Tuning the Morphological Appearance of Iron(III) Fumarate: Impact on Material Characteristics and Biocompatibility

Abstract

Iron(III) fumarate materials are well suited for biomedical applications as they feature biocompatible building blocks, porosity, chemical functionalizability, and magnetic resonance imaging (MRI) activity. The synthesis of these materials however is difficult to control and it has been challenging to produce monodisperse particle sizes and morphologies that are required in medical use. Here, we report the optimization of iron(III) fumarate nano and microparticles synthesis by surfactant-free methods, including room temperature, solvothermal, microwave, and microfluidic conditions. Four variants of iron(III) fumarate with distinct morphologies were isolated and are characterized in detail. Structural characterization shows that all iron(III) fumarate variants exhibit the metal-organic framework (MOF) structure of MIL-88A. Nanoparticles with a diameter of 50 nm were produced, which contain crystalline areas not exceeding 5 nm. Solvent-dependent swelling of the crystalline particles was monitored using in-situ X-ray diffraction. Cytotoxicity experiments showed that all iron(III) fumarate variants feature adequate bio-tolerability and no distinct interference with cellular metabolism at low concentrations. Magnetic resonance relaxivity studies using clinical MRI equipment, on the other hand, proved that the MRI contrast characteristics depend on particle size and morphology. All in all, this study demonstrates the possibility of tuning the morphological appearance of iron(III) fumarate particles and illustrates the importance of optimizing synthesis conditions for the development of new biomedical materials.

Single Crystals Heterogeneity Impacts the Intrinsic and Extrinsic Properties of Metal–Organic Frameworks

“…We draw our attention to MIL-88A since it is frequently employed for applications including drug delivery, [19] sensing, [20] and photocatalysis, [21] but also synthesized in a large variety of different morphologies. [22] We exploited the label-free modalities of our microscope in combination with spatially resolved spectroscopy since the quenching behavior of the iron centers in MIL-88A renders fluorescence-based single-particle studies challenging.…”

From Molecules to Frameworks to Superframework Crystals

“…To use these crystals as building blocks for the next-level augmentation, a control over their size and shape is critical, and significant progress has been made. [22][23][24][25]…”

Beyond Frameworks: Structuring Reticular Materials across Nano‐, Meso‐, and Bulk Regimes

“…[96] Modulators can also be used to control the facets present on the nanoparticles,a nd tuning the modulator type and concentration can yield objects with increasing size and morphologies ranging from nanoparticles to 1D or 2D meso-objects. [97] Similar to molecular systems,t he purification and recycling of colloidal dispersions of reticular materials is possible through techniques such as centrifugation, dialysis,a nd filtration, which effectively remove excess reactants,g uests, and reaction products after catalytic reactions.T hese separation methods can also be applied to purify framework nanoparticles according to their sizes and functionalities. Figure 5.…”