Core-shell vector-mediated co-delivery of CRISPR/Cas9 system and hydrophobic drugs against triple-negative breast cancer stem cells.

Cancer stem cells (CSCs) play an important role in the development of triple-negative breast cancer (TNBC), including metastasis, invasion, tumorigenicity, and drug resistance. Moreover, non-CSCs can spontaneously transform into CSCs in special tumor microenvironments, thereby leading to poor prognosis or even failed treatments. Therefore, reversing CSCs into normal tumor cells in a sustained-acting manner is a promising strategy. It has been reported that down-regulation of FBXO44 protein expression inhibits tumor cell stemness. Moreover, CRISPR/Cas9 technology, a well-known precise gene editing tool, was adopted to permanently block FBXO44 within the genome upon its successful implementation. Given this, a core-shell nanoparticle (NP) consisting of amphiphilic polymer core and crosslinked-hyaluronic acid shell (nDOX-PL/pFBXO44 NPs) is developed in this work to concurrently deliver FBXO44-targeted CRISPR/Cas9 plasmids (pFBXO44) and doxorubicin (DOX) for combinational CSC reprogramming and chemotherapy of TNBC, which exhibits tumor cell targeting, endosomal escape, and reduction responsiveness to release DOX and plasmids in the cytoplasma. CRISPR/Cas9-mediated downregulation of FBXO44 expression could convert CSC into normal tumor cells, and effectively inhibit tumor growth without obvious side effects in vivo after combining with chemotherapy. In summary, we developed an intelligent system to co-deliver genetic and hydrophobic drugs, achieving effective cancer stemness reversal and synergistic suppression of contractable TNBC.