Porphyrin-based covalent organic framework nanoparticles for photoacoustic imaging-guided photodynamic and photothermal combination cancer therapy

Synthesis of theranostic covalent organic framework for Tumor-targeted Chemo-photodynamic therapy

Covalent organic frameworks (COFs) are a novel class of organic porous materials that, in recent years, have gained much attention for their applications as nanocarriers toward nanomedicine development. Inspired by this, we introduce for the first time a novel theranostic nanoplatform that combines iodine ligand 5-amino-2,4,6-triiodoisophthalic acid (ATIPA)-decorated porphyrin-based covalent organic frameworks (pCOF-I) designed for effective photodynamic therapy (PDT), doxorubicin (DOX) encapsulation, and computed tomography (CT) imaging toward melanoma treatment. In the design of this COF, we have successfully integrated the iodine ligand with porphyrin. The synthesized mesoporous nanoplatform was loaded with DOX and further modified by COOH-PEG-NH2, which was conjugated with the AS1411 aptamer to be targeted to B16F0 melanoma cells. Comprehensive characterizations verified the successful synthesis and controlled release of DOX from the synthesized COF. In vitro evaluation against B16F0 showed combined chemo-PDT therapy. In addition, higher cellular uptake and toxicity were observed for the targeted platform compared to the non-targeted one towards B16F0. The porphyrin molecules imparted to the pCOF-I nanoparticles (NPs) a significant capacity for light-induced reactive oxygen species (ROS) generation, demonstrating remarkable PDT efficacy in both in vivo and in vitro environments. An in vivo investigation on B16F0 ectopic tumor model of melanoma in mice confirmed the potential for showed combined chemo-PDT therapy chemo-PDT in preclinical stage while approving guided delivery and tumor accumulation of AS1411 aptamer-tagged systems. On the other hand, the prepared platform demonstrated desirable CT-scan imaging of B16F0 tumorized mice 6 and 24 h post-injection. Notably, this is the first report of an AS1411 aptamer-targeted pCOF-I system for CT imaging-guided combined chemo-PDT, marking a significant step forward in multimodal cancer treatment strategies.

Semiconducting Covalent Organic Frameworks

Semiconductors form the foundational bedrock of modern electronics and numerous cutting-edge technologies. Particularly, semiconductors crafted from organic building blocks hold immense promise as next-generation pioneers, thanks to their vast array of chemical structures, customizable frontier orbital energy levels and bandgap structures, and easily adjustable π electronic properties. Over the past 50 years, advancements in chemistry and materials science have facilitated extensive investigations into small organic π compounds, oligomers, and polymers, resulting in a rich library of organic semiconductors. However, a longstanding challenge persists: how to organize π building units or chains into well-defined π structures, which are crucial for the performance of organic semiconductors. Consequently, the pursuit of methodologies capable of synthesizing and/or fabricating organic semiconductors with ordered structures has emerged as a frontier in organic and polymeric semiconductor research. In this context, covalent organic frameworks (COFs) stand out as unique platforms allowing for the covalent integration of organic π units into periodically ordered π structures, thus facilitating the development of semiconductors with extended yet precisely defined π architectures. Since their initial report in 2008, significant strides have been made in exploring various chemistries to develop semiconducting COFs, resulting in a rich library of structures, properties, functions, and applications. This review provides a comprehensive yet focused exploration of the general structural features of semiconducting COFs, outlining the basic principles of structural design, illustrating the linkage chemistry and synthetic strategies based on typical one-pot polymerization reactions to demonstrate the growth of bulk materials, nanosheets, films, and membranes. By elucidating the interactions between COFs and various entities such as photons, phonons, electrons, holes, ions, molecules, and spins, this review categorizes semiconducting COFs into nine distinct sections: semiconductors, photoconductors, light emitters, sensors, photocatalysts, photothermal conversion materials, electrocatalysts, energy storage electrodes, and radical spin materials, focusing on disclosing structure-originated properties and functions. Furthermore, this review scrutinizes structure-function correlations and highlights the unique features, breakthroughs, and challenges associated with semiconducting COFs. Furnished with foundational knowledges and state-of-the-art insights, this review predicts the fundamental issues to be addressed and outlines future directions for semiconducting COFs, offering a comprehensive overview of this rapidly evolving and remarkable field.

Porphyrin-based covalent organic framework with NIR absorption: Preparation, hyaluronic acid modification, and cascading a hypoxia-sensitive drug for synergistic therapy of cancer phototherapy/chemotherapy

Porphyrins are popular photosensitizers for photodynamic therapy of diseases. However, the poor water solution and short absorption wavelengths of porphyrins limit their clinical application. In this work, a novel worm-like porphyrin covalent organic framework (Por-COF) with excellent dispersibility and near-infrared absorption was prepared via a facile method. First, a pH-responsive macromolecule was prepared using Schiff base bonds between porphyrin and terephthalaldehyde, and the spatial arrangement of macromolecules was controlled to prepare Por-COF. Second, the hypoxia-responsive drug tirapazamine (TPZ) and tumor-targeted hyaluronic acid (HA) were loaded to Por-COF through the electrostatic effect to prepare a multifunction nanomedicine (Por-COF@TPZ/HA) that could simultaneously produce abundant reactive oxygen species and high temperature via808 nm laser irradiation. TPZ was cascaded for the synergistic therapy of cancers. In vitro cytotoxicity showed that the inhibition rate of cell activity in the Por-COF@TPZ/HA + Laser group was 1.2 times higher than that in the Por-COF/HA + Laser group. In vivo experiments also demonstrated that the aggravated tumor hypoxia caused by photodynamic therapy could activate TPZ to achieve high-efficiency chemotherapy. Combined photodynamic-photothermal therapy and chemotherapy had an outstanding synergistic effect. This work provides a promising method for Por-COF preparation and a feasible strategy for the synergistic therapy of cancers.

Efficient photoresponsive one-dimensional covalent organic framework as oxidase-like enzyme for ultrasensitive detection of antioxidants

Natural polyphenolic antioxidants are widely present in foods such as fruits and vegetables, meanwhile applied in food processing and storage to prevent the formation of harmful compounds. While excessive antioxidants lead to negative impacts on human health. Hence, it is crucial to accurately detect antioxidant levels in order to enhance the overall nutritional content and food safety. Herein, a novel one-dimensional covalent organic framework (COF-Por-DPP) was constructed using 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphyrin and 4,4'-(2,6-pyrazinediyl)bisbenzaldehyde. The unique photoresensitive properties and topological structures endowed COF-Por-DPP excellent oxidase-like activity. The COF-Por-DPP based colorimetric assay was established for three antioxidants (gallic acid, tannic acid and caffeic acid). Moreover, this method was used to analyze real samples and a hydrogel sensor was constructed, which demonstrated good accuracy and practicability.

Engineered bacterial membrane biomimetic covalent organic framework as nano-immunopotentiator for cancer immunotherapy

The cellular uptake and tissue dispersion efficiency of nanomedicines are crucial for realizing their biological functionality. As a cutting-edge category of nanomedicine, covalent organic frameworks (COFs)-based photosensitizers, have been extensively employed in cancer phototherapy in recent years. However, the inherent aggregation tendency of COFs hinders their uptake by tumor cells and dispersion within tumor tissues, thereby limiting their therapeutic efficacy. In this study, we employed Fusobacterium nucleatum (F.n.), a prevalent intratumoral bacterium, to construct a bacterium membrane-wrapped COF, COF-306@FM, which is readily taken up by cancer cells and uniformly dispersed within tumor tissues. Meanwhile, the F.n. membrane can also serve as an immune adjuvant to warm up the "cold" tumor immune microenvironment by enhancing the CD8+ T and B cells infiltration, and inducing the formation of tumor-located tertiary lymphoid structures. Consequently, the response rate of αPD-L1 immunotherapy was drastically promoted to efficiently prevent tumor metastasis and recurrence, causing 84.6 % distant tumor inhibition and complete suppression of tumor metastasis. In summary, this innovative approach not only enhances the therapeutic potential of COFs but also opens up new avenues for integrating microbial and nanotechnological strategies in cancer treatment.

