목차

I. INTRODUCTION 1
A. Spinal cord injury 1
B. The mechanism of primary and secondary damage following SCI 2
1. Primary Injury 2
2. Secondary Injury 2
C. Challenges in SCI Regeneration 4
1. Extrinsic Influences on Neural Repair 4
a. Cystic cavity formation after SCI 4
b. Glial Scar 4
c. Fibrotic Scar 5
2. Intrinsic Influences on Neural Repair 7
D. Therapeutic Strategies for Spinal Cord Injury 8
1. Surgical Techniques for SCI 8
2. Cellular therapeutic interventions after SCI 9
3. Pharmacological therapy for SCI 10
4. Biomaterials for SCI repair 11
E. Aims of this study 12
II. MATERIALS AND METHODS 14
1. Animal and surgical procedures 14
2. Injection of PEI-Mannose hydrogel 14
3. Tissue processing and histological assessments 14
4. Primary meningeal fibroblast, cerebral astrocyte cultures 15
5. Astrocyte-fibroblast co-culture system 16
6. In vitro drug testing 16
7. Quantitative assessment of co-culture size and numbers 17
8. Quantitative assessment of astrocytic process lengths 17
9. Quantitative analysis of immunoreactivity 17
10. Immunocytochemistry 17
11. Statistical analysis 18
III. RESULTS 19
Part A. Creating biologically meaningful in vitro fibrotic scar model that resembles the hydrogel-created matrix 19
1. PEI-Mannose hydrogel eliminates the cystic cavities that are formed after SCI with a growth incompetent fibronectin-rich matrix 19
2. Hydrogel mediated fibrotic scar can be reconstructed in vitro 22
3. Meningeal fibroblasts form clusters when they are cultured on top of astrocytes 24
4. TGF-β1 treatment increased FN and GFAP immunoreactivity of co-cultured cells 27
5. TGF-β1 treatment to co-cultures enhances fibrotic scar markers vastly present in in vivo hydrogel induced fibrotic scar 29
6. TGF-β1 promotes scar fibroblasts proliferation and enhances the fibrotic scar marker expression 31
7. TGF-β1 is a modulator of astrocytic GFAP expression, and phenotypic alterations when co-cultured with primary fibroblasts 33
8. Addition of TGF-β1 to co-cultures induces the phenotype of the scar-forming astrocytes 35
Part B. Screening anti-fibrotic drugs that can modulate hydrogel-induced fibrotic matrix 37
1. Inhibiting fibrotic scar formation with microtubule stabilizers 37
2. Targeting tyrosine kinases and PDGFRβ in the pathogenesis of fibrosis 40
3. Second screening with promising anti-fibrotic drugs using common fibrotic scar markers 45
IV. DISCUSSION 48
V. CONCLUSION 54
REFERENCES 55