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A "green" strategy to construct non-covalent, stable and bioactive coatings on porous MOF nanoparticles.

Agostoni V, Horcajada P, Noiray M, Malanga M, Aykaç A, Jicsinszky L, Vargas-Berenguel A, Semiramoth N, Daoud-Mahammed S, Nicolas V, Martineau C, Taulelle F, Vigneron J, Etcheberry A, Serre C, Gref R - Sci Rep (2015)

Bottom Line: Here we bring the proof of concept that the outer surface of porous nanoMOFs can be specifically functionalized in a rapid, biofriendly and non-covalent manner, leading to stable and versatile coatings.The coating procedure did not affect the nanoMOF porosity, crystallinity, adsorption and release abilities.The stable cyclodextrin-based coating was further functionalized with: i) targeting moieties to increase the nanoMOF interaction with specific receptors and ii) poly(ethylene glycol) chains to escape the immune system.

View Article: PubMed Central - PubMed

Affiliation: Institut Galien, Université Paris-Sud, UMR CNRS 8612, 92290 Chatenay Malabry, France.

ABSTRACT
Nanoparticles made of metal-organic frameworks (nanoMOFs) attract a growing interest in gas storage, separation, catalysis, sensing and more recently, biomedicine. Achieving stable, versatile coatings on highly porous nanoMOFs without altering their ability to adsorb molecules of interest represents today a major challenge. Here we bring the proof of concept that the outer surface of porous nanoMOFs can be specifically functionalized in a rapid, biofriendly and non-covalent manner, leading to stable and versatile coatings. Cyclodextrin molecules bearing strong iron complexing groups (phosphates) were firmly anchored to the nanoMOFs' surface, within only a few minutes, simply by incubation with aqueous nanoMOF suspensions. The coating procedure did not affect the nanoMOF porosity, crystallinity, adsorption and release abilities. The stable cyclodextrin-based coating was further functionalized with: i) targeting moieties to increase the nanoMOF interaction with specific receptors and ii) poly(ethylene glycol) chains to escape the immune system. These results pave the way towards the design of surface-engineered nanoMOFs of interest for applications in the field of targeted drug delivery, catalysis, separation and sensing.

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Related in: MedlinePlus

Schematic representation of nanoMOFs “green” synthesis, drug loading and surface modification procedures.(a) NanoMOFs formed by spontaneous coordination between Fe(III) trimers and trimesic acid into hybrid supertetrahedra which further assemble giving rise to a porous zeotypic architecture. Two different types of mesoporous cages delimited by microporous windows are present in this structure: small cages (25 Å) simplified as dodecahedrons with 12 pentagonal faces (openings 5.6 Å) and large cages (29 Å) symbolized as polyhedra consisting of 12 pentagonal and 4 hexagonal faces (openings 8.6 Å). Drug loading can be achieved simply by soaking in aqueous solution. (b) Drug molecules provided with suitable size can be absorbed within the porous core interacting with the nanoparticles matrix by non covalent links with the organic linkers or/and with the Lewis acid Fe(III) sites. (c) Due to their phosphate groups, CD-P strongly interact with the nanoMOFs by coordination with the available Fe(III) sites at the surface, but cannot penetrate inside the matrix because they are too bulky to cross the nanoparticles microporous windows. (d) Coating materials able to penetrate within the MOF porosity can lead to uncontrolled drug release.
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f1: Schematic representation of nanoMOFs “green” synthesis, drug loading and surface modification procedures.(a) NanoMOFs formed by spontaneous coordination between Fe(III) trimers and trimesic acid into hybrid supertetrahedra which further assemble giving rise to a porous zeotypic architecture. Two different types of mesoporous cages delimited by microporous windows are present in this structure: small cages (25 Å) simplified as dodecahedrons with 12 pentagonal faces (openings 5.6 Å) and large cages (29 Å) symbolized as polyhedra consisting of 12 pentagonal and 4 hexagonal faces (openings 8.6 Å). Drug loading can be achieved simply by soaking in aqueous solution. (b) Drug molecules provided with suitable size can be absorbed within the porous core interacting with the nanoparticles matrix by non covalent links with the organic linkers or/and with the Lewis acid Fe(III) sites. (c) Due to their phosphate groups, CD-P strongly interact with the nanoMOFs by coordination with the available Fe(III) sites at the surface, but cannot penetrate inside the matrix because they are too bulky to cross the nanoparticles microporous windows. (d) Coating materials able to penetrate within the MOF porosity can lead to uncontrolled drug release.

Mentions: To achieve these goals, biodegradable nanoMOFs were synthesis here by a “green” microwave assisted hydrothermal method. The non-toxic mesoporous iron(III) carboxylate MIL-100(Fe) (MIL standing for Material from Institute Lavoisier) nanoMOFs are built up from iron(III) octahedra trimers and trimesate linkers (1,3,5 benzene tricarboxylate) that self-assemble to build a porous architecture delimiting large (29 Å) and small (24 Å) mesoporous cages (Fig.1a). The two types of cages are accessible through microporous pentagonal (5.6 Å) or hexagonal windows (8.6 Å)37. Drug loading was typically achieved by soaking the nanoMOFs in solutions of drugs, leading to rapid adsorption of the active molecules within the pores (Fig. 1b). Drugs such as azidothymidine-triphosphate (AZT-TP), the active form of AZT, possessing polar complexing groups, bind eventually the coordinatively unsaturated iron Lewis acid sites (CUS), leading to almost perfect (>99%) encapsulation efficiencies, high payloads and controlled release24.