Porphyrins and Their Derivatives in Cancer Therapy: Current Advances, Mechanistic Insights, and Prospective Directions

Porphyrin and its derivatives are widely used in cancer therapy due to their strong photon absorption capabilities and moderate light stability. Due to their hydrophobic nature, porphyrins with tetrapyrrolic macrocycles ease self-aggregation in physiological conditions. Instead, exploiting the C4 symmetry structure for self-assembly is beneficial to improve the bioavailability of porphyrin and its derivatives. Herein, this Review outlines porphyrin-based nanoformulations for therapeutic applications in cancer treatment. The typical pharmaceutical application of the integrated porphyrinic structure is systematically summarized, focusing on the typical synthetic methodologies and structure-functionality relationship. Additionally, therapeutic modalities (e.g., photothermal, photodynamic, and sonodynamic) and their synergy mechanism in regulated cell death are overviewed. Special attention is given to emerging technologies in nanocatalytic therapy, therapeutic vaccines, and proteolysis-targeting chimeras, which align with the trend toward personalization and minimal invasiveness in healthcare. Finally, we discuss the challenges and limitations of porphyrinic nanoformulations and explore their future directions in the healthcare sector, aiming to bridge the gap between research and practical clinical application.

Evolution of nMOFs in photodynamic therapy: from porphyrins to chlorins and bacteriochlorins for better efficacy

Photodynamic therapy (PDT) has gained significant attention due to its non-invasive nature, low cost, and ease of operation. Nanoscale metal-organic frameworks (nMOFs) incorporating porphyrins, chlorins, and bacteriochlorins have emerged as one of the most prominent photoactive materials for tumor PDT. These nMOFs could enhance the water solubility, stability and loading efficiency of photosensitizers (PSs). Their highly ordered porous structure facilitates O2 diffusion and enhances the generation of 1O2 from hydrophobic porphyrins, chlorins, and bacteriochlorins, thereby improving their efficacy of phototherapy. This review provides insights into the PDT effects of nMOFs derived from porphyrins, chlorins, and bacteriochlorins. It overviews the design strategies, types of reactive oxygen species (ROS), ROS generation efficiency, and the unique biological processes involved in inhibiting tumor cell proliferation, focusing on the mechanism by which molecular structure leads to enhanced photochemical properties. Finally, the review highlights the new possibilities offered by porphyrins, chlorins, and bacteriochlorins-based nMOFs for tumor PDT, emphasizing how optimized design can further improve the bioapplication of porphyrin derivatives represented PSs. With ongoing research and technological advancements, we anticipate that this review will garner increased attention from scientific researchers toward porphyrin-based nMOFs, thereby elevating their potential as a prominent approach in the treatment of malignant tumors.

Covalent organic frameworks in cancer theranostics: advancing biomarker detection and tumor-targeted therapy

In recent years, covalent organic frameworks (COFs) have garnered considerable attention in the field of onco-nanotechnology as a new type of nanoporous construct due to their promising physicochemical properties, ease of modification, and ability to be coupled with several moieties and therapeutic molecules. They can not only be used as biocompatible nanocarriers to deliver therapeutic payloads to the tumor zone selectively but can also be combined with a variety of therapeutic modalities to achieve the desired treatments. This review comprehensively presented recent achievements and progress in COF-based cancer diagnosis, detection, and cancer therapy to provide a better prospect for further research. Herein our primary emphasis lies on exploring the application of COFs as potential sensors for cancer-derived biomarkers that have received comparatively less attention in previous discussions. While the utilization of COFs in solid tumor therapy has faced significant challenges in scientific research and clinical applications, we reviewed the most promising features that underscore their potential in cancer theranostics.

Enhanced integrated therapy for breast cancer employing Honokiol-loaded mesoporous polydopamine nanoparticles in conjunction with photothermal effects and low-dose metformin

Breast cancer remains a significant global health challenge, emphasizing the pressing need for innovative therapeutic approaches. Our thorough research investigates the potential of mesoporous polydopamine nanoparticles (MPDA) as a targeted treatment for breast cancer. Meticulously crafted, these nanoparticles were loaded with honokiol (HK), which is a natural product, and then coated with functionalized hyaluronic acid (HA) to boost their ability to target breast cancer cells that overexpress CD44 receptors. The deep penetrating and photothermal (PTT) composite nanosystem combined with low-dose metformin (Met) improves the efficacy of synergetic therapy against breast tumors. The designed nanosystem exhibited exceptional biocompatibility and stability, suggesting its suitability for therapeutic use. Our in vitro studies demonstrated that the nanosystem precisely targeted and penetrated breast cancer cells, resulting in significant cell death. Additionally, in vivo studies showed that the nanosystem markedly inhibited tumor growth compared to the control group. This tumor-inhibiting effect was due to the combined action of the encapsulated HK, free Met, and the photothermal effect induced by near-infrared laser irradiation. This combination potently stimulates the expression of cleaved caspase-3 and cleaved PARP proteins, ultimately triggering cell apoptosis and effectively curbing tumor proliferation. Our research not only underscores the promising potential of nanoparticles for targeted breast cancer therapy but also sets the stage for further exploration and development of novel nanomedicine-based therapeutic strategies.

CRISPR/Cas12a-mediated fluorescent aptasensor based on DNA walker amplification for oxytetracycline detection

Nowadays, although most oxytetracycline (OTC) are used only in animals, their leaching into the environment and residues in food lead to noticeable health problems. Fortunately, by studying the molecular dynamics of OTC aptamers and the mutations of key bases, aptamer's base fragments involved in identifying OTC was confirmed for the first time, which provided theoretical guidance for the ingenious design of aptamer detection. Thereafter, benefiting from the amplification impact by DNA walker, the disadvantage of low efficiency caused by CRISPR/Cas12a was effectively avoided. In the established delicate aptasensing platform, small quantity of OTC promoted DNA walker to produce a massive of activators, which stimulated the trans-cleavage activity of CRISPR/Cas12a. By implying nanoclusters (NCs) with covalent organic framework (COF), the sensitive fluorescence "turn-on" method for OTC detection was realized. Under the optimum conditions, the linear range of aptasensor was 0.05-50 μM, and the detection limit was 0.041 μM. In addition, the aptasensing method can be successfully used for the quantitative detection of OTC in milk and honey samples with a recovery rate of 95.67%-104.10% and 95.33%-109.70%, implying excellent analytical performance and practical application prospect.

Hybrid Nanoplatforms Based on Photosensitizers and Metal/Covalent Organic Frameworks for Improved Cancer Synergistic Treatment Nano-Delivery Systems

Researchers have extensively investigated photosensitizer (PS) derivatives for various applications due to their superior photophysical and electrochemical properties. However, inherent problems, such as instability and self-quenching under physiological conditions, limit their biological applications. Metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) represent two relatively new material types. These materials have high surface areas and permanent porosity, and they show a tremendous deal of potential for applications like these. This review summarizes key synthesis processes and highlights recent advancements in integrating PS-based COF and MOF nanocarriers for biomedical applications while addressing potential obstacles and prospects.

Recent Advances in Glutathione Depletion-Enhanced Porphyrin-Based nMOFs for Photodynamic Therapy

Photodynamic therapy has established itself as a clinical treatment for certain superficial cancers by converting oxygen into cytotoxic singlet oxygen to eradicate cancer cells. Porphyrin-based nanoscale metal-organic frameworks have emerged as promising photosensitive platforms due to their ability to prevent the hydrophobic aggregation quenching of porphyrin molecules and enhance accumulation at the tumor site, thereby becoming a focal point in photodynamic materials research. However, the elevated levels of glutathione and other reductive substances within cancer cells can alleviate the oxidative stress induced by singlet oxygen from the photodynamic therapy process, thus protecting intracellular biomolecular structures from damage. Consequently, it is crucial to design functionalized nanoplatforms that integrate glutathione depletion with porphyrin-based metal-organic frameworks to significantly boost photodynamic therapy efficacy. Moreover, the excess glutathione within cells can disrupt the structure of porphyrin-based metal-organic frameworks, which not only increases the capacity of porphyrin molecules to generate singlet oxygen upon light exposure but also aids in the recovery of their fluorescence imaging capabilities. Additionally, this specificity minimizes the photosensitizing harm of porphyrin-based metal-organic frameworks to other normal tissues. This review compiles recent advancements in developing porphyrin-based metal-organic frameworks for enhanced phototherapy through glutathione depletion. It aims to promote the further application of porphyrin-based metal-organic frameworks in phototherapy and provide valuable insights for preclinical applications. By highlighting strategies that improve therapeutic outcomes while maintaining safety profiles, this summary seeks to advance the development of more effective and targeted cancer treatments.

