Calcium Phosphate Nanoparticles: Toxicology and Lymph Node Targeting for Cancer Metastasis Prevention

Abstract

Applications of nanoparticles in biology are rapidly developing areas in nanomedicine. In cancer therapy, nanoparticles are being used for the detection, diagnosis, and imaging of tumors. Calcium phosphate has long been used as a bone substitute biomaterial and is FDA approved. It is biocompatible, easy to synthesize and relatively cheap. Due to these favorable conditions, it has been investigated for numerous drug delivery of anti-tumor drug applications. Tumor metastases are a major health issue before and after surgical removal of a tumor. Presently, chemotherapy is being used to tackle metastases, but an anti-tumor drug does not differentiate between healthy tissue and tumors. It simply kills all cells it interacts with, and hence there is a need to develop an effective targeted drug delivery system which only releases the drug in tumor cell conditions. Anti-tumor drugs can be easily adsorbed onto the surface of calcium phosphates through electrostatic interactions. Calcium phosphate nanoparticles dissolve in the acidic micro-environment of the tumor, thus, releasing the drug which eventually kills the tumor cells. Most importantly, the calcium phosphate nanoparticles can be targeted to the sentinel lymph node where they can probe tumor metastases. This chapter will cover the history and future promises of using calcium phosphate nanoparticles to treat cancer, including its safety and toxicity in such applications.