Bioprintable Lung Extracellular Matrix Hydrogel Scaffolds for 3D Culture of Mesenchymal Stromal Cells

Abstract

Mesenchymal stromal cell (MSC)-based cell therapy in acute respiratory diseases is based on MSC secretion of paracrine factors. Several strategies have proposed to improve this are being explored including pre-conditioning the MSCs prior to administration. We here propose a strategy for improving the therapeutic efficacy of MSCs based on cell preconditioning by growing them in native extracellular matrix (ECM) derived from the lung. To this end, a bioink with tunable stiffness based on decellularized porcine lung ECM hydrogels was developed and characterized. The bioink was suitable for 3D culturing of lung-resident MSCs without the need for additional chemical or physical crosslinking. MSCs showed good viability, and contraction assays showed the existence of cell–matrix interactions in the bioprinted scaffolds. Adhesion capacity and length of the focal adhesions formed were increased for the cells cultured within the lung hydrogel scaffolds. Also, there was more than a 20-fold increase of the expression of the CXCR4 receptor in the 3D-cultured cells compared to the cells cultured in plastic. Secretion of cytokines when cultured in an in vitro model of lung injury showed a decreased secretion of pro-inflammatory mediators for the cells cultured in the 3D scaffolds. Moreover, the morphology of the harvested cells was markedly different with respect to conventionally (2D) cultured MSCs. In conclusion, the developed bioink can be used to bioprint structures aimed to improve preconditioning MSCs for therapeutic purposes.

hLMSC Secretome Affects Macrophage Activity Differentially Depending on Lung-Mimetic Environments

“…Interestingly, this decrease was only seen for CYR61 in the L-Scaffold, which indicates that there is an interplay between the ultrastructure and mechanical confinement. The cell-to-cell interactions seem to primarily drive the response of CTGF, while CYR61 seems to be more closely linked to stiffness of the substrate as the difference in stiffness was neglectable between L-Hydrogel and L-Scaffold in comparison to plastic (KPa to GPa; Figure 1 A) [ 24 , 25 ]. Adding cyclic stretch further indicated the role of the microenvironment.…”

“…For this reason, it is of high relevance to develop culture conditions that can predict the “quality” of the intended population of MSCs for therapy. We and others have demonstrated that major changes can be induced in the MSC secretome and, therefore, its paracrine actions when cultured under physiomimetic cues [ 2 , 25 , 30 ]. Intriguingly, L-Hydrogel and plastic conditions bore some overlapping features in their secretome cluster profiles despite sizeable differences in CTGF and CYR61 expression ( Figure 1 C), while L-Scaffold displayed a distinct phenotype despite having a similar gene expression to plastic with regard to mechanoreceptors.…”

Decellularized Tissues for Wound Healing: Towards Closing the Gap Between Scaffold Design and Effective Extracellular Matrix Remodeling

“…For their part, Falcones et al examined the feasibility of using lung dECM bio-inks for enhancing the therapeutic effect of MSCs, in the context of MSC-based therapies for the treatment of respiratory diseases (Falcones et al, 2021).…”

Novel Decellularization Method for Tissue Slices

“…Accordingly, decellularized ECM scaffolds have great potential for tissue engineering and regenerative medicine. In fact, decellularized tissues can be used for the generation of ECM hydrogels ( Falcones et al, 2021 ), for the recellularization of whole acellular organs ( Ohata and Ott 2020 ), as well as applications in tissue regeneration ( Zhu et al, 2019 ). Thus, it is unsurprising the growing interest to work on physiomimetic tissue scaffolds by decellularizing different types of tissues ( Mendibil et al, 2020 ).…”