טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentMerdler Uri
SubjectVascularization of Engineered 3D Neural Structures
DepartmentDepartment of Biomedical Engineering
Supervisor Professor Shulamit Levenberg


Abstract

Neural tissue engineering presents a tremendous potential as a tool aiming to produce 3D neural tissue constructs under controlled lab conditions. These constructs may be designed to repair or substitute damaged neural tissues as well as a research model to investigate neural tissue morphology, functionality and development. Vascularization of neural engineered tissues in greatly desired to elevate integration between engineered tissue and host tissue, as well as due to signal interplay between neural cells and endothelial cells. Furthermore, to accurately model numerous neurodegenerative diseases a neural-vascular structure is essential, as these conditions present and sometime caused by impairment of the blood-brain barrier.

We hypothesize that by promoting vascularization within engineered neural tissues, we can modulate their morphology, functionality and development. Several approaches were attempted in order to produce 3D tissue models carrying viable and functional neural-vascular structure. Formed structures were assessed using live imaging, calcium imaging and neural or endothelial immunostaining.

Initially, a straight forward approach of co-seeding neural, endothelial and a variety of supporting cells was examined. Next, neural seeding on prevascularized structure was carried out, using plasma treated scaffold as a platform for sequential procedure.  Finally, a developmental approach was executed, examining the induction of sprouting vessels from a prevascularized structure into a neural domain. Aiming to generate a human relevant neural model, as well as establishing a neural developmental model, iPSCs-derived neural 3D structure was produced. Also, to further enhance compatibility between neural and vascular tissue, a novel co-culture system to produce vascular tissue comprised of cell types specific to neural vasculature was achieved.

Most positive results were obtained in the developmental model, through induction of sprouting vessels into a neural domain during neural differentiation. Our results indicate neural protection and modulation was achieved through co-culture with prevascularized structure, which we speculate that might induce neural maturation via signal interaction between the neural and vascular structure. We believe that further calibration and optimization can greatly elevate both vessel sprouting to neural region and neural-vascular interaction, which will allow further investigation of vascularized neural tissue both in vitro and in vivo.