MiRNA-520a-3p Combined with Folic Acid Conjugated Fe2O3@PDA Multifunctional Nanoagents for MR Imagine and Antitumor Gene-Photothermal Therapy.

Osteosarcoma (OS) is a primary malignant bone tumor that occurs mainly in adolescents.
Researchers are devoting to develop combination therapy methods in a multifunctional nanoplatform for
the treatment of osteosarcoma. The results of previous research have shown that up-regulation of miR-
520a-3p could induce anticancer effects in osteosarcoma. In order to improve the effect of gene therapy
(GT), we attempted to carry miR-520a-3p in a multifunctional vector for comprehensive therapy. Fe 2 O 3
is a type of magnetic resonance imaging contrast that is widely used as a drug delivery agent. When
coated with polydopamine (PDA), it can also be used as a photothermal therapy (PTT) agent (Fe 2 O 3 @
PDA). To deliver nanoagents targeted to a tumor site, folic acid (FA) conjugated with Fe 2 O 3 @PDA was
manufactured as FA-Fe 2 O 3 @PDA. FA was chosen as the target molecule to enhance utilization and
reduce toxicity of nanoparticles. However, the therapeutic efficacy of FA-Fe 2 O 3 -PDA combined with
miR-520a-3p has not yet been studied. In this study, we synthesized FA-Fe 2 O 3 @PDA-miRNA and
investigated the potential of combining PDA regulated PTT and miR-520a-3p regulated GT to kill
osteosarcoma cells. The results indicated that down-regulation of interleukin 6 receptor (IL6R) by miR-
520a-3p and the photothermal ability of PDA could induce satisfactory anticancer effects in osteosarcoma,
and the curative ratio was better than that used alone PTT or GT. Moreover, as a kind of T 2 magnetic
contrast, miRNA-Fe 2 O 3 @PDA-FA can be used for magnetic resonance imaging (MRI). These findings
indicated that miRNA-Fe 2 O 3 @PDA-FA is an effective anti-tumor nanovector for PTT combined with
GT.&#xD.