Exploration of artificial scaffolds for improving grafthost integration in cerebral transplantation therapy

Abstract

Neurodegenerative disease or injury often result in devastating consequences for affected individuals. Treatment options available remain inefficient, and the hunt for new innovative approaches to halt and reverse the effects of neural cell loss continues. Regenerative medicine focuses on a combination of cell transplantation coupled with tissue engineering approaches (3D scaffolds and biomaterials) to restore normal brain function. However, much work is yet needed to in-depth evaluate the use of scaffolds in the development of cell transplantation therapies.

Lately our laboratory reported the efficient use of poly-ε-caprolactone (PCL) fibrous scaffolds, and demonstrated the development of biomimetic and functional 3D human neural networks using human neural progenitor cells (hNPCs) as a tool donor cell. In this study, we wanted to further investigate the influence of scaffolds on hNPCs using a more in vivo like setting. Therefore, we developed a system for co-culture of organotypic mouse brain slices and hNPCs- bioscaffolds through media tests and technical optimization. In the membrane control co-cultures without bioscaffolds, we confirmed survival of hNPCs and organotypic brain slices co-cultured for 10 days, and indications of possible migration and integration between the two. Bioscaffolded co-cultures showed good survival of both donor cells and brain slice, however, no significant impact of bioscaffolds, judged by donor-host integration compared to control. Hence, future studies using a further optimized hNPC-bioscaffold co-culture protocol is motivated for mapping the crucial factors for advancing cell transplantation efficacy.

Popular Abstract

Exploring scaffold influence on co-cultured cell/brain explants

The brain is like a central computer and its most abundant components are the nerve cell specifically neurons which are estimated to be 86 billion. Neurons communicate with other neurons through long extensions called processes (axon and dendrites), electrical current is sent through the processes almost like through power lines. Neurons are dependent on another type of nerve cell, the glial cells. Glial cells form support for the neurons, like the many structures supporting power lines. If a power line is cut or the structural support is damaged, the electrical current will not reach its destination, if this happens a repair man from the electrical company restores the connection. In the central nervous system where most nerve cells reside connections can be broken through disease or traumatic injury and there is no equivalent to a repair man, making damage very hard to fix.

Today many researchers are focused on becoming the repair men, using a big tool box containing stem cells, support structures and other means available. One problem is that many tools exist, and damage is often very specific and thus can only be fixed by a very specific tool. In my study, I focused on evaluating one such tool, that is supporting scaffolds in combination with stem cells, co-cultured with mouse brain slices. The stem cells I used, were human neural progenitor cells, that are committed to the neural lineage, meaning they can differentiate into glial cell types or neurons. What I was trying to see was if the progenitor cells differentiated, could establish or re-establish connections in the brain, and if the support scaffolds would have any effect on this. I was also interested in how the cells behaved in co-culture with organotypic brain slices, cultured on either membrane or scaffolds. Prior to my experiment, I did a lot of optimization, ensuring that the environment I had for my setup up worked with both cells and brain slices. The test system had to closely resemble a natural environment, several different settings were compared and a variety of tests were carried out to confirm the general health of both cells and brains.

My results showed that brains and cells survived together in co-culture, in the environment I had previously optimized, some migration of cells was also observed with possible integration. This supports the possibility of using stem cells to repair a broken connection, however I did not see any improved effect from the scaffolds, but testing was limited and more extensive testing needs to be done to elucidate its effects. In conclusion, this work confirms that co-cultures are possible to maintain between brain slices and human neural progenitor cells, but it requires evaluation of environment for both cells and brain. This setup could be valuable for future studies of damage and repair relationships in the central nervous system.




Master’s Degree Project in Molecular Biology 45 credits 2017
Department of Biology, Lund University

Advisor: Ulrica Englund Johansson
Department of Clinical Sciences in Lund, Ophthalmology, Lund University

• author: Bruzelius, Andreas
• supervisor: Ulrica Englund Johansson; Marina Castro Zalis
• organization: Degree Projects in Molecular Biology
• course: MOBN01 20171
• year: 2018
• type: H2 - Master's Degree (Two Years)
• subject: Biology and Life Sciences
• language: English
• id: 8938037
• date added to LUP: 2018-03-26 10:04:34
• date last changed: 2018-03-26 10:04:34