Date of Award
Master of Science (MS)
Chemical & Biochemical Engineering
Stephanie J. Bryant
This thesis investigates the incorporation of hydroxyapatite (HA)
nanoparticles into poly(ethylene glycol) (PEG) hydrogels as a scaffold to enhance
osteogenic differentiation of the encapsulated murine pre-osteoblast MC3T3-E1
cells for applications in tissue engineering.
Specifically, poly(ethylene-glycol) (PEG) hydrogels have been chosen because
they offer several advantages that make them promising scaffolds to investigate.
They provide an adequate 3D matrix that mimics the ECM and helps cell growth
and proliferation maintaining an elevated cell viability and improve the formation
of new bone. They are also highly tunable for a number cell types easing the
incorporation of biological moieties which make possible to regulate the degradation
rate in order to match the rate of tissue formation. Hydroxyapatite, which is a
bioactive mineral, was incorporated into the synthetic PEG hydrogels because it is
known that it helps providing a biomimetic environment for the hydrogels which
enhance their osteoconductive and osteoinductive capabilities.
However, it is known that, in vivo, synthetic materials elicit a foreign body
reaction (FBR) when they are implanted. The FBR, which is an immune reponse
that is regulated by activated macrophages, is characterized by the formation of a
fibrous capsule around the hydrogels that limits their performance.
Therefore, the purpose of this thesis is first, to characterize an 8-arm thiolnorbornene
PEG hydrogel with added HA nanoparticles to elucidate how they affect
the differentiation into osteoblasts of the encapsulated MC3T3-E1 cells. After
understanding the effects of adding HA nanoparticles to the synthetic scaffolds, and
showing that they enhanced bone tissue depositon, the hydrogels containing 1%
(w/w) of hydroxyapatite were used to study how the foreign body response impacts
the performance of this MMP-sensitive PEG hydrogels. This was done by characterizing the influence that the macrophages have over encapsulated preosteoblast MC3T3-E1 cells in vitro when they are activated in a co-culture system.
Carles-Carner, Maria, "A Biomimetic and Biodegradable Hydrogel and the Impact of Macrophages for Bone Tissue Engineering" (2017). Chemical Engineering Graduate Theses & Dissertations. 15.