Chemotherapeutic and radiation therapy have emerged as two most important treatment strategies to treat cancer in clinical practice; however, to improve anticancer efficacy, combination chemotherapy still remains challenge. Dichloroacetate (DCA) could produce significant cytotoxic effects in certain tumor cells through its distinct mechanism. Radiation therapy with fast neutrons (FNT) has high relative biolgical effectiveness compared to other radiotherapeutics. Herein, we reported the combination chemotherapy with FNT for effective tumor growth inhibition with the assistance of a multilayered nanofiber loading DCA and DCA derivatives. We first synthesized a biodegradable polylysine to condense DCA with negative charge, or to conjugate DCA by condensing synthesis, to obtain Ion-DCA and Co-DCA, respectively. DCA, Ion-DCA or Co-DCA was then loaded into fibers to form multilayer drug-loaded mats. Upon adhesion on the surface of subcutaneous and orthotopic liver tumors, the multilayer drug-loaded mats realized a controllable release of DCA, which reversed the Warburg effect and inhibited cancer cell proliferation. Meantime, irradiation of fast neutrons could seriously damage DNA structure. Combination of the controllable release of DCA and FNT resulted in synergistic cell apoptosis in vitro, and the tumor inhibition in vivo. This study thus provides a new approach to integrate chemotherapy and FNT with the assistance of biocompatible nanofiber for synergistic tumor therapy.

CRISPR/Cas9 system has become a promising gene editing tool for cancer treatment. However, development of a simple and effective nanocarrier to incorporate CRISPR/Cas9 system and chemotherapeutic drugs to concurrently tackle the biological safety and packaging capacity of viral vectors and combine gene editing-chemo for cancer therapy still remains challenges. Herein, a chain-shattering Pt(IV)-backboned polymeric nanoplatform is developed for the delivery of EZH2-targeted CRISPR/Cas9 system (NP_CSPt/pEZH2) and synergistic treatment of prostate cancer. The pEZH2/Pt(II) could be effectively triggered to unpack/release from NP_CSPt/pEZH2 in a chain-shattering manner in cancer cells. The EZH2 gene disruption efficiency could be achieved up to 32.2% of PC-3 cells in vitro and 21.3% of tumor tissues in vivo, leading to effective suppression of EZH2 protein expression. Moreover, significant H3K27me3 downregulation could occur after EZH2 suppression, resulting in a more permissive chromatin structure that increases the accessibility of released Pt(II) to nuclear DNA for enhanced apoptosis. Taken together, substantial proliferation inhibition of prostate cancer cells and further 85.4% growth repression against subcutaneous xenograft tumor could be achieved. This chain-shattering Pt(IV)-backboned polymeric nanoplatform system not only provides a prospective nanocarrier for CRISPR/Cas9 system delivery, but also broadens the potential of combining gene editing-chemo synergistic cancer therapy.