Thorsnes Quinn S, Turner Paul R, Ali Mohammed Azam, Cabral Jaydee D
Department of Oral Rehabilitation, School of Dentistry, University of Otago, Dunedin 9054, New Zealand.
Department of Microbiology & Immunology, University of Otago, Dunedin 9054, New Zealand.
Biomedicines. 2023 Nov 24;11(12):3139. doi: 10.3390/biomedicines11123139.
We demonstrate for the first time the combination of two additive manufacturing technologies used in tandem, fused deposition modelling (FDM) and melt electrowriting (MEW), to increase the range of possible MEW structures, with a focus on creating branched, hollow scaffolds for vascularization. First, computer-aided design (CAD) was used to design branched mold halves which were then used to FDM print conductive polylactic acid (cPLA) molds. Next, MEW was performed over the top of these FDM cPLA molds using polycaprolactone (PCL), an FDA-approved biomaterial. After the removal of the newly constructed MEW scaffolds from the FDM molds, complementary MEW scaffold halves were heat-melded together by placing the flat surfaces of each half onto a temperature-controlled platform, then pressing the heated halves together, and finally allowing them to cool to create branched, hollow constructs. This hybrid technique permitted the direct fabrication of hollow MEW structures that would otherwise not be possible to achieve using MEW alone. The scaffolds then underwent in vitro physical and biological testing. Specifically, dynamic mechanical analysis showed the scaffolds had an anisotropic stiffness of 1 MPa or 5 MPa, depending on the direction of the applied stress. After a month of incubation, normal human dermal fibroblasts (NHDFs) were seen growing on the scaffolds, which demonstrated that no deleterious effects were exerted by the MEW scaffolds constructed using FDM cPLA molds. The significant potential of our hybrid additive manufacturing approach to fabricate complex MEW scaffolds could be applied to a variety of tissue engineering applications, particularly in the field of vascularization.
我们首次展示了串联使用的两种增材制造技术——熔融沉积建模（FDM）和熔体静电纺丝（MEW）的结合，以扩大MEW结构的可能性范围，重点是创建用于血管化的分支、中空支架。首先，使用计算机辅助设计（CAD）设计分支模具半体，然后用于FDM打印导电聚乳酸（cPLA）模具。接下来，使用聚己内酯（PCL，一种FDA批准的生物材料）在这些FDM cPLA模具顶部进行MEW。从FDM模具中取出新构建的MEW支架后，通过将每个半体的平面放置在温度控制平台上，然后将加热的半体压在一起，最后让它们冷却，将互补的MEW支架半体热熔合在一起，以创建分支、中空结构。这种混合技术允许直接制造中空MEW结构，否则仅使用MEW是无法实现的。然后对支架进行体外物理和生物学测试。具体而言，动态力学分析表明，根据施加应力的方向，支架的各向异性刚度为1 MPa或5 MPa。孵育一个月后，观察到正常人皮肤成纤维细胞（NHDFs）在支架上生长，这表明使用FDM cPLA模具构建的MEW支架没有产生有害影响。我们的混合增材制造方法在制造复杂MEW支架方面的巨大潜力可应用于各种组织工程应用，特别是在血管化领域。
