Extremely low frequency alternating magnetic field–triggered and MRI–traced drug delivery by optimized magnetic zeolitic imidazolate framework-90 nanoparticles

Abstract

An extremely low frequency alternating magnetic field of 20 Hz was proved to be able to remarkably accelerate the drug release from optimized ZIF-90 nanospheres with incorporated Fe3O4 nanoparticles acting as actuator.

Metal‐organic‐frameworks for biomedical applications in drug delivery, and as MRI contrast agents

“…The appropriate surface modifications of the MOFs can alter the bulk properties of those MOFS; can help to avoid or reduce the interaction of the MOFs with the biological medium or the unwanted healthy cells; improves the colloidal stability and the blood circulation lifetimes of the nanoparticles, and facilitates the drugs to cross the physical barriers, and to achieve a targeted drug delivery . Evidently it is found that when the MOFs were appropriately modified, these materials were not only stabilised and were prevented from their aggregation, but it also helped to achieve a selective, target‐specific drug release, and cell imaging capabilities; and these modified MOFs exhibited the successful internalisation by variety of cells through a facile endocytosis process while interacting with the cells.…”

“…When an extremely low frequency alternating magnetic field of 20 Hz was applied to these MOFs, then these MOFs showed an enhanced drug release. Although the drug loaded ZIF‐90 showed a reasonable drug release (22% of 5‐Fu was released in 1.5 h and 50% was released after 7 h) behaviour without the influence of any magnetic field, however once the external magnetic field was applied, the drug release was dramatically accelerated (50% of 5‐Fu was released in the first 1.5 h, and >80% was released after 7 h) (see Fig. ).…”

“…Apparently the MOFs were either designed in a way that facilitated to act as a MRI contrast agent or otherwise various commercially available MRI contrast agents (chelates or complexes) were incorporated or conjugated to the pre‐synthesised MOFs structure using variety of techniques. The examples are: the Gd‐containing cyano‐bridged metallic coordination polymer nanoparticles coated with chitosan (Gd 3+ /[Fe(CN) 6 ] 3− /chitosan); the Gd 3+ ‐based MOFs doped with the lanthanide ions for example, Eu 3+ or Tb 3 + 46 ; the nanoparticles of polyelectrolyte‐stabilised Gd(III) complexes; the metal cyanide containing Mn‐based MOFs coated with a biocompatible polymer; the coordination polymers between Gd 3+ ion and hexacyano‐metallate [M(CN) 6 ] n‐25 ; the Gd‐based MOFs consecutively attached to a RAFT copolymer, methotrexate drug, cell targeting ligands, and tags; the PEGylated iron containing MIL‐MOFs; the core‐shell containing PB@MIL‐100(Fe) dual metal‐organic‐frameworks (d‐MOFs); the iso‐reticular MOFs containing (IRMOF‐3) Fe 3 O 4 nanoparticles, and were consecutively conjugated to folic acid, paclitaxel drug, and rhodamine B isothiocyanate; the Fe 3 O 4 or Gd 2 O 3 nanoparticles coated with polyvinylpyrrolidone (PVP) using oleic acid followed by embedding them into the core of the ZIF‐90 MOFs; and, the Mn‐based MOFs coated with a thin silica‐shell and then functionalized with a fluorophore (rhodamine B), and a cell targeting cyclic peptide, cyclo(‐RGDfK) or cyclo(‐Arg‐Gly‐Asp‐ d ‐Phe‐Lys) [c(RGDfk)] via a grafting process …”

“…Few examples are, the Gd 3+ ‐based MOFs doped with the lanthanide ions showed their relaxivities as ( r 1 = 20.1–35.8 mM −1 s −1 and r 2 = 45.7–55.6 mM −1 s −1 ) (see Fig. ); the nanoparticles of polyelectrolyte‐stabilised Gd(III) complexes ( r 1 = 9.2–14.5 mM −1 s −1 at the magnetic fields of 0.47 T and 1.41 T); the metal cyanide containing Mn‐based MOFs ( r 1 = 7.3 mM −1 s −1 and r 2 = 204 mM −1 s −1 at 11.7 T and r 1 = 6.07 mM −1 s −1 and r 2 = 117 mM −1 s −1 at 7.0 T); the coordination polymers between the Gd 3+ ‐ion and the hexacyano‐metallate [M(CN) 6 ] n‐ showed ( r 1 = 16.8 mM −1 s −1 and r 2 = 23.9 mM −1 s −1 ); the transversal relaxivity ( r 2 ) of the MIL‐88 A, PEGylated MIL‐88A, MIL‐100, and the PEGylated MIL‐100 MOFs were ranged from 56 to 95 mM −1 s −1 where the iron content of those MOFs ranged from 0.15–0.43 mmol L −123 ; the PB@MIL‐100(Fe) d‐MOFs showed ( r 1 = 1.313 mM −1 s −1 and r 2 = 22.258 mM −1 s −1 ); the Fe 3 O 4 @IRMOF‐3 showed (saturation magnetisation = 80.46 emu g −1 and 48.87 emu g −1 ); and, the Fe 3 O 4 nanoparticles embedded into the ZIF‐90 MOFs displayed their relaxivities as ( r 1 = 4.7 mM −1 s −1 and r 2 = 133.7 mM −1 s −1 at 7T) …”

Gated Materials: Installing Macrocyclic Arenes‐Based Supramolecular Nanovalves on Porous Nanomaterials for Controlled Cargo Release

“…In the past decade, researchers have been intrigued by the hybridization between MOFs and other inorganic nanomaterials to afford multifunctional cargo delivery materials, such as magnetic core‐shell MOFs . For example, our group developed a multifunctional pillarene‐based nanovalve‐gated core‐shell hybrid nanoplatform (Fe 3 O 4 @UiO‐66) for imaging‐mediated controlled drug release, with Fe 3 O 4 nanoparticles serving as the core and UiO‐66 as the shell .…”