Date of Award


Document Type


Degree Name

Master of Science (MS)



Committee Member

Jeremy Mercuri, Ph.D., Co-Committee Chair

Committee Member

M. Aaron Vaughn, Ph.D., Co-Committee Chair

Committee Member

Delphine Dean, Ph.D.


The Center for Disease Control has found that between 2013-2015, 26% of women and 19% of men reported doctor-diagnosed cartilage disease or damage. Currently, there exists a substantial population with cartilage damage or disease needing a solution to increasing pain and decreasing function and mobility. Many of these individuals are young and thus looking for a treatment to delay a total knee replacement. Many others are elderly and thus looking to avoid major surgeries, as the riskiness of these procedures increases with age. As researchers look towards a method of cartilage replacement, hydrogels show measurable potential as a synthetic substitute for the natural tissue.

Treatments such as cartilage regrowth using scaffolds and growth factors as well as microfracture have faced unique challenges in patients over the age of 40, who comprise the majority of those suffering from cartilage defects. The arthritic environments and low cellular metabolism in older patients make it difficult to utilize these treatments. Existing hydrogel cartilage substitute solutions have fallen short of multiple major mechanical requirements of cartilage tissue. Cartilage properties such as compressive modulus, stress at a given strain, tensile modulus, ultimate tensile strength, dynamic modulus, and phase angle must be closely matched by a replacement material in order to increase the likelihood of success once placed into the physiological environment. Additionally, it follows that the test methods used to obtain these properties must be conducted in a manner resembling natural physiological conditions as closely as possible to ensure the applicability of the test results to real-life usage.

The present study was conducted in order to determine the mechanical viability of a formulated double network hydrogel for use as a tibiofemoral cartilage substitute. Hydrogel formulations varying in water content were tested using 5 methods: unconfined compression, confined compression, indentation, tensile testing, and dynamic mechanical analysis. The resulting mechanical properties were compared to corresponding natural articular cartilage values found in literature.

While the double network hydrogel fell short in ultimate tensile strength, it sufficiently matched values of compressive modulus, stress at a given strain, tensile modulus, dynamic modulus, and phase angle. For many of the tests, a range of results were found based on sample sets of varying water content, and the values of natural articular cartilage were encompassed by these ranges. The customizability of the material as well as its ability to match articular cartilage mechanical characteristics identify it as a high-potential material in the pursuit of cartilage defect solutions.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.