Development of Quantum Dot-Embedded Nanoparticles for Biothermal Imaging

Recent surgical management of cancer tends toward minimally invasive surgical techniques since tumors can be detected smaller than ever due to the advance of cancer diagnostic technologies. Many of these surgical procedures are thermal therapies where a localized freezing or heating zone (i.e. thermal lesion) is created to destroy tumors without damaging adjacent normal tissues. The outcomes of these innovative and less invasive surgeries, however, are significantly impaired by the limited image-guidance of the thermal lesion during the procedures. Since the primary clinical objective of these surgeries is to eradicate diseased tissues while sparing the adjacent normal tissue, accurate intra-operative monitoring of the thermal lesion is critical. Moreover, in many surgical situations, sparing adjacent tissue is not only desired, but imperative since major blood vessels, nerve bundles and surrounding organs are susceptible to thermal injury. However, currently available monitoring techniques have limited accuracy or accessibility, and/or are not capable of monitoring the lesion in real-time during the procedure. In our recent study [1], we demonstrated the feasibility of non-invasive thermometry using quantum dot (QD) as temperature probe. Although its feasibility was demonstrated, several limitations should be addressed before more rigorous clinical applications. Especially the lower quantum yield of core/shell QDs should be significantly improved for deeper tissue imaging. In the present study, QD-embedded nano-composite particles were developed for deeper tissue imaging and its temperature dependent fluorescence was characterized.