Nucleolus-Targeting Carbon Dot Nanocomplexes for Combined Photodynamic/Photothermal Therapy

The low cure rate and high mortality associated with cancer pose significant threats to human health. Photodynamic and photothermal therapies have emerged as promising treatment strategies for various types of cancers. In this study, we successfully synthesized a novel type of carbon dot (CD) using 1,2,4-aminobenzene and ethylenediamine as precursors. Surprisingly, these CDs exhibited outstanding nucleolus-targeting capabilities coupled with a remarkable photothermal effect. Through the integration of these nucleolus-targeting CDs with indocyanine green (ICG) and folic acid (FA), we created CDs-ICG-FA nanocomplexes suitable for combined photodynamic and photothermal therapy. In vitro experiments demonstrated that CDs-ICG-FA maintained a robust photothermal ability, achieving a conversion efficiency of up to 34.3%. Furthermore, CDs-ICG-FA generated abundant reactive oxygen species, effectively inducing cancer cell death and demonstrating its potential for photodynamic therapy. In MCF-7 cancer cells, CDs-ICG-FA exhibited a pronounced synergistic photothermal/photodynamic anticancer effect. Subsequent in vivo experiments in mice revealed that CDs-ICG-FA could selectively accumulate at tumor sites, significantly inhibiting tumor growth upon exposure to an 808 nm laser. These findings suggest that the developed nucleolus-targeting CDs-ICG-FA hold promising potential for cancer targeting and the application of combined photothermal/photodynamic therapy.

Synthesis and Biomedical Applications of Covalent Organic Frameworks for Disease Diagnosis and Therapy

Covalent organic frameworks (COFs) have emerged as a distinguished class of porous materials. Owing to their ability to be constructed through covalent bonds involving light elements, such as hydrogen, boron, carbon, nitrogen, and oxygen, COFs offer greater stability and lower cytotoxicity than metal-organic frameworks do, addressing critical limitations in in vivo applications. Their unique attributes, such as high surface area, customizable pore sizes, and versatile surface functionalities, make them ideal for various biomedical applications. This review aims to provide an overview of the recent advancements in modern COFs for biomedical uses. First, a variety of methods for the synthesis of COFs are outlined, which ensures their suitability for medical use. Next, we delve into innovative biomedical applications, emphasizing their roles in disease diagnosis and therapies. Finally, challenges, such as clinical translation, biocompatibility, and controlled drug release, are critically discussed, providing comprehensive insight into the potential of COFs in revolutionizing biomedical technologies. Overall, this review offers a comprehensive overview of COFs' capabilities and future prospects in enhancing biomedical technologies.

Antibacterial cationic porous organic polymer coatings via an adsorption-contact-photodynamic inactivation strategy for treatment of drug-resistant bacteria

Although photodynamic therapy (PDT) has great potential for treating severely infected wounds, it is restricted by the short lifetime, limited diffusion distance of reactive oxygen species (ROS), and incomplete contact with bacteria. Herein, we report a novel nanosized ionic porous organic polymer (TPAPy-IPOP) based on the triphenylamine (TPA) moiety. Strong electron-deficient cationic groups were introduced into TPA to construct the donor-acceptor (D-A) system, in which the photoelectric effect of TPAPy-IPOP was greatly enhanced, and it was easily excited to produce ROS under irradiation with visible light. The introduction of cations not only facilitated bacterial adsorption by TPAPy-IPOP via electrostatic attraction, which was more conducive to killing bacteria by ROS, but also inactivated bacteria by the cations directly. The nanosized TPAPy-IPOP remained suspended in water for several months and could be sprayed onto various substrates to form a durable coating with excellent antibacterial properties. The in vivo results proved that the silk fibroin/polyvinyl alcohol non-woven fabric (SF/PVA) coated with TPAPy-IPOP could create and maintain a sterile microenvironment at a wound site. The rapid reduction in inflammation resulting from its bactericidal action accelerated the wound healing rate. Collectively, this design is expected to offer a generalizable approach for developing novel antibacterial therapeutic photosensitizers, especially for infected wound treatment.

Potent Covalent Organic Framework Nanophotosensitizers with Staggered Type I/II Motifs for Photodynamic Immunotherapy of Hypoxic Tumors

Photodynamic therapy (PDT) using oxygen-dependent type II photosensitizers is frequently limited by the hypoxic microenvironment of solid tumors. Type I photosensitizers show oxygen-independent reactive oxygen species (ROS) generation upon light irradiation but still face the challenges of aggregation-caused quenching (ACQ) and low efficiency to produce ROS. Herein, we first prepare an efficient type I photosensitizer from a perylene derivative via intramolecular donor-acceptor binding and sulfur substitution, which significantly enhance intersystem crossing between singlet and triplet states and electron transfer capability. After reaction with a type II photosensitizer, the covalent organic framework (COF) nanophotosensitizer is formed with alternated type I and II photosensitizer motifs in the same layer and staggered AB stacking between layers to avoid ACQ. The nanophotosensitizer exhibits high-efficiency generation of singlet oxygen (1O2) and superoxide anion radicals (O2•-) via type I and II mechanism under normoxia upon exposure to light irradiation. Under hypoxia, massive O2•- can be produced continuously. The potent ROS generation capability results in efficient cellular apoptosis and immunogenic cell death (ICD) efficiently. After combination with immune checkpoint inhibitors, tumor immunosuppressive microenvironment is reversed, which effectively ablates bulky hypoxic primary tumors and suppresses metastases via photodynamic immunotherapy. The COF nanophotosensitizers with staggered type I and II photosensitizer motifs represent a promising strategy to boost photodynamic immunotherapy of hypoxic tumors.

Recent Advances in Porphyrin-Based Covalent Organic Frameworks for Synergistic Photodynamic and Photothermal Therapy

Porphyrin's excellent biocompatibility and modifiability make it a widely studied photoactive material. However, its large π-bond conjugated structure leads to aggregation and precipitation in physiological solutions, limiting the biomedical applications of porphyrin-based photoactive materials. It has been demonstrated through research that fabricating porphyrin molecules into nanoscale covalent organic frameworks (COFs) structures can circumvent issues such as poor dispersibility resulting from hydrophobicity, thereby significantly augmenting the photoactivity of porphyrin materials. Porphyrin-based COF materials can exert combined photodynamic and photothermal effects, circumventing the limitations of photodynamic therapy (PDT) due to hypoxia and issues in photothermal therapy (PTT) from heat shock proteins or the adverse impact of excessive heat on the protein activity of normal tissue. Furthermore, the porous structure of porphyrin COFs facilitates the circulation of oxygen molecules and reactive oxygen species and promotes sufficient contact with the lesion site for therapeutic functions. This review covers recent progress regarding porphyrin-based COFs in treating malignant tumors and venous thrombosis and for antibacterial and anti-inflammatory uses via combined PDT and PTT. By summarizing relevant design strategies, ranging from molecular design to functional application, this review provides a reference basis for the enhanced phototherapy application of porphyrin-based COFs as photoactive materials. This review aims to offer valuable insights for more effective biomedical applications of porphyrin-based COFs through the synthesis of existing experimental data, thereby paving the way for their future preclinical utilization.

CsxWO3@NBs as a Multi-Image Guided Photothermal/Photodynamic Combination Therapy Platform for the Treatment of Hepatocellular Carcinoma

Purpose

Effective cancer treatment relies on the precise deployment of clinical imaging techniques to accurately treat tumors. One highly representative technology among these is multi-imaging guided phototherapy. This work introduces a new and innovative theranostic drug that combines near-infrared (NIR) irradiation-induced photodynamic therapy (PDT) and photothermal therapy (PTT) to treat malignancies. Moreover, it can be utilized as a contrasting substance for X-ray computed tomography (CT) imaging and contrast-enhanced ultrasound (CEUS) to aid in the administration of therapy.

Methods

Cesium tungsten bronze nanobubbles (CsxWO3@NBs) were constructed via a water-controlled solvothermal synthesis and thin film hydration of phospholipid. Various methods, including dynamic light scattering, transmission electron microscopy, and X-ray photoelectron spectroscopy, were used to analyze and describe the size, shape, and chemical characteristics of the nanoparticles. In this study, hepatoma cell lines HepG2 and HUH7 were employed in vitro, and xenotransplantation mouse models were used to assess their antitumor effects. A series of in vitro and in vivo trials were conducted to assess the effectiveness of combining photodynamic and photothermal therapies, as well as using CEUS and CT imaging.

