Читать книгу Sustainable Nanotechnology - Группа авторов - Страница 18

Histological assessment of solid tumors includes imaging and biopsy, and in most cases, surgery is performed to remove the primary tumor and evaluate the surrounding lymph nodes. Visible, fluorescent, and radiolabeled small molecules have been used as contrast agents to improve detection during real‐time intraoperative imaging, but unfortunately, the current dyes lack the tissue specificity, stability, and signal penetration needed for optimal performance. Graphene quantum dots are used in cancer‐targeted drug delivery. It was recorded that the mean survival time of tumor‐bearing mice can be extended by 2.5 times when treated with Qdots [20]. Semiconductor quantum dots having superior optical properties are well‐established fluorescent imaging probes.

Compared to conventional small molecule dyes, their size, high stability, non‐photobleaching, and water solubility made them a unique fluorophore. At the same time, there have been major concerns regarding their potential nanotoxicity because high‐quality Qdots often contain heavy metal elements [21, 22]. Newly emerged theranostic drug delivery system using quantum dots helped in a better understanding of the drug delivery mechanism inside the cells. Nanoscale quantum dots, with unique optical properties, have been used for the development of theranostics. Surface‐modified quantum dots and their applications became widespread in bioimaging, immune histochemistry, tracking intracellular drug, and intracellular molecules target [23]. Chemotherapy or PTT is always inefficient due to their inherent limitations, but their combination for the treatment of cancers has attracted great interest during the past few years. A promising theranostic agent, black phosphorus quantum dots (BPQDs), due to its excellent photothermal property, extinction coefficient, and good biocompatibility and biodegradability, hold great potential for cancer treatment. However, the rapid degradation of BP with oxygen and moisture causes the innate instability that is the Achilles’ heel of BP, hindering its further applications in cancer theranostics. The BPQDs‐based drug delivery system exhibited pH‐ and photo‐responsive release properties, which could reduce the potential damage to normal cells. The in vitro cell viability study showed a synergistic effect in suppressing cancer cell proliferation [24, 25]. Studies show that nanoplatform of BPQDs camouflaged with a platelet membrane (PLTm) carrying hederagenin (HED) significantly enhances tumor targeting and promotes mitochondria‐mediated cell apoptosis and autophagy in tumor cells [26].