PURPOSE: To improve the targeted therapy of hepatocellular carcinoma (HCC), SP94-modified calcium phosphate lipid nanoparticles loaded with Bcl-2 siRNA and doxorubicin (SP94-LCP/DOX&Bcl-2 siRNA) were prepared.
METHODS: SP94-LCP/DOX&Bcl-2 siRNA was fabricated via reversed-phase microemulsion. Its physicochemical properties (particle size, zeta potential, morphology), pharmaceutical performance (drug loading, encapsulation efficiency, stability, in vitro release), and in vitro activities (targeting, cytotoxicity, apoptosis, apoptosis-related proteins) were evaluated using HepG2 cells via cellular uptake, wound healing, Hoechst 33,258 staining, MTT, and Western blot assays. In vivo antitumor efficacy was tested in HepG2 xenograft nude mice.
RESULTS: SP94-LCP/DOX&Bcl-2 siRNA had a mean diameter of 130 nm and a zeta potential of 20 mV, showing a spherical morphology with uniform distribution. The encapsulation efficiency of siRNA reached 92% and that of doxorubicin is 81%. It exhibited good stability and a significant sustained-release effect. SP94-LCP/DOX&Bcl-2 siRNA significantly reduced the IC₅₀ values of DOX + Bcl-2siRNA, and enhanced the uptake capacity of HepG2 cells for LCP. It remarkably inhibited the migration ability of HepG2 cells, concomitantly downregulating Bcl-2 and upregulating Bax expression, thereby facilitating apoptotic cell death. SP94-LCP/DOX&Bcl-2 siRNA could better inhibit tumor growth in mice and reduce the toxic and side effects on normal tissues of mice.
CONCLUSIONS: In this study, SP94-LCP/DOX&Bcl-2 siRNA was successfully prepared. It exhibited remarkable targeting ability and antitumor activity, significantly enhancing the therapeutic effect of doxorubicin and siRNA on HCC. The construction of this drug delivery system provided a novel strategy for the clinical treatment of HCC.
