Iron phosphide nanoparticles as a pH-responsive T1 contrast agent for magnetic resonance tumor imaging

Tumor Diagnosis and Therapy Mediated by Metal Phosphorus-Based Nanomaterials

Metal phosphorus-based nanomaterials (Metal-P NMs) including metal phosphate nanomaterials, metal phosphide nanomaterials, and metal-black phosphorus (Metal-BP) nanocomposite are widely used in the field of biomedicine owing to their excellent physical and chemical properties, biocompatibility, and biodegradability. In recent years, metal phosphate nanomaterials and Metal-BP nanocomposite acted as medicine delivery system have made breakthroughs in tumor diagnosis including magnetic resonance imaging, fluorescence imaging, photoacoustic imaging, nuclear imaging, and therapies including chemotherapy, gene therapy, photothermal therapy, photodynamic therapy, and radiation therapy. Metal phosphate nanomaterials have good biodegradability, especially calcium-based metal phosphate nanomaterials can be dissolved into nontoxic ions and participate in the metabolisms of normal organs. Compared with metal phosphate nanomaterials, metal phosphide nanomaterials have excellent optical, magnetic, and catalytic properties, which can be used as multifunctional diagnostic nanoplatforms and therapeutic agents for chemodynamic therapy, photothermal therapy, or immunotherapy. The latest developments in Metal-P NMs, covering the range of preparation methods and biological applications, such as serving as drug carriers, tumor diagnosis, and therapy, are focused. All in all, the current trends, key issues, future prospects and challenges of Metal-P NMs are concluded and discussed, which are important for the development of this research field and shining more lights on this direction.

In situ embedding dual-Fe nanoparticles in synchronously generated carbon for the synergistic integration of magnetic resonance imaging and drug delivery

In situ incorporating versatile magnetic iron nanoparticles into ordered mesoporous carbon (OMC) by means of synthetic methodology for functional integration is a great challenge. Inspired by the phenomenon of uniovular twins in nature, a homometallic [Fe₉(μ₃-O)₄(O₃PPh)₃(O₂CCMe₃)₁₃] ({Fe₉P₃}) cluster was synthesized and used as the ovulum to in situ produce dual-Fe nanoparticle (γ-Fe₂O₃ and Fe(PO₃)₃)-functionalized OMC (dual-Fe/OMC). In vitro magnetic resonance imaging (MRI) studies showed a longitudinal relaxation (r ₁) and transverse relaxation (r ₂) of 9.74 and 26.59 mM^-1 s^-1 with a r ₂/r ₁ ratio of 2.73 at 0.5 T. The MRI performances were further examined by mouse model with a subcutaneous HeLa tumor. In addition, the low cytotoxicity, considerable loading capacity and delivery of doxorubicin hydrochloride (DOX) were also studied in vitro. These results demonstrate the feasibility of the concept of uniovular twins in the one-pot preparation of dual-Fe/OMC for functional integration.