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<p>Articular cartilage is a connective tissue that lines the surfaces of diarthrodial
joints; and functions to support and distribute loads as wells as facilitate smooth
joint articulation. Unfortunately, cartilage possesses a limited capacity to self-repair.
Once damaged, cartilage continues to degenerate until widespread cartilage loss results
in the debilitating and painful disease of osteoarthritis. Current treatment options
are limited to palliative interventions that seek to mitigate pain, and fail to recapitulate
the native function. Cartilage tissue engineering offers a novel treatment option
for the repair of focal defects as well as the complete resurfacing of osteoarthritic
joints. Tissue engineering combines cells, growth factors, and biomaterials in order
to synthesize new cartilage tissue that recapitulates the native structure, mechanical
properties, and function of the native tissue. In this endeavor, there has been a
growing interest in the use of scaffolds derived from the native extracellular matrix
of cartilage. These cartilage-derived matrix (CDM) scaffolds have been show to recapitulate
the native epitopes for cell-matrix interactions as well as provide entrapped growth
factors; and have been shown to stimulate chondrogenic differentiation of a variety
of cell types. Despite the potent chondroinductive properties of CDM scaffolds, they
possess very weak mechanical properties that are several orders of magnitude lower
than the native tissue. These poor mechanical properties lead to CDM scaffolds succumbing
to cell-mediated contraction, which dramatically and unpredictably alters the size
and shape of CDM constructs. Cell-mediated contraction not only prevents the fabrication
of CDM constructs with specific, pre-determined dimensions, but also limits cellular
proliferation and metabolic synthesis of cartilage proteins. This dissertation utilized
collagen crosslinking techniques as well as ice-templating in order to enhance the
mechanical properties of CDM scaffolds and prevent cell-mediated contraction. Furthermore,
the decellularization of CDM was investigated in order to remove possible sources
of immunogenicity. This work found that both physical and chemical crosslinking techniques
were capable of preventing cell-mediated contraction in CDM scaffolds; however, the
crosslinking techniques produced distinct effects on the chondroinductive capacity
of CDM. Furthermore, the mechanical properties of CDM scaffolds were able to be enhanced
by increasing the CDM concentration; however, this led to a concomitant decrease in
pore size, which limited cellular infiltration. The pore size was able to be rescued
through the use of an ice-templating technique that led to the formation of large
aligned grooves, which enabled cellular infiltration. Additionally, a decellularization
protocol was developed that successfully removed foreign DNA to the same order of
magnitude as clinically approved materials, while preserving the native GAG content
of the CDM, which has been shown to be critical in preserving the mechanical properties
of the CDM. Altogether, this body of work demonstrated that dehydrothermal crosslinking
was best suited for maintaining the chondroinductive capacity of the CDM, and given
the appropriate scaffold fabrication parameters, such as CDM concentration and ice-templating
technique, dehydrothermal treatment was able to confer mechanical properties that
prevented cell-mediated contraction. To emphasize this finding, this work culminated
in the fabrication of an anatomically-relevant hemispherical scaffold entirely from
CDM alone. The CDM hemispheres not only supported chondrogenic differentiation, but
also retained the original scaffold dimensions and shape throughout chondrogenic culture.
These findings illustrate that CDM is a promising material for the fabrication of
tailor-made scaffolds for cartilage tissue engineering.</p>
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