Chloe Hotze, “Fabrication of a Polymer-Based Biomaterial for Bone Healing”
Mentors: Priyatha Premnath and Sara Travia, Biomedical Engineering

Polymers are an integral component of biomaterial research, especially in drug delivery systems due to their structural adaptability, ease of production, and low cost. The aim of this project was to make a double walled microsphere with drugs to encourage bone growth. Using two different polymers, Polylactic-co-glycolic acid (PLGA) and polylactic acid (PLLA) we created the layers to encase the drugs. The outer layer consists of PLGA which encapsulates cobalt chloride(II). Cobalt chloride(II) has been shown to create a hypoxic environment which is conducive for chondrogenesis, the first step in healing a large bone fracture. The inner layer is composed of PLLA which encapsulates hydroxyapatite. Prior studies have demonstrated that hydroxyapatite can support bone healing by inducing osteogenesis, the second major step in bone healing. The first step in the fabrication was the production of the single layer particles which consisted of emulsifying the polymer with the associated drug. After the individual polymer layers were combined, they were vortexed, sonicated and then stirred in a polyvinyl alcohol (PVA) solution for several hours to complete the emulsion. After stirring, the particles were filtered, rinsed, and dried under desiccate before further analysis. Next, the double layered particles were fabricated by emulsifying the single layers together until the solution appeared homogeneous. The solution was then added dropwise to the stirring PVA solution and the same particle collection process was followed. After the particles are produced several characterization methods are being used to investigate them, such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and selective dissolution techniques. The fabrication of these microparticles is the first step in improving bone healing outcomes by targeting both chondrogenesis and osteogenesis.

Click the thumbnail below to open the full sized poster in a new tab.