Results

The CsxWO3@NBs exhibit photothermal effects and the generation of reactive oxygen species (ROS) under laser irradiation, thereby enabling effective photothermal and photodynamic combinatorial therapy. Following combined treatment, the activity and invasive capacity of hepatocellular carcinoma cells were markedly diminished, the development rate of the tumor was noticeably reduced, and the level of biological toxicity was low. Additionally, CsxWO3@NBs possess the capacity to serve as both a CT imaging agent and a contrast-enhanced ultrasound agent.

Conclusion

CsxWO3@NBs represent a promising theranostic agent for image-guided cancer therapy.

Therapeutic types and advantages of functionalized nanoparticles in inducing ferroptosis in cancer therapy

BACKGROUND

The clinical efficacy of cancer treatment protocols remains unsatisfactory; however, the emergence of ferroptosis-driven therapy strategies has renewed hope for tumor treatment, owing to their remarkable tumor suppression effects. Biologically based small-molecule inducers are used in conventional method to induce ferroptosis. Nevertheless, some molecular drugs have limited solubility, poor ability to target cells, and fast metabolism, which hinder their ability to induce ferroptosis over a prolonged period. Fortunately, further investigations of ferroptosis and the development of nanotechnology have demonstrated that nanoparticles (NPs) are more efficient in inducing ferroptosis than drugs alone, which opens up new perspectives for cancer therapy.

OBJECTIVE

In order to organize a profile of recent advance in NPs for inducing ferroptosis in cancer therapy, and NPs were comprehensively classified in a new light.Materials and methods: We comprehensively searched the databases such as PubMed and Embase. The time limit for searching was from the establishment of the database to 2023.11. All literatures were related to "ferroptosis", "nanoparticles", "nanodelivery systems", "tumors", "cancer".

RESULTS

We summarized and classified the available NPs from a new perspective. The NPs were classified into six categories based on their properties: (1) iron oxide NPs (2) iron - based conversion NPs (3) core-shell structure (4) organic framework (5) silica NPs (6) lipoprotein NPs. According to the therapeutic types of NPs, they can be divided into categories: (1) NPs induced ferroptosis-related immunotherapy (2) NPs loaded with drugs (3) targeted therapy of NPs (4) multidrug resistance therapy (5) gene therapy with NPs (6) energy conversion therapy.

CONCLUSIONS

The insights gained from this review can provide ideas for the development of original NPs and nanodelivery systems, pave the way for related nanomaterials application in clinical cancer therapy, and advance the application and development of nanotechnology in the medical field.

Advancing gastric cancer treatment: nanotechnology innovations and future prospects

Gastric cancer (GC) is the fifth most common cancer worldwide, particularly prevalent in Asia, especially in China, where both its incidence and mortality rates are significantly high. Meanwhile, nanotechnology has demonstrated great potential in the treatment of GC. In particular, nanodrug delivery systems have improved therapeutic efficacy and targeting through various functional modifications, such as targeting peptides, tumor microenvironment responsiveness, and instrument-based methods. For instance, silica (SiO2) has excellent biocompatibility and can be used as a drug carrier, with its porous structure enhancing drug loading capacity. Polymer nanoparticles regulate drug release rates and mechanisms by altering material composition and preparation methods. Lipid nanoparticles efficiently encapsulate hydrophilic drugs and promote cellular uptake, while carbon-based nanoparticles can be used in biosensors and drug delivery. Targets such as integrins, HER2 receptors, and the tumor microenvironment have been used to improve drug efficacy in GC treatment. Nanodrug delivery techniques not only enhance drug efficacy and delivery capabilities but also selectively target tumor cells. Currently, there is a lack of systematic summarization and synthesis regarding the relationship between nanodrug delivery systems and GC treatment, which to some extent hinders researchers and clinicians from efficiently searching for and referencing related studies, thereby reducing work efficiency. This study aims to systematically summarize the existing research on the relationship between nanodrug delivery systems and GC treatment, making it easier for professionals to search and reference, and thereby promoting further research on the role of nanodrug delivery systems and their clinical applications in GC. This review discusses the applications of functionalized nanocarriers in the treatment of GC in recent years, including surface modifications with targeted markers, the combination of phototherapy, chemotherapy, and immunotherapy, along with their advantages and challenges. It also examines the future prospects of targeted nanomaterials in GC treatment. The review particularly focuses on the combined application of nanocarriers in multiple treatment modalities, such as phototherapy, chemotherapy, and immunotherapy, demonstrating their potential in multimodal treatments. Furthermore, it thoroughly explores the specific challenges that nanocarriers face in GC treatment, such as biocompatibility, drug release control, and clinical translation issues, while providing a systematic outlook on future developments. Additionally, this study emphasizes the potential value and feasibility of nanocarriers in clinical applications, contrasting with most reviews that focus on basic research. Through these innovations, we offer new perspectives and directions for the development of nanotechnology in the treatment of GC.

Photothermal Conversion Porous Organic Polymers: Design, Synthesis, and Applications

Solar energy is a primary form of renewable energy, and photothermal conversion is a direct conversion process with tunable conversion efficiency. Among various kinds of photothermal conversion materials, porous organic polymers (POP) are widely investigated owing to their controllable molecular design, tailored porous structures, good absorption of solar light, and low thermal conductivity. A variety of POP, such as conjugated microporous polymers (CMP), covalent organic frameworks (COF), hyper-crosslinked porous polymers (HCP), polymers of intrinsic microporosity (PIM), porous ionic polymers (PIP), are developed and applied in photothermal conversion applications of seawater desalination, latent energy storage, and biomedical fields. In this review, a comprehensive overview of the recent advances in POP for photothermal conversion is provided. The micro molecular structure characteristics and macro morphology of POP are designed for applications such as seawater desalination, latent heat energy storage, phototherapy and photodynamic therapy, and drug delivery. Besides, a probe into the underlying mechanism of structural design for constructing POP with excellent photothermal conversion performance is methodicalized. Finally, the remaining challenges and prospective opportunities for the future development of POP for solar energy-driven photothermal conversion applications are elucidated.

Boosting photothermal conversion through array aggregation of metalloporphyrins in bismuth-based coordination frameworks

Materials capable of efficiently converting near-infrared (NIR) light into heat are highly sought after in biotechnology. In this study, two new three-dimensional (3D) porphyrin-based metal-organic frameworks (MOFs) with a sra-net, viz. CoTCPP-Bi/NiTCPP-Bi, were successfully synthesized. These MOFs feature bismuth carboxylate nodes interconnected by metalloporphyrinic spacers, forming one-dimensional (1D) arrays of closely spaced metalloporphyrins. Notably, the CoTCPP-Bi exhibits an approximate Co⋯C distance of 3 Å, leading to enhanced absorption of NIR light up to 1400 nm due to the presence of strong interlayer van der Waals forces. Furthermore, the spatial arrangement of the metalloporphyrins prevents axial coordination at the centers of porphyrin rings and stabilizes a CoII-based metalloradical. These characteristics promote NIR light absorption and non-radiative decay, thereby improving photothermal conversion efficiency. Consequently, CoTCPP-Bi can rapidly elevate the temperature from room temperature to 190 °C within 30 seconds under 0.7 W cm-2 energy power from 808 nm laser irradiation. Moreover, it enables solar-driven water evaporation with an efficiency of 98.5% and a rate of 1.43 kg m-2 h-1 under 1 sun irradiation. This research provides valuable insights into the strategic design of efficient photothermal materials for effective NIR light absorption, leveraging the principles of aggregation effect and metalloradical chemistry.

Photoacoustic Imaging Using Polysaccharide-Porphyrin Complexes by Photoirradiation at Long Wavelengths

Photoacoustic (PA) imaging is a novel biological imaging technique with superior depth resolution compared to fluorescence imaging. The efficacy of PA imaging depends on contrast agents that possess considerable absorbance at longer wavelengths, coupled with high permeability in biological tissue and minimal fluorescence, achieved through mitigating aggregation-caused quenching (ACQ) that attenuates PA intensity. Despite the successful transfer of porphyrin 2 featuring amino moieties from polysaccharides to liposomes, most of 2 incorporated within λ-carrageenan (CGN-2 complex) remained in CGN under acidic lysosomal conditions (pH 5.0). Consequently, the CGN-2 complex exhibited a strong PA signal under 680 nm photoirradiation in Colon26 cells owing to the ACQ of 2. Moreover, the PA intensity of the CGN-2 complex was further enhanced under 780 nm photoirradiation owing to the increased absorbance at 780 nm facilitated by the redshift of the Q-band at pH 5.0.

