Recently, magnetic nanomaterials have emerged as multifunctional materials for a wide range of biomedical applications. Functional magnetic iron oxide nanoparticles (FMIONs) are typical magnetic nanomaterials with inherent advantages for disease diagnosis, prevention, and treatment: high specific surface area, excellent superparamagnetism, good colloidal stability, and remarkable biosafety. Therefore, FMION‐based biomedicine has advanced at an unprecedented rate in recent years. However, the performance of FMIONs cannot yet meet complicated physiological circumstances. To overcome these limitations, researchers have designed and manipulated the geometric shapes, sizes, compositions, and surfaces to endow these FMIONs with high performance. This review summarizes recent advances in the controlled synthesis of FMIONs, cover corresponding theories of nucleation and growth in solution, and the tuning of FMION properties for disease diagnosis and therapy. After discussing the biomedical applications in cancer theranostics—tumor hyperthermia, magnetic resonance imaging and drug delivery system—in detail, the review concludes with current challenges and outlooks for the development of FMIONs.

The design and synthesis of functional heterocyclic sulfonic acid polymers would provide much help in studying the coordination behavior, structural optimization, and application of the polymers. In this work, a three-dimensional (3D) supramolecular structure [Na₂Cu(P–SO₃)₄]_n (P–SO₃H = pyrazine sulfonic acid) is synthesized by a hydrothermal method with the “soft–hard” strategy. The produced polymer is characterized by the elemental analysis, IR spectroscopy, and X-ray crystallography. Crystal diffraction data indicate that the polymer belongs to the P4/ncc space group. Notably, the introduction of a soft alkali metal ion can trigger the specific affinity binding with sulfonate oxygen atoms to give rise to a Na–O-μ₄ bridging pattern. The flexible bridging pattern combined with the rigid structure of copper pyrazine sulfonate is likely to be responsible for the production of the final 3D supramolecular structure. Moreover, powder X-ray diffraction data indicated a good phase purity. Thermal stability, Raman features as well as solid-state fluorescent properties are also investigated in detail.

Coordination nature in the structures between the heterocyclic sulfonic acid group and heavy metal atoms, structural optimization, their physical and chemical properties have been studied. Herein, a new compound [Hg₂(P–SO₃)(NO₃)]_n (1) has been synthesized via solvent volatilization method, according to which pyrazine sulfonic acid (P–SO₃H) has been used as the major ligand, and nitrate has been used as the precursor. X-Ray single-crystal diffraction analysis demonstrates that 1 belongs to the Pca21 space group. Both pyrazine sulfonate and nitrate serve as chelate bridging linkers for the dimercury(I) ions (Hg₂²⁺or Hg^I–Hg^I) forming the 2D layer coordination polymer involved in further construction of the stable 3D network through the π–π stacking of pyrazine rings. Thermal stability and fluorescence properties of 1 have been closely studied.

Investigating the electromagnetic properties of magnetite nanoparticles (Fe₃O₄ NPs) is beneficial for expanding their biomedical applications, especially in tumor hyperthermia. In this study, monodisperse Fe₃O₄ NPs of various shapes (i.e., quadrilateral-like, hexagon-like, rod-like, and triangle-like) were successfully prepared by a microwave-assisted thermal decomposition approach. The magnetic properties and inductive heating performance, as well as electromagnetic properties were analyzed systematically. The results showed that quadrilateral-like Fe₃O₄ NPs possessed excellent magneto-thermal effects and maximum specific absorption rate values of 226.4 W/g and 1409.6 W/g (390 kHz and 780 kHz, 12 A). Moreover, a sample filled with 70 wt. % quadrilateral-like NPs in paraffin showed a minimum reflection loss (RL) value of −33.4 dB, along with a broad absorption bandwidth of RL < −10 dB covering 2 GHz–18 GHz. The high magnetic loss may be derived from the eddy current loss and natural resonance. This study would deepen the understanding of microwave absorption properties of Fe₃O₄ NPs and enrich their microwave applications based on shape anisotropy.

Background: Liver cancer is one of the most prevalent cancers globally, with approximately 90% of primary liver cancers being hepatocellular carcinomas (HCC). However, current systemic treatment options (whether monotherapy or combination therapy) are limited and offer only modest survival benefits. The effectiveness of a drug is largely determined by its concentration at the target site. Therefore, an effective drug delivery system must enhance drug accumulation at the target site, enable selective drug release there, and facilitate escape from lysosomes. Methods: cRGD-Lipo@Ce6/DOX was prepared by modifying c(RGDyK) onto the surface of drug-loaded liposomes containing Chlorin e6 (Ce6) and doxorubicin (DOX) through an amide reaction. The targeting capability and uptake mechanism of cRGD-Lipo@Ce6/DOX for HCC were analyzed using flow cytometry. To investigate drug release mechanisms and changes in subcellular distribution following ultrasound stimulation, further studies were conducted. The therapeutic efficacy and biosafety of this dual-modality therapy were then evaluated in an HCC subcutaneous tumor-bearing mouse model. Results: The prepared nanocomplex exhibits a surface charge of − 9.91 ± 2.94 mV and an apparent size of 118.07 ± 1.46 nm. Modification of the RGD cyclic peptide on the surface of the drug-carrying liposomes enhanced the targeting and penetration efficiency for HCC. In vitro experiments on drug uptake mechanisms and release demonstrated that reactive oxygen species (ROS) generated by sonodynamic therapy (SDT) promote effective drug release from the carrier into the non-lysosomal region. The combined SDT and chemotherapy treatment achieved a 94% tumor inhibition rate and showed excellent biosafety in HCC subcutaneous tumor-bearing mice. Conclusion: Therefore, the effectiveness of the combination treatment strategy utilizing SDT in conjunction with chemotherapy provides additional treatment options for patients with HCC.