Department of Surgery, The University of Melbourne, St Vincent's Hospital, Melbourne, VIC, Australia. ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, Innovation Campus, University of Wollongong, NSW, Australia. Biofab3D@ACMD, St Vincent's Hospital, Melbourne, VIC, Australia.
Biomed Mater. 2019 Mar 27;14(3):035007. doi: 10.1088/1748-605X/ab09c4.
3D printing is a rapid and accessible fabrication technology that engenders creative custom design solutions for cell scaffolds, perfusion systems and cell culture systems for tissue engineering. Critical to its success is the biocompatibility of the materials used, which should allow long-term tissue culture without affecting cell viability or inducing an inflammatory response for in vitro and in vivo applications. Polyjet 3D printers offer arguably the highest resolution with the fewest design constraints of any commercially available 3D printing systems. Although widely used for rapid-prototyping of medical devices and 3D anatomical modelling, polyjet printing has not been adopted by the tissue engineering field, largely due to the cytotoxicity of leachates from the printed parts. Biocompatibility in the context of cell culture is not commonly addressed for polyjet materials, as they tend to be optimised for their ability to fabricate complex structures. In order to study the potential issues surrounding the leaching of toxins, we prepared cell culture substrates using the commercially available MED610 photopolymer. The substrates were cleaned using either the manufacturer-specified 'biocompatible' washing procedures, or a novel protocol incorporating a sonication in isopropanol and water step. We then compared the effectiveness of these both in vitro and in vivo. Using primary mouse myoblast cultures, the manufacturer's protocol led to inconsistent and poorer cell viability when compared to the sonication protocol (p = 0.0002 at 48 h after indirect exposure). Subdermal implantation of MED610 into nude rats demonstrated a significant foreign body response with a greater number of giant cells (p = 0.0161) and foreign bodies (p = 0.0368) when compared to the sonication protocol, which was comparable to the control (sham) groups. These results present an improved, cytocompatible cleaning protocol of printable photopolymers to facilitate creative 3D-printed custom designs for cell culture systems for both in vitro and in vivo tissue engineering applications.
3D 打印是一种快速且易于使用的制造技术，可为细胞支架、灌注系统和细胞培养系统生成具有创意的定制设计解决方案，用于组织工程学。其成功的关键是所使用材料的生物相容性，这应该允许进行长期的组织培养，而不会影响细胞活力或引起体外和体内应用的炎症反应。Polyjet 3D 打印机提供了可商购的 3D 打印系统中分辨率最高、设计限制最少的解决方案。尽管 Polyjet 打印已广泛用于医疗器械的快速原型制作和 3D 解剖模型制作，但由于打印部件浸出物的细胞毒性，它尚未被组织工程领域采用。在细胞培养的背景下，Polyjet 材料的生物相容性通常未得到解决，因为它们往往是针对其制造复杂结构的能力进行优化的。为了研究与毒素浸出相关的潜在问题，我们使用市售的 MED610 光聚合物制备细胞培养底物。这些基底使用制造商指定的“生物相容”清洗程序或包括异丙醇和水超声清洗步骤的新型方案进行清洗。然后，我们比较了这两种方案在体外和体内的效果。使用原代小鼠成肌细胞培养物，与超声清洗方案相比，制造商的方案导致细胞活力不一致且较差（间接暴露后 48 小时时 p = 0.0002）。将 MED610 皮下植入裸鼠中，与超声清洗方案相比，显示出明显的异物反应，巨细胞数量更多（p = 0.0161）和异物（p = 0.0368），而超声清洗方案与对照组（假手术）相似。这些结果提出了一种改进的、细胞相容的可打印光聚合物清洁方案，以促进用于体外和体内组织工程应用的细胞培养系统的创造性 3D 打印定制设计。