Comprehensive Computational Investigation of the Porphyrin-Based COF as a Nanocarrier for Delivering Anti-Cancer Drugs: A Combined MD Simulation and DFT Calculation

As nanomaterials have gained prominence in drug delivery technology, exploring their feasibility through computational methods is beneficial before practical tests. In this study, we aim to evaluate the capability of the porphyrin-based covalent organic framework COF-366 as a nanocarrier for two anticancer drugs, irinotecan (IRI) and doxorubicin (DOX). The optimal binding conformation of the drug molecules on the COF surface was predicted by using molecular docking. Subsequently, molecular dynamic simulation (MD) was performed to assess the adsorption mechanism of drug molecules on the COF in the aqueous environment. The free energy of adsorption for DOX and IRI was estimated to be -20.07 and -23.89 kcal/mol, respectively. The adsorption of both drugs on the COF surface is mainly influenced by the π-π interaction. Furthermore, density functional theory (DFT) calculation, natural bond orbital (NBO), and quantum theory of atoms in molecules (QTAIM) analyses were employed to investigate the structural stability of Drug@COF complexes and gain a detailed understanding of the interaction between them at the molecular level. Based on DFT results, it was found that in addition to π-π interaction, the bis-piperidine-phenylene interaction affects the adsorption of IRI on the COF surface. Moreover, the diffusion behavior of the drug molecule inside the COF pore was simulated using a ten-layer COF. Based on the mean square displacement analysis, the diffusion coefficients of DOX and IRI within the COF pore were calculated to be 108 and 97 um2/s, respectively. This computational study sheds light on how different types of interactions between the drug molecule and COF affect the adsorption and diffusion process. Our findings validated that the porphyrin-based COF-366 can serve as a nanobased platform for delivering DOX and IRI.

Ultra-Strong Janus Covalent Organic Framework Membrane with Smart Response to Organic Vapor

Vapor-driven smart Janus materials have made significant advancements in intelligent monitoring, control, and interaction, etc. Nevertheless, the development of ultrafast response single-layer Janus membrane, along with a deep exploration of the smart response mechanisms, remains a long-term endeavor. Here, the successful synthesis of a high-crystallinity single-layer Covalent organic framework (COF) Janus membrane is reported by morphology control. This kind of membrane displays superior mechanical properties and specific surface area, along with excellent responsiveness to CH2Cl2 vapor. The analysis of the underlying mechanisms reveals that the vapor-induced breathing effect of the COF and the stress mismatch of the Janus structure play a crucial role in its smart deformation performance. It is believed that this COF Janus membrane holds promise for complex tasks in various fields.

Supramolecular dye nanoassemblies for advanced diagnostics and therapies

Dyes have conventionally been used in medicine for staining cells, tissues, and organelles. Since these compounds are also known as photosensitizers (PSs) which exhibit photoresponsivity upon photon illumination, there is a high desire towards formulating these molecules into nanoparticles (NPs) to achieve improved delivery efficiency and enhanced stability for novel imaging and therapeutic applications. Furthermore, it has been shown that some of the photophysical properties of these molecules can be altered upon NP formation thereby playing a major role in the outcome of their application. In this review, we primarily focus on introducing dye categories, their formulation strategies and how these strategies affect their photophysical properties in the context of photothermal and non-photothermal applications. More specifically, the most recent progress showing the potential of dye supramolecular assemblies in modalities such as photoacoustic and fluorescence imaging, photothermal and photodynamic therapies as well as their employment in photoablation as a novel modality will be outlined. Aside from their photophysical activity, we delve shortly into the emerging application of dyes as drug stabilizing agents where these molecules are used together with aggregator molecules to form stable nanoparticles.

Ambient Synthesis of Porphyrin-Based Fe-Covalent Organic Frameworks for Efficient Infected Skin Wound Healing

Reactive oxygen species (ROS) have emerged as a promising treatment option for antibacterial and biofilm eradication. However, their therapeutic efficacy is significantly hampered by the unique microenvironments of diabetic wounds. In this study, we designed and synthesized porphyrin-based Fe covalent organic frameworks (Fe-COF) through a Schiff base condensation reaction. Subsequently, Fe-COF were encapsulated with hyaluronic acid (HA) through electrostatic adsorption, resulting in a novel formulation named HA-Fe-COF for diabetic wound healing. HA-Fe-COF were engineered to respond to hyaluronidase in the infected wound, leading to the controlled release of Fe-COF. Those released Fe-COF served a dual role as photosensitizers, generating singlet oxygen and localized heating when exposed to dual light sources. Additionally, they acted as peroxidase-like nanozymes, facilitating the production of ROS through enzymatic reactions. This innovative approach enabled a synergistic therapeutic effect combining photodynamic, photothermal, and chemodynamic modalities. Furthermore, the sustained release of HA from HA-Fe-COF promoted angiogenesis, collagen deposition, and re-epithelialization during the diabetic wound healing process. This "all-in-one" strategy offers a novel approach for the development of antimicrobial and biofilm eradication strategies that minimize damage to healthy tissues in vivo.

Simultaneous Protonation and Metalation of a Porphyrin Covalent Organic Framework Enhance Photodynamic Therapy

Covalent organic frameworks (COFs) have been explored for photodynamic therapy (PDT) of cancer, but their antitumor efficacy is limited by excited state quenching and low reactive oxygen species generation efficiency. Herein, we report a simultaneous protonation and metalation strategy to significantly enhance the PDT efficacy of a nanoscale two-dimensional imine-linked porphyrin-COF. The neutral and unmetalated porphyrin-COF (Ptp) and the protonated and metalated porphyrin-COF (Ptp-Fe) were synthesized via imine condensation between 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and terephthalaldehyde in the absence and presence of ferric chloride, respectively. The presence of ferric chloride generated both doubly protonated and Fe3+-coordinated porphyrin units, which red-shifted and increased the Q-band absorption and disrupted exciton migration to prevent excited state quenching, respectively. Under light irradiation, rapid energy transfer from protonated porphyrins to Fe3+-coordinated porphyrins in Ptp-Fe enabled 1O2 and hydroxyl radical generation via type II and type I PDT processes. Ptp-Fe also catalyzed the conversion of hydrogen peroxide to hydroxy radical through a photoenhanced Fenton-like reaction under slightly acidic conditions and light illumination. As a result, Ptp-Fe-mediated PDT exhibited much higher cytotoxicity than Ptp-mediated PDT on CT26 and 4T1 cancer cells. Ptp-Fe-mediated PDT afforded potent antitumor efficacy in subcutaneous CT26 murine colon cancer and orthotopic 4T1 murine triple-negative breast tumors and prevented metastasis of 4T1 breast cancer to the lungs. This work underscores the role of fine-tuning the molecular structures of COFs in significantly enhancing their PDT efficacy.

Dialdehyde cellulose films covalently crosslinked with porphyrin-based covalent organic polymers for photodynamic sterilization

Foodborne pathogens result in a great harm to human, which is an urgent problem to be addressed. Herein, a novel cellulose-based packaging films with excellent anti-bacterial properties under visible light were prepared. A porphyrin-based covalent organic polymer (Por-COPs) was constructed, then covalently grafted onto dialdehyde cellulose (DAC). The addition of Por-COPs enhanced the mechanical, hydrophobicity, and water resistance of the DAC-based composite films. DAC/Por-COP-2.5 film exhibited outstanding properties for the photodynamic inactivation of bacteria under visible light irradiation, delivering inactivation efficiencies of 99.90 % and 99.45 % towards Staphylococcus aureus and Escherichia coli within 20 min. The DAC/Por-COPs films efficiently generated •O2- and 1O2 under visible light, thereby causing oxidative stress to cell membranes for bacterial inactivation. The prepared composite film forms a protective barrier against bacterial contamination. Results guide the development of high performance and more sustainable packaging films for the food sector.

