Multi-material stereolithographic 3D-printing for prototyping Tissue Chips

项目总结/摘要 组织芯片-微流控装置，包含3D架构中的人类细胞，试图重现 人体组织和器官的生理学和病理生理学-包含先进的设计， 3D/模块化制造，多种材料和功能的结合，以及流体自动化。 绝大多数组织芯片仍以聚二甲基硅氧烷（PDMS）为原型。然而， PDMS作为组织芯片材料仍然存在障碍。PDMS的表面是多孔的和疏水的，所以两者都是 吸附到PDMS中和吸附到PDMS上可以通过改变 目标浓度和通过在微流体装置的不期望区域中分配分子。 3D打印为组织芯片提供了明显的潜力。特别是立体光刻（SL）已经成为一种新的技术。 在高分辨率下调制3D形状的绝佳选择，但调制材料成分仍然是一个 挑战.迫切需要更先进、高分辨率和多材料的SL打印 构建未来组织芯片的方法，该组织芯片可以集成设备的结构组件（通道 和瓣膜）与生物制品（细胞和支架）的组合。然而，没有现成的解决方案SL打印多材料 具有广泛适用性的微流体装置。 本申请提出了甲基丙烯酸环辛炔酯（COMA）树脂的合成和SL印刷， 将能够将任何选择的生物分子叠氮化物固定到COMA印刷的表面上。 在这种情况下，COMA用于通过简单的无铜（生物相容性）点击化学来衍生打印部件 通过与叠氮基共轭，叠氮基在水溶液中自发地和特异性地与COMA基团反应， 解决方案使用生物素叠氮化物（市售）和抗生物素蛋白连接，我们将能够 将所选的生物素化生物分子转移到COMA打印的表面上。我们还将使用基准丙烯酸酯树脂 由聚（乙二醇）二丙烯酸酯（MW~258）（PEG-DA-258）组成，已成功用于 微流体技术，并将实验与共混PEG-DA-258与其他二丙烯酸酯和/或 单丙烯酸酯以获得具有不同性能的树脂，例如更高的柔性。打印设备， 部分用PEG-DA-258树脂（或共混物）和部分用COMA树脂（或共混物），我们将利用一种策略 用于共同打印Folch实验室最近使用的多种丙烯酸酯树脂，包括暂停打印， 交换缸中的树脂。该方案将广泛适用于3D打印微流体装置， 具有分子功能（例如生物分子检测、细胞捕获）的多个区域和/或具有 不同的感测/致动特性（例如微型阀、力传感器等）。示例包括3D打印 基于COMA衍生区域的多重免疫传感器，用于药物筛选的细胞捕获装置，以及 类器官芯片自动化平台等。

PROJECT SUMMARY / ABSTRACT Tissue Chips – microfluidic devices containing human cells in 3D architectures that attempt to recapitulate the physiology and pathophysiology of human tissues and organs – contain advanced designs that critically require 3D/modular fabrication, the incorporation of multiple materials and functionalities, and fluidic automation. The vast majority of Tissue Chips are still prototyped in poly(dimethylsiloxane) (PDMS). However, difficult barriers remain for PDMS as a Tissue Chip material. The surface of PDMS is porous and hydrophobic, so both absorption into PDMS and adsorption onto PDMS can potentially alter experimental outcomes by changing the target concentrations and by partitioning molecules in undesired regions of a microfluidic device. 3D-Printing holds an obvious potential for Tissue Chips. Stereolithography (SL), in particular, has been an excellent choice for modulating shapes in 3D at high resolution but modulating material composition is still a challenge. There is a critical need for more advanced, high-resolution and multi-material SL-printing approaches to building future Tissue Chips that can integrate the structural components of a device (channels and valves) with biofabrication (cells and scaffolds). Yet there is no off-the-shelf solution to SL-print multi-material microfluidic devices of wide applicability. This application proposes the synthesis and SL-printing of cyclo-octyne methacrylate (COMA) resin, which will enable the immobilization of any biomolecule-azide of choice onto the COMA-printed surfaces. COMA for derivatizing printed parts via straightforward copper-free (biocompatible) click chemistry, in this case by conjugation to an azide group which spontaneously and specifically reacts with the COMA group in aqueous solutions. Using biotin-azide (commercially available) and an avidin linkage, we will be able to immobilize any biotinylated biomolecule of choice onto the COMA-printed surfaces. We will also use a baseline acrylate resin composed of poly(ethylene glycol) diacrylate (MW~258) (PEG-DA-258), which has successfully been used in microfluidics by several labs, and will experiment with blending PEG-DA-258 with other diacrylates and/or monoacrylates to obtain resins with differing properties, such as higher flexibility. To print devices that are made partially with PEG-DA-258 resin (or blends) and partially with COMA resin (or blends), we will utilize a strategy for co-printing multiple acrylate resins recently utilized by the Folch lab that consists of pausing the print and exchanging the resins in the vat. This scheme will have wide applicability to 3D-print microfluidic devices with multiple regions bearing molecular functionalities (e.g. biomolecular detection, cell capture) and/or elements with distinct sensing/actuating properties (e.g. microvalves, force sensors, etc.). Examples include 3D-printed multiplexed immunosensors based on COMA-derivatized regions, cell trapping devices for drug screening, and organoid-on-a-chip automated platforms, among others.