Extracellular‐Matrix‐Reinforced Bioinks for 3D Bioprinting Human Tissue

Abstract

Recent advances in 3D bioprinting allow for generating intricate structures with dimensions relevant for human tissue, but suitable bioinks for producing translationally relevant tissue with complex geometries remain unidentified. Here, a tissue‐specific hybrid bioink is described, composed of a natural polymer, alginate, reinforced with extracellular matrix derived from decellularized tissue (rECM). rECM has rheological and gelation properties beneficial for 3D bioprinting while retaining biologically inductive properties supporting tissue maturation ex vivo and in vivo. These bioinks are shear thinning, resist cell sedimentation, improve viability of multiple cell types, and enhance mechanical stability in hydrogels derived from them. 3D printed constructs generated from rECM bioinks suppress the foreign body response, are pro‐angiogenic and support recipient‐derived de novo blood vessel formation across the entire graft thickness in a murine model of transplant immunosuppression. Their proof‐of‐principle for generating human tissue is demonstrated by 3D bioprinting human airways composed of regionally specified primary human airway epithelial progenitor and smooth muscle cells. Airway lumens remained patent with viable cells for one month in vitro with evidence of differentiation into mature epithelial cell types found in native human airways. rECM bioinks are a promising new approach for generating functional human tissue using 3D bioprinting.

Harnessing the ECM Microenvironment to Ameliorate Mesenchymal Stromal Cell-Based Therapy in Chronic Lung Diseases

“…Recombinantly produced biomaterials such as the elastin-like recombinamer polymer allows for the precise composition of structural and chemical properties, with gene technology introducing sequences for cell attachment and MMP degradation and at the same time exposing functional groups for binding of for example growth factors to promote or maintain the MSC therapeutic effect (Ibáñez-Fonseca et al, 2020). De Santis et al recently demonstrated the functional outcome of a 3D bioprinted hybrid hydrogel combining decellularized lung tissue with alginate to form human airways containing primary human airway epithelial progenitor cells (De Santis et al, 2020). Transplanted in mice, the cells showed evidence of differentiation into mature epithelial cells.…”

“…Transplanted in mice, the cells showed evidence of differentiation into mature epithelial cells. The hydrogel properties both had matched biomechanical properties and contained ECM instructive factors from the native lung tissue (De Santis et al, 2020). Hydrogels based on collagen type I, one of the major structural components of tissues, has been extensively explored in combination with other materials such as silk, a highly elastic protein, to improve the mechanical properties to mimic the viscoelastic properties of tissues (Sanz-Fraile et al, 2020).…”

Engineering Tissue-Informed Biomaterials to Advance Pulmonary Regenerative Medicine

“…Epithelial progenitor cells were seeded into this hybrid bioink and 3D printed as a hollow tube and then subjected to ALI differentiation for 28 days. The study found that the hybrid bioink allowed for the differentiation of progenitor cells into ATUB-expressing ciliated cells and that the constructs remained stable and patent for the full 28 days (60). In contrast, culturing human lung organoids (HLOs) derived from pluripotent stem cells within Matrigel enabled cells to spontaneously form physiologically elaborate 3D structures in vitro.…”

Implications for Extracellular Matrix Interactions With Human Lung Basal Stem Cells in Lung Development, Disease, and Airway Modeling

“…Biomaterial inks have been developed from regenerated silk fibroin (SF) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized bacterial cellulose (OBC) nanofibrils and engineered for 3D printing of lung tissue scaffolds ( Huang et al, 2020 ). Another group has developed a tissue-specific hybrid bioinks from the naturally occurring polymer alginate along with ECM derived from decellularized tissue ( De Santis et al, 2021 ). In both models HBECs were able to adhere and proliferate, maintaining expression of basal cell markers TP63 and KRT5.…”

“…In both models HBECs were able to adhere and proliferate, maintaining expression of basal cell markers TP63 and KRT5. De Santis and colleagues evaluated differentiation over a month on 3D bio-printed human airways composed of regionally specified airway smooth muscle and human bronchial epithelial cells and observed basolateral localization of BCs and evidence of differentiation to mucus-producing cells (MUC5AC + ) and ciliated cells shown directly through scanning electron microscopy and alpha-tubulin expression ( De Santis et al, 2021 ). The results of this study do demonstrate that a combination of exogenously and endogenously derived ECM materials supports epithelial development and offers the potential of printing customized airway scaffolds which has not yet been achieved with native ECM alone.…”