Gold nanorod–based poly(lactic-co-glycolic acid) with manganese dioxide core–shell structured multifunctional nanoplatform for cancer theranostic applications

Abstract

Recently, photothermal therapy has become a promising strategy in tumor treatment. However, the therapeutic effect was seriously hampered by the low tissue penetration of laser. Therefore, in this study, radiofrequency (RF) with better tissue penetration was used for tumor hyperthermia. First, one type of gold nanorods (AuNRs) suitable for RF hyperthermia was selected. Then, poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with AuNRs and docetaxel (DTX) (PLGA/AuNR/DTX) NPs were constructed. Finally, manganese dioxide (MnO 2 ) ultrathin nanofilms were coated on the surfaces of PLGA/AuNR/DTX NPs by the reduction of KMnO 4 to construct the PLGA/AuNR/DTX@MnO 2 drug delivery system. This drug delivery system can not only be used for the combined therapy of chemotherapy and RF hyperthermia but can also produce Mn 2+ to enable magnetic resonance imaging. Furthermore, the RF hyperthermia and the degradation of MnO 2 can significantly promote the controlled drug release in a tumor region. The in vitro and in vivo results suggested that the PLGA/AuNR/DTX@MnO 2 multifunctional drug delivery system is a promising nanoplatform for effective cancer theranostic applications.

Dendrimer- and copolymer-based nanoparticles for magnetic resonance cancer theranostics

“…In vivo rat experiments showed that the MnO 2 -, DOX-, and Ce6-loaded copolymer nanoparticle inhibited tumor growth effectively with an inhibition ratio of 92.35% (calculated by tumor weight), statistically (n =5 for each group) much higher than all 7 control groups. Wang et al 186 used PLGA to load gold nanorods (AuNRs) and DTX to form a PLGA/AuNR/DTX core, then coated it with MnO 2 ultrathin nanofilms. The higher GSH level in the tumor microenvironment caused the degradation of MnO 2 into Mn 2+ , enabling T 1 -MRI as well as controlled release of DTX at the tumor site.…”

Strategies for the functionalisation of gold nanorods to reduce toxicity and aid clinical translation

“…Once the PSA antibody was detected, the hydrogen peroxide generated from the ELISA system etches the silver layer in the nanostructure, thus producing silver ions, leading to an enhanced photoacoustic signal at 780 nm 46 . Manganese(IV) oxide, MnO 2 47 , has also been of interest due to its ability to release small amounts of paramagnetic Mn 2+ ions, which can be used to enhance contrast in magnetic resonance imaging (MRI). However, elevated levels of Mn 2+ can cause a toxic effect in humans (manganism) so a greater understanding of the form (e.g., chelated or unchelated) in which these ions are released would be needed before this approach can be translated to the clinic.…”

Improvement of Gold Nanorods in Photothermal Therapy: Recent Progress and Perspective

“…Wang et al prepared PLGA nanoparticles loaded with GNRs and DTX (PLGA/ AuNR/DTX) and then coated the ultra-thin nanofilm with MnO 2 on the surface of it, constructing a new drug delivery system. Radiofrequency heating and MnO 2 degradation can significantly promote controlled drug release in tumor regions (Wang et al, 2017).…”