Basic Science Perspective on Engineering and Modeling the Large Airways.

Area of Science:

• Pulmonary biology and respiratory medicine.
• Tissue engineering and regenerative medicine.
• Immunology and host defense.

Background:

• The airway epithelium forms a critical physical and biochemical barrier in the lungs.
• This barrier protects against pathogens and environmental irritants, maintaining tissue homeostasis and innate immunity.
• Chronic exposure to insults compromises barrier function, leading to inflammation and infection.

Purpose of the Study:

• To explore the structure-function relationships within the airway epithelium.
• To discuss the challenges in developing complex engineered models of the human airway.
• To highlight the components necessary for recreating physiological and pathological airway models.

Main Methods:

• Review of existing literature on airway epithelium structure and function.
• Analysis of cellular and extracellular matrix components critical for airway modeling.
• Identification of challenges in replicating the complexity of the airway niche.

Main Results:

• The airway epithelium's barrier effectiveness depends on mucociliary clearance, immune surveillance, and regeneration.
• Successful engineering of airway models requires integrating surface and submucosal gland epithelia, extracellular matrix, and niche cells (smooth muscle, fibroblasts, immune cells).
• Current models face difficulties in fully recapitulating the intricate structure-function dynamics of native human airways.

Conclusions:

• Understanding airway epithelium structure-function is essential for developing accurate disease models.
• Recreating the complex cellular and matrix environment is key to advancing airway engineering.
• Further research is needed to overcome challenges in building sophisticated, physiologically relevant human airway models.