Bioprinting microporous functional living materials from protein-based core-shell microgels

Abstract

Living materials have emerged as systems bringing together material science and biology to allow the engineering and augmenting of living systems with novel functionalities. Bioprinting promises accurate control over the formation of such complex materials through programmable deposition of cells in soft materials, but current approaches had limited success on fine-tunning cell microenvironments while generating robust macroscopic morphologies. Here, we address this challenge through the use of microgel ink to bioprint functional living materials. Jammed core-shell microgels are microfluidically functionalized with cells in the aqueous cores which can promote the growth of both microbial communities and mammalian cellular spheroids, followed by an interparticle annealing to give covalently stabilized functional scaffolds with controlled microporosity that enhances the mass transfer of nutrients and metabolites. Different microbial consortia are immobilized in scaffolds towards versatile applications; more importantly, by compartmentalizing microbial consortia at microscale, the collective bioactivities of both consortia are significantly enhanced, shedding light on strategies to augment living materials with bioprocessing capabilities.

Engineered Living Materials For Sustainability

“…Gelatin derivatives, particularly gelMA, can be rapidly photo-cross-linked into a 3D network with durable structural stability at physiological temperatures. They have been used as scaffolding materials to encapsulate various prokaryotic or eukaryotic cells. , In a study led by Cui et al, researchers created living materials composed of gelatin, GelMA, and Streptococcus zooepidemicus for the catalytic synthesis of HA . The gelatin/GelMA composites exhibited typical shear-thinning behavior and temperature-dependent rheology, which facilitated the 3D printing of the gels.…”

3D printing of microbial communities: A new platform for understanding and engineering microbiomes

“…However, it was only recently that these technologies have been applied to microbes. Thus far, the focus in microbiology has been quite different to that in human cell printing: rather than seeking to recreate microbial communities in their natural states, it was realised that microbes can be combined with abiotic matrices to create novel living materials (Duraj‐Thatte et al, 2021 ; González et al, 2020 ; Huang et al, 2019 ; Johnston et al, 2020 ; Lehner et al, 2017 ; Liu et al, 2018 ; Ou et al, 2022 ; Schaffner et al, 2017 ). Bacteria, in particular, can be mixed with biocompatible aqueous solutions that usually contain nutrients and chemical components to form a self‐supporting hydrogel.…”

“…They hypothesised that, when segregated, the species in question are not in direct competition for nutrients and so are better able to coexist and sustain production of betaxanthin. Another example uses this idea of spatial segregation to improve the production of 2‐phenylethanol (commonly used as rose scent) in a two‐species community comprising E. coli and Meyerozyma guilliermondii (Figure 1G ) (Ou et al, 2022 ). The authors use E. coli to convert glucose into 1‐phenylalanine, which is then further transformed into 2‐phenylethanol by M. guilliermondii .…”