Covalent organic frameworks (COFs) are a class of organic crystalline porous materials discovered in the early 21st century that have become an attractive class of emerging materials due to their ...high crystallinity, intrinsic porosity, structural regularity, diverse functionality, design flexibility, and outstanding stability. However, many chemical and physical properties strongly depend on the presence of metal ions in materials for advanced applications, but metal-free COFs do not have these properties and are therefore excluded from such applications. Metalated COFs formed by combining COFs with metal ions, while retaining the advantages of COFs, have additional intriguing properties and applications, and have attracted considerable attention over the past decade. This review presents all aspects of metalated COFs, from synthetic strategies to various applications, in the hope of promoting the continued development of this young field.
This review highlights the recent advances of metalated covalent organic frameworks, including synthetic strategies and applications, and discusses the current challenges and future directions.
As newly emerged crystalline porous materials, covalent organic frameworks (COFs) possess fascinating structures and some specific features such as modularity, crystallinity, porosity, stability, ...versatility, and biocompatibility. Besides adsorption/separation, sensing, catalysis, and energy applications, COFs have recently shown a promise in biomedical applications. This contribution provides an overview of the recent developments of COF‐based medicines in cancer therapeutics, including drug delivery, photodynamic therapy (PDT), photothermal therapy (PTT), and combined therapy. Furthermore, the major challenges and developing trends in this field are also discussed. These recent developments are summarized and discussed to help encourage further contributions in this emerging and promising field.
Magic bullet: In this minireview, recent advances in the field of covalent organic frameworks (COFs) for cancer therapeutic applications are highlighted, including those for drug delivery, phototherapy, and combined therapy.
Ca2+, a ubiquitous but nuanced modulator of cellular physiology, is meticulously controlled intracellularly. However, intracellular Ca2+ regulation, such as mitochondrial Ca2+ buffering capacity, can ...be disrupted by 1O2. Thus, the intracellular Ca2+ overload, which is recognized as one of the important cell pro‐death factors, can be logically achieved by the synergism of 1O2 with exogenous Ca2+ delivery. Reported herein is a nanoscale covalent organic framework (NCOF)‐based nanoagent, namely CaCO3@COF‐BODIPY‐2I@GAG (4), which is embedded with CaCO3 nanoparticle (NP) and surface‐decorated with BODIPY‐2I as photosensitizer (PS) and glycosaminoglycan (GAG) targeting agent for CD44 receptors on digestive tract tumor cells. Under illumination, the light‐triggered 1O2 not only kills the tumor cells directly, but also leads to their mitochondrial dysfunction and Ca2+ overload. An enhanced antitumor efficiency is achieved via photodynamic therapy (PDT) and Ca2+ overload synergistic therapy.
A multifunctional COF‐based nanoagent, which is equipped with BODIPY‐2I photosensitizer, CaCO3 nanoparticle, and glycosaminoglycan (GAG) targeting agent, can be a highly efficient and selective antitumor nanomedicine for colon tumor via photodynamic therapy (PDT) and Ca2+ overload synergistic therapy.
Chemodynamic therapy (CDT), which induces cell death by decomposing high levels of H2O2 in tumor cells into highly toxic ·OH, is recognized as a promising antineoplastic approach. However, current ...CDT approaches are often restricted by the highly controlled and upregulated cellular antioxidant defense. To enhance ·OH‐induced cellular damage by CDT, a covalent organic framework (COF)‐based, ferrocene (Fc)‐ and glutathione peroxidase 4 (GPX4) inhibitor‐loaded nanodrug, RSL3@COF–Fc (2b), is fabricated. The obtained 2b not only promotes in situ Fenton‐like reactions to trigger ·OH production in cells, but also attenuates the repair mechanisms under oxidative stress via irreversible covalent GPX4 inhibition. As a result, these two approaches synergistically result in massive lipid peroxide accumulation, subsequent cell damage, and ultimately ferroptosis, while not being limited by intracellular glutathione. It is believed that this research provides a paradigm for enhancing reactive oxygen species‐mediated oncotherapy through redox dyshomeostasis and may provide new insights for developing COF‐based nanomedicine.
Versatile covalent organic frameworks (COFs)! The organic nanodrug RSL3@COF–Fc (2b), which integrates the glutathione peroxidase 4 inhibitor RSL3 and Fenton‐like reaction catalyst ferrocene (Fc) into a nanoscale COF, induces ferroptosis to enhance chemodynamic therapy by blocking lipid repair and disrupting cellular redox homeostasis.
Covalent organic frameworks (COFs), as a new emerging class of highly crystalline advanced porous materials with fascinating structural tunability and diversity as well as the desired semiconductor ...properties, have gained significant attention as highly promising and efficient photocatalysts or designer platforms for a variety of photocatalytic applications in recent years; thus a comprehensive review is timely to summarize the advances of this field. In this review, a background and brief timeline concerning the developments and key achievements of COFs are provided. Afterwards, a systematic overview of the potential photocatalytic applications realized to date in the fast growing field of COFs is provided with the aim of presenting a full blueprint of COFs for possible photochemical energy conversion and reactions. Finally, the challenges remaining and personal perspectives on further development of this type of material for photocatalysis are presented.
In this review, a comprehensive summary of the potential photocatalytic applications realized to date in the fast-growing field of COFs is provided with the aim to present a full blueprint of COFs for photochemical energy conversion and reactions.
