Biological Barriers in Health and Disease

Dear Colleagues,

Biological barriers protect organs and tissues from physical, chemical and biological damage and maintain homeostasis within the tissues. In this context, they also represent important interfaces between organs and their "outside world", such as air or body fluids (e.g., blood and saliva). The main components of biological barriers are either endothelial or epithelial cell layers. The function of these cell layers is highly regulated by their microenvironment, which includes neighboring cell types and the extracellular matrix or physical stimuli such as shear stress exerted by blood flow. It is known that the functionality of biological barriers is altered in many diseases. These functional changes affect the paracellular barrier, active transport of molecules, the metabolic barrier, but also the signaling between the body fluid and the tissue, and the clearance of waste from the tissues. It is assumed that changes in biological barriers are not only symptoms but also causally related to disease progression. In addition, biological barriers can be direct targets for therapeutic approaches. They also determine the permeability of biomarkers from the tissue into the body fluid but can also release biomarkers themselves.

This Special Issue serves to highlight the role of biological barriers in health and disease with a focus on in silico, in vitro and in vivo animal and human data, contributing to the translation from the animal to human situation. We accept all articles related to biological barriers including in vitro model development with a focus on multicellular and microfluidic systems, pathogen-host interactions, drug permeability, drug actions, therapeutic strategy evaluations, drug delivery systems, novel disease models, signaling pathways and omics data.