Fracture healing is critical to restoring physical and mechanical properties of bone. However, various co-morbidities result in approximately 10% of fracture non-unions, a major clinical and economic concern. Approximately 100,000 fractures result in non-union each year in the United States. Drug delivery using high-dose systemic administration leads to significant accumulation in non-skeletal tissues and very poor accumulation in injured bone, reducing therapeutic potential. To overcome the limitations with systemic administration, a bone-targeted nanoparticle was developed for specific drug targeting to bone fractures. To analyze fracture localization, a near-IR model drug for visualization was used to measure nanoparticle accumulation. Through qualitative histological imaging of the entrapped model drug, IR780, greater nanoparticle accumulation was observed in callus and periosteum in fractures treated with targeted nanoparticles versus saline controls. In this project, we investigated a method to quantify nanoparticle accumulation observed in similar slides using hydrogel tissue phantoms and image analysis software. The significance of this project is to develop a standardized method to quantify tissue localized nanoparticle and drug concentrations from histology images.
