Beads for Cell Immobilization: Comparison of Alternative Additive Manufacturing Techniques

Abstract

The attachment or entrapment of microbial cells and enzymes are promising solutions for various industrial applications. When the traps are beads, they are dispersed in a fluidized bed in a vessel where a pump guarantees fresh liquid inflow and waste outflow without washing out the cells. Scientific papers report numerous types of cell entrapment, but most of their applications remain at the laboratory level. In the present research, rigid polymer beads were manufactured by two different additive manufacturing (AM) techniques in order to verify the economy, reusability, and stability of the traps, with a view toward a straightforward industrial application. The proposed solutions allowed for overcoming some of the drawbacks of traditional manufacturing solutions, such as the limited mechanical stability of gel traps, and they guaranteed the possibility of producing parts of constant quality with purposely designed exchange surfaces, which are unfeasible when using conventional processes. AM proved to be a viable manufacturing solution for beads with complex shapes of two different size ranges. A deep insight into the production and characteristics of beads manufactured by AM is provided. The paper provides biotechnologists with a manufacturing perspective, and the results can be directly applied to transit from the laboratory to the industrial scale.

Features of Vat-Photopolymerized Masters for Microfluidic Device Manufacturing

“…All benchmark masters were produced by the VPP process using an acrylic acid ester commercially known as VITRA DL375 (DWS, Thiene, Italy), as detailed in a previous paper by the authors [39] (VITRA DL375 specifications are listed in the Supplementary Materials [40]). In addition to the masters, the analysis of the replicas was a crucial aspect for validating the entire production process and guiding biotechnologists' decisions for production improvement, especially in the presence of significant variability in device dimensions and shapes.…”

“…The objective is to significantly impact the time-to-market required for producing PDMS microfluidic devices. Three distinct benchmark masters (BM1, BM2, and BM3) were specifically designed to assess the feasibility and dimensional limits of ribs produced by VPP, employing a set of process parameters and a material that has been previously optimized and described by the authors [39]. Building upon the insights gained from BM1-BM3, two additional benchmark masters (BM4 and BM5) were designed for applications in the microfluidic field.…”

Rapid Prototyping Technologies: 3D Printing Applied in Medicine

“…This material is made of Si-O and Si-C chains in a matrix of linear polymers, which enables the free exchange of molecules and low interfacial energy. Therefore, the cast material is not exposed to a reaction with the surface of the mold [ 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ].…”

Magnetically‐actuated microcages for cells entrapment, fabricated by laser direct writing via two photon polymerization

“…For example, restraining the cells attachment to certain surfaces, directing cells growth and inducing cells differentiation are some of the main goals in designing complex 3D architectures for biomedical applications ( Liao et al, 2020 ; Paun et al, 2020a ; Sharaf et al, 2022 ). Until present, different cells entrapment techniques have been extensively studied regarding their ability to immobilize cells in different pathologies, such as cancer metastasis ( Ju et al, 2020 ; Preciado et al, 2021 ), microbial infections ( Li et al, 2021a ) or inflammation ( Schmidt and Wittrup, 2009 ), etc., as well as for tissue engineering applications (Khetan et al, 2009; Guvendiren and Burdick, 2012 ) or for “cell delivery” applications ( Gatto et al, 2023 ).…”

“…The cells are kept inside the device through physical immobilization ( Zhou et al, 2018 ; Shao et al, 2020 ; Veernala et al, 2021 ; Hasturk et al, 2022 ), extracellular‐matrix‐like adherence ( Rao and Winter 2009 ), specific antigen‐antibody recognition ( Roupioz et al, 2011 ; Boulanger et al, 2022 ), barrier containing ( Spagnolo et al, 2015 ; Larramendy et al, 2019 ; Li et al, 2021b ) and external stimuli‐activated entrapment ( Fu et al, 2008 ; Long et al, 2020 ), etc. The entrapment of cells can be switched on and off through enzymatic control ( Chen et al, 2003 ), pH variations ( Kocak et al, 2017 ), barrier containing ( Seifan et al, 2017 ; Larramendy et al, 2019 ; Gatto et al, 2023 ) or radiation switch ( Fu et al, 2008 ; Long et al, 2020 ).…”