Worcester Polytechnic Institute Electronic Theses and Dissertations Collection

Title page for ETD etd-050407-104302


Document Typedissertation
Author NameCornwell, Kevin G.
URNetd-050407-104302
TitleCollagen and Fibrin Biopolymer Microthreads For Bioengineered Ligament Regeneration
DegreePhD
DepartmentBiomedical Engineering
Advisors
  • George D. Pins, Advisor
  • Kristen Billiar, Committee Member
  • Glenn Gaudette, Committee Member
  • Paul Fanning, Committee Member
  • Karl Helmer, Committee Member
  • Peter Grigg, Committee Chair
  • Keywords
  • ligament
  • ACL
  • collagen
  • fibrin
  • microthread
  • fiber
  • thread
  • FGF-2
  • fibroblast
  • tissue regeneration
  • tissue engineering
  • Date of Presentation/Defense2007-05-04
    Availability unrestricted

    Abstract

    Rupture of the anterior cruciate ligament (ACL) of the knee leads to chronic joint instability and reduced range of motion while the long term results are marred by a high prevalence of degenerative joint disease especially osteoarthritis. Bundles of collagen threads have been widely investigated for the repair of torn ACL, but are limited by insufficient tissue ingrowth to repopulate and completely regenerate these grafts. We have developed a novel in vitro method of characterizing fiber-based thread matrices by probing their ability to promote tissue ingrowth from a wound margin as a measure of their ability to promote repopulation and regeneration. This method is useful in the optimization of thread scaffolds, and is sensitive enough to distinguish between subtle variations in biopolymer chemistry and organization. Furthermore, this method was used to characterize the effects of crosslinking on the cell outgrowth and correlated the findings with the mechanical properties of collagen threads. The results suggest that crosslinking is required to achieve sufficient mechanical properties for high stress applications such as ACL replacement, but regardless of technique, crosslinking attenuated the cell outgrowth properties of the threads. To improve the regenerative capacity of these scaffolds, novel fibrin microthread matrices were developed with a similar morphology to collagen threads and sufficient mechanical strength to be incorporated in composite thread scaffold systems. These fibrin microthreads were loaded with FGF-2, a potent mitogen and chemotactic agent that works synergistically with fibrin in regulating cell signaling and gene expression. Increases in fibroblast migration and proliferation in FGF-2-loaded fibrin threads were successfully demonstrated with the concomitant promotion of oriented, aligned, spindle-like fibroblast morphology. These results suggest that fibrin-FGF-2 microthreads have distinct advantages as a biomaterial for the rapid regeneration of injured tissues such as the ACL.

    Files
  • Cornwell_PHD_Dissertation.pdf

  • Browse by Author | Browse by Department | Search all available ETDs

    [WPI] [Library] [Home] [Top]

    Questions? Email etd-questions@wpi.edu
    Maintained by webmaster@wpi.edu