Quantum Dots tor Early Detection And Smart Drug Delivery In Cancer Treatment

Cancer nanotechnology is an interdisciplinary area of research in science, engineering, andmedicine with broad applications for molecular imaging, molecular diagnosis, and targetedtherapy. Quantum dots (QDs) are semiconductor inorganic nanomaterials ranging from 1–10 nm.They contain elements found in groups II–IV(eg, CdSe, CdTe, CdS, and ZnSe) or III–V (eg, InP andInAs)of the periodic table. Considerable interest has been shown toward these materials in recentyears, especially in view of their potential applications in biology and medicine. They are gainingmomentum as imaging molecules with life science and clinical applications. Clinically they can beused for localization of cancer cells due to their nano size and ability to penetrate individual cancercells and high-resolution imaging derived from their narrow emission bands compared with organicdyes. Owing to their unique properties such as photostability, size- and composition-tunableemission properties (from visible to infrared wavelengths), and their ability to deliver multiplediagnostic or targeting agents, QDs have emerged as a promising nanotechnology for cancerdetection.By combination of functional biomolecule-nanoparticle hybrid systems and the opticalimaging and biophysics, QDs have been used as optical reporter units of biocatalytictransformations and can probe intracellular processes in vitro. QDs as a novel probe for in vivoanalysis and clinic therapy such as cancer research, and in vivo photodynamic therapy (PDT) openan attractive new field with promising prospectives in biomedicine.Their longhalf-life, highphotostabilityandexcellent brightness allow the imaging and monitoringof drug delivery pathwaysin vivo with sharp resolutionand reduced background autofluorescence. These propertiesmake QDssuitable candidates for the use as drugdeliveryvehicle.The development of QD labeling promotesthe research in the nano-drugs in cellular, even at live animal level. The development offluorescence imaging technology of QDs and the therapy-based multifunctional nano-drugs isexpected to apply to diagnosis and treatment of cancers. At the same time, surface modificationswith targeting ligands are also commonly used to increase drug-delivery efficiency.