New insights into targeted therapy of glioblastoma using smart nanoparticles

In recent times, the intersection of nanotechnology and biomedical research has given rise to nanobiomedicine, a captivating realm that holds immense promise for revolutionizing diagnostic and therapeutic approaches in the field of cancer. This innovative fusion of biology, medicine, and nanotechnology aims to create diagnostic and therapeutic agents with enhanced safety and efficacy, particularly in the realm of theranostics for various malignancies. Diverse inorganic, organic, and hybrid organic-inorganic nanoparticles, each possessing unique properties, have been introduced into this domain. This review seeks to highlight the latest strides in targeted glioblastoma therapy by focusing on the application of inorganic smart nanoparticles. Beyond exploring the general role of nanotechnology in medical applications, this review delves into groundbreaking strategies for glioblastoma treatment, showcasing the potential of smart nanoparticles through in vitro studies, in vivo investigations, and ongoing clinical trials.

An Azulene-Based Crystalline Porous Covalent Organic Framework for Efficient Photothermal Conversion

The designed synthesis of a crystalline azulene-based covalent organic framework (COF-Azu-TP) is presented and its photothermal property is investigated. Azulene, a distinctive 5-7 fused ring non-benzenoid aromatic compound with a large intramolecular dipole moment and unique photophysical characteristics, is introduced as the key feature in COF-Azu-TP. The incorporation of azulene moiety imparts COF-Azu-TP with broad-spectrum light absorption capability and interlayer dipole interactions, which makes COF-Azu-TP a highly efficient photothermal conversion material. Its polyurethane (PU) composite exhibits a solar-to-vapor conversion efficiency (97.2%) and displays a water evaporation rate (1.43 kg m-2 h-1) under one sun irradiation, even at a very low dosage of COF-Azu-TP (2.2 wt%). Furthermore, COF-Azu-TP is utilized as a filler in a polylactic acid (PLA)/polycaprolactone (PCL) composited shape memory material, enabling rapid shape recovery under laser stimulation. A comparison study with a naphthalene-based COF isomer further emphasizes the crucial role of azulene in enhancing photothermal conversion efficiency. This study demonstrates the significance of incorporating specific building blocks into COFs for the development of functional porous materials with enhanced properties, paving the way for future applications in diverse fields.

A Nanoscale Trans-Platinum(II)-Based Supramolecular Coordination Self-Assembly with a Distinct Anticancer Mechanism

Drug resistance significantly hampers the clinical application of existing platinum-based anticancer drugs. New platinum medications that possess distinct mechanisms of action are highly desired for the treatment of Pt-resistant cancers. Herein, a nanoscale trans-platinum(II)-based supramolecular coordination self-assembly (Pt-TCPP-BA) is prepared via using trans-[PtCl2(pyridine)(NH3)] (transpyroplatin), tetracarboxylporphyrin (TCPP), and benzoic acid (BA) as building blocks to combat drug resistance in platinum-based chemotherapy. Mechanistic studies indicate that Pt-TCPP-BA shows a hydrogen-peroxide-responsive dissociation behavior along with the generation of bioactive trans-Pt(II) and TCPP-Pt species. Different from cisplatin, these degradation products interact with DNA via interstrand cross-links and small groove binding, and induce significant upregulation of cell-death-related proteins such as p53, cleaved caspase 3, p21, and phosphorylated H2A histone family member X in cisplatin-resistant cancer cells. As a result, Pt-TCPP-BA exhibits potent killing effects against Pt-resistant tumors both in vitro and in vivo. Overall, this work not only provides a new platinum drug for combating drug-resistant cancer but also offers a new paradigm for the development of platinum-based supramolecular anticancer drugs.

Hypoxia-triggered degradable porphyrinic covalent organic framework for synergetic photodynamic and photothermal therapy of cancer

Nanomedicines receive great attention in cancer treatment. Nevertheless, nonbiodegradable and long-term retention still limit their clinical translation. Herein, we successfully synthesize a hypoxia-triggered degradable porphyrinic covalent organic framework (HPCOF) for antitumor therapy in vivo. HPCOF possesses wide absorption in near infrared region (NIR) which endows HPCOF excellent photothermal conversion efficiency and photoacoustic (PA) imaging ability. Moreover, HPCOF exhibits excellent photodynamic and photothermal effect under special-wavelength laser irradiation. For the first time, the in vitro and in vivo tests demonstrate that HPCOF shows effective therapeutic effect for the combination of PDT and PTT under the monitoring of PA imaging. Importantly, in tumor region, HPCOF could be triggered by hypoxia microenvironment and collapsed gradually, then cleared from the body after treatment. This work fabricates a novel COF for cancer treatment and testifies great potential of HPCOF in clinical application with reducing long-term toxicity.

Nanocatalysts for modulating antitumor immunity: fabrication, mechanisms and applications

Immunotherapy harnesses the inherent immune system in the body to generate systemic antitumor immunity, offering a promising modality for defending against cancer. However, tumor immunosuppression and evasion seriously restrict the immune response rates in clinical settings. Catalytic nanomedicines can transform tumoral substances/metabolites into therapeutic products in situ, offering unique advantages in antitumor immunotherapy. Through catalytic reactions, both tumor eradication and immune regulation can be simultaneously achieved, favoring the development of systemic antitumor immunity. In recent years, with advancements in catalytic chemistry and nanotechnology, catalytic nanomedicines based on nanozymes, photocatalysts, sonocatalysts, Fenton catalysts, electrocatalysts, piezocatalysts, thermocatalysts and radiocatalysts have been rapidly developed with vast applications in cancer immunotherapy. This review provides an introduction to the fabrication of catalytic nanomedicines with an emphasis on their structures and engineering strategies. Furthermore, the catalytic substrates and state-of-the-art applications of nanocatalysts in cancer immunotherapy have also been outlined and discussed. The relationships between nanostructures and immune regulating performance of catalytic nanomedicines are highlighted to provide a deep understanding of their working mechanisms in the tumor microenvironment. Finally, the challenges and development trends are revealed, aiming to provide new insights for the future development of nanocatalysts in catalytic immunotherapy.

Covalent Organic Frameworks: Opportunities for Rational Materials Design in Cancer Therapy

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.

Covalent-Organic Framework-Based Materials in Theranostic Applications: Insights into Their Advantages and Challenges

Nanomedicine has been essential in bioimaging and cancer therapy in recent years. Nanoscale covalent-organic frameworks (COFs) have been growing as an adequate classification of biomedical nanomaterials with practical application prospects because of their increased porosity, functionality, and biocompatibility. The high sponginess of COFs enables the incorporation of distinct imaging and therapeutic mechanisms with a better loading efficiency. Nevertheless, preliminary biocompatibility limits their possibility for clinical translation. Thus, cutting-edge nanomaterials with high biocompatibility and improved therapeutic efficiency are highly expected to fast-track the clinical translation of nanomedicines. The inherent effects of nanoscale COFs, such as proper size, modular pore geometry and porosity, and specific postsynthetic transformation through simple organic changes, make them particularly appealing for prospective nanomedicines. The organic building blocks of COFs may also be postmodified for particular binding to biomarkers. The exceptional features of COFs cause them to be an encouraging nanocarrier for bioimaging and therapeutic applications. In this review, we have systematically discussed the advances of COFs in the field of theranostics by providing essential features of COFs along with their synthetic methods. Further, the applications of COFs in the field of theranostics (such as drug delivery systems, photothermal, and photodynamic therapy) are discussed in detail with the help of available literature to date. Furthermore, the advantages of COFs over other materials for therapeutics and drug delivery are discussed. Finally, the review concludes with potential future COF applications in the theranostic field.

Advancing Cancer Treatment: Enhanced Combination Therapy through Functionalized Porous Nanoparticles

Cancer remains a major global health challenge, necessitating the development of innovative treatment strategies. This review focuses on the functionalization of porous nanoparticles for combination therapy, a promising approach to enhance cancer treatment efficacy while mitigating the limitations associated with conventional methods. Combination therapy, integrating multiple treatment modalities such as chemotherapy, phototherapy, immunotherapy, and others, has emerged as an effective strategy to address the shortcomings of individual treatments. The unique properties of mesoporous silica nanoparticles (MSN) and other porous materials, like nanoparticles coated with mesoporous silica (NP@MS), metal-organic frameworks (MOF), mesoporous platinum nanoparticles (mesoPt), and carbon dots (CDs), are being explored for drug solubility, bioavailability, targeted delivery, and controlled drug release. Recent advancements in the functionalization of mesoporous nanoparticles with ligands, biomaterials, and polymers are reviewed here, highlighting their role in enhancing the efficacy of combination therapy. Various research has demonstrated the effectiveness of these nanoparticles in co-delivering drugs and photosensitizers, achieving targeted delivery, and responding to multiple stimuli for controlled drug release. This review introduces the synthesis and functionalization methods of these porous nanoparticles, along with their applications in combination therapy.

