Background. Amphiphilic block copolymers used as nanomicelle drug carriers can effectively overcome poor drug solubility and specificity issues. Hence, these platforms have a broad applicability in cancer treatment. In this study, Pluronic F127 was used to fabricate nanomicelles containing the histone deacetylase inhibitor SAHA, which has an epigenetic-driven anti-cancer effect in several tumor types. SAHA loaded nanomicelles were prepared using a thin-film drying method and characterized for size, surface charge, drug content and drug release properties. Loaded particles were tested for in vitro activity and their effect on cell-cycle and markers of cancer progression.
Results. Following detailed particle characterization, cell proliferation experiments demonstrated that SAHA loaded nanomicelles more effectively inhibited the growth of HeLa and MCF-7 cell lines compared with free drug formulations. The 30nm SAHA containing nanoparticles were able to release up to 100% of the encapsulated drug over a 72h time window. Moreover, gene and protein expression analyses suggested that their cytoreductive effect was achieved through the regulation of p21 and p53 expression. SAHA was also shown to upregulate E-cadherin expression, potentially influencing tumor migration.
Conclusions. This study highlights the opportunity to exploit pluronic-based nanomicelles for the delivery of compounds that regulate epigenetic processes, thus inhibiting cancer development and progression.