Evaluation of poly(octamethylene citrate glycerophosphate) for enhanced cell differentiation and bone regeneration

Open Access
Author:
Chomos, Sarah Katherine
Area of Honors:
Biomedical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Cheng Dong, Thesis Supervisor
  • Nanyin Zhang, Honors Advisor
Keywords:
  • citrate-based biomaterials
  • glycerophosphate
  • osteogenic differentiation
Abstract:
As needs across the regenerative medicine field evolve and become increasingly complex, citrate-based biomaterials have been developed to provide unique physical, chemical and biological properties, and have been improved to include antioxidant, osteopromotive adhesive, antimicrobial and fluorescent properties. Poly(octamethylene citrate) polymers, a major class of citrate-based materials, have been doped with beta-glycerophosphate salts (βGP), a mineralization factor and osteogenic differentiation promoter, for the purpose of improving mechanical properties and enhancing bone regeneration in tissue engineering. The POC-GP (βGP-Na and GP-Ca) polymers were composited with hydroxyapatite (HA) and subsequently fabricated into POC-GP/HA composites and micro-particles to observe the effect of the POC-GP materials doped with different salts, surface morphologies and particle sizes on osteogenic differentiation of human mesenchymal stem cells in vitro. The use of particles allows for cells to more easily infiltrate into the degradable POC-GP/HA scaffold, achieving great integration, and has also been previously shown to improve vascularization and oxygen delivery to cells. Osteogenic differentiation was measured by levels of alkaline phosphatase expression and observed through SEM imaging, with existence of extracellular matrix and mineral deposit formation on surfaces. POC-GP-Ca/HA composites showed the best osteogenic progression and enhanced differentiation of stem cells, in addition to excellent material properties and biocompatibility, rendering POC-GP-Ca/HA as a better choice of material for future orthopedic applications.