Gold nanoparticles

Gold nanoparticles (GNPs) can be used not only as a delivery vehicle but also as a therapeutic agent (Hashemi Goradel et al., 2018; Negahdari, Darvishi, & Saeedi, 2019). In several studies, GNPs have been used as effective siRNA carriers, as they encompass various suitable characteristics including surface plasmon resonance property, easily controllable size and shape, and easy modification with other molecules (Y. Gao, Liu, & Li, 2011). GNPs exhibit effective gene knockdown with no detectable toxicity and off-target effects. Recently Gold Nanoclusters (GNCs) with fluorescent tags have gained more attention because of their unique properties. In addition to their ultra-small size, GNCs have fluorescence emission from near-infrared to the visible region (Zheng, Lai, Liu, Jiang, & Wang, 2017).
Perineural invasion is one of the most important pathologic characteristics of pancreatic cancer (Bapat, Hostetter, Von Hoff, & Han, 2011). NGFs (nerve growth factors) are crucial regulators of the tumor-induced neurogenesis and their overexpression has been associated with pancreatic cancer (Z. Zhu et al., 2002). Recently Lei et al . (Lei et al., 2017) aimed to develop GNCs to deliver NGF siRNA (GNC–siRNA) in pancreatic cancer. The results showed high silencing of NGF gene and suppression of tumor progression in three pancreatic tumor models. The GNC–siRNA conjugate showed high stability of siRNA in serum, improved siRNA circulation lifetime in blood, increased cellular uptake, and no apparent toxicity.
Yin et al . (Yin et al., 2015) used layered structure of gold nanorods (AuNR) with anionic PSS polymer coating to gravitate doxorubicin and on the other hand, cationic PAH polymer was used to take up K-ras siRNA (AuNRs/DOX/K-ras). This compound inhibits tumor growth for at least 25 days through the controlled release of doxorubicin and K-ras siRNA in cancer cells and subsequent laser light exposure.