A general and efficient organocatalytic asymmetric polymerization approach for the synthesis of chiral covalent organic frameworks (CCOFs) has been developed. With a chiral 2‐methylpyrrolidine ...catalyst, a series of tris(N‐salicylideneamine)‐derived β‐ketoenamine‐CCOFs are directly constructed from prochiral aldehyde‐ and primary amine‐monomers. The adopted aminocatalytic asymmetric Schiff‐base condensation herein is performed under ambient conditions with clear green synthetic advantages over the conventional acid‐catalysed solvothermal methods. The obtained β‐ketoenamine‐CCOFs can be further metalated by a solid‐state coordination approach, and the resulting CuII@CCOFs can highly promote an asymmetric A3‐coupling reaction. Specifically, a CuII@CCOF@chitosan aerogel was fabricated as a highly efficient fixed‐bed model reactor for scaled‐up catalysis. The concept of aminocatalytic asymmetric polymerization might open a new way for constructing the CCOFs via asymmetric organocatalysis.
A new and general organocatalytic asymmetric polymerization approach for the chiral covalent organic framework (CCOF) synthesis under ambient conditions is presented. The metalated CCOF can be further shaped into a fixed‐bed reactor by incorporation with ecofriendly and low‐cost chitosan to realize the scaled‐up catalytic asymmetric A3‐coupling reaction in a green and facile way.
For seeking high enantiopurity, the previously reported thermal asymmetric catalysis is usually carried out at low temperature sometimes with limited yield, that is, the high enantiomeric excess (ee) ...usually at the cost of high yield. Thus, the achieving both high stereoselectivity and yield is an enormous challenge. We report herein two metal nanoparticle (M NP)-loaded and porphyrin-containing homochiral covalent organic framework (CCOF)-based composite catalysts, and their application in the thermally-driven asymmetric one-pot Henry and A
-coupling reactions. All the reactions are conducted at elevated temperatures with both excellent stereoselectivity and yield which resulted from the synergy of CCOF confinement effect and M NP catalytic activation. Notably, the needed thermal energy for the asymmetric reactions herein is derived from the photothermal conversion via porphyrin-based CCOF upon irradiation with visible light. Remarkably, the CCOF confinement effect can be effectively maintained up to 100 °C for the asymmetric one-pot Henry and A
-coupling reactions herein.
Direct synthesis, postsynthetic modification, and chiral induction have been recognized as three powerful methods to synthesize chiral covalent organic frameworks (CCOFs). However, catalytic ...asymmetric methodology, as the most important and effective synthetic approach to access chiral organics, has not been enabled for CCOFs synthesis thus far. Herein we report, for the first time, the construction of CCOFs from prochiral monomers via catalytic asymmetric polymerization. The obtained propargylamine-linked CCOFs can be the highly reusable chiral catalysts to promote asymmetric Michael addition reactions. The concept of catalytic asymmetric polymerization might open a new route for constructing the CCOFs that are not possible with the existing CCOF synthetic methods.
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•This review comprehensively overviews the potential of COFs for photocatalysis and photothermal catalysis.•The synthetic strategies for the COF-based photocatalysts are discussed in ...detail.•The application scope and corresponding reaction mechanism of COF-based photocatalysts is systematically investigated.•Foreseeable challenges and perspectives for the development of COF-based photocatalysts are proposed.
Light-involved catalysis, including photocatalysis and photothermal catalysis, has been considered as one of the most promising alternatives to traditional thermocatalysis for various organic transformation reactions, while the development of highly efficient photocatalysts is the prerequisite and of significant importance in the field of light-mediated catalysis. Covalent organic frameworks (COFs) represent a new class of crystalline molecular solids with periodically ordered skeletons that feature a series of unique properties, such as structural designability and durability, extensive π-electron conjugations, light-harvesting as well as semiconducting characteristics. Benefiting from these outstanding properties, the blooming development of COFs in recent years has brought promising impetus for the realization of visible-light induced organic transformations by photocatalysis or photothermal catalysis. In this review, the up-to-date applications of COFs as versatile platforms for various selective light-initiated organic transformations were comprehensively summarized and discussed. Firstly, the general background and synthetic strategies of COF-based photocatalysts were briefly introduced, followed by the detailed classification and discussion of each type of reactions reported thus far. Finally, the limitations, critical challenges, and future perspectives of COF photocatalysis and photothermal catalysis were provided. It is anticipated that this review can serve as a starting point for the researchers to get in-depth insight into this largely unexplored but promising field and stimulate more intensive research for rational design of more efficient COF-based photocatalysts to achieve more creative visible-light involved photosynthesis.
Nanomedicines are extensively used in cancer therapy. Covalent organic frameworks (COFs) are crystalline organic porous materials with several benefits for cancer therapy, including porosity, design ...flexibility, functionalizability, and biocompatibility. This review examines the use of COFs in cancer therapy from the perspective of reticular chemistry and function‐oriented materials design. First, the modification sites and functionalization methods of COFs are discussed, followed by their potential as multifunctional nanoplatforms for tumor targeting, imaging, and therapy by integrating functional components. Finally, some challenges in the clinical translation of COFs are presented with the hope of promoting the development of COF‐based anticancer nanomedicines and bringing COFs closer to clinical trials.
The exceptional customizability of covalent organic frameworks (COFs) has attracted significant interest for function‐oriented materials design. Recent advances in functionalization strategies and constructing COF‐based therapeutic nanoplatforms for cancer therapy are highlighted, and some challenges in the clinical translation of COFs are discussed to promote the development of COF‐based anticancer nanomedicines.
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