Highly chelating stellate mesoporous silica nanoparticles for specific iron removal from biological media

Abstract

In this work, the design of a new generation of functionalized large pore silica nanoparticles is addressed for the specific removal of iron from biological environments. Herein, mesoporous silica with a large pore stellate morphology, denoted STMS, were grafted with the highly specific iron chelating agent desferrioxamine B, DFoB. The challenge of this work was the step by step elaboration of the nanoplatform and the evaluation of its chelating efficiency and selectivity. Hence, the controlled covalent grafting of DFoB specific iron chelator, was successfully achieved ensuring a high grafting rate of chelating ligand of 730 nmol•mg -1 (i.e., 0.85 ligand•nm²). Furthermore, these highly chelating STMS silica were able to capture iron(III) stabilized with nitrilotriacetic acid (NTA) in solution at physiological pH with a fast kinetics (less than 30 minutes). For a stoichiometry 0.85:1 (FeNTA : DFoB), the STMS-DFoB nanoparticles allowed reaching capture capacity and efficiency of 480 nmolFe 3+ /mg SiO 2 and 78%, respectively. Regarding the selectivity features of the removal process, studies were performed with two different media composed of various metal ions: (i) an equimolar solution of various metal cations and (ii) a Barth's buffer mimicking the brain solution composition. In both cases, the chelating STMS-DFoB showed a high selectivity for iron versus other ions at the same (Al 3+ ) or different valency (Na + , K + …). Finally, this work paves the way for new nanosystems for metal overload treatments as well as for future highly chelating nanoplatforms that can be used at the interface between depollution and nanomedecine.

Protein sustained release from isobutyramide-grafted stellate mesoporous silica nanoparticles

“…The synthesis of STMS has been done as reported previously ( Bizeau et al, 2021 ; Duenas-Ramirez et al, 2020 ; Perton et al, 2019a ). Briefly, the NPs were synthesized using the sol-gel method in presence of CTATos as surfactant in order to obtain a stellate morphology, based on the work reported by Zhang et al ( Zhang et al, 2013a ).…”

“…The protocol was used as described previously ( Bizeau et al, 2021 ; Duenas-Ramirez et al, 2020 ; Perton et al, 2019a ). CTATos (3.8 g) and AHMPD (0.436 g) were introduced in a 500 mL flask with 200 mL of deionized water (dH 2 O) and stirred at 75 °C up to full dissolution (about 30 min).…”

“…15 nm especially adapted for protein dimensions ( Zhang et al, 2013a ). These STMS were shown to be easily modifiable and thus were used as bimodal imaging probes by functionalizing them with quantum dots ( Perton et al, 2019b ) or for iron removal from brain mimicking fluid by binding a deferrioxamine ligand on their surface ( Duenas-Ramirez et al, 2020 ). In these last cases, the binding was of covalent nature, but for ensuring therapeutics loading and release, the interactions between silica NPs and the drug has to be better finely tailored.…”

Serum Albumin Antifouling Effects of Hydroxypropyl‐Cellulose and Pluronic F127 Adsorbed on Isobutyramide‐Grafted Stellate Silica Nanoparticles

“…Results (Figure S2) indicate that APTES grafting accounts for 93.5 μg mg À 1 (1.9/nm 2 ) and IBAM moieties account for 131.1 μg mg À 1 (2.3/nm 2 ) which is in agreement with previous works. [5,10] Then, the adsorption of each polymer was performed with several FWRs (Equation (2)), which was defined as:…”

“…10-15 nm whose initial synthesis was described by Zhang et al [8] Such STMS were recently functionalized with various inorganic NPs (quantum dots, iron oxide) [9] for bimodal imaging combined to magnetic hyperthermia or grafted with high affinity ligand for iron removal in brain mimicking fluid. [10] However, given the strong affinity of IBAM surface observed with many proteins, and in particular serum albumin, it is anticipated that a protein corona will form around these NPs when used for biomedical application. Indeed, it is now wellknown that when NPs are introduced in a biological fluid, they interact with biomolecules and a protein corona ultimately forms at its surface.…”