The cellular uptake of antisense oligonucleotid of E6 mRNA into cervical cancer cells by DOPE-modified hydroxyapatite nanoparticles

Although several chemical and physical methods for gene delivery have been introduced, their cytotoxicity, non-specific immune responses and the lack of biodegradability remain the main issues. In this study, hydroxyapatite nanoparticles (NPs) and 1,2-dioleoyl-sn-glycero-3-phosphoethanol​amine (DOPE)-modified hydroxyapatite NPs was coated with antisense oligonucleotide of E6 mRNA, and their uptakes into the cervical cancer cell line were evaluated. Calcium nitrate and diammonium phosphate were used for the synthesis of the hydroxyapatite nanoparticle. Thus, they were coated with polyethylene glycol (PEG), DOPE and antisense oligonucleotide of E6 mRNA using a cross-linker. Then, hydroxyapatite NPs and DOPE-modified hydroxyapatite NPs were incubated 48 hours with cervical cancer cells and their uptakes were evaluated by fluorescent microscopy. The hydroxyapatite NPs had different shapes and some agglomeration with average size of 100 nm. The results showed DOPE-modified hydroxyapatite NPs had higher uptake than hydroxyapatite NPs (P<0.05). Hydroxyapatite NPs conjugated with DOPE are a good choice for gene delivery and silencing of viral genes in cervical cancer cells, but their efficacy should be addressed more in future studies.