Subcategory: Materials Science
Tambre A.Tolliver - Alabama State University
Co-Author(s): Derrick Dean, Alabama State University, Montgomery,AL; Mohamed Abdlla, Tuskegee University, Tuskegee, AL
There is an estimated 27 million Americans that suffer from osteoarthritis in the age range of 25 and older. Osteoarthritis causes the degeneration of joint cartilage that cannot be restored by the body. Cartilage lacks its own blood supply to promote regeneration of harmed tissue. Therefore there is a need for 3D scaffolds for the regeneration of a synthetic cartilage. We have investigated the synthesis and characterization of a tri-phase hydrogel scaffold for cartilage restoration. The overall goal of our work is to study the processing-property-function relationships to formulate bioink for 3D printing of these hydrogels. Hydrogels are well known in the biomedical realm, as being the first biomaterial created for human use. They are water swollen structures that can hold three dimensional shapes. Research has been conducted that shows hydrogels can possibly be used to replace cartilage. Polyvinyl alcohol and Sodium alginate are polymers commonly studied for their similarities to cartilage. Bioinks are formed to duplicate the extracellular matrix to aid in the adhesion, proliferation, and differentiation of cells. The hydrogel system is based on polyvinyl alcohol (PVA), sodium alginate (SA) and hydroxyapatite (HA). Varying amounts of SA (1%, 3%,5%) were added to the PVA hydrogel. The scaffold was subjected to the process of freeze-thawing, gas foaming, and cross linking to form a synthetic articular cartilage. The processability and properties were studied as a function of SA composition and degree of crosslinking. The modulus of the solutions was found to increase with increasing amounts of SA and degree of crosslinking. FTIR confirms the presence of SA at 1550, HA at 1040, O-H at 3610, and C-H at 2950. Rheology was used to measure the viscosity to select a sample that fits the target range for 3D printing. Morphology of the scaffolds was characterized with scanning electron microscopy. A tri-phase structure was evident in all of the sample compositions. The porosity level increased as the amount of SA decreased. We successfully created three tri-phase hydrogel scaffolds that varied in porosity, sodium alginate concentration, and viscosity. SA concentration affects the mechanical properties and porosity of the scaffolds directly. As the SA concentration increases, porosity decreases and structural support increases. Future studies will focus on using these hydrogels as bioinks to produce 3D printed scaffolds for cell studies.
References: K. Rezwana, Q.Z. Chena, J.J. Blakera, Aldo Roberto Boccaccinia, Biodegradable and bioactive porous polymer/inorganic composite scaffolds for bone tissue engineering, Biomaterials 27 (2006) 3413-3431.Not Submitted
Funder Acknowledgement(s): This work was supported by NSF/ RUI award 1510479
Faculty Advisor: Derrick Dean, email@example.com
Role: I am responsible for creating all Tri-phase Hydrogel scaffolds and collecting data from various experiments and test.