Biocompatible Graphene Quantum Dots for Noninvasive Near-infrared Bioimaging

项目总结/文摘

Project Summary/Abstract Near-infrared (NIR) imaging is one of the most rapidly developing perspective techniques in biomedical diagnostics enabling 10 - 100 times deeper tissue imaging than regular visible fluorescence techniques. There is a significant clinical need for such imaging: high-depth CT and MRI imaging strategies are complex and less suitable for low-depth biosensing and intraoperative applications. Furthermore, in animal studies NIR imaging can enable in situ fluorescence tracking of tested therapeutics or tumor visualization inside a living small animal. However, as NIR imaging field is still developing, there is a lack of biocompatible and multifunctional platforms suitable for imaging, sensing and even drug transport highly desired in animal studies. In this project we will develop and test the feasibility of a novel NIR imaging platform based on graphene quantum dots (GQDs) addressing the critical needs of NIR bioimaging: fluorescence in the NIR (above 950 nm) with NIR excitation, high biocompatibility, photostability, and capabilities for drug tracing and in vivo NIR imaging in live animal models. This will be implemented in 3 steps: (1) synthesizing NIR-emissive GQDs via bottom-up and top-down approaches and characterizing their optical and physical properties, (2) testing GQDs for NIR in vitro imaging and assessing their biocompatibility and (3) performing in vivo imaging of GQD NIR fluorescence in live animals as well as ex vivo organ tissue imaging quantifying GQD content in excised organs. We will concomitantly assess potential adverse effects to select non-toxic GQD candidates. Throughout this process a variety of synthesized GQD structures will undergo rigorous 3-step selection for the capabilities of (1) high yield NIR fluorescence, (2) high biocompatibility and NIR imaging in cells, (3) NIR imaging inside a live sedated animal with minimal/no toxicity. The selected GQD candidates will enable in vivo animal testing of therapeutic delivery with noninvasive real-time image tracking reducing the number of animals sacrificed. In a longer term, we expect these GQD platforms to become a basis of the noninvasive NIR in vivo sensing in patients. As a result, the proposed initiative will address several significant areas of biotechnology and its development will ultimately contribute to the improvement of human health.