One of the major challenges in the field of controlled drug delivery systems involves overcoming the poor bioavailability of some therapeutic compounds. Polymeric microspheres can be used to deliver these drugs efficiently and safely. This novel method requires understanding the biodistribution of the microspheres within the tissues of interest. Previously, research has validated the presence of polystyrene microspheres in several organs; however, the methods required the tissues to be homogenized. The current study focuses on optimizing routine staining methods to account for polymeric microspheres within biological tissues. We found that adjusting some of the solvents used in routine staining procedures will allow for the preservation of hydrophobic polymer microspheres for further study and imaging. This could potentially give us more insight into the mechanisms of uptake after administration. The second focus of this study was to utilize these optimized procedures to analyze cell recruitment after delivery of growth factors and cytokines encapsulated in biodegradable polymeric microspheres. Our objective in this study was shifted from visualizing polymer microspheres to qualitatively assessing cell recruitment using histological methods. After optimizing the procedures necessary to visualize tissue morphology, we observed that the treatments with specific growth factors resulted in some recruitment of cells to the site of administration.
"Visualizing Nanoparticles: Integration of Methods Used for Biological and Polymeric Interfaces"
Molecular Pharmacology, Physiology, and Biotechnology Theses and Dissertations.
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