Monet Wilson - Alabama State University
Co-Author(s): Antwan Parker, Alabama State University, Montgomery, AL ; Derrick Dean, Alabama State University, Montgomery, AL
Articular cartilage is a smooth, transparent tissue that covers the ends of bones in joints such as the knee and elbow. Defects and loss of cartilage can be caused by traumatic injuries and degenerative joint diseases. Unfortunately because of its lack of vasculature, cartilage has a limited capacity to undergo self-repair. While some treatments are available to repair defective cartilage, they do not present a long term solution. Tissue engineering presents an approach to synthetically develop replacements for articular cartilage. The aim of this research is to fabricate 3-dimensional scaffolds that mimic the complex architecture and biochemical nature of articular cartilage. Methods: We have fabricated scaffolds based on electro-spun nanofibers of poly lactic acid (PLA) infused with a hydrogel system based on polyvinyl alcohol (PVA) and sodium alginate (SA). A highly porous, nonwoven mat of PLA was prepared using electrospinning. A hydrogel coating of approximately 500 microns was applied to the surface of the PLA mat using a syringe. The gel coating was then crosslinked by exposing it to a calcium chloride solution. The microstructure, chemical composition, mechanical properties and cell attachment and proliferation have been studied.
Microscopy of the scaffolds reveals a two-phase, porous structure. A gradient in the structure and properties is also evident, with good mixing at the interface between the two phases. The chemical composition of the gradient was characterized using infrared spectroscopy. The data confirms the presence of the PLA and the hydrogel system. The coated scaffold exhibited a modulus (i.e. stiffness) that was 20% higher than the uncoated scaffold. Therefore the coating enhanced the mechanical properties of the electrospun scaffold.
We have fabricated a hybrid, three dimensional scaffold that mimics the structure and of articular cartilage. The samples exhibit and two phase system with interconnected porosity in each phase. The sample also exhibits a well-defined, diffuse interphase region. Future work will involve using a 3-D printer to precisely control the thick ad pore geometry of the hydrogel coating and characterize the mechanical properties.
Funder Acknowledgement(s): NSF/ CBET/RUI award 1510479
Faculty Advisor: Derrick Dean, firstname.lastname@example.org
Role: I actually completed each part of this research along with my fellow co-authors who completed each step included on our own. I first started off just making a simple scaffold out of my PLA in DCM solution which my first few times turned out pretty well. I did this through many different forms of electro-spinning. I then went on to coat my scaffold with PVA/ SA gel and was able to check out if the sample piece was porous or not in my results.