Development of a biologically-inspired airway epithelial model using a bronchial decellularized scaffold: applicability for pulmonary preclinical studies

Abstract

The search for physiologically relevant 3D airway models in vitro has made significant progress in recent decades. The goal has been to replace animal-based methods with assays that mimic the human response to toxicants exposure through inhalation. However, replicating the entire composition of the extracellular matrix (ECM) microenvironment has proven challenging. Some strategies, such as 3D bioprinting and commercial hydrogels and biomatrixes, have addressed this issue. Yet, it remains difficult to recreate tissue topography, the location of anchorage proteins, and the exact protein and non-protein composition of ECM. In this study, we aimed to obtain and characterize a low-cost decellularized bronchial porcine scaffold derived from food industry waste. This scaffold was intended for the reconstruction of 3D bronchial models using human cells for long-term cultivation. Fragments from the main right and left bronchi underwent various matrix decellularization methods, including surfactant solutions, osmotic gradient, and nuclease treatment. The results showed that all these approaches efficiently promoted cell removal while preserving collagen content, glycosaminoglycans, and the basal membrane. Next, we repopulated the decellularized ECM (dECM) with Calu-3 epithelial cells and cultivated them in an air-liquid interface (ALI) to assess cell behavior within the scaffold. Over 7 and 14 days of ALI cultivation, the cells exhibited progressive growth on the bronchial dECM, expressing regular pan-cytokeratin, MUC1, and E-cadherin. In summary, we successfully developed a low-cost, biologically relevant dECM that was employed for reconstructing human airway models. These models hold promises for use in preclinical respiratory research studies.