Nanoscale MOFs in nanomedicine applications: from drug delivery to therapeutic agents

Metal-organic frameworks (MOFs) hold great promise for widespread applications in biomedicine and nanomedicine. MOFs are one of the most fascinating nanocarriers for drug delivery, benefiting from their high porosity and facile modification. Furthermore, the tailored components of MOFs can be therapeutic agents for various treatments, including drugs as organic ligands of MOFs, active metal as central metal ions of MOFs, and their combinations as carrier-free MOF-based nanodrug. In this review, the advances in delivery systems and applications as therapeutic agents for nanoscale MOF-based materials are summarized. The challenges of MOFs in clinical translation and the future directions in the field of MOFs therapy are also discussed. We hope that more researchers will focus their attention on advancing and translating MOF-based nanodrugs into pre-clinical and clinical applications.

Biomolecule-Based Optical Metamaterials: Design and Applications

Metamaterials are broadly defined as artificial, electromagnetically homogeneous structures that exhibit unusual physical properties that are not present in nature. They possess extraordinary capabilities to bend electromagnetic waves. Their size, shape and composition can be engineered to modify their characteristics, such as iridescence, color shift, absorbance at different wavelengths, etc., and harness them as biosensors. Metamaterial construction from biological sources such as carbohydrates, proteins and nucleic acids represents a low-cost alternative, rendering high quantities and yields. In addition, the malleability of these biomaterials makes it possible to fabricate an endless number of structured materials such as composited nanoparticles, biofilms, nanofibers, quantum dots, and many others, with very specific, invaluable and tremendously useful optical characteristics. The intrinsic characteristics observed in biomaterials make them suitable for biomedical applications. This review addresses the optical characteristics of metamaterials obtained from the major macromolecules found in nature: carbohydrates, proteins and DNA, highlighting their biosensor field use, and pointing out their physical properties and production paths.

Proton-conducting metal–organic frameworks with linkers containing anthracenyl and sulfonate groups

Co(dia)1.5(Hsip)(H2O)·H2O (1) and Zn2(μ-OH)(dia)2(sip)·2H2O (2) were prepared from the same set of ligand precursors. They exhibited bnn and dia topologies, respectively. Factors that contributed to the higher proton conductivity of 1 were presented.

Sustainable solid form screening: mechanochemical control over nucleobase hydrogen-bonded organic framework polymorphism

The choice is yours! Liquid-assisted grinding can be used to control HOF polymorphism.

7-Connected FeIII3-Based Bio-MOF: Pore Space Partition and Gas Separations

We reported herein a new 3D bio-MOF (NbU-12) using a pore space partition strategy: MIL-88D was selected as a primary framework, and adenine connected two independent MIL-88D to form a self-interpenetrated structure. Because of this, the hexagonal channel in MIL-88D split into two small rectangular channels. Different from the reported series CPM-35 materials, NbU-12 simultaneously maximized the retention of open metal sites from MIL-88D and introduced a Watson-Crick face to the pore surface of NbU-12. Remarkably, NbU-12 exhibits an excellent selectivity performance toward C₂H₆/C₂H₄ and C₂H₆/CH₄, which was proven by ideal adsorbed solution theory calculation and breakthrough experiments.

The rise of metal-organic polyhedra

Metal-organic polyhedra are a member of metal-organic materials, and are together with metal-organic frameworks utilized as emerging porous platforms for numerous applications in energy- and bio-related sciences. However, metal-organic polyhedra have been significantly underexplored, unlike their metal-organic framework counterparts. In this review, we will cover the topologies and the classification of metal-organic polyhedra and share several suggestions, which might be useful to synthetic chemists regarding the future directions in this rapid-growing field.

A twofold interpenetrating two-dimensional zinc(II) coordination polymer: synthesis, crystal structure and physical properties

A novel twofold interpenetrating two-dimensional (2D) Zn^II coordination framework, poly[[(μ-1,3-bis(2-methyl-1H-imidazol-1-yl)benzene-κ²N³:N³)(μ-naphthalene-2,6-dicarboxylato-κ²O²:O⁶)zinc(II)] dimethylformamide monosolvate], {[Zn(C₁₂H₆O₄)(C₁₄H₁₄N₄)]·C₃H₇NO}_n or {[Zn(1,3-BMIB)(NDC)]·DMF}_n (I), where H₂NDC is naphthalene-2,6-dicarboxylic acid, 1,3-BMIB is 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene and DMF is dimethylformamide, was prepared and characterized through IR spectroscopy, elemental analysis, thermal analysis and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analysis revealed that (I) exhibits an unusual twofold interpenetrating 2D network. In addition, it displays strong fluorescence emissions and a high photocatalytic activity for the degradation of Rhodamine B (RhB) under UV-light irradiation.

Metal-Organic Framework Nanocarriers for Drug Delivery in Biomedical Applications

Investigation of metal-organic frameworks (MOFs) for biomedical applications has attracted much attention in recent years. MOFs are regarded as a promising class of nanocarriers for drug delivery owing to well-defined structure, ultrahigh surface area and porosity, tunable pore size, and easy chemical functionalization. In this review, the unique properties of MOFs and their advantages as nanocarriers for drug delivery in biomedical applications were discussed in the first section. Then, state-of-the-art strategies to functionalize MOFs with therapeutic agents were summarized, including surface adsorption, pore encapsulation, covalent binding, and functional molecules as building blocks. In the third section, the most recent biological applications of MOFs for intracellular delivery of drugs, proteins, and nucleic acids, especially aptamers, were presented. Finally, challenges and prospects were comprehensively discussed to provide context for future development of MOFs as efficient drug delivery systems.

