Recent advances in nano-architectonics of metal-organic frameworks for chemodynamic therapy

Metal-organic frameworks as candidates for tumor sonodynamic therapy: Designable structures for targeted multifunctional transformation

Sonodynamic therapy (SDT), utilizing ultrasound (US) as the trigger, has gained popularity recently as a therapeutic approach with significant potential for treating various diseases. Metal-organic frameworks (MOFs), characterized by structural flexibility, are prominently emerging in the SDT realm as an innovative type of sonosensitizer, offering functional tunability and biocompatibility. However, due to the inherent limitations of MOFs, such as low reactivity to reactive oxygen species and challenges posed by the complex tumor microenvironment, MOF-based sonosensitizers with singular functions are unable to demonstrate the desired therapeutic efficacy and may pose risks of toxicity, limiting their biological applications to superficial tissues. MOFs generally possess distinctive crystalline structures and properties, and their controlled coordination environments provide a flexible platform for exploring structure-effect relationships and guiding the design and development of MOF-based nanomaterials to unlock their broader potential in biological fields. The primary focus of this paper is to summarize cases involving the modification of different MOF materials and the innovative strategies developed for various complex conditions. The paper outlines the diverse application areas of functionalized MOF-based sonosensitizers in tumor synergistic therapies, highlighting the extensive prospects of SDT. Additionally, challenges confronting SDT are briefly summarized to stimulate increased scientific interest in the practical application of MOFs and the successful clinical translation of SDT. Through these discussions, we strive to foster advancements that lead to early-stage clinical benefits for patients. STATEMENT OF SIGNIFICANCE: 1. An overview for the progresses in SDT explored from a novel and fundamental perspective. 2. Different modification strategies to improve the MOFs-mediated SDT efficacy are provided. 3. Guidelines for the design of multifunctional MOFs-based sonosensitizers are offered. 4. Powerful tumor ablation potential is reflected in SDT-led synergistic therapies. 5. Future challenges in the field of MOFs-based SDT in clinical translation are suggested.

Surface ligand-assisted synthesis and biomedical applications of metal-organic framework nanocomposites

Metal-organic framework (MOF) nanocomposites have recently gained intensive attention for biosensing and disease therapy applications owing to their outstanding physiochemical properties. However, the direct growth of MOF nanocomposites is usually hindered by the mismatched lattice in the interface between the MOF and other nanocomponents. Surface ligands, molecules with surfactant-like properties, are demonstrated to exhibit the robust capability to modify the interfacial properties of nanomaterials and can be utilized as a powerful strategy for the synthesis of MOF nanocomposites. Besides this, surface ligands also exhibit significant functions in the morphological control and functionalization of MOF nanocomposites, thus greatly enhancing their performance in biomedical applications. In this review, the surface ligand-assisted synthesis and biomedical applications of MOF nanocomposites are comprehensively reviewed. Firstly, the synthesis of MOF nanocomposites is discussed according to the diverse roles of surface ligands. Then, MOF nanocomposites with different properties are listed with their applications in biosensing and disease therapy. Finally, current challenges and further directions of MOF nanocomposites are presented to motivate the development of MOF nanocomposites with elaborate structures, enriched functions, and excellent application prospects.

Bibliometric and visualized analysis of metal-organic frameworks in biomedical application

Background: Metal-organic frameworks (MOFs) are hybrid materials composed of metal ions or clusters and organic ligands that spontaneously assemble via coordination bonds to create intramolecular pores, which have recently been widely used in biomedicine due to their porosity, structural, and functional diversity. They are used in biomedical applications, including biosensing, drug delivery, bioimaging, and antimicrobial activities. Our study aims to provide scholars with a comprehensive overview of the research situations, trends, and hotspots in biomedical applications of MOFs through a bibliometric analysis of publications from 2002 to 2022. Methods: On 19 January 2023, the Web of Science Core Collection was searched to review and analyze MOFs applications in the biomedical field. A total of 3,408 studies published between 2002 and 2022 were retrieved and examined, with information such as publication year, country/region, institution, author, journal, references, and keywords. Research hotspots were extracted and analyzed using the Bibliometrix R-package, VOSviewer, and CiteSpace. Results: We showed that researchers from 72 countries published articles on MOFs in biomedical applications, with China producing the most publications. The Chinese Academy of Science was the most prolific contributor to these publications among 2,209 institutions that made contributions. Reference co-citation analysis classifies references into 8 clusters: synergistic cancer therapy, efficient photodynamic therapy, metal-organic framework encapsulation, selective fluorescence, luminescent probes, drug delivery, enhanced photodynamic therapy, and metal-organic framework-based nanozymes. Keyword co-occurrence analysis divided keywords into 6 clusters: biosensors, photodynamic therapy, drug delivery, cancer therapy and bioimaging, nanoparticles, and antibacterial applications. Research frontier keywords were represented by chemodynamic therapy (2020-2022) and hydrogen peroxide (2020-2022). Conclusion: Using bibliometric methods and manual review, this review provides a systematic overview of research on MOFs in biomedical applications, filling an existing gap. The burst keyword analysis revealed that chemodynamic therapy and hydrogen peroxide are the prominent research frontiers and hot spots. MOFs can catalyze Fenton or Fenton-like reactions to generate hydroxyl radicals, making them promising materials for chemodynamic therapy. MOF-based biosensors can detect hydrogen peroxide in various biological samples for diagnosing diseases. MOFs have a wide range of research prospects for biomedical applications.

