Synergistic Effect of Ferroptosis-Inducing Nanoparticles and X-Ray Irradiation Combination Therapy

Ferroptosis, characterized by the induction of cell death via lipid peroxidation, has been actively studied over the last few years and has shown the potential to improve the efficacy of cancer nanomedicine in an iron-dependent manner. Radiation therapy, a common treatment method, has limitations as a stand-alone treatment due to radiation resistance and safety as it affects even normal tissues. Although ferroptosis-inducing drugs help alleviate radiation resistance, there are no safe ferroptosis-inducing drugs that can be considered for clinical application and are still in the research stage. Here, the effectiveness of combined treatment with radiotherapy with Fe and hyaluronic acid-based nanoparticles (FHA-NPs) to directly induce ferroptosis, considering the clinical applications is reported. Through the induction of ferroptosis by FHA-NPs and apoptosis by X-ray irradiation, the therapeutic efficiency of cancer is greatly improved both in vitro and in vivo. In addition, Monte Carlo simulations are performed to assess the physical interactions of the X-rays with the iron-oxide nanoparticle. The study provides a deeper understanding of the synergistic effect of ferroptosis and X-ray irradiation combination therapy. Furthermore, the study can serve as a valuable reference for elucidating the role and mechanisms of ferroptosis in radiation therapy.

The Potential of Campanula takesimana Callus Extract to Enhance Skin Barrier Function

Atopic dermatitis (AD) is a prevalent inflammatory skin disease characterized by epidermal barrier dysfunction and Th2-skewed inflammation. Campanula takesimana (C. takesimana), a Korean endemic plant grown on Ulleng Island, has long been associated with a traditional alternative medicine for asthma, tonsillitis, and sore throat. In this study, we reported the effect of C. takesimana callus extract on upregulating epidermal barrier-related proteins dysregulated by Th2 cytokines. C. takesimana callus extract induced the expression of skin barrier proteins, such as filaggrin, claudin-1, and zonula occludens-1, in both human primary keratinocytes and Th2-induced AD-like skin-equivalent models. Additionally, RNA sequencing analysis demonstrated that C. takesimana callus extract partially restored Th2 cytokine-induced dysregulation of the epidermal development and lipid metabolic pathways. Considering the advantages of callus as a sustainable eco-friendly source of bioactive substances, and its effect on skin barrier proteins and lipid metabolic pathways, C. takesimana callus extracts can possibly be utilized to improve the integrity of the skin barrier.

Biocompatible and Oxidation-Resistant Ti3 C2 Tx MXene with Halogen-Free Surface Terminations

Surface chemistry influences not only physicochemical properties but also safety and applications of MXene nanomaterials. Fluorinated Ti3 C2 Tx MXene, synthesized using conventional HF-based etchants, raises concerns regarding harmful effects on electronics and toxicity to living organisms. In this study, well-delaminated halogen-free Ti3 C2 Tx flakes are synthesized using NaOH-based etching solution. The transversal surface plasmon mode of halogen-free Ti3 C2 Tx MXene (833 nm) confirmed red-shift compared to conventional Ti3 C2 Tx (752 nm), and the halogen-free Ti3 C2 Tx MXene has a different density of state by the high proportion of -O and -OH terminations. The synthesized halogen-free Ti3 C2 Tx exhibits a lower water contact angle (34.5°) and work function (3.6 eV) than those of fluorinated Ti3 C2 Tx (49.8° and 4.14 eV, respectively). The synthesized halogen-free Ti3 C2 Tx exhibits high biocompatibility with the living cells, as evidenced by no noticeable cytotoxicity, even at very high concentrations (2000 µg mL⁻1 ), at which fluorinated Ti3 C2 Tx caused ≈50% reduction in cell viability upon its oxidation. Additionally, the oxidation stability of halogen-free Ti3 C2 Tx is enhanced unexpectedly, which cumulatively provides a good rationale for pursuing the halogen-free routes for synthesizing MXene materials for their uses in biomedical and therapeutic applications.

Fast and High-Yield Anhydrous Synthesis of Ti3 C2 Tx MXene with High Electrical Conductivity and Exceptional Mechanical Strength

2D transition metal carbides or nitrides (MXenes) have attracted considerable attention from materials scientists and engineers owing to their physicochemical properties. Currently, MXenes are synthesized from MAX-phase precursors using aqueous HF. Here, in order to enhance the production of MXenes, an anhydrous etching solution is proposed, consisting of dimethylsulfoxide as solvent with its high boiling point, NH₄ HF₂ as an etchant, CH₃ SO₃ H as an acid, and NH₄ PF₆ as an intercalant. The reaction temperature can be increased up to 100 °C to accelerate the etching and delamination of Ti₃ AlC₂ MAX crystals; in addition, the destructive side reaction of the produced Ti₃ C₂ T_x MXene is suppressed in the etchant. Consequently, the etching reaction is completed in 4 h at 100 °C and produces high-quality monolayer Ti₃ C₂ T_x with an electrical conductivity of 8200 S cm^-1 and yield of over 70%. The Ti₃ C₂ T_x MXene fabricated via this modified synthesis exhibits different surface structures and properties arising from more F-terminations than those of Ti₃ C₂ T_x synthesized in aqueous HF₂ T. The atypical surface structure of Ti₃ C₂ T_x MXene results in an exceptionally high ultimate tensile strength (167 ± 8 MPa), which is five times larger than those of Ti₃ C₂ T_x MXenes synthesized in aqueous HF solution (31.7 ± 7.8 MPa).