A microfluidic printhead for printing photo-cross linkable hydrogels

对器官修复和移植的需求，以及可用供体的短缺，使得临床需要开发创新的治疗策略，以长期修复和再生受伤或患病的组织和器官。3D打印是一种通过在计算机控制的构建平台上逐层沉积材料来构建3D对象的过程。生物打印结合了3D打印技术、细胞生物学和材料科学，通过将构建平台与能够沉积生物墨水的设备相结合。生物打印技术适用于广泛的生物材料（即合成和天然聚合物，血液来源的蛋白质和去细胞化的细胞外基质（ECM）），适应各种细胞来源的生长和增殖，包括干细胞和体细胞。Aspect Biosystems的专利Lab-on-PrinterTM技术利用同轴流聚焦的概念，逐层沉积细胞负载生物纤维，形成3D组织样结构。Aspect Biosystems计划扩展其Bioink库，包括光交联材料，包括明胶甲基丙烯酰（GelMA）和聚乙二醇二丙烯酸酯（PEGDA）。Lab-on- a- printertm技术与一系列低粘度和中粘度生物墨水兼容，由于良好的机械性能和高比例的生物活性和细胞含量与支架成分相结合，特别适合于促进组织功能。使用这些材料可以显著提高打印分辨率，从而更好地控制所制备支架的微观和宏观结构。该项目的总体目标是修改当前的打印头墨盒，以打印光交联明胶作为组织工程界广泛使用的生物材料。我们将进行系统的表征研究，以制定一种制造光交联水凝胶结构的方案。细胞将被装入制备的结构体中，以评估该工艺的生物相容性。

The demand for organ repair and transplantation, and a shortage of available donors necessitates the clinicalneed to develop innovative treatment strategies for long-term repair and regeneration of injured or diseasedtissues and organs. 3D printing is a process used to construct 3D objects by relying on the layer-by-layerdeposition of materials onto a computer-controlled build platform. Bioprinting combines 3D printingtechnology, cell biology, and materials science, by coupling the build platform with a device that enables thedeposition of bioinks. Bioprinting technology is adaptive to a wide range of biomaterials (i.e., synthetic andnatural polymers, blood-derived proteins, and de-cellularized extracellular matrix (ECM)), accommodating thegrowth and proliferation of various cell sources, including stem cells and somatic cells. Aspect Biosystems'proprietary Lab-on-PrinterTM technology utilizes the concept of coaxial-flow focusing to deposit cell-ladenbiological fibers layer-by-layer and form 3D tissue-like constructs. Aspect Biosystems is planning to extendtheir Bioink library to include photo-crosslinkable materials including gelatin methacryloyl (GelMA) andpolyethylene glycol diacrylate (PEGDA). Lab-on- a-PrinterTM technology is compatible with a range of lowand medium viscosity Bioinks that are particularly well suited to promoting tissue function due to acombination of favorable mechanical properties and high ratios of bioactive and cellular content to scaffoldcomponents. Using these materials can significantly improve the printing resolution which will lead to bettercontrol on the micro- and macrostructure of the fabricated scaffolds. The overarching goals of this Engageproject are to modify the current printhead cartridges to print photo-crosslinkable gelatin as a widely usedbiomaterial in the tissue engineering community. We will perform a systematic characterization study todevelop a protocol for the fabrication of photo-crosslinkable hydrogel constructs. Cells will be loaded in thefabricated constructs to evaluate the biocompatibility of the process.