Magnetic Nanocomposite Materials Based on Fe3O4 Nanoparticles with Iron and Silica Glycerolates Shell: Synthesis and Characterization

Novel magnetic nanocomposite materials based on Fe3O4 nanoparticles coated with iron and silica glycerolates (MNP@Fe(III)Glyc and MNP@Fe(III)/SiGlyc) were obtained. The synthesized nanocomposites were characterized using TEM, XRD, TGA, VMS, Mössbauer and IR spectroscopy. The amount of iron and silica glycerolates in the nanocomposites was calculated from the Mössbauer spectroscopy, ICP AES and C,H-elemental analysis. Thus, it has been shown that the distribution of Fe in the shell and core for MNP@Fe(III)Glyc and MNP@Fe(III)/SiGlyc is 27:73 and 32:68, respectively. The synthesized nanocomposites had high specific magnetization values and a high magnetic response to the alternating magnetic field. The hydrolysis of shells based on Fe(III)Glyc and Fe(III)/SiGlyc in aqueous media has been studied. It has been demonstrated that, while the iron glycerolates shell of MNP@Fe(III)Glyc is resistant to hydrolysis, the silica glycerolates shell of MNP@Fe(III)/SiGlyc is rather labile and hydrolyzed by 76.4% in 24 h at 25 °C. The synthesized materials did not show cytotoxicity in in vitro experiments (MTT-assay). The data obtained can be used in the design of materials for controlled-release drug delivery.

Oxygen-Generating Organic/Inorganic Self-Assembled Nanocolloids for Tumor-Activated Dual-Model Imaging-Guided Photodynamic Therapy

Tumor phototheranostics is usually compromised by the hypoxic tumor microenvironment and poor theranostic efficiency. The interplay between organic polymers and inorganic nanoparticles in novel nanocomposites has proven to be advantageous, overcoming previous limitations and harnessing their full potential through activation via the tumor microenvironment. This study successfully fabricated hypoxia-activated nanocolloids called HOISNDs through a process of self-assembly involving superparamagnetic iron oxide nanoparticles (SPIONs) and an organic polymer ligand called tetrakis(4-carboxyphenyl) porphyrin (TCPP)-engineered organic polymer ligand [methoxy poly(ethyleneglycol)-block-poly(dopamine-ethylenediamine-conjugated-4-nitrobenzyl chloroformate)-l-glutamate, mPEG-b-P(Dopa-EDA-co-NBCF)LG-TCPP)]. The SPIONs act as an oxygen generator to overcome the challenges posed by hypoxic tumors and enable the use of hypoxic-activatable MR/fluorescence dual-modal imaging-guided photodynamic therapy (PDT). The colloid stability of these HOISNDs proved to be exceptional in diverse biomimetic environments. Furthermore, they not only augment T₂-weighted contrast capability as an MRI contrast agent but also function as an oxygen-producing device to amplify the generation and release of reactive oxygen species (ROS). The HOISNDs can significantly target to tumor sites through the enhanced permeability and retention (EPR) effect with prolonged blood circulation time and subsequently are effectively endocytosed into a hypoxic intracellular environment that "turn on" the imaging function and photodynamic activity. Moreover, HOISNDs possess the ability to effectively decompose naturally occurring H₂O₂ into oxygen (O₂) within the tumor utilizing the Fenton reaction. This method can mitigate the impact of hypoxia on oxygen-dependent PDT. The outcomes of in vivo diagnostic and therapeutic evaluations indicated that HOISNDs are a highly promising tool for dual-model imaging-guided cancer theranosis by ameliorating hypoxic conditions and augmenting PDT efficiency.

Magnetic Nanoparticles: Current Advances in Nanomedicine, Drug Delivery and MRI

Magnetic nanoparticles (MNPs) have evolved tremendously during recent years, in part due to the rapid expansion of nanotechnology and to their active magnetic core with a high surface-to-volume ratio, while their surface functionalization opened the door to a plethora of drug, gene and bioactive molecule immobilization. Taming the high reactivity of the magnetic core was achieved by various functionalization techniques, producing MNPs tailored for the diagnosis and treatment of cardiovascular or neurological disease, tumors and cancer. Superparamagnetic iron oxide nanoparticles (SPIONs) are established at the core of drug-delivery systems and could act as efficient agents for MFH (magnetic fluid hyperthermia). Depending on the functionalization molecule and intrinsic morphological features, MNPs now cover a broad scope which the current review aims to overview. Considering the exponential expansion of the field, the current review will be limited to roughly the past three years.