Abstract:
Advances in digital light projection(DLP) based (bio) printers have made printing of intricate structures at high resolution possible using a wide range of photosensitive bioinks. A typical setup of a DLP bioprinter includes a vat or reservoir filled with liquid bioink, which presents challenges in terms of cost associated with bioink synthesis, high waste, and gravity-induced cell settling, contaminations, or variation in bioink viscosity during the printing process. Here, we report a vat-free, low-volume, waste-free droplet bioprinting method capable of rapidly printing 3D soft structures at high resolution using model bioinks and model cells. A multiphase many-body dissipative particle dynamics model was developed to simulate the dynamic process of droplet-based DLP printing and elucidate the roles of surface wettability and bioink viscosity. Process variables such as light intensity, photo-initiator concentration, and bioink formulations were optimized to print 3D soft structures (∼0.4-3 kPa) with a typical layer thickness of 50µm, an XY resolution of 38 ± 1.5μm and Z resolution of 237 ± 5.4µm. To demonstrate its versatility, droplet bioprinting was used to print a range of acellular 3D structures such as a lattice cube, a Mayan pyramid, a heart-shaped structure, and a microfluidic chip with endothelialized channels. Droplet bioprinting, performed using model C3H/10T1/2 cells, exhibited high viability (90%) and cell spreading. Additionally, microfluidic devices with internal channel networks lined with endothelial cells showed robust monolayer formation while osteoblast-laden constructs showed mineral deposition upon osteogenic induction. Overall, droplet bioprinting could be a low-cost, no-waste, easy-to-use, method to make customized bioprinted constructs for a range of biomedical applications.
摘要:
背景技术基于数字光处理(DLP)的(生物)打印机的进步使得能够使用宽范围的光敏生物墨水以高分辨率打印复杂结构。DLP生物打印机的典型设置包括充满液体生物墨水的大桶或储液器,这在与生物墨水合成相关的成本方面提出了挑战,高浪费,和重力诱导的细胞沉降,污染,或在印刷过程中生物墨水粘度的变化。这里,我们报告无增值税,低音量,无浪费的液滴生物打印方法,能够使用模型生物墨水以高分辨率快速打印3D软结构。建立了多相多体耗散粒子动力学(mDPD)模型,以模拟基于液滴的DLP打印的动态过程,并阐明了表面润湿性和生物墨水粘度的作用。过程变量,如光强度,光引发剂浓度,和生物墨水配方进行了优化,以打印3D软结构(〜0.4至3kPa),XY分辨率为38±1.5μm,Z分辨率为237±5.4µm。为了展示它的多功能性,液滴生物打印用于打印一系列无细胞3D结构,如晶格立方体,玛雅金字塔,心形结构,和带有内皮化通道的微流控芯片。液滴生物打印,使用模型C3H/10T1/2细胞进行,表现出高活力(90%)和细胞扩散。此外,具有内衬内皮细胞的内部通道网络的微流体装置显示出强大的单层形成,而载有成骨细胞的构建体在成骨诱导时显示出矿物质沉积。总的来说,液滴生物打印可能是低成本的,没有浪费,易于使用,方法为一系列生物医学应用制作定制的生物打印构建体。