(527a) Probing and Modeling Spatial Distributions of Particulate Vaccines at the Respiratory Tract

Mucosal surfaces are the portal for various pathogens. Vaccination of mucosal surfaces would greatly reduce the risk of a wide range of infections, such as influenza and sexually transmitted diseases. Among all the mucosal surfaces, the respiratory tract is an effective and easy-to-access site for immunization. Dendritic cells (DCs) resident in the respiratory tract represent the most powerful antigen presenting cells, which would be an ideal target for efficient vaccination. However, complicated spatial distribution of DCs and intricate airflow at the respiratory tract pose as difficulties for targeting antigens to DCs. A detailed understanding of the deposition of particulate vaccines would facilitate the design of vaccines to target DCs in a specific region of the respiratory tract. We are particularly interested in vaccines composed of biodegradable nano/microparticles. In this study, we developed a set of sensitive fluorescent nano/microbeads based on biodegradable polymers. By using confocal microscopy, we are able to image the deposition of nano/microbeads throughout the respiratory tract. In addition, a preliminary mathematical model is developed to predict the deposition of nano/microbeads. These results can give us insight into controlling physical properties of particulate vaccines to target DCs at the respiratory tract.