Silica nanowire conjugated with loop-shaped oligonucleotides: A newstructure to silence cysteine proteinase gene in Leishmania tropica

tThe main aim of this study was to evaluate the capability of silica nanowire conjugated with loop-shapedoligonucleotides (SNWCLSOs) to silence cysteine proteinase b (Cpb) gene in Leishmania (L) tropica. Onthe other hand, its toxicity on amastigotes and mouse peritoneal macrophages was evaluated by 5-diphenyl-tetrazolium bromide (MTT) assay. For control, two loop-shaped oligonucleotides (LSO) wereconsidered. LSO1 and LSO2 were 5-NH2-cccccaaaaaaaaaaaaaaaaaaaaaaaaaggggg-COOH-3and LSO2:5-NH2-cccccttttttttttttttttttttttttttttttttttttttggggg-COOH-3, respectively. After 72 h incubation at 37◦C,AMSNW, LSO1, and LSO2 had no remarkable toxicity on L. tropica amastigote (2 × 105/mL) and mouseperitoneal macrophages (2 × 105/mL). In case of SNWCLSOs, they had high toxicity on L. tropica amastig-ote, but they had no effect on mouse peritoneal macrophages. At concentrations of 1, 10, and 25 g/mL,AMSNW, LSO1 and LSO2 had no effect on the gene expression. But, at concentration of 50 and 100 g/mL,decrease of gene expression was observed. In case of SNWCLSOs, they could dramatically decrease thegene expression. It could be concluded that since SNWCLSOs could silence Cpb gene with no remarkabletoxicity, they are good choice for treat cutaneous leishmaniasis in future. As a new agent, it must bechecked in vivo

Silica nanowireLoop-shaped oligonucleotidesCysteine proteinaseLeishmania tropica