Defect-engineered porphyrinic metal-organic framework nanoparticles for targeted multimodal cancer phototheranostics

Dramatic fluorescence enhancement of PCN-224 and its application in "turn off" immunoassay for sensitive detection of E. coli O157:H7 in milk

In this study, a type of luminescent porous coordination network-224 (PCN-224) in alkaline conditions was synthesized with the dramatic fluorescence enhancement by 20.4 times, which was explained by the fact that the decrease of Zr4+ content in alkaline conditions resulted in the partial recovery of the electron cloud density of 4,4',4'',4'''-(Porphine-5,10,15,20-tetrayl) tetrakis(benzoic acid) (TCPP). Given the large overlap between the excitation spectrum of PCN-224 and the absorption band of Ag nanoparticles (Ag NPs), the coating of the Ag layer on PCN-224 triggered the fluorescence quenching effect, which was applied to "turn off" fluorescence immunoassay for sensitive detection of Escherichia coli O157:H7 (E. coli O157:H7) in milk. The proposed immunoassay reached a low limit of detection (LOD) of 3.3 × 102 CFU mL-1, 29.7 times more sensitive than the conventional ELISA. It will provide a novel alternative strategy for sensitively detecting pathogenic bacteria in the field of food safety.

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.

DNA-Functionalized Porphyrinic Metal-Organic Framework-Based Drug Delivery System for Targeted Bimodal Cancer Therapy

A DNA-functionalized porphyrinic MOF (porMOF) drug delivery system was successfully constructed. porMOF as a photosensitizer and drug delivery carrier can integrate photodynamic therapy (PDT) and chemotherapy. Via the strong coordination interaction between the zirconium cluster of porMOF and the terminal phosphate group of DNA, the stable modification of the DNA layer on the porMOF surface is achieved. Meanwhile, the introduction of C/G-rich base pairs into the DNA double-stranded structure provides more binding sites of chemotherapeutic drug doxorubicin (DOX). AS1411, an aptamer of nucleolin proteins that are overexpressed by cancer cells, is introduced in the double-stranded terminal, which can endow the nanosystem with the ability to selectively recognize cancer cells. C-rich sequences in DNA double strands form an i-motif structure under acidic conditions to promote the highly efficient release of DOX in cancer cells. In vitro and in vivo experiments demonstrate that the synergistic PDT/chemotherapy modality achieves highly efficient cancer cell killing and tumor ablation without undesirable side effects.

A self-monitoring microneedle patch for light-controlled synergistic treatment of melanoma

Melanoma is the most aggressive and malignant form of skin cancer. Current melanoma treatment methods generally suffer from frequent drug administration as well as difficulty in direct monitoring of drug release. Here, a self-monitoring microneedle (MN)-based drug delivery system, which integrates a dissolving MN patch with aggregation-induced emission (AIE)-active PATC microparticles, is designed to achieve light-controlled pulsatile chemo-photothermal synergistic therapy of melanoma. The PATC polymeric particles, termed D/I@PATC, encapsulate both of chemotherapeutic drug doxorubicin (DOX) and the photothermal agent indocyanine green (ICG). Upon light illumination, PATC gradually dissociates into smaller particles, causing the release of encapsulated DOX and subsequent fluorescence intensity change of PATC particles, thereby not only enabling direct observation of the drug release process under light stimuli, but also facilitating verification of drug release by fluorescence recovery after light trigger. Moreover, encapsulation of ICG in PATC particles displays significant improvement of its photothermal stability both in vitro and in vivo. In a tumor-bearing mouse, the application of one D/I@PATC MN patch combining with two cycles of light irradiation showed excellent controllable chemo-photothermal efficacy and exhibited ∼97% melanoma inhibition rate without inducing any evident systemic toxicity, suggesting a great potential for skin cancer treatment in clinics.