Engineering of Nanoscale Coordination Polymers with Biomolecules for Advanced Applications

Nanoscale coordination polymers (NCPs) have shown extraordinary advantages in various research areas due to their structural diversity and multifunctionality. Recently, integration of biomolecules with NCPs received extensive attention and the formed hybrid materials exhibit superior properties over the individual NCPs or biomolecules. In this review, the state-of-the-art of approaches to engineer NCPs with different types of guest biomolecules, such as amino acids, nucleic acids, enzymes and lipids are systematically introduced. Additionally, advanced applications of these biomolecule-NCP composites in the areas of sensing, catalysis, molecular imaging and therapy are thoroughly summarized. Finally, current challenges and prospects are also discussed.

Metal organic frameworks based on bioactive components

This review highlights the latest advances of Metal Organic Frameworks (MOFs) in the promising biomedical domain, from their synthesis to their biorelated activities.

Self-assembly of two supramolecular indium(iii) metal–organic frameworks for reversible iodine capture and large band gap change semiconductor behavior

Conjunction of benzimidazole and metal In(iii) to construct supramolecular MOFs opens up an ingenious direction for synthesizing materials with multi-functionality.

Synthesis, structure and properties of an octahedral dinuclear-based Cu12 nanocage of trimesoyltri(l-alanine)

We report here a Mo₆C1₈⁴⁺-like dinuclear-based octahedral nanocage, presenting antiferromagnetic interactions between the Cu(ii) ions and nice selectivity on gas adsorption.

Hydrothermal syntheses, structural characterizations, and magnetic properties of five MOFs assembled from C2-symmetric ligand of 1,3-di(2′,4′-dicarboxylphenyl)benzene with various coordination modes

Five new complexes with appealing structural features from 0D paddle wheel {Cu₂(COO)₄} SBUs to 3D frameworks were reported to better understand the synthon selectivity in multifunctional crystal structures.

Structural diversities and related properties of four coordination polymers synthesized from original ligand of 3,3′,5,5′-azobenzenetetracarboxylic acid

Four CPs, derived from the original 3,3′,5,5′-azobenzenetetracarboxylic acid ligand were obtained under solvothermal conditions.

Metal–organic molecular cages: applications of biochemical implications

New well-designed materials are highly demanded with the prospect of versatile properties, offering successful applications as alternates to conventional materials.

Syntheses, structures, topologies, and luminescence properties of four coordination polymers based on bifunctional 6-(4-pyridyl)-terephthalic acid and bis(imidazole) bridging linkers

Four CPs, with the structure ranged from 2D sheet to 3D 3-fold penetrated net, have been designed with the mixed-ligand strategy of bifunctional 6-(4-pyridyl)-terephthalic acid and bis(imidazole) bridging linkers.

Increasing the Stability of Metal-Organic Frameworks

Metal-organic frameworks (MOFs) are a new category of advanced porous materials undergoing study by many researchers for their vast variety of both novel structures and potentially useful properties arising from them. Their high porosities, tunable structures, and convenient process of introducing both customizable functional groups and unsaturated metal centers have afforded excellent gas sorption and separation ability, catalytic activity, luminescent properties, and more. However, the robustness and reactivity of a given framework are largely dependent on its metal-ligand interactions, where the metal-containing clusters are often vulnerable to ligand substitution by water or other nucleophiles, meaning that the frameworks may collapse upon exposure even to moist air. Other frameworks may collapse upon thermal or vacuum treatment or simply over time. This instability limits the practical uses of many MOFs. In order to further enhance the stability of the framework, many different approaches, such as the utilization of high-valence metal ions or nitrogen-donor ligands, were recently investigated. This review details the efforts of both our research group and others to synthesize MOFs possessing drastically increased chemical and thermal stability, in addition to exemplary performance for catalysis, gas sorption, and separation.

Structural diversity and magnetic properties of six metal–organic polymers based on semirigid tricarboxylate ligand of 3,5-bi(4-carboxyphenoxy)benzoic acid

Six new metal–organic complexes with structural diversities constructed from 3,5-bi(4-carboxyphenoxy)benzoic acid and metal ions were synthesized and characterized.

Rational design of metal–organic frameworks with anticipated porosities and functionalities

This highlight review will outline the recent advances on rational design of MOFs from both our and other groups based on their structure–property relationships, and provide a systematic overview of different methods for rational design of MOFs with desired porosities and functionalities.

Syntheses, structures, and luminescence properties of four metal–organic polymers with undocumented topologies constructed from 3,5-bis((4′-carboxylbenzyl)oxy)benzoate ligand

Four 3D metal–organic polymers with new topologies based on 3,5-bis((4′-carboxylbenzyl)oxy)benzoic acid were synthesized and characterized.

Syntheses, structures, and magnetic properties of six coordination polymers based on 4,5-di(4′-carboxylphenyl)phthalic acid and different bis(imidazole) bridging linkers

Six multi-dimensional metal–organic polymers based on 4,5-di(4′-carboxylphenyl)phthalic acid and bis(imidazole) bridging linkers were synthesized and characterized.