Subcategory: Biomedical Engineering
Monet Wilson - Alabama State University
Co-Author(s): Derrick Dean and Antwan Parker, 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 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. 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. The impact of the interphase structure on the mechanical properties will be presented.
References: Iwona Gibas and Helena Janik, Review: synthetic polymer hydrogels for biomedical Applications, Chemistry & Chemical Technology, Vol. 4, No. 4, 2010; 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;H. Hosseinzadeh, Synthesis and swelling properties of a poly (vinyl alcohol)-based super absorbing Hydrogel, Current Chemistry Letters 2 (2013) 153-158; Z. Izadifar , X. Chen and W. Kulyk, Strategic Design and Fabrication of Engineered Scaffolds for Articular Cartilage Repair, J. Funct. Biomater. 2012, 3, 799-838.
Funder Acknowledgement(s): NSF/ CBET/RUI award 1510479.
Faculty Advisor: Derrick Dean, firstname.lastname@example.org
Role: The part of the research I did was making the solution of PLA in DCM. Then electrospinning the solution to make the scaffold. once that was done I then cut a piece of the scaffold to let sit in the PVA gel to check for porosity. The last thing I did was test the interconnected porosity of the scaffold after sitting in the gel and found that it did work.