Methods in Molecular Biology (2022) 2436: 257–266

DOI 10.1007/7651_2021_444

© Springer Science+Business Media, LLC 2021

Published online: 02 November 2021

Bioreactor-Based Adherent Cells Harvesting from

Microcarriers with 3D Printed Inertial Microfluidics

Lin Ding, Reza Moloudi, and Majid Ebrahimi Warkiani

Abstract

Harvesting adherent cells from microcarriers has become one of the major challenges of the downstream

bioprocessing at large scale the current method has high maintenance and operation cost, which are the

results of frequent clogging, due to cell lysing effect and microcarrier cake formation on membrane-based

technology. These problems hugely impede the adaptation of microcarriers technologies in large-scale cell

culture and hampered the supply of cells to the clinical need. Here, we describe two 3D printing-based

methods to fabricate inertial microfluidic devices for separating adherent cells from microcarriers which

overcome the above-mentioned limitations. The spiral devices are employed to separate mesenchymal stem

cells from the microcarriers with 99% microcarrier removal rate and 77% cell recovery rate in one round of

separation.

Key words Stem cells, Inertial microfluidics, Cell harvesting, Microcarrier-based culture, Cell therapy

industry

1

Introduction

Microcarrier-based cell culture is considered as the future standard

of adherent cells culture in large-scale [1, 2]. They have large

surface area-to-volume ratio for the cells to attach and provide a

better environment for cells interaction and secretion [1]. However,

multilayer flasks are still the most common way of adherent cells

production. The slow adaptation of new technology can be mainly

attributed to the complicated cell harvesting procedure of

microcarrier-based culture method. Harvesting cells from micro-

carriers heavily relies on membrane-based technologies Cells and

microcarriers solution is passed through the physical filters which

are frequently blocked by cell clumps, results in cell lysis and are

expensive to change and operate [2].

One of the potential substitutions of membrane-based tech-

nologies is inertial microfluidic devices. Inertial microfluidics has

been used widely for separation of cells from a heterogeneous

population recently. It focuses particles with different sizes at dif-

ferent cross-sectional positions inside the channel, allowing the

particles to be collected from different outlets [3, 4]. In a straight

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