In vivo photodynamic therapy of cancer via a near infrared agent encapsulated in calcium phosphate nanoparticles

Abstract

Nano-encapsulated photosensitizers and their use in the treatment of tumors and/or imaging is described. Preferably, the photosensitizers are encapsulated in a calcium phosphate nanoparticle (CPNP). Encapsulating the PS in a CPNP increases the half-life of the PS, increases absorption of the PS into the target cell tissue, increases the photostability of the PS, increases the photoefficiency of the PS, increases in vivo retention of the PS, or combinations thereof, ultimately making it a highly efficacious agent for use in photodynamic therapy, imaging target tissues, vessels, or tumors, and/or detecting or locating tumors.

What is claimed is: 
     
         1 . A composition comprising a calcium phosphate nanoparticle (CPNP) comprising:
 a near-infrared photosensitizer (PS), wherein the nano-encapsulated near-infrared PS has an increased quantum yield as compared to the quantum yield of a control wherein the photosensitizer is not nano-encapsulated,   wherein the CPNP is non-toxic to humans,   wherein the CPNP is biocompatible,   wherein the CPNP is colloidally stable,   wherein the CPNP has a diameter of less than about 100 nm,   wherein the CPNP is non-agglomerating in a physiological fluid,   wherein the nano-encapsulated near-infrared PS has an increased half as compared to the half life of a control, wherein the PS is not nano-encapsulated, and   wherein the CPNP prevents dimerization of the PS.