3D Printed Microfluidic Spiral Separation Device for Continuous, Pulsation-Free and Controllable CHO Cell Retention

Abstract

The development of continuous bioprocesses—which require cell retention systems in order to enable longer cultivation durations—is a primary focus in the field of modern process development. The flow environment of microfluidic systems enables the granular manipulation of particles (to allow for greater focusing in specific channel regions), which in turn facilitates the development of small continuous cell separation systems. However, previously published systems did not allow for separation control. Additionally, the focusing effect of these systems requires constant, pulsation-free flow for optimal operation, which cannot be achieved using ordinary peristaltic pumps. As described in this paper, a 3D printed cell separation spiral for CHO-K1 (Chinese hamster ovary) cells was developed and evaluated optically and with cell experiments. It demonstrated a high separation efficiency of over 95% at up to 20 × 106 cells mL−1. Control over inlet and outlet flow rates allowed the operator to adjust the separation efficiency of the device while in use—thereby enabling fine control over cell concentration in the attached bioreactors. In addition, miniaturized 3D printed buffer devices were developed that can be easily attached directly to the separation unit for usage with peristaltic pumps while simultaneously almost eradicating pump pulsations. These custom pulsation dampeners were closely integrated with the separator spiral lowering the overall dead volume of the system. The entire device can be flexibly connected directly to bioreactors, allowing continuous, pulsation-free cell retention and process operation.

A 3D-printed microfluidic gradient generator with integrated photonic silicon sensors for rapid antimicrobial susceptibility testing

“…The device is fabricated from a biocompatible and heat-resistant 34 polyacrylate material by high-resolution 3D printinga technique that enables the manufacturing of microfluidic devices and has accordingly assumed increasing importance in many biotechnology-related fields, ranging from diagnostics to cell culture. [35][36][37][38][39] Compared to standard fabrication processes such as polydimethylsiloxane-based soft-lithography, 10,12,40 3D printing offers rapid prototyping of complex structures in a single step, 38,41 the use of various and versatile materials, 34,40,42 and does not require sophisticated microfabrication facilities. 12,38 The functionality of the GG is first established off-chip, see Fig.…”

Label-Free Physical Techniques and Methodologies for Proteins Detection in Microfluidic Biosensor Structures

“…The geometrical configurations of microfluidic platforms can be very different (for example, channels, tanks, separators, mixers, etc. [ 57 , 58 ]) and depend on the application. If microfluidic devices are created only for detecting certain biological components, they usually have a simple geometric structure in the form of one or more channels with sizes from micrometers to millimeters in cross-section.…”

“…For example, it is necessary to sort out certain components or particles to increase the concentration of the detected component. In this case, the geometry of the microfluidic system will be more complex and passive, or active separation structures can be added to the chip [ 57 , 58 ]. For labelled techniques, the microfluidic chip can be expanded with microfluidic mixers [ 59 ] to blend the material under test (MUT) with fluorescent components or nanoparticles.…”

3D printing in biotechnology—An insight into miniaturized and microfluidic systems for applications from cell culture to bioanalytics

“…While 3D-printed inertial focusing devices for bioprocess applications are still rare, we believe that these tools will increasingly be employed for such operations in the future. For example, Enders et al have shown that these 3D-printed spiral cell separator devices can be used for cell retention to enable continuous cultivation processes [64]. Such systems could also potentially be used to concentrate cells with the aim to improve the transient transfection of mammalian cell lines used for protein production.…”