Nanoparticle Drug Delivery in Dogs With Osteosarcoma

Researchers from the University of Illinois (U. of I.) have gone beyond the traditional mouse model used when testing a bone cancer drug delivery system…they went to the dogs. Timothy Fan, Ph.D., U. of I. veterinary clinical medicine professor, led the study with JianJun Chang, Ph.D., a materials science and engineering professor.

According to the July 25, 2016 news release, “In clinical trials, the dogs tolerated the highest planned doses of cancer-drug-laden nanoparticles with no signs of toxicity. As in mice, the particles homed in on tumor sites, thanks to a coating of the drug pamidronate, which preferentially binds to degraded sites in bone. The nanoparticles also showed anti-cancer activity in mice and dogs. These findings are a proof-of-concept that nanoparticles can be used to target bone cancers in large mammals….”

“We wanted to see if we could evaluate these drug-delivery strategies, not only in a mouse model, but also at a scale that would mimic what a person would get, ” Dr. Fan said. “The amount of nanoparticle that we ended up giving to these dogs was a thousand-fold greater in quantity than what we would typically give a mouse.”

“Human bone tumors are much bigger than those of mice, ” Dr. Cheng said. “Nanoparticles must penetrate more deeply into larger tumors to be effective. That is why we must find animal models that are closer in scale to those of humans.”

Dr. Fan told OTW, “This investigation sought to define the feasibility and activity of a bone-targeting nanoparticle encapsulating chemotherapy as a systemic therapy for focal malignant osteolysis. Through the combined use of a murine tumor model and pet dogs with naturally-occurring bone cancer, we were able to demonstrate the biocompatibility and activity of the nanoparticle technology for controlling bone cancer growth.

“The impetus for this work was the clinical need for identifying novel treatment strategies for companion animals and people alike diagnosed with skeletal malignancies.

“Orthopedic surgeons might be interested in this delivery platform, i.e., bone-seeking nanoparticles for future application of various payloads for the management of different clinical problems including delayed fracture healing (payload- bone morphogenetic proteins), refractory infectious osteomyelitis (payload- antibiotics), or other pathologies that could be managed more effectively with some form of targeted and local depot strategy.”