Recent bio-applications of covalent organic framework-based nanomaterials

Appearing as a new class of functional organic materials, covalent organic frameworks (COFs) have aroused a huge wave of interest in versatile fields ever since they were first proposed in 2005. Thanks to but not limited to their ultralight weights, high surface areas, ordered channels, variable functional groups and well-defined crystal structures, the applications of COF-based biomaterials in the fields of drug loading and delivery, photodynamic therapy, photothermal therapy, bioimaging, etc. are comprehensively summarized and introduced. The existing challenges and future prospects for this emerging but hot research direction are also discussed. It is hoped that this review will serve as a guidance for future research on COFs as multifunctional bioplatforms.

Nanoscale Covalent Organic Framework with Staggered Stacking of Phthalocyanines for Mitochondria-Targeted Photodynamic Therapy

Phthalocyanine photosensitizers (PSs) have shown promise in fluorescence imaging and photodynamic therapy (PDT) of malignant tumors, but their practical application is limited by the aggregation-induced quenching (AIQ) and inherent photobleaching of PSs. Herein, we report the synthesis of a two-dimensional nanoscale covalent organic framework (nCOF) with staggered (AB) stacking of zinc-phthalocyanines (ZnPc), ZnPc-PI, for fluorescence imaging and mitochondria-targeted PDT. ZnPc-PI isolates and confines ZnPc PSs in the rigid nCOF to reduce AIQ, improve photostability, enhance cellular uptake, and increase the level of reactive oxygen species (ROS) generation via mitochondrial targeting. ZnPc-PI shows efficient tumor accumulation, which allowed precise tumor imaging and nanoparticle tracking. With high cellular uptake and tumor accumulation, intrinsic mitochondrial targeting, and enhanced ROS generation, ZnPc-PI exhibits potent PDT efficacy with >95% tumor growth inhibition on two murine colon cancer models without causing side effects.

Applications of Pyrrole and Pyridine-based Heterocycles in Cancer Diagnosis and Treatment

BACKGROUND

The escalation of cancer worldwide is one of the major causes of economy burden and loss of human resources. According to the American Cancer Society, there will be 1,958,310 new cancer cases and 609,820 projected cancer deaths in 2023 in the United States. It is projected that by 2040, the burden of global cancer is expected to rise to 29.5 million per year, causing a death toll of 16.4 million. The hemostasis regulation by cellular protein synthesis and their targeted degradation is required for normal cell growth. The imbalance in hemostasis causes unbridled growth in cells and results in cancer. The DNA of cells needs to be targeted by chemotherapeutic agents for cancer treatment, but at the same time, their efficacy and toxicity also need to be considered for successful treatment.

OBJECTIVE

The objective of this study is to review the published work on pyrrole and pyridine, which have been prominent in the diagnosis and possess anticancer activity, to obtain some novel lead molecules of improved cancer therapeutic.

METHODS

A literature search was carried out using different search engines, like Sci-finder, Elsevier, ScienceDirect, RSC etc., for small molecules based on pyrrole and pyridine helpful in diagnosis and inducing apoptosis in cancer cells. The research findings on the application of these compounds from 2018-2023 were reviewed on a variety of cell lines, such as breast cancer, liver cancer, epithelial cancer, etc. Results: In this review, the published small molecules, pyrrole and pyridine and their derivatives, which have roles in the diagnosis and treatment of cancers, were discussed to provide some insight into the structural features responsible for diagnosis and treatment. The analogues with the chromeno-furo-pyridine skeleton showed the highest anticancer activity against breast cancer. The compound 5-amino-N-(1-(pyridin-4- yl)ethylidene)-1H-pyrazole-4-carbohydrazides was highly potent against HEPG2 cancer cell. Redaporfin is used for the treatment of cholangiocarcinoma, biliary tract cancer, cisplatin-resistant head and neck squamous cell carcinoma, and pigmentation melanoma, and it is in clinical trials for phase II. These structural features present a high potential for designing novel anticancer agents for diagnosis and drug development.

CONCLUSION

Therefore, the N- and C-substituted pyrrole and pyridine-based novel privileged small Nheterocyclic scaffolds are potential molecules used in the diagnosis and treatment of cancer. This review discusses the reports on the synthesis of such molecules during 2018-2023. The review mainly discusses various diagnostic techniques for cancer, which employ pyrrole and pyridine heterocyclic scaffolds. Furthermore, the anticancer activity of N- and C-substituted pyrrole and pyridine-based scaffolds has been described, which works against different cancer cell lines, such as MCF-7, A549, A2780, HepG2, MDA-MB-231, K562, HT- 29, Caco-2 cells, Hela, Huh-7, WSU-DLCL2, HCT-116, HBL-100, H23, HCC827, SKOV3, etc. This review will help the researchers to obtain a critical insight into the structural aspects of pyrrole and pyridine-based scaffolds useful in cancer diagnosis as well as treatment and design pathways to develop novel drugs in the future.

Applications of supramolecular assemblies in drug delivery and photodynamic therapy

One of the world's serious health challenges is cancer. Anti-cancer agents delivered to normal cells and tissues pose several problems and challenges. In this connection, photodynamic therapy (PDT) is a minimally invasive therapeutic technique used for selectively destroying malignant cells while sparing the normal tissues. Development in photosensitisers (PSs) and light sources have to be made for PDT as a first option treatment for patients. In the pursuit of developing new attractive molecules and their formulations for PDT, researchers are working on developing such type of PSs that perform better than those being currently used. For the widespread clinical utilization of PDT, effective PSs are of particular importance. Host-guest interactions based on nanographene assemblies such as functionalized hexa-cata-hexabenzocoronenes, hexa-peri-hexabenzocoronenes and coronene have attracted increasing attention owing to less complicated synthetic steps and purification processes (gel permeation chromatography) during fabrication. Noncovalent interactions provide easy and facile approaches for building supramolecular PSs and enable them to have sensitive and controllable photoactivities, which are important for maximizing photodynamic effects and minimizing side effects. Various versatile supramolecular assemblies based on cyclodextrins, cucurbiturils, calixarenes, porphyrins and pillararenes have been designed in order to make PDT an effective therapeutic technique for curing cancer and tumours. The supramolecular assemblies of porphyrins display efficient electron transfer and fluorescence for use in bioimaging and PDT. The multifunctionalization of supramolecular assemblies is used for designing biomedically active PSs, which are helpful in PDT. It is anticipated that the development of these functionalized supramolecular assemblies will provide more fascinating advances in PDT and will dramatically expand the potential and possibilities in cancer treatments.

Covalent organic framework-based nanoplatforms with tunable mechanical properties for drug delivery and cancer therapy

Covalent organic frameworks (COFs) are emerging crystalline porous materials composed of covalently linked and periodically arranged organic molecules, which exhibit mechanical properties mediated by structural diversity. Meanwhile, the tunable mechanical properties of COFs have been widely applied in drug delivery and cancer therapy. Herein, we first summarize the regulation strategies of COFs with different mechanical strengths, such as structural dimensions, pore sizes, and host-guest interaction forces. Then, the remarkable achievements of COFs with different mechanical properties in drug delivery and cancer therapy in recent years are introduced. Finally, the mechanical strength regulation of COFs and the remaining challenges for biomedical applications are presented. This review provides a more comprehensive understanding of the application of COFs systems with tunable mechanical properties in the field of biomedicine, and promotes the development of interdisciplinary research between COFs materials and nanomedicine.

Acoustic platforms meet MXenes - a new paradigm shift in the palette of biomedical applications

The wide applicability of acoustics in the life of mankind spread over health, energy, environment, and others. These acoustic technologies rely on the properties of the materials with which they are made of. However, traditional devices have failed to develop into low-cost, portable devices and need to overcome issues like sensitivity, tunability, and applicability in biological in vivo studies. Nanomaterials, especially 2D materials, have already been proven to produce high optical contrast in photoacoustic applications. One such wonder kid in the materials family is MXenes, which are transition metal carbides, that are nowadays flourishing in the materials world. Recently, it has been demonstrated that MXene nanosheets and quantum dots can be synthesized by acoustic excitations. In addition, MXene can be used as a mechanical sensing material for building piezoresistive sensors to realize sound detection as it produces a sensitive response to pressure and vibration. It has also been demonstrated that MXene nanosheets show high photothermal conversion capability, which can be utilized in cancer treatment and photoacoustic imaging (PAI). In this review, we have rendered the role of acoustics in the palette of MXene, including acoustic synthetic strategies of MXenes, applications such as acoustic sensors, PAI, thermoacoustic devices, sonodynamic therapy, artificial ear drum, and others. The review also discusses the challenges and future prospects of using MXene in acoustic platforms in detail. To the best of our knowledge, this is the first review combining acoustic science in MXene research.

