Kastrinaki Georgia, Pechlivani Eleftheria-Maria, Gkekas Ioannis, Kladovasilakis Nikolaos, Gkagkari Evdokia, Petrakis Spyros, Asimakopoulou Akrivi
Chemical Process Engineering Research Institute, Centre for Research and Technology Hellas, 57001 Thessaloniki, Greece.
Information Technologies Institute, Centre for Research and Technology Hellas, 57001 Thessaloniki, Greece.
J Funct Biomater. 2023 Sep 9;14(9):465. doi: 10.3390/jfb14090465.
The latest developments in tissue engineering scaffolds have sparked a growing interest in the creation of controlled 3D cellular structures that emulate the intricate biophysical and biochemical elements found within versatile in vivo microenvironments. The objective of this study was to 3D-print a monolithic silica scaffold specifically designed for the cultivation of neural precursor cells. Initially, a preliminary investigation was conducted to identify the critical parameters pertaining to calcination. This investigation aimed to produce sturdy and uniform scaffolds with a minimal wall-thickness of 0.5 mm in order to mitigate the formation of cracks. Four cubic specimens, with different wall-thicknesses of 0.5, 1, 2, and 4 mm, were 3D-printed and subjected to two distinct calcination profiles. Thermogravimetric analysis was employed to examine the freshly printed material, revealing critical temperatures associated with increased mass loss. Isothermal steps were subsequently introduced to facilitate controlled phase transitions and reduce crack formation even at the minimum wall thickness of 0.5 mm. The optimized structure stability was obtained for the slow calcination profile (160 min) then the fast calcination profile (60 min) for temperatures up to 900 °C. In situ X-ray diffraction analysis was also employed to assess the crystal phases of the silicate based material throughout various temperature profiles up to 1200 °C, while scanning electron microscopy was utilized to observe micro-scale crack formation. Then, ceramic scaffolds were 3D-printed, adopting a hexagonal and spherical channel structures with channel opening of 2 mm, and subsequently calcined using the optimized slow profile. Finally, the scaffolds were evaluated in terms of biocompatibility, cell proliferation, and differentiation using neural precursor cells (NPCs). These experiments indicated proliferation of NPCs (for 13 days) and differentiation into neurons which remained viable (up to 50 days in culture). In parallel, functionality was verified by expression of pre- (SYN1) and post-synaptic (GRIP1) markers, suggesting that 3D-printed scaffolds are a promising system for biotechnological applications using NPCs.
组织工程支架的最新进展引发了人们对创建可控三维细胞结构的日益浓厚的兴趣，这些结构能够模拟多种体内微环境中复杂的生物物理和生化元素。本研究的目的是3D打印一种专门为神经前体细胞培养设计的整体式二氧化硅支架。最初，进行了一项初步研究以确定与煅烧相关的关键参数。该研究旨在生产坚固且均匀的支架，其最小壁厚为0.5毫米，以减轻裂缝的形成。打印了四个壁厚分别为0.5、1、2和4毫米的立方体标本，并对其进行两种不同的煅烧曲线处理。采用热重分析来检查新打印的材料，揭示与质量损失增加相关的临界温度。随后引入等温步骤以促进可控的相变，即使在最小壁厚为0.5毫米时也能减少裂缝形成。对于高达900°C的温度，在缓慢煅烧曲线（160分钟）后采用快速煅烧曲线（60分钟）可获得优化的结构稳定性。还采用原位X射线衍射分析来评估高达1200°C的各种温度曲线下基于硅酸盐材料的晶相，同时利用扫描电子显微镜观察微观尺度的裂缝形成。然后，3D打印陶瓷支架，采用通道开口为2毫米的六边形和球形通道结构，随后使用优化的缓慢曲线进行煅烧。最后，使用神经前体细胞（NPC）对支架的生物相容性、细胞增殖和分化进行评估。这些实验表明NPC增殖（持续13天）并分化为仍存活的神经元（培养长达50天）。同时，通过突触前（SYN1）和突触后（GRIP1）标记物的表达验证了功能，表明3D打印支架是使用NPC进行生物技术应用的有前景的系统。