A "green" strategy to construct non-covalent, stable and bioactive coatings on porous MOF nanoparticles.

Agostoni V, Horcajada P, Noiray M, Malanga M, Aykaç A, Jicsinszky L, Vargas-Berenguel A, Semiramoth N, Daoud-Mahammed S, Nicolas V, Martineau C, Taulelle F, Vigneron J, Etcheberry A, Serre C, Gref R - Sci Rep (2015)

Schematic representation of nanoMOFs “green” synthesis, drug loading and surface modification procedures.(a) NanoMOFs formed by spontaneous coordination between Fe(III) trimers and trimesic acid into hybrid supertetrahedra which further assemble giving rise to a porous zeotypic architecture. Two different types of mesoporous cages delimited by microporous windows are present in this structure: small cages (25 Å) simplified as dodecahedrons with 12 pentagonal faces (openings 5.6 Å) and large cages (29 Å) symbolized as polyhedra consisting of 12 pentagonal and 4 hexagonal faces (openings 8.6 Å). Drug loading can be achieved simply by soaking in aqueous solution. (b) Drug molecules provided with suitable size can be absorbed within the porous core interacting with the nanoparticles matrix by non covalent links with the organic linkers or/and with the Lewis acid Fe(III) sites. (c) Due to their phosphate groups, CD-P strongly interact with the nanoMOFs by coordination with the available Fe(III) sites at the surface, but cannot penetrate inside the matrix because they are too bulky to cross the nanoparticles microporous windows. (d) Coating materials able to penetrate within the MOF porosity can lead to uncontrolled drug release.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4300503&req=5

f1: Schematic representation of nanoMOFs “green” synthesis, drug loading and surface modification procedures.(a) NanoMOFs formed by spontaneous coordination between Fe(III) trimers and trimesic acid into hybrid supertetrahedra which further assemble giving rise to a porous zeotypic architecture. Two different types of mesoporous cages delimited by microporous windows are present in this structure: small cages (25 Å) simplified as dodecahedrons with 12 pentagonal faces (openings 5.6 Å) and large cages (29 Å) symbolized as polyhedra consisting of 12 pentagonal and 4 hexagonal faces (openings 8.6 Å). Drug loading can be achieved simply by soaking in aqueous solution. (b) Drug molecules provided with suitable size can be absorbed within the porous core interacting with the nanoparticles matrix by non covalent links with the organic linkers or/and with the Lewis acid Fe(III) sites. (c) Due to their phosphate groups, CD-P strongly interact with the nanoMOFs by coordination with the available Fe(III) sites at the surface, but cannot penetrate inside the matrix because they are too bulky to cross the nanoparticles microporous windows. (d) Coating materials able to penetrate within the MOF porosity can lead to uncontrolled drug release.
Mentions: To achieve these goals, biodegradable nanoMOFs were synthesis here by a “green” microwave assisted hydrothermal method. The non-toxic mesoporous iron(III) carboxylate MIL-100(Fe) (MIL standing for Material from Institute Lavoisier) nanoMOFs are built up from iron(III) octahedra trimers and trimesate linkers (1,3,5 benzene tricarboxylate) that self-assemble to build a porous architecture delimiting large (29 Å) and small (24 Å) mesoporous cages (Fig.1a). The two types of cages are accessible through microporous pentagonal (5.6 Å) or hexagonal windows (8.6 Å)37. Drug loading was typically achieved by soaking the nanoMOFs in solutions of drugs, leading to rapid adsorption of the active molecules within the pores (Fig. 1b). Drugs such as azidothymidine-triphosphate (AZT-TP), the active form of AZT, possessing polar complexing groups, bind eventually the coordinatively unsaturated iron Lewis acid sites (CUS), leading to almost perfect (>99%) encapsulation efficiencies, high payloads and controlled release24.

Bottom Line: Here we bring the proof of concept that the outer surface of porous nanoMOFs can be specifically functionalized in a rapid, biofriendly and non-covalent manner, leading to stable and versatile coatings.The coating procedure did not affect the nanoMOF porosity, crystallinity, adsorption and release abilities.The stable cyclodextrin-based coating was further functionalized with: i) targeting moieties to increase the nanoMOF interaction with specific receptors and ii) poly(ethylene glycol) chains to escape the immune system.

View Article: PubMed Central - PubMed

Affiliation: Institut Galien, Université Paris-Sud, UMR CNRS 8612, 92290 Chatenay Malabry, France.

ABSTRACT
Nanoparticles made of metal-organic frameworks (nanoMOFs) attract a growing interest in gas storage, separation, catalysis, sensing and more recently, biomedicine. Achieving stable, versatile coatings on highly porous nanoMOFs without altering their ability to adsorb molecules of interest represents today a major challenge. Here we bring the proof of concept that the outer surface of porous nanoMOFs can be specifically functionalized in a rapid, biofriendly and non-covalent manner, leading to stable and versatile coatings. Cyclodextrin molecules bearing strong iron complexing groups (phosphates) were firmly anchored to the nanoMOFs' surface, within only a few minutes, simply by incubation with aqueous nanoMOF suspensions. The coating procedure did not affect the nanoMOF porosity, crystallinity, adsorption and release abilities. The stable cyclodextrin-based coating was further functionalized with: i) targeting moieties to increase the nanoMOF interaction with specific receptors and ii) poly(ethylene glycol) chains to escape the immune system. These results pave the way towards the design of surface-engineered nanoMOFs of interest for applications in the field of targeted drug delivery, catalysis, separation and sensing.

Show MeSH
Related in: MedlinePlus