Nanomedicine Platform Uses Fluorescence Imaging To Seek and Destroy Cancer Cells

Oleh Taratula, Ph. D. Assistant Professor of Pharmaceutics Department of Pharmaceutical Sciences College of Pharmacy Oregon State University Corvallis, OR 97331-3507 MedicalResearch.com Interview with:
Oleh Taratula, Ph. D.
Assistant Professor of Pharmaceutics
Department of Pharmaceutical Sciences
College of Pharmacy Oregon State University
Corvallis, OR 97331-3507

Medical Research: What is the background for this study? What are the main findings?

Dr. Taratula: Our research group is focused on the development of novel nanotechnology-based approaches to treat different cancers, including ovarian cancer. For many cancers, surgery is a first choice of treatment. For example, only optimal surgical resection of most abdominal metastases can significantly reduce ovarian cancer recurrence and, therefore, improve patient survival. However, it is challenging to remove most of the cancer tumors and residual cancer cells eventually may lead to cancer relapse. Therefore, our aim is to develop a nanomedicine platform, which could help surgeons achieve maximal tumor resection, using the intraoperative guidance with real-time near infrared (NIR) fluorescence signal. Moreover, we expect that the same nanoplatform could further enhance surgical outcomes by combinatorial phototherapy to be performed intraoperatively after tumor resection to eradicate unresected cancer cells.

Our data published in Nanoscale is the first step towards our main goal. At this point, by utilizing naphthalocyanine, we have developed a single-agent-based nanomedicine platform capable of both NIR fluorescence imaging and combinatorial phototherapy. Naphthalocyanine is a commercially available compound, but its potential clinical application is limited by low water solubility and aggregation. Especially, aggregation diminishes the imaging ability and phototherapeutic efficacy of this compound. To address these shortcomings, we discovered that the loading of naphthalocyanine into the dendrimers significantly enhances water solubility, prevents aggregation and preserves imaging and therapeutic abilities. Our data demonstrated that naphthalocyanine-based nanoplatform can generate a NIR fluorescence signal in the cancer tumors, required for elimination of autofluorescence from healthy tissue and body fluids. Furthermore, our results also indicated that the developed nanoplatform is an efficient therapeutic agent which, upon exposure to NIR light, destroys chemotherapy-resistant ovarian cancer tumors by producing both heat and toxic reactive oxygen species.

Finally, many organic fluorophores, including naphthalocyanine, can undergo photobleaching under exposure to light, which could be misinterpreted as a lack of fluorescence signal during the surgery. We demonstrated that the dendrimer encapsulated naphthalocyanine exhibits extremely high photostability and could overcome the above mentioned issue.

Medical Research: What should clinicians and patients take away from your report?

Dr. Taratula: Our findings highlight substantial progress in employing a single-agent-based nanomedicine platform capable of both NIR fluorescence imaging and anti-cancer therapy (combinatorial phototherapy in this case) with the near future prospective to detect and eradicate unresected cancer cells intraoperatively. What we have learned from these studies and would be the most interesting for patients and clinicians is that it is possible to visualize and destroy cancer cells with a single agent minimizing the cost, time and toxicity of intraoperative anti-cancer therapy.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Taratula: With our current findings demonstrating a simple nanomedicine platform capable of both imaging and phototherapy that can potentially promote NIR fluorescence image-guided surgery and intraoperative combinatorial phototherapy for cancer treatment, researchers can look into other types of theranostic systems, and we should continue to improve and study current system in mice and larger animals (like dogs) to move to clinical trials.

Citation:

Taratula, O., Schumann, C., Duong, T., Taylor, K. L., & Taratula, O. (2015). Dendrimer-encapsulated naphthalocyanine as a single agent-based theranostic nanoplatform for near-infrared fluorescence imaging and combinatorial anticancer phototherapy. . Nanoscale. doi:10.1039/c4nr06050d