Abstract:
With the development of nanotechnology, various drug delivery systems including inorganic nanoparticles, liposomes, polymers, etc. have been developed over the past decade. Some of these nanoparticles are also forthcoming candidates for the successful delivery of small interfering RNA (siRNA) for targeted gene silencing. Upon its discovery, siRNA was perceived as a highly promising agent in the treatment of various diseases. However, it could not exhibit the expected clinical outcomes owing to the unfavorable challenges during delivery. One such challenge was identified as the lack of an effective carrier. Among the carriers, calcium phosphate (CaP) nanoparticles have attracted remarkable attention due to the superior biochemical properties and hold great promise for siRNA. It is well known that synthesis conditions influence the types of crystalline phases of CaPs as well as morphology. In this study, to address the influence of these parameters on the success of siRNA delivery, three different arginine (Arg) modified CaP nanoparticles having different chemical and morphological characteristics were synthesized as being the carriers of two specific siRNAs against survivin and cyclin B1. The functioning of CaP surfaces with Arg results in positive zeta potential on the surfaces. Functionalized nanoparticles have a higher loading capacity compared to unmodified particles, as they have a cationic surface that can be easily attached to negatively charged siRNAs. The gene silencing ability and the consequent in vitro antitumor activity of these CaP-Arg-siRNA complexes were investigated using A549 non-small-cell lung cancer cells. We found that high survivin and cyclin B1 expression is associated with worse survival in patients with lung cancer based on the Kaplan-Meier database. Considering the promoting role of survivin and cyclin B1 in cancer development and progression, CaP-Arg-siRNA mediated suppression of these genes resulted in a significant decrease in cell growth and induction of apoptosis. Our data suggest that all three CaP-Arg nanoparticles synthesized in this work can be used as safe and efficient nanocarriers for siRNA delivery, offering the opportunity to develop new therapeutic strategies for the treatment of lung cancer.