Project Title: Dynamic tracking of exosome nanoparticle communication

Project Duration: May 25 – August 1, 2015 (10 weeks), 40 hours per week.

Project Mentors –

• Primary Faculty Mentor (Name, Affiliation, website and Email/Phone): Luke Mortensen, Animal and Dairy Science Department/College of Engineering, http://www.rbc.uga.edu/leaders/Mortensen.php, mortensen@uga.edu, 706-542-0985
• Secondary Faculty Mentor (Name, Affiliation, website and Email/Phone): Steve Stice, Animal and Dairy Science Department, http://stice.uga.edu, 706-543-0071 

• Graduate Student/PostDoc mentors (Name, Affiliation and Email/Phone): Seth Andrews, College of Engineering, sha72433@uga.edu

Project Description: One of the great unsolved mysteries in biology is that of cell communication. Many responses in nerve development, immunology, and cancer metastasis occur in distant organs, and cannot be explained through traditional mechanisms like secreted factors or cell contact. In the past few years, a piece of the puzzle has fallen into place with the discovery of exosome communication. Exosomes are biologically formed nanoparticles that carry RNA, proteins, and surface receptors. They have recently uncovered roles in immune conditioning, cell differentiation, and inflammation. Despite their secretion in high quantities by cells such as mesenchymal stem cells (MSCs), isolation of the nanoparticles, direct observation of their uptake, and evaluation of their function remains challenging. Multiphoton microscopy provides high sensitivity and high resolution imaging, and could potentially visualize the uptake of exosomes by target cells. The project will focus on the generation and imaging of exosomes, with a goal of tracking a resultant change in cell behavior in vitro and in vivo. Long term, the stimulation of bone regeneration and neovascularization using acellular exosome loaded matrices will enable healing of critically sized bone defects.

REU Student Role and Responsibility: During this new research initiative, the REU student will first learn to isolate and characterize exosomes generated by in vitro cells. The REU student will then learn to label exosomes and visualize their uptake in a target cell population. Several promising approaches to dynamically monitor exosome uptake will be attempted by the REU student and evaluated using a multiphoton imaging platform. Exosomes will be isolated from bone differentiation primed MSCs. These exosomes will be then be used to stimulate cell differentiation in vitro. The student will learn a variety of skills and have the opportunity to work on an exciting project at the interface of nanoscience and biology.

Expected Outcome for REU student: The proposed work is expected to advance a project focusing on the use of exosomes in bone regeneration, and will likely contribute to a future peer reviewed publication that will be targeted at a journal like Biomaterials or the Journal of Bone and Mineral Research. Results are anticipated to be presented at national and international meetings such as the Biomedical Engineering Society Annual Meeting and the Materials Research Society.

Payne REU Poster