Gallium Metal-Organic Nanoparticles with Albumin-Stabilized and Loaded Graphene for Enhanced Delivery to HCT116 Cells

Background

Gallium (III) metal-organic complexes have been shown to have the ability to inhibit tumor growth, but the poor water solubility of many of the complexes precludes further application. The use of materials with high biocompatibility as drug delivery carriers for metal-organic complexes to enhance the bioavailability of the drug is a feasible approach.

Methods

Here, we modified the ligands of gallium 8-hydroxyquinolinate complex with good clinical anticancer activity by replacing the 8-hydroxyquinoline ligands with 5-bromo-8-hydroxyquinoline (HBrQ), and the resulting Ga(III) + HBrQ complex had poor water solubility. Two biocompatible materials, bovine serum albumin (BSA) and graphene oxide (GO), were used to synthesize the corresponding Ga(III) + HBrQ complex nanoparticles (NPs) BSA/Ga/HBrQ NPs and GO/Ga/HBrQ NPs in different ways to enhance the drug delivery of the metal complex.

Results

Both of BSA/Ga/HBrQ NPs and GO/Ga/HBrQ NPs can maintain stable existence in different solution states. In vitro cytotoxicity test showed that two nanomedicines had excellent anti-proliferation effect on HCT116 cells, which shown higher level of intracellular ROS and apoptosis ratio than that of cisplatin and oxaliplatin. In addition, the superior emissive properties of BSA/Ga/HBrQ NPs and GO/Ga/HBrQ NPs allow their use for in vivo imaging showing highly effective therapy in HCT116 tumor-bearing mouse models.

Conclusion

The use of biocompatible materials for the preparation of NPs against poorly biocompatible metal-organic complexes to construct drug delivery systems is a promising strategy that can further improve drug delivery and therapeutic efficacy.

Targeting Tumor Microenvironment by Metal Peroxide Nanoparticles in Cancer Therapy

Solid tumors have a unique tumor microenvironment (TME), which includes hypoxia, low acidity, and high hydrogen peroxide and glutathione (GSH) levels, among others. These unique factors, which offer favourable microenvironments and nourishment for tumor development and spread, also serve as a gateway for specific and successful cancer therapies. A good example is metal peroxide structures which have been synthesized and utilized to enhance oxygen supply and they have shown great promise in the alleviation of hypoxia. In a hypoxic environment, certain oxygen-dependent treatments such as photodynamic therapy and radiotherapy fail to respond and therefore modulating the hypoxic tumor microenvironment has been found to enhance the antitumor impact of certain drugs. Under acidic environments, the hydrogen peroxide produced by the reaction of metal peroxides with water not only induces oxidative stress but also produces additional oxygen. This is achieved since hydrogen peroxide acts as a reactive substrate for molecules such as catalyse enzymes, alleviating tumor hypoxia observed in the tumor microenvironment. Metal ions released in the process can also offer distinct bioactivity in their own right. Metal peroxides used in anticancer therapy are a rapidly evolving field, and there is good evidence that they are a good option for regulating the tumor microenvironment in cancer therapy. In this regard, the synthesis and mechanisms behind the successful application of metal peroxides to specifically target the tumor microenvironment are highlighted in this review. Various characteristics of TME such as angiogenesis, inflammation, hypoxia, acidity levels, and metal ion homeostasis are addressed in this regard, together with certain forms of synergistic combination treatments.