Covalent organic frameworks: linkage types, synthetic methods and bio-related applications

Covalent organic frameworks (COFs) are composed of small organic molecules linked via covalent bonds, which have tunable mesoporous structure, good biocompatibility and functional diversities. These excellent properties make COFs a promising candidate for constructing biomedical nanoplatforms and provide ample opportunities for nanomedicine development. A systematic review of the linkage types and synthesis methods of COFs is of indispensable value for their biomedical applications. In this review, we first summarize the types of various linkages of COFs and their corresponding properties. Then, we highlight the reaction temperature, solvent and reaction time required by different synthesis methods and show the most suitable synthesis method by comparing the merits and demerits of various methods. To appreciate the cutting-edge research on COFs in bioscience technology, we also summarize the bio-related applications of COFs, including drug delivery, tumor therapy, bioimaging, biosensing and antimicrobial applications. We hope to provide insight into the interdisciplinary research on COFs and promote the development of COF nanomaterials for biomedical applications and their future clinical translations.

Near-infrared photodynamic and photothermal co-therapy based on organic small molecular dyes

Near-infrared (NIR) organic small molecule dyes (OSMDs) are effective photothermal agents for photothermal therapy (PTT) due to their advantages of low cost and toxicity, good biodegradation, and strong NIR absorption over a wide wavelength range. Nevertheless, OSMDs have limited applicability in PTT due to their low photothermal conversion efficiency and inadequate destruction of tumor regions that are nonirradiated by NIR light. However, they can also act as photosensitizers (PSs) to produce reactive oxygen species (ROS), which can be further eradicated by using ROS-related therapies to address the above limitations of PTT. In this review, the synergistic mechanism, composition, and properties of photodynamic therapy (PDT)-PTT nanoplatforms were comprehensively discussed. In addition, some specific strategies for further improving the combined PTT and PDT based on OSMDs for cancer to completely eradicate cancer cells were outlined. These strategies include performing image-guided co-therapy, enhancing tumor infiltration, increasing H2O2 or O2 in the tumor microenvironment, and loading anticancer drugs onto nanoplatforms to enable combined therapy with phototherapy and chemotherapy. Meanwhile, the intriguing prospects and challenges of this treatment modality were also summarized with a focus on the future trends of its clinical application.

Synthesis of lenvatinib-loaded upconversion@polydopamine nanocomposites for upconversion luminescence imaging-guided chemo-photothermal synergistic therapy of anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is the most malignant and aggressive of all classifications of thyroid cancer. ATC normally has poor prognosis after classic treatments such as surgery, endocrine therapy, radiotherapy and chemotherapy. Herein, a novel nanocomposite (named as UCNP@PDA@LEN) has been synthesized for chemo-photothermal therapy of ATC, which is based on a NaErF4:Tm3+@NaYbF4@NaYF4:Nd3+ upconverting nanoparticle (UCNP) as the core, a near-infrared light (NIR)-absorbing polydopamine (PDA) as the shell, and lenvatinib (LEN) as a chemotherapeutic drug. The as-prepared multifunctional UCNP@PDA@LEN exhibits excellent photothermal conversion capability (η = 30.7%), good photothermal stability and reasonable biocompatibility. Owing to the high UCL emission and good tumor accumulation ability, the UCL imaging of mouse-bearing ATC (i.e., C643 tumor) has been achieved by UCNP@PDA@LEN. Under 808 nm NIR laser irradiation, the UCNP@PDA@LEN shows a synergistic interaction between photothermal therapy (PTT) and chemotherapy (CT), resulting in strongly suppressed mouse-bearing C643 tumor. The results provide an explicit approach for developing theranostics with high anti-ATC efficiency.

Multifunctional Bacterial Cellulose/Covalent Organic Framework Composite Membranes with Antifouling and Antibacterial Properties for Dye Separation

Covalent organic frameworks (COFs) have a wide application prospect in wastewater treatment because of their unique structure and properties; however, the preparation of pure COF membranes remains a great challenge by reason of the insolubility and unprocessability of COF powders formed at high temperature and high pressure. In this study, a continuous and defect-free bacterial cellulose/covalent organic framework composite membrane was prepared by using bacterial cellulose (BC) and a porphyrin-based COF with their unique structures and hydrogen bonding forces. The dye rejection rate of this composite membrane toward methyl green and congo red was up to 99%, and the permeance was about 195 L m^-2 h^-1 bar^-1. It showed excellent stability under different pH conditions, long-time filtration, and cyclic experimental conditions. In addition, the hydrophilicity and surface negativity of the BC/COF composite membrane made it have certain antifouling performance, and the flux recovery rate can reach 93.72%. More importantly, the composite membrane exhibited excellent antibacterial properties due to the doping of the porphyrin-based COF, and the survival rates of both Escherichia coli and Staphylococcus aureus were less than 1% after exposure to visible light. The self-supporting BC/COF composite membrane synthesized by this strategy also has outstanding antifouling and antibacterial properties, in addition to excellent dye separation effects, which greatly broaden the application of COF materials in water treatment.

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.

Photodynamic and Photothermal Therapies: Synergy Opportunities for Nanomedicine

Tumoricidal photodynamic (PDT) and photothermal (PTT) therapies harness light to eliminate cancer cells with spatiotemporal precision by either generating reactive oxygen species or increasing temperature. Great strides have been made in understanding biological effects of PDT and PTT at the cellular, vascular and tumor microenvironmental levels, as well as translating both modalities in the clinic. Emerging evidence suggests that PDT and PTT may synergize due to their different mechanisms of action, and their nonoverlapping toxicity profiles make such combination potentially efficacious. Moreover, PDT/PTT combinations have gained momentum in recent years due to the development of multimodal nanoplatforms that simultaneously incorporate photodynamically- and photothermally active agents. In this review, we discuss how combining PDT and PTT can address the limitations of each modality alone and enhance treatment safety and efficacy. We provide an overview of recent literature featuring dual PDT/PTT nanoparticles and analyze the strengths and limitations of various nanoparticle design strategies. We also detail how treatment sequence and dose may affect cellular states, tumor pathophysiology and drug delivery, ultimately shaping the treatment response. Lastly, we analyze common experimental design pitfalls that complicate preclinical assessment of PDT/PTT combinations and propose rational guidelines to elucidate the mechanisms underlying PDT/PTT interactions.

Porphyrin-Based Covalent Organic Frameworks: Design, Synthesis, Photoelectric Conversion Mechanism, and Applications

Photosynthesis occurs in high plants, and certain organisms show brilliant technology in converting solar light to chemical energy and producing carbohydrates from carbon dioxide (CO₂). Mimicking the mechanism of natural photosynthesis is receiving wide-ranging attention for the development of novel materials capable of photo-to-electric, photo-to-chemical, and photocatalytic transformations. Porphyrin, possessing a similar highly conjugated core ring structure to chlorophyll and flexible physical and chemical properties, has become one of the most investigated photosensitizers. Chemical modification and self-assembly of molecules as well as constructing porphyrin-based metal (covalent) organic frameworks are often used to improve its solar light utilization and electron transfer rate. Especially porphyrin-based covalent organic frameworks (COFs) in which porphyrin molecules are connected by covalent bonds combine the structural advantages of organic frameworks with light-capturing properties of porphyrins and exhibit great potential in light-responsive materials. Porphyrin-based COFs are expected to have high solar light utilization, fast charge separation/transfer performance, excellent structural stability, and novel steric selectivity by special molecular design. In this paper, we reviewed the research progress of porphyrin-based COFs in the design, synthesis, properties, and applications. We focused on the intrinsic relationship between the structure and properties, especially the photoelectric conversion properties and charge transfer mechanism of porphyrin-based COFs, and tried to provide more valuable information for the design of advanced photosensitizers. The applications of porphyrin-based COFs in photocatalysis and phototherapy were emphasized based on their special structure design and light-to-electric (or light-to-heat) conversion control.