Biological barriers are the protective structures of our bodies that separate the “inside” from the “outside” with the role to provide the body with a stable environment. Each barrier has its own distinct design and biological structure but common to all is that they comprise several different cell types that strictly control the passage of molecules to avoid the introduction of compounds that could be harmful for us. Whilst this has evolved to benefit us, at the same time it can be a challenge for drug delivery, as all pharmaceuticals have to cross at least one biological barrier before they can work.
The group of drugs that faces the most challenging route of delivery is medication against neurodegenerative diseases, such as Alzheimer’s. These drugs have to cross from the blood capillaries in the brain, which is termed the blood-brain barrier. Neurodegenerative diseases have recently seen a drastic increase and it is estimated that the economic burden to care for this group of patients in Europe lies close to 800 billion EUR annually so there is a tremendous need to identify effective new drug formulations with efficient delivery pathways to improve current treatment strategies. A reliable cell-based in vitro model of the blood-brain barrier could speed up the drug delivery process and align with the 3R ambition to replace animals in research.
The overall goal of SONGBIRD was to develop a microfabrication tool-box for biologically-derived hydrogels to realise next-generation in vitro models, so-called organs-on-chip systems. The research results obtained during the project and the methodology developed could unlock the use of next generation animal-free ‘barrier-on-chip’ models used to speed up drug development, serve as screening platforms for nanotoxicology and help medical researchers to understand fundamental biologial processes involved in molecular transport across biological membranes.
