VISUALIZATION AND QUANTITATION OF STEM CELL MEDIATED MINERALIZATION OF A DEMINERALIZED COLLAGEN SAFFOLD IN A TISSUE ENGINEERING MODEL

Restricted (Penn State Only)
Author:
Mckellar, Brian U
Graduate Program:
Bioengineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
March 31, 2017
Committee Members:
  • Justin Brown, Thesis Advisor
  • Sarindr "Ik" Bhumiratana, Thesis Advisor
  • William Hancock, Committee Member
  • XIAOJUN "Lance" LIAN, Committee Member
Keywords:
  • Tissue Engineering
  • Stem cell
  • Biomineralization
  • Bone
  • Osteogenic differentiation
Abstract:
Tissue engineering fabrication of mineralized collagen for bone graft applications is a progressing field, but we still lack a sufficient understanding of the underpinnings of biomineralization on a macro scale. Clinically, bone grafts are used to treat congenital abnormalities, trauma, and cancer surgeries, each which carry a specific set of requirements. Successfully engineered grafts must exhibit biological and structural functions similar to native tissue and have ability to integrate into the surrounding tissue. Stem cells have the capability to differentiate and deposit mineral in culture on a three dimensional scaffold. In this thesis, the visualization and quantitation of stem cell mediated remineralization of a demineralized collagen scaffold was demonstrated. The overall investigational approach was to first test feasibility of mineralization on demineralized and decellularized scaffolds in vitro using static culture (aim 1) and then use a perfusion bioreactor to create a physiologically relevant environment and further quantify and visualize the mineralization (aim 2). This novel, imaging-compatible bioreactor system yielded native bone architecture and enhanced bone volume when compared to static culture. Biomineralization was accomplished by remineralizing a collagen scaffold derived from bovine tissue in a trabecular anatomical pattern which was then quantified and visualized. Since stem cells are the biological powerhouse of this model, it is crucial to understand their specific role and behavior. Biomineralization is driven by osteogenic differentiation and protein expression of the stem cells. As fabricated mineralized collagen becomes better understood, laboratory tissue engineering work will translate into improved clinical applications.