Organ-on-Chip Teknik: Framsteg i utvecklingen av en tredminensionell modell av blod-hjärnbarriären
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesisAlternative title
Organ-on-Chip Technology: Advances in the Development of a Three-Dimensional Model of the Blood-Brain Barrier. (English)
The blood-brain barrier plays a vital role in protecting the central nervous system from variations in blood composition and toxins, it is also known to play a key role in diseases of the central nervous system. Most of our current understanding about biological mechanisms and disease comes from comprehensive studies of tissues or studies in live animals. An in vitro model of the blood-brain barrier can provide a platform which is more relatable to human physiology, is cost effective and ethically responsible. It has been previously described that the cells microenvironment coupled with other factors such as mechanical shear stress can lead to improved cell differerentiation and thus a more realistic in vitro model. Despite this very little has been achieved in the creation of a truly three-dimensional in vitro model of blood-brain-barrier.
This resport describes a microfluidic chip with a three-dimensional in vitro co-culture of human neurovascular cell types that closely resembles the organiszation of the blood-brain barrier - a '3D BBB Chip'. Said model was created by seeding cells in and around a circular lumen embedded in a three dimensional collagen hydrogel. The circular lumen was created by establishing a Saffman-Taylor instability with culture media which rather elegantly fingered through the more viscous collagen solution thus forming a long lumen like structure. Engineering the circular lumen required numerous studies to explore the chips surface chemistry and the composition of the collagen hydrogel.
It was found that addition of transglutaminase, a crosslinking enzyme improved the long-term viability of the hydrogel from six days to more than eight days when subjected to a fluidic flow rate of 100 µl/hr. Additionally it was observed that altering the hydrostatic pressure during the lumen formation allows the user to create circular lumens of varying diameter. Confocal imaging shows that human astrocytes and human brain pericytes were successfully embedded in the collage gel prior to the three-dimensopnal patterning and that human cerebral cortex microvascular endothelial cells were used to cover the entire lumen with a monolayer. Finally, initial permeability experiments show that the permeability of the cocultures for 3 kDa dextrand was recorded to be as low as 2x10-6 cm/s.
Place, publisher, year, edition, pages
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-173906OAI: oai:DiVA.org:kth-173906DiVA: diva2:855915
Andersson Svahn, Helene