Iron oxide-EDTA nanoparticles for chelation-enhanced chemodynamic therapy and ion interference therapy.

As an emerging anti-tumor strategy, chemodynamic therapy (CDT) utilizes a Fenton/Fenton-like reaction to generate highly toxic hydroxyl radicals to kill tumor cells. However, the efficiency of CDT is still hindered by the low Fenton/Fenton-like reaction rate. Herein, we report the combination of ion interference therapy (IIT) and chemodynamic therapy (CDT) via an amorphous iron oxide (AIO) nanomedicine with encapsulated EDTA-2Na (EDTA). Iron ions and EDTA are released from the nanomedicine in acidic tumors and chelate to form iron ion-EDTA, which improves the efficiency of CDT and promotes the generation of reactive oxygen species (ROS). In addition, EDTA can disrupt the homeostasis of Ca2+ in tumor cells by chelating with Ca2+ ions, which induces the separation of tumor cells and affects normal physiological activities. Both in vitro and in vivo experiments show that the nano chelating drugs exhibit significant improvement in Fenton reaction performance and excellent anti-tumor activity. This study based on chelation provides a new idea for designing efficient catalysts to enhance the Fenton reaction and provides more revelations on future research on CDT.

Ferrocene and glucose oxidase-installed multifunctional hydrogel reactors for local cancer therapy.

A hyaluronic acid (HA)-based one-pot hydrogel reactor with single syringe injection and immediate gelation was developed for starvation therapy (ST), chemodynamic therapy (CDT), ferroptosis, and photothermal therapy (PTT) against breast cancer. A rheologically tuned hydrogel network, composed of HA-phenylboronic acid (HP) and HA-dopamine (HD), was designed by introducing a boronate ester linkage (phenylboronic acid-dopamine interaction) and polydopamine bond (pH control). Ferrocene (Fc)-conjugated HP (Fc-HP) was synthesized to achieve ferroptosis, Fenton reaction-involved toxic hydroxyl radical (•OH) generation, and photothermal ablation in cancer therapy. Glucose oxidase (GOx) was entrapped in the pH-modulated Fc-HP (Fc-HP°)/HD hydrogel network for converting intracellular glucose to H2O2 to enable its own supply. The GOx/Fc combination-installed hydrogel reactor system can provide sustained ST/CDT/PTT functions along with ferroptosis. Injection of Fc-HP°/HD/GOx hydrogel with single-syringe injectability, shear-thinning feature, and self-healing capability offered a slow biodegradation rate and high safety profiles. Peritumorally injected Fc-HP°/HD/GOx hydrogel also efficiently suppressed the growth of breast cancer based on multifunctional therapeutic approaches with reduced dosing frequency. Hyperthermia induced by near-infrared (NIR) laser absorption may amplify the therapeutic effects of free radicals. It is expected that this Fc-HP°/HD/GOx hydrogel system can be applied to local cancer therapy with high efficacy and safety profiles.

Multifunctional hetero-nanostructures of hydroxyl-rich polycation wrapped cellulose-gold hybrids for combined cancer therapy.

The development of new hetero-nanostructures for multifunctional applications in cancer therapy has attracted widespread attention. In this work, we put forward a facile approach to synthesize multifunctional hetero-nanostructures of cellulose nanocrystal (CNC)-gold nanoparticle hybrids wrapped with low-toxic hydroxyl-rich polycations to integrate versatile functions for effective cancer therapy. Biocompatible CNCs with the superior rod-like morphology for high cellular uptake were employed as substrates to flexibly load spherical gold nanoparticles (Au NPs) or gold nanorods (Au NRs) through gold-thiolate bonds, producing hetero-layered nanohybrids of CNC-Au NPs or CNC-Au NRs. Profound hydroxyl-rich cationic gene carrier, CD-PGEA (comprising ß-cyclodextrin cores and ethanolamine-functionalized poly(glycidyl methacrylate) arms), was then assembled onto the surface of CNC-Au nanohybrids through host-guest interaction and gold-thiolate bonds, where PEG was employed as the intermediate and spacer. The resultant CNC-Au-PGEA hetero-nanostructures exhibited excellent performances as gene carriers. Furthermore, CNC-Au NR-PGEA comprising Au NRs demonstrated favorable optical absorption properties and were validated for photoacoustic imaging and combined photothermal/gene therapy with considerable antitumor effects. The present work provided a flexible strategy for the construction of new multifunctional hetero-nanostructures with high antitumor efficacy.