PSMA-Targeting Redox Hyperbranched Poly (Amido Amine)-Mediated miR-133a-3p Delivery to Inhibit Bone Metastasis of Prostate Cancer

Treatment of bone metastasis of prostate cancer remains a formidable challenge. The skeleton has a poorer blood supply, leading to inadequate drug distribution into the bone after administration. This study aimed to develop aptamer-anchored hyperbranched poly (amido amine) (HPAA) for the systemic delivery of miRNA-133a-3p and to evaluate its therapeutic potential against bone metastasis of prostate cancer in vivo and in vitro. A glutathione (GSH)-responsive cationic HPAA was prepared by the Michael addition reaction. Furthermore, HPAA-PEG was produced by PEGylation, and then the aptamer targeted to prostate-specific membrane antigen (PSMA) was conjugated to the HPAA-PEG. The obtained HPAA-PEG-APT could form nanocomplexes with miRNA-133a-3p through electrostatic adsorption. The results of immunocytochemistry indicated that the complexes could target PSMA-expressing LNCaP cells. The ability of HPAA-PEG-APT to facilitate the delivery of miRNA-133a-3p into LNCaP cells was proven, and HPAA-PEG-APT/miRNA-133a-3p demonstrated enhanced antitumor activity, lower cytotoxicity and better biocompatibility in vitro. Moreover, in a mouse tibial injection tumor model, the intravenous injection of the HPAA-PEG-APT/miRNA-133a-3p complex significantly inhibited cancer growth and extended the survival time. In summary, this study provided an aptamer-anchored HPAA-loaded gene system to deliver miRNA-133a-3p for better therapeutic efficacy of bone metastasis of prostate cancer.