Research development of porphyrin-based metal-organic frameworks: targeting modalities and cancer therapeutic applications

Porphyrins are naturally occurring organic molecules that have attracted widespread attention for their potential in the field of biomedical research. Porphyrin-based metal-organic frameworks (MOFs) that utilize porphyrin molecules as organic ligands have gained attention from researchers due to their excellent results as photosensitizers in tumor photodynamic therapy (PDT). Additionally, MOFs hold significant promise and potential for other tumor therapeutic approaches due to their tunable size and pore size, excellent porosity, and ultra-high specific surface area. Active delivery of nanomaterials via targeted molecules for tumor therapy has demonstrated greater accumulation, lower drug doses, higher therapeutic efficacy, and reduced side effects relative to passive targeting through the enhanced permeation and retention effect (EPR). This paper presents a comprehensive review of the targeting methods employed by porphyrin-based MOFs in tumor targeting therapy over the past few years. It further discusses the applications of porphyrin-based MOFs for targeted cancer therapy through various therapeutic methods. The objective of this paper is to provide a valuable reference and source of ideas for targeted therapy using porphyrin-based MOF materials and to inspire further exploration of their potential in the field of cancer therapy.

CeO2-Decorated Metal-Organic Framework for Enhanced Photodynamic Therapy

Photodynamic therapy (PDT) is quickly developing as a hopeful cancer treatment. However, hypoxic tumors, poor targeting, and photosensitizers (PS) aggregation limited the efficiency of PDT. Here, we report a hyaluronic acid (HA)-modified CeO₂-nanoparticle-decorated metal-organic framework (PCN-224@CeO₂-HA) to enhance PDT and achieve targeted treatment. CeO₂ catalyzes H₂O₂ to produce O₂ to solve hypoxia problems. HA could target the CD44 receptor, which is highly expressed on the tumor cell membranes. The growth of tumor cells 4T1 and MCF-7 was controlled distinctly after being incubated with PCN-224@CeO₂-HA under laser irradiation, while the survival ability of normal cell LO2 was nearly unchanged. Importantly, PCN-224@CeO₂-HA could be effectively aggregated within the tumor area after 12 h of injection, and the tumor growth was remarkably inhibited under laser irradiation. PCN-224@CeO₂-HA presented good biocompatibility and an excellent antitumor effect, providing a new strategy to produce O₂ in situ for enhanced PDT.

Metal-organic frameworks for hepatocellular carcinoma therapy and mechanism

In recent years, metal organic frameworks (MOFs) have attracted increasing attention in cancer therapy, because they can enhance the anticancer efficacy of photodynamic therapy (PDT), photothermal therapy (PTT), photoacoustic imaging, and drug delivery. Owing to stable chemical adjustability, MOFs can be used as carriers to provide excellent loading sites and protection for small-molecule drugs. In addition, MOFs can be used to combine with a variety of therapeutic drugs, including chemotherapeutics drugs, photosensitizers, and radiosensitizers, to efficiently deliver drugs to tumor tissue and achieve desired treatment. There is hardly any review regarding the application of MOFs in hepatocellular carcinoma. In this review, the design, structure, and potential applications of MOFs as nanoparticulate systems in the treatment of hepatocellular carcinoma are presented.

Systematic Review Registration: website, identifier registration number

Metalloporphyrin Metal–Organic Frameworks: Eminent Synthetic Strategies and Recent Practical Exploitations

The emergence of metal–organic frameworks (MOFs) in recent years has stimulated the interest of scientists working in this area as one of the most applicable archetypes of three-dimensional structures that can be used as promising materials in several applications including but not limited to (photo-)catalysis, sensing, separation, adsorption, biological and electrochemical efficiencies and so on. Not only do MOFs have their own specific versatile structures, tunable cavities, and remarkably high surface areas, but they also present many alternative procedures to overcome emerging obstacles. Since the discovery of such highly effective materials, they have been employed for multiple uses; additionally, the efforts towards the synthesis of MOFs with specific properties based on planned (template) synthesis have led to the construction of several promising types of MOFs possessing large biological or bioinspired ligands. Specifically, metalloporphyrin-based MOFs have been created where the porphyrin moieties are either incorporated as struts within the framework to form porphyrinic MOFs or encapsulated inside the cavities to construct porphyrin@MOFs which can combine the peerless properties of porphyrins and porous MOFs simultaneously. In this context, the main aim of this review was to highlight their structure, characteristics, and some of their prominent present-day applications.