Lanthanum-based metal organic framework (La-MOF) use of 3,4-dihydroxycinnamic acid as drug delivery system linkers in human breast cancer therapy

Metal organic frameworks (MOFs) have received a lot of attention in the research community due to their unique physical properties, which make them ideal materials for targeted drug delivery systems. In this paper, we describe the synthesis of a non-toxic La-based MOF with 3,4-dihydroxycinnamic acid (3,4-DHCA) as a linker. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), nitrogen adsorption–desorption measurements, and X-ray powder diffraction (XRD) have all been used to characterize it thoroughly. The La-based MOF showed good biocompatibility with the human breast cancer cell line MDA-MB-468. The ability of 3,4-DHCA to treat MDA-MB-468 cells was confirmed by 40.35% cell viability with La-based MOF. Based on the findings, La-based MOF can be recommended as a promising candidate for anticancer delivery.

Recent advances in the electrochemical applications of Ni-based metal organic frameworks (Ni-MOFs) and their derivatives

Nickel-based metal-organic skeletal materials (Ni-MOFs) are a new class of inorganic materials that have aroused attention of investigators during past couple of years. They offer advantages such as high specific surface area, structural diversity, tunable framework etc. This assorted class of materials exhibited catalytic activity and electrochemical properties and display wide range of applications in the fields of electrochemical sensing, electrical energy storage and electrocatalysis. In this context, the presented review focuses on strategies to improve the electrochemical performance and stability of Ni-MOFs through the optimization of synthesis conditions, the construction of composite materials, and the preparation of derivatives of precursors. The review also presents the applications of Ni-MOFs and their derivatives as electrochemical sensors, energy storage devices, and electrocatalysts. In addition, the challenges and further electrochemical development prospects of Ni-MOFs have been discussed.

Recent advances of the core-shell MOFs in tumour therapy

Coordination chemistry has always been vital to explore the material prominence of metal-organic systems. The metal-organic chemistry plays a fundamental role in decisive structural features, which are accountable for tuning the properties of materials. Tumour therapy has become an important research field of medical treatment in the world. Metal-organic frameworks (MOFs) have attracted extensive interest in medical science research due to their large effective surface area, clear pore network, and critical catalytic performance. Compared with traditional MOF materials, MOF materials with core-shell structures have a higher loading rate and better stability, which can overcome a single function. They have been successfully used in tumour medical research and have excellent prospects for diagnosing and treating various tumours. The current review article thoroughly describes the various synthetic approaches for engineering core-shell MOF materials, the structural types, and the potential functional applications. We also discussed core-shell MOF materials for the various treatment of tumours, such as tumour chemotherapy, tumour phototherapy and tumour microenvironment anti-hypoxia therapy. In this paper, the synthesized procedures of core-shell MOFs and their applications for tumour treatment have been discussed, and their future research has prospected. The current improved strategies, challenges, and prospects are also presented because of the metal-organic chemistry governing the structural modification of core-shell MOFs for tumour therapy applications. Therefore, the present review article opens a new door for medicinal chemists to tune the structural features of the core-shell MOF materials to modulate tumour therapy with simple, low-cost materials for better human lives.

Recent advances in Ti-based MOFs in biomedical applications

Currently, metal-organic frameworks (MOFs), basically inorganic-organic hybrid materials, have gained tremendous attention due to their vast applications. MOFs have shown enormous applications in almost every research field. However, the area of designing MOF materials for their biological applications is still an emerging field that needs attention. Titanium-based metal-organic framework (Ti-MOF) materials are used in many research areas due to their structural advantages, such as small particle size and large effective surface area. On the other hand, they have also shown unique advantages such as good biocompatibility, excellent catalytic oxidation and photocatalytic properties and ease of functionalization. This study reviews the recent research progress on Ti-MOFs in therapeutic areas such as antibacterial, oncology, anti-inflammation, and bone injury, which will provide new directions for further research in this biomedical field. Therefore, this article will help scientists working in the particular field to enhance their understanding of Ti-based MOFs for functional biomedical applications.

Construction strategies to modulate the photocatalytic efficiency of Cd(ii) MOFs to photodegrade organic dyes

Two new tuned 3D Cd(ii) MOFs were synthesized and used as photocatalysts for dye degradation.

A new 3D 8-connected Cd(ii) MOF as a potent photocatalyst for oxytetracycline antibiotic degradation

1 exhibits the best photocatalytic decomposition efficiency towards antibiotic OXY. The plausible photocatalytic mechanism has been explained with the help of the density of states calculations and Hirshfeld surface analysis.