Advances in Chemotherapy Dramatically Increase Precision

Scientific research at UC Irvine has breached a new barrier. Specifically, two UCI scientists and their team have made significant advancements in the field of cancer treatment.

Dr. Richard Robertson, Professor of Anatomy and Neurobiology, and Dr. Kenneth Longmuir, Associate Professor of Physiology and Biophyiscs, have developed a system to deliver chemotherapy drugs to the site of interest with more precision.

They were assisted by Sherry Haynes and Janie Baratta, staff research associates in the School of Medicine, and Natasha Kasabwalla, an undergraduate researcher, in conducting this study.

Robertson and Longmuir discuss the focus of their study and what their results demonstrate.

“We are developing a new strategy for the targeted delivery of therapeutic drug carriers (“nanoparticle”) in the body. In the recently published work, we have taken a specific amino acid sequence from a microorganism that very selectively targets the liver, and incorporated this sequence into our nanoparticle delivery system. When injected intravenously, the result was an extraordinary specific targeting of the system to the liver, with virtually no uptake by other organ systems. The results indicate that nanoparticle delivery systems can be engineered to recognize the organ-specific composition of the polysaccharides that surround all organs and tissues,”  Robertson and Longmuir said.

Specifically, a protein from the malaria microorganism Plasmodium was bonded to liposomes that have been inserted with the cancer chemotherapeutic drug doxorubicin for delivery to the liver.

The precision generated by their method is significant because doxorubicin is highly toxic to some normal organs, including the heart. Without the addition of the protein, the drug targets not only regions with tumors but the body as a whole indiscriminately. As a result, malignant side effects can be manifested.

When the team conducted tests on mice, they found that the drug transport system was capable of delivering the drug to the site of interest with more than a 99 percent success rate.

Robertson and Longmuir believe that the method uncovered by their study could be utilized to recognize polysaccharide features of tumors in other parts of the body because all cell types, including tumor cells, have characteristic polysaccharide compositions in their extracellular space that would allow it to be targeted by the nanoparticle delivery system.

With the completion of this study, Robertson and Longmuir intend to conduct further investigation on this specific topic.

“Tumors are surrounded by polysaccharides. The composition of these polysaccharides appears to be different compared to normal tissue. The next step in our investigation is to develop amino acid sequences that specifically recognize polysaccharide compositions found in tumors, but not in normal tissue. Once identified, these sequences will be engineered into our nanoparticle delivery system, and tested for specific targeting tumors,” Robertson and Longmuir said.

At the point that cancer is one of the leading causes of death, this breakthrough is definitely one welcomed with open arms – narrowing down the umbrella quality of this disease into one of a more manageable size.