Porphyrin-Based Nanoparticles: A Promising Phototherapy Platform

Phototherapy, including photodynamic therapy and photothermal therapy, is an emerging form of non-invasive treatment. The combination of imaging technology and phototherapy is becoming an attractive development in the treatment of cancer, as it allows for highly effective therapeutic results through image-guided phototherapy. Porphyrins have attracted significant interest in the treatment and diagnosis of cancer due to their excellent phototherapeutic effects in phototherapy and their remarkable imaging capabilities in fluorescence imaging, magnetic resonance imaging and photoacoustic imaging. However, porphyrins suffer from poor water solubility, low near-infrared absorption and insufficient tumor accumulation. The development of nanotechnology provides an effective way to improve the bioavailability, phototherapeutic effect and imaging capability of porphyrins. This review highlights the research results of porphyrin-based small molecule nanoparticles in phototherapy and image-guided phototherapy in the last decade and discusses the challenges and directions for the development of porphyrin-based small molecule nanoparticles in phototherapy.

Porphyrin NanoMetal-Organic Frameworks as Cancer Theranostic Agents

Metal-Organic Frameworks (MOFs) are hybrid multifunctional platforms that have found remarkable applications in cancer treatment and diagnostics. Independently, these materials can be employed in cancer treatment as intelligent drug carriers in chemotherapy, photothermal therapy, and photodynamic therapy; conversely, MOFs can further be used as diagnostic tools in fluorescence imaging, magnetic resonance imaging, computed tomography imaging, and photoacoustic imaging. One essential property of these materials is their great ability to fine-tune their composition toward a specific application by way of a judicious choice of the starting building materials (metal nodes and organic ligands). Moreover, many advancements were made concerning the preparation of these materials, including the ability to downsize the crystallites yielding nanoporous porphyrin MOFs (NMOFs) which are of great interest for clinical treatment and diagnostic theranostic tools. The usage of porphyrins as ligands allows a high degree of multifunctionality. Historically these molecules are well known for their reactive oxygen species formation and strong fluorescence characteristics, and both have proved helpful in cancer treatment and diagnostic tools. The anticipation that porphyrins in MOFs could prompt the resulting materials to multifunctional theranostic platforms is a reality nowadays with a series of remarkable and ground-breaking reports available in the literature. This is particularly remarkable in the last five years, when the scientific community witnessed rapid development in porphyrin MOFs theranostic agents through the development of imaging technologies and treatment strategies for cancer. This manuscript reviews the most relevant recent results and achievements in this particular area of interest in MOF chemistry and application.

Current status and future prospects of nanoscale metal–organic frameworks in bioimaging

The importance of diagnosis and in situ monitoring of lesion regions and transportation of bioactive molecules has a pivotal effect on successful treatment, reducing side effects, and increasing the chances of survival in the case of diseases.

Thiadiazoloquinoxaline-Based Semiconducting Polymer Nanoparticles for NIR-II Fluorescence Imaging-Guided Photothermal Therapy

Phototheranostics have gained more and more attention in the field of cancer diagnosis and therapy. Among a variety of fluorophores for phototheranostics, semiconducting polymer nanoparticles (SPNs), which are usually constructed by encapsulating hydrophobic semiconducting polymers (SPs) with amphiphilic copolymers, have shown great promise. As second near-infrared (NIR-II) fluorescence imaging has both higher imaging resolution and deeper tissue penetration compared with first near-infrared (NIR-I) fluorescence imaging, NIR-II fluorescent SPNs have been widely designed and prepared. Among numerous structural units for semiconducting polymers (SPs) synthesis, thiadiazoloquinoxaline (TQ) has been proved as an efficient electron acceptor unit for constructing NIR-II fluorescent SPs by reacting with proper electron donor units. Herein, we summarize recent advances in TQ-based SPNs for NIR-II fluorescence imaging-guided cancer photothermal therapy. The preparation of TQ-based SPNs is first described. NIR-II fluorescence imaging-based and multimodal imaging-based phototheranostics are sequentially discussed. At last, the conclusion and future perspectives of this field are presented.