Neurotrophic factor gradient generation for 2D and 3D in vitro and in vivo neuronal and Schwann cell guidance

Gradient;Nerve Regeneration;Biomedical Engineering

Krick, Kellin DanielMao, Hai-Quan ;

Johns Hopkins University

关键词: Gradient;    Nerve Regeneration;    Biomedical Engineering;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/39732/KRICK-DISSERTATION-2016.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

Delivery of neurotrophic factor gradients offers exciting potential for improving the regenerative outcomes in peripheral nerve injuries by enhancing the complete regeneration of nerves across large injury gaps. However, a major limitation to current gradient generation platforms has been the inability to develop gradient generation methodologies that exhibit control of gradient characteristics suitable for in vitro gradient screening while also being scalable to length scales relevant for in vivo nerve regeneration paradigms. Few studies have reported the influence of NF gradients on Schwann cell migration. We developed two gradient generation platforms capable of highly controlled, centimeter-scale gradient generation, which are capable of gradient delivery in both in vitro and in vivo gradient guidance paradigms. Furthermore, we developed a novel combinatorial cell migration platform, which combines topographical and biochemical guidance to investigate the effect of surface topography and gradient characteristics on the guidance of human Schwann cells. Using a live-cell imaging and analysis platform, we elucidated extensive details of the influence of these cues on the migration kinetics of Schwann cells, examining the roles of aligned fiber diameter and NF gradient characteristics in directing Schwann cell migration. Finally, we created a nerve guide that combines topographical and biochemical gradient guidance and demonstrated the utility of NF gradient delivery in enhancing regeneration in acute, short gap and long-term, large gap in vivo peripheral nerve injury models. The advances in gradient generation and delivery presented in this thesis offer new platforms for characterizing gradient guidance of a variety of neuronal and glial cell types and for enhancing nerve regeneration through in vivo NF gradient delivery.