Periodic Reporting for period 4 - SONGBIRD (SOphisticated 3D cell culture scaffolds for Next Generation Barrier-on-chip In vitro moDels)
Reporting period: 2022-07-01 to 2023-03-31
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.
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.
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 project has resulted in 15 scientific publications and 15 conference contributions.
The research was structured around four objectives, namely:
Objective 1: Microfabrication of hydrogels. Methods based on UV lithography to chemically functionalise hydrogels were developed. This platform was used to gain valuable insight into the coordinated movement of the actin fibres forming the cell cytoskeleton and the cell nucleus as the cells attach and orient themselves on patterned surfaces.
Objective 2: 3D cell culture. Astrocytes were cultured in hydrogels prepared as droplet structures in a microfluidic system. This research, together with my expertise in integrated acoustics form the basis of my newly started ERC Consolidator grant PHOENIX that will continue the research direction focused on 3D cell cultures as novel in vitro platforms.
Objective 3: Preparation of a multi-layer hydrogel structure were developed by integrating a solid “scaffold” in the hydrogel films and bonding this hybrid structure onto a Transwell support. Free-hanging hydrogels in GelMA (methacrylated gelatine), PEG (polyethyleneglycol) and Hylauronic acid have been demonstrated and have been used for (2D) culture of cells on the soft substrates for 9 days as well as the assembly of a multi-layer structure.
Objective 4: Microfluidic platform integration. An important aspect of microfluidic systems used for barrier models is that they must include a method for in situ read-out of barrier integrity. To this end, transparent ITO was used to integrate miniaturised electrodes for continuous TEER (trans-endothelial electrical resistance) measurements in a microfluidic barrier-on-chip system was developed. The developed read-out platform, has also been used in a collaborative project at Uppsala University (Dr. Behrendt) to study effects of climate change on coral reefs.
The research was structured around four objectives, namely:
Objective 1: Microfabrication of hydrogels. Methods based on UV lithography to chemically functionalise hydrogels were developed. This platform was used to gain valuable insight into the coordinated movement of the actin fibres forming the cell cytoskeleton and the cell nucleus as the cells attach and orient themselves on patterned surfaces.
Objective 2: 3D cell culture. Astrocytes were cultured in hydrogels prepared as droplet structures in a microfluidic system. This research, together with my expertise in integrated acoustics form the basis of my newly started ERC Consolidator grant PHOENIX that will continue the research direction focused on 3D cell cultures as novel in vitro platforms.
Objective 3: Preparation of a multi-layer hydrogel structure were developed by integrating a solid “scaffold” in the hydrogel films and bonding this hybrid structure onto a Transwell support. Free-hanging hydrogels in GelMA (methacrylated gelatine), PEG (polyethyleneglycol) and Hylauronic acid have been demonstrated and have been used for (2D) culture of cells on the soft substrates for 9 days as well as the assembly of a multi-layer structure.
Objective 4: Microfluidic platform integration. An important aspect of microfluidic systems used for barrier models is that they must include a method for in situ read-out of barrier integrity. To this end, transparent ITO was used to integrate miniaturised electrodes for continuous TEER (trans-endothelial electrical resistance) measurements in a microfluidic barrier-on-chip system was developed. The developed read-out platform, has also been used in a collaborative project at Uppsala University (Dr. Behrendt) to study effects of climate change on coral reefs.
The methodology developed during SONGBIRD can now be applied to realise multi-layer, multi-material blood-brain barrier models.