Small interfering RNA (siRNA) has been widely proposed to treat various diseases by silencing genes, but its delivery remains a challenge. A well-controlled assembly approach was applied to prepare a protease assisted nanodelivery system. Onto a gold nanoparticles (AuNPs), protease degradable poly-L-lysine (PLL) and siRNA were fabricated by alternating the charged polyelectrolytes. In this study, up to 4 layers of PLL and 3 layers of siRNA (sR3P) were coated. Due to slow degradation of PLL, the incorporated siRNA was released gradually and showed extended gene silencing effect. Importantly, the inhibition effect in cells was found to correlate with the number of siRNA layers.

Iridovirus is a causative agent of epizootics among cultured rock bream (Oplegnathus fasciatus) in Korea. Here, we report the complete genomic sequence of rock bream iridovirus (RBIV). The genome of RBIV was 112080 bp long and contained at least 118 putative open reading frames (ORFs), and its genome organization was similar to that of infectious spleen and kidney necrosis virus (ISKNV). Of the RBIV's 118 ORFs, 85 ORFs showed 60-99% amino acid identity to those of ISKNV. Phylogenetic analysis of major capsid protein (MCP), DNA repair protein RAD2, and DNA polymerase type-B family indicated that RBIV is closely related to red sea bream iridovirus (RSIV), Grouper sleepy disease iridovirus (GSDIV), Dwarf gourami iridovirus (DGIV), and ISKNV. The genome sequence provides useful information concerning the evolution and divergence of iridoviruses in cultured fish.

Triple-negative breast cancer (TNBC) patients exhibit the worst clinical outcome due to its aggressive clinical course, higher rate of recurrence, and a conspicuous lack of FDA approved targeted therapies. Here, we show that multilayered nanoparticles (NPs) carrying the metastasis suppressor microRNA miR-708 (miR708-NP) localize to orthotopic primary TNBC, and efficiently deliver the miR-708 cargo to reduce lung metastasis. Using a SOX2/OCT4 promoter reporter, we identified a population of miR-708low cancer cells with tumor-initiating properties, enhanced metastatic potential and marked sensitivity to miR-708 treatment. In vivo, miR708-NP directly targeted the SOX2/OCT4-mCherry+ miR-708low tumor cells to impair metastasis. Together, our preclinical findings provide a mechanism-based anti-metastatic therapeutic approach for TNBC, with a marked potential to generate miR-708 replacement therapy for high-risk TNBC patients in the clinic. To our knowledge, this gold nanoparticle-based delivery of microRNA-mimetic is the first oligonucleotide-based targeted therapy for TNBC.