLP) 3D printing has been utilized to fabricate controlled porous β-tricalcium phosphate (β-TCP) scaffolds, which promote cell adhesion and angiogenesis during bone regeneration. However, the current limitation of DLP 3D printing for the fabrication of β-TCP scaffold is how to prepare a low viscosity ceramic slurry and remove the toxicity of residual non-polymerized slurry. The present study has developed a low viscosity ceramic slurry system by mixing β-TCP with photosensitive acrylate resin, and the viscosity of slurry is about 3 Pa s and the solid content of β-TCP can be as high as 60 wt%. After optimizing the ratio of slurry, printing, degreasing and sintering processes, the maximum compressive strength of the DLP printed scaffolds reaches up to 9.89 MPa, while the porosity keeps ca. 40%. According to the proliferation of cells, it confirms the preserved biocompatibility of DLP-fabricated β-TCP scaffolds. These porous scaffolds made by DLP 3D printing technology is of great significance for bone regeneration, and will also help to expand the application of DLP technology in biomedical field.     

3D打印条件对可降解聚乳酸力学性能的影响

采用3D打印方式制备降解左旋聚乳酸（PLLA）样品,通过冲击及拉伸试验研究不同打印条件对样品冲击强度、拉伸强度、拉伸模量及断裂伸长率的影响。结果表明,随着打印填充密度的增加,样品的冲击强度、拉伸强度及拉伸模量增大,断裂伸长率先增后减;随着打印速度的增加,样品的拉伸强度和拉伸模量增大,冲击强度及断裂伸长率减小;随着打印温度的增加,样品的冲击强度、拉伸强度和拉伸模量增大,断裂伸长率减小;打印填充密度、打印速度、打印温度分别为70 %、100 mm/s、210 ℃时,样品的综合性能最佳。