Facile Route for 3D Printing of Transparent PETg-Based Hybrid Biomicrofluidic Devices Promoting Cell Adhesion

Abstract

3D printing has emerged as a promising fabrication technique for microfluidic devices, overcoming some of the challenges associated with conventional soft lithography. Filament-based polymer extrusion (popularly known as fused deposition modeling (FDM)) is one of the most accessible 3D printing techniques available, offering a wide range of low-cost thermoplastic polymer materials for microfluidic device fabrication. However, low optical transparency is one of the significant limitations of extrusion-based microfluidic devices, rendering them unsuitable for cell culture-related biological applications. Moreover, previously reported extrusion-based devices were largely dependent on fluorescent dyes for cell imaging because of their poor transparency. First, we aim to improve the optical transparency of FDM-based microfluidic devices to enable bright-field microscopy of cells. This is achieved using (1) transparent polymer filament materials such as poly­(ethylene terephthalate) glycol (PETg), (2) optimized 3D printing process parameters, and (3) a hybrid approach by integrating 3D printed microfluidic devices with cast poly­(dimethylsiloxane) (PDMS) blocks. We begin by optimizing four essential 3D printing process parameters (layer height, printing speed, cooling fan speed, and extrusion flow), affecting the overall transparency of 3D printed devices. Optimized parameters produce exceptional optical transparency close to 80% in 3D printed PETg devices. Next, we demonstrate the potential of FDM-based 3D printing to fabricate transparent micromixing devices with complex planar and nonplanar channel networks. Most importantly, cells cultured on native 3D printed PETg surfaces show excellent cell attachment, spreading, and proliferation during 3 days of culture without extracellular matrix coating or surface treatment. Next, we introduce L929 cells inside hybrid PETg-PDMS biomicrofluidic devices as a proof of concept. We demonstrate that 3D printed hybrid biomicrofluidic devices promote cell adhesion, allow bright-field microscopy, and maintain high cell viability for 3 days. Finally, we demonstrate the applicability of the proposed fabrication approach for developing 3D printed microfluidic devices from other FDM-compatible transparent polymers such as polylactic acid (PLA) and poly­(methyl methacrylate) (PMMA).

3D Printed Platform for Impedimetric Sensing of Liquids and Microfluidic Channels

“…We successfully printed microchannels with the width down to 80 μm. This value represents a better manufacturing resolution than that achieved by FDM-3DP in other reported studies, ,,,,− with the only exception being that of Nelson et al (width of 40 μm). Our work introduces a non-destructive impedimetric approach for sensing microfluidic architectures.…”

Digital manufacturing for accelerating organ-on-a-chip dissemination and electrochemical biosensing integration

“…Mehta et al demonstrated that L929 cells showed excellent cell attachment, spreading, and proliferation for 3 days on native PETg surfaces. 61 Another popular technique for 3D printing is SLA popularly known as resin printers. In this case, light is directed with a specific pattern on a tank filled with a photopolymerizable polymer which is cured by the light forming 3D structures.…”

“…Mehta et al demonstrated that L929 cells showed excellent cell attachment, spreading, and proliferation for 3 days on native PETg surfaces. 61…”

A Review on Additive Manufacturing of Micromixing Devices

“…Nonetheless, the popularity of PET-G, ASA, and PP is gradually increasing. The temperature recommended to work with these materials during the process [71][72][73][74][75] is indicated in Table 2, although they can vary depending on the specific composition of the material used [72]. As a general rule, it should be noted that the higher the extrusion temperature, the lower the viscosity.…”