Photodynamic therapy (PDT) remains underutilized as a primary cancer treatment due to the limited lethality of reactive oxygen species (ROS) and poor targeting efficiency of traditional photosensitizers. This the aim of the study is to develop a Fe₃O₄@ZnO nanoparticle photosensitizer co-loaded with anti-EGFR antibody, brusatol, and Nrf2-siRNA to improve the therapeutic effect of PDT. This system can be guided to tumors by a magnetic field and further targets cancer cells through EGFR-specific binding. Under UVA light, brusatol and Nrf2-siRNA are released, enabling combined chemo-, gene, and photodynamic therapy. With the photosensitizer treatment, ROS levels in cutaneous squamous cell carcinoma cells were elevated by 191.09 ± 10.02 % through suppression of Nrf2 and its associated antioxidant defenses, significantly enhancing cell lethality and reducing cell viability by 80.43 ± 9.37 %. In vivo studies further demonstrated a tumor suppression rate of 76.30 ± 5.12 % in nude mice, highlighting the robust anti-tumor efficacy of the photosensitizer and its potential for clinical application in targeted cancer therapy. The biocompatibility and high therapeutic efficacy of this photosensitizer highlight its promise as a safer and more effective option for treating cutaneous squamous cell carcinoma.
Activated anti-oxidation reactions in cells partially diminish the anticancer effect of photodynamic therapy (PDT), significantly hindering efforts to increase the efficacy of PDT. The expression of transcription factor E2 related factor 2 (Nrf2), an important redox-regulated transcription factor, can be downregulated by Nrf2 siRNA, leading to greatly enhanced PDT effects. However, the efficient co-delivery of photosensitizers and siRNAs remains a key problem because these agents are complex to synthesize, exhibit poor biocompatibility and load drugs with a low efficiency. Herein, we designed a carrier–free and extremely simple strategy to co-deliver a photosensitizer and Nrf2 siRNA to cancer cells. In this nanoplatform, an indocyanine green (ICG) photosensitizer, siRNA and FeⅡ were self-assembled to form a spherical hybrid structure with a uniform size, high loading ratio and adjustable component ratio. The platform can effectively transfer photosensitizers and siRNAs into cells and effectively inhibit tumour growth in vivo . Overall, the self-assembly approach shows great potential for clinical application and provides a simple method to achieve photodynamic therapy and enhanced photothermal therapy.
Maiquan Li,Tao Xu,Fei Zhou,Mengmeng Wang,Huaxin Song,Xing Xiao,Baiyi Lu
Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor against oxidative stress and neurodegenerative disorders. Phenylethanoid glycosides (PhGs; salidroside, acteoside, isoacteoside, and echinacoside) exhibit antioxidant and neuroprotective bioactivities. This study was performed to investigate the neuroprotective effect and molecular mechanism of PhGs. PhGs pretreatment significantly suppressed H2O2-induced cytotoxicity in PC12 cells by triggering the nuclear translocation of Nrf2 and reversing the downregulated protein expression of heme oxygenase 1 (HO-1), NAD(P)H quinone oxidoreductase 1 (NQO1), glutamate cysteine ligase-catalytic subunit (GCLC), and glutamate-cysteine ligase modifier subunit (GCLM). Nrf2 siRNA or HO-1 inhibitor zinc protoporphyrin (ZnPP) reduced the neuroprotective effect. PhGs showed potential interaction with the Nrf2 binding site in Kelch-like ECH-association protein 1 (Keap1). This result may support the hypothesis that PhGs are activators of Nrf2. We demonstrated the potential binding between PhGs and the Keap1-activated Nrf2/ARE pathway, and that PhGs with more glycosides had enhanced effects.Keywords:Keap1;Nrf2;Neuroprotective;PC12 cells;PhGs