Table 2 Comparison of the different models used to study lung biology

Physical architecture

•Structural mimics

pseudostratified epithelium in vitro

3D multicellular tissue construct in vitro

ex vivo tissue system

in vivo disease models

•Cell composition

predominated cell types are ciliated cells, goblet cells and basal cells

multiple differentiated cell types contain basal cells, multiciliated cells, secretory goblet cells and alveolar epithelial cells

all relevant cell types including structural and immune cells

all cell types

•Cell origin

primary and immortalized bronchial epithelial cells

primary airway cells and human pluripotent stem cells

all resident cells

all resident and migratory cells

•Recruitable immune cells

not available unless co-cultured

not available unless co-cultured

resident only

fully available

•Extracellular matrix

not available

exogenous matrigel and hydrogels

endogenous

endogenous

Physiological function

•Physiological relevance

mucociliary differentiation; heterogeneous cell populations; epithelial barrier function; physiological responses to insults

morphological and functional mimicking of the airway; heterogeneous cell composition and spatial organization; self-renewal and differentiation

preservation of the lung architecture including small airways, respiratory parenchyma, cell populations and connective tissue; physiological responses to challenge and stimuli

intact lung; physiological responses to challenge and stimuli; mimicking of human respiratory diseases

•Homeostasis

no

yes

yes

yes

•Immune responses

epithelium related responses

epithelium related responses

collective responses from tissue components

whole lung responses including recruitable immune cells

•Coculture potentials

yes, with fibroblasts and immune component

no data available

pre-existed multiple differentiated cell types

pre-existed multiple differentiated cell types