The Role of Nanofiber Architecture in NF-κB Signaling

Open Access
Author:
Hong, Christopher Xighlun
Area of Honors:
Bioengineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Justin Lee Brown, Thesis Supervisor
  • Peter J Butler, Honors Advisor
Keywords:
  • NF-κB
  • OPG
  • RANKL
  • RANK
  • MC3T3
  • bone
  • tissue engineering
  • scaffolds
  • nanofibers
  • electrospinning
  • PMMA
  • osteoblasts
  • osteoclasts
Abstract:
The emerging field of tissue engineering and regenerative medicine involves the application of stem cells, biomaterial scaffolds and growth factors either alone or in combination to generate or regenerate damaged or diseased tissue. Previous studies have demonstrated that polymer nanofiber scaffolds provide a suitable environment for mineralized matrix formation and may serve as a substrate for bone tissue growth. In this thesis, we seek to understand the effect of nanofiber substrates on bone growth by studying the regulation of the nuclear factor κ B (NF-κB) signaling pathway. NF-κB is a transcription factor responsible for the regulation of the differentiation and activity of many skeletal cell types, including osteocytes, osteoblasts, osteoclasts, and chondrocytes. Poly(methyl methacrylate) nanofibers of varying diameters and densities were successfully synthesized via electrospinning. MC3T3-E1 Subclone 4 cells were cultured on control and nanofiber substrates for 12, 24 and 48 hours. Two important proteins in the NF-κB pathway, osteoprotegerin (OPG) and the receptor activator for NFκB-ligand (RANKL) were characterized through Western blotting and immunofluorescence assays. Results indicate that electrospun PMMA nanofiber scaffolds encourage a pro-remodeling phenotype in osteoblasts and may be a suitable substrate for bone tissue engineering applications. Through this study, we seek to understand the mechanisms behind osteoblast differentiation on nanofiber scaffolds leading to the engineering of scaffolds in such a way to promote mineralized bone formation.