3D printed devices with integrated collagen scaffolds for cell culture studies including transepithelial/transendothelial electrical resistance (TEER) measurements.

In this paper, we describe the use of 3D printed devices for both static and flow studies that contain electrospun collagen scaffolds and can accommodate transepithelial/transendothelial electrical resistance (TEER) measurements. Electrospinning was used to create the collagen scaffold, followed by an optimized 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-Hydroxysuccinimide (EDC/NHS) cross-linking procedure to produce stable collagen fibers that are similar in size to fibers in vivo. LC/MS was used to study the leaching of solvent and NHS from the scaffold, with several rinsing steps being shown to eliminate the leaching and promote the culture of Madin-Darby Canine Kidney (MDCK) epithelial cells on the scaffold.

PolyJet-Based 3D Printing against Micromolds to Produce Channel Structures for Microchip Electrophoresis.

In this work, we demonstrate the ability to use micromolds along with a stacked three-dimensional (3D) printing process on a commercially available PolyJet printer to fabricate microchip electrophoresis devices that have a T-intersection, with channel cross sections as small as 48 × 12 μm being possible. The fabrication process involves embedding removable materials or molds during the printing process, with various molds being possible (wires, brass molds, PDMS molds, or sacrificial materials). When the molds are delaminated/removed, recessed features complementary to the molds are left in the 3D prints.

Evaluation and optimization of PolyJet 3D-printed materials for cell culture studies.

Use of 3D printing for microfluidics is a rapidly growing area, with applications involving cell culture in these devices also becoming of interest. 3D printing can be used to create custom-designed devices that have complex features and integrate different material types in one device; however, there are fewer studies studying the ability to culture cells on the various substrates that are available. This work describes the effect of PolyJet 3D-printing technology on cell culture of two cell lines, bovine pulmonary artery endothelial cells (BPAECs) and Madin-Darby Canine Kidney (MDCK) cells, on two different types of printed materials (VeroClear or MED610).

Fully 3D printed fluidic devices with integrated valves and pumps for flow injection analysis.

The use of a PolyJet 3D printer to create a microfluidic device that has integrated valves and pumps is described. The process uses liquid support and stacked printing to result in fully printed devices that are ready to use within minutes of fabrication after minimal post-processing. A unique feature of PolyJet printing is the ability to incorporate several different materials of varying properties into one print.

3D-Printed Microfluidic Device with In-line Amperometric Detection that Also Enables Multi-Modal Detection.

Microfluidic amperometric detectors often include a reservoir to house auxiliary and reference electrodes, making subsequent detection downstream challenging. Here, we present an in-line microfluidic device with amperometric detection that incorporates a three-electrode set-up, made possible by threading electrodes into a 3D-printed flow cell. The electrodes consist of a commercially available threaded reference electrode and electrodes fabricated in commercially available fittings.

A novel 3D-printed centrifugal ultrafiltration method reveals in vivo glycation of human serum albumin decreases its binding affinity for zinc.

Plasma proteins are covalently modified in vivo by the high-glucose conditions in the bloodstreams of people with diabetes, resulting in changes to both structure and function. Human Serum Albumin (HSA) functions as a carrier-protein in the bloodstream, binding various ligands and tightly regulating their bioavailability. HSA is known to react with glucose via the Maillard reaction, causing adverse effects on its ability to bind and deliver certain ligands, such as metals.

Direct embedding and versatile placement of electrodes in 3D printed microfluidic-devices.

In this paper, we describe how PolyJet 3D printing technology can be used to fully integrate electrode materials into microfluidic devices during the print process. This approach uses stacked printing (separate printing steps and stage drops) with liquid support to result in devices where electrodes and a capillary fluidic connection are directly integrated and ready to use when printing is complete. A key feature of this approach is the ability to directly incorporate electrode materials into the print process so that the electrode(s) can be placed anywhere in the channel (at any height).

Review of 3D Cell Culture with Analysis in Microfluidic Systems.

A review with 105 references that analyzes the emerging research area of 3D cell culture in microfluidic platforms with integrated detection schemes. Over the last several decades a central focus of cell culture has been the development of better mimics. This has led to the evolution from planar cell culture to cell culture on 3D scaffolds, and the incorporation of cell scaffolds into microfluidic devices.

PolyJet 3D-Printed Enclosed Microfluidic Channels without Photocurable Supports.

Microfluidic devices have historically been prepared using fabrication techniques that often include photolithography and/or etching. Recently, additive manufacturing technologies, commonly known as 3D-printing, have emerged as fabrication tools for microfluidic devices. Unfortunately, PolyJet 3D-printing, which utilizes a photocurable resin that can be accurately printed, requires the use of support material for any designed void space internal to the model.

Ultrafiltration binding analyses of glycated albumin with a 3D-printed syringe attachment.

Protein-ligand binding assays facilitate the understanding of biomolecular interactions. Classical equilibrium dialysis methods are often used for accurate determination of binding properties. While accurate, the long equilibration times associated with the technique (> 6 h) hinder throughput.