Characterization of the size and porous temperature sensitivity of Pluronic F127‒Coated MIL‒88B(Fe) for drug release

Metal-organic frameworks (MOFs) have had varied applications in the biomedical field for decades, with considerable attention on intelligence-triggered drug delivery. In this study, MIL‒88B(Fe) nanomaterials, with gas capture and good biocompatibility, were developed in a fusiform shape. For optimal drug delivery release tests, three Fe sources of MIL‒88B(Fe) were considered for comparing the crystallinity, particle size, morphology, and surface area or pore size distribution. Here, a Pluronic F127 with positive temperature sensitivity was applied during MIL‒88B(Fe) synthesis in a polytetrafluoroethylene-lined autoclave. The pyrolyzed polymer monomers, doped into the lattice during the MIL reassembly, supported the crystallinity and increased the surface area by four times. DLS was used to demonstrate the effectiveness of the changes in particle size distribution. The size distribution of F127‒MIL‒88B(Fe) was sensitive to the increase in temperature, and the size of particles decreased with increasing temperature. As the temperature increased from 25 to 37 °C, the drug release rate of F127‒MIL‒88B(Fe) doubled. The MOFs split into smaller crystals with increase in temperature, which released the drug loaded in the mesoporous frameworks. Thus, polymer-supported F127‒MIL‒88B(Fe) was synthesized with a higher drug capacity based on surface enhancement. Furthermore, a smart temperature-sensitive drug-releasing system was proposed, and it was designed with a releasing allometric kinetics model with release times of t = 0–14.5 h.