New insights into the degradation mechanism of metal-organic frameworks drug carriers

Abstract

A versatile method based on Raman microscopy was developed to follow the degradation of iron carboxylate Metal Organic Framework (MOF) nano- or micro-particles in simulated body fluid (phosphate buffer). The analysis of both the morphology and chemical composition of individual particles, including observation at different regions on the same particle, evidenced the formation of a sharp erosion front during particle degradation. Interestingly, this front separated an intact non eroded crystalline core from an amorphous shell made of an inorganic network. According to Mössbauer spectrometry investigations, the shell consists essentially of iron phosphates. Noteworthy, neither drug loading nor surface modification affected the integrity of the tridimensional MOF network. These findings could be of interest in the further development of next generations of MOF drug carriers.

Compartmentalized Encapsulation of Two Antibiotics in Porous Nanoparticles: an Efficient Strategy to Treat Intracellular Infections

“…In agreement with these findings, a large number of nanoMOFs were observed in phagolysosomal and endosomal compartments of noninfected cells (Figure e). After 6 h incubation, the nanoMOFs were presumably degraded inside these compartments, apparent as the NPs become blurry transparent (Figure f), a conjecture supported by previous in vitro nanoMOF degradation studies in PBS …”

Nanoparticles of Metal‐Organic Frameworks: On the Road to In Vivo Efficacy in Biomedicine

“…However, this is in contradiction with the findings of Ruyra et al who have proven that a few nanoMOFs once in contact with cell culture medium became amorphous and underwent structural rearrangements and/or reactions that generated new inorganic species, responsible for adverse effects . In a more recent study, this phenomenon has been described in detail for MIL‐100(Fe) nano‐ or microparticles, confirming the progressive formation of dense phases (iron oxide and phosphate) associated with a degradation under physiological simulated conditions …”

Bimetallic Metal Organic Frameworks as Magnetically Separable Heterogeneous Catalysts and Photocatalytic Dye Degradation

“…The bands spotted at 635, 864, 1139, 1433, and 1615 cm −1 resemble for MOF‐5 respectively . Further, the present BMOF shows specific Fe‐MIL MOF bands in its spectrum featuring at 210 and 450 to 600 cm −1 which may be attributed to crystalline iron based framework structure and lattice vibrations with network binding modes respectively . The band spotted at 1617 cm −1 could be assigned to C=C stretching mode of BDC only appears due to g parity under C i symmetry.…”