Biodegradable Poly(γ-glutamic acid)@glucose oxidase@carbon dot nanoparticles for simultaneous multimodal imaging and synergetic cancer therapy

Progress on Carbon Dots with Intrinsic Bioactivities for Multimodal Theranostics

Carbon dots (CDs) with intrinsic bioactivities are candidates for bioimaging and disease therapy due to their diverse bioactivities, high biocompatibility, and multiple functionalities in multimodal theranostics. It is a multidisciplinary research hotspot that includes biology, physics, materials science, and chemistry. This progress report discusses the CDs with intrinsic bioactivities and their applications in multimodal theranostics. The relationship between the synthesis and structure of CDs is summarized and analyzed from a material and chemical perspective. The bioactivities of CDs including anti-tumor, antibacterial, anti-inflammatory etc. are discussed from biological points of view. Subsequently, the optical and electronic properties of CDs that can be applied in the biomedical field are summarized from a physical perspective. Based on the functional review of CDs, their applications in the biomedical field are reviewed, including optical diagnosis and treatment, biological activity, etc. Unlike previous reviews, this review combines multiple disciplines to gain a more comprehensive understanding of the mechanisms, functions, and applications of CDs with intrinsic bioactivities.

Tumor Microenvironment Specific Regulation Ca-Fe-Nanospheres for Ferroptosis-Promoted Domino Synergistic Therapy and Tumor Immune Response

Reactive oxygen species (ROS)-mediated emerging treatments exhibit unique advantages in cancer therapy in recent years. While the efficacy of ROS-involved tumor therapy is greatly restricted by complex tumor microenvironment (TME). Herein, a dual-metal CaO2@CDs-Fe (CCF) nanosphere, with TME response and regulation capabilities, are proposed to improve ROS lethal power by a multiple cascade synergistic therapeutic strategy with domino effect. In response to weak acidic TME, CCF will decompose, accompanied with intracellular Ca2+ upregulated and abundant H2O2 and O2 produced to reverse antitherapeutic TME. Then the exposed CF cores can act as both Fenton agent and sonosensitizer to generate excessive ROS in the regulated TME for enhanced synergistic CDT/SDT. In combination with calcium overloading, the augmented ROS induced oxidative stress will cause more severe mitochondrial damage and cellular apoptosis. Furthermore, CCF can also reduce GPX4 expression and enlarge the lipid peroxidation, causing ferroptosis and apoptosis in parallel. These signals of damage will finally initiate damage-associated molecular patterns to activate immune response and to realize excellent antitumor effect. This outstanding domino ROS/calcium loading synergistic effect endows CCF with excellent anticancer effect to efficiently eliminate tumor by apoptosis/ferroptosis/ICD both in vitro and in vivo.

Targeting tumor microenvironment with photodynamic nanomedicine

Photodynamic therapy (PDT) is approved for the treatment of certain cancers and precancer lesions. While early Photosensitizers (PS) have found their way to the clinic, research in the last two decades has led to the development of third-generation PS, including photodynamic nanomedicine for improved tumor delivery and minimal systemic or phototoxicity. In terms of nanoparticle design for PDT, we are witnessing a shift from passive to active delivery for improved outcomes with reduced PS dosage. Tumor microenvironment (TME) comprises of a complex and dynamic landscape with myriad potential targets for photodynamic nanocarriers that are surface-modified with ligands. Herein, we review ways to improvise PDT by actively targeting nanoparticles (NPs) to intracellular organelles such as mitochondria or lysosomes and so forth, overcoming the limitations caused by PDT-induced hypoxia, disrupting the blood vascular networks in tumor tissues-vascular targeted PDT (VTP) and targeting immune cells for photoimmunotherapy. We propose that a synergistic outlook will help to address challenges such as deep-seated tumors, metastasis, or relapse and would lead to robust PDT response in patients.

Advances in H2O2-supplying materials for tumor therapy: synthesis, classification, mechanisms, and applications

Hydrogen peroxide (H2O2) as a reactive oxygen species produced by cellular metabolism can be used in antitumor therapy. However, the concentration of intracellular H2O2 limits its application. Some materials could enhance the concentration of intracellular H2O2 to strengthen antitumor therapy. In this review, the recent advances in H2O2-supplying materials in terms of promoting intracellular H2O2 production and exogenous H2O2 supply are summarized. Then the mechanism of H2O2-supplying materials for tumor therapy is discussed from three aspects: reconstruction of the tumor hypoxia microenvironment, enhancement of oxidative stress, and the intrinsic anti-tumor ability of H2O2-supplying materials. In addition, the application of H2O2-supplying materials for tumor therapy is discussed. Finally, the future of H2O2-supplying materials is presented. This review aims to provide a novel idea for the application of H2O2-supplying materials in tumor therapy.

Opportunities for nanomaterials in enzyme therapy

In recent years, enzyme therapy strategies have rapidly evolved to catalyze essential biochemical reactions with therapeutic potential. These approaches hold particular promise in addressing rare genetic disorders, cancer treatment, neurodegenerative conditions, wound healing, inflammation management, and infectious disease control, among others. There are several primary reasons for the utilization of enzymes as therapeutics: their substrate specificity, their biological compatibility, and their ability to generate a high number of product molecules per enzyme unit. These features have encouraged their application in enzyme replacement therapy where the enzyme serves as the therapeutic agent to rectify abnormal metabolic and physiological processes, enzyme prodrug therapy where the enzyme initiates a clinical effect by activating prodrugs, and enzyme dynamic or starving therapy where the enzyme acts upon host substrate molecules. Currently, there are >20 commercialized products based on therapeutic enzymes, but approval rates are considerably lower than other biologicals. This has stimulated nanobiotechnology in the last years to develop nanoparticle-based solutions that integrate therapeutic enzymes. This approach aims to enhance stability, prevent rapid clearance, reduce immunogenicity, and even enable spatio-temporal activation of the therapeutic catalyst. This comprehensive review delves into emerging trends in the application of therapeutic enzymes, with a particular emphasis on the synergistic opportunities presented by incorporating enzymes into nanomaterials. Such integration holds the promise of enhancing existing therapies or even paving the way for innovative nanotherapeutic approaches.

Recent breakthroughs in graphene quantum dot-enhanced sonodynamic and photodynamic therapy

Water-soluble graphene quantum dots (GQDs) have recently exhibited considerable potential for diverse biomedical applications owing to their exceptional optical and chemical properties. However, the pronounced heterogeneity in the composition, size, and morphology of GQDs poses challenges for a comprehensive understanding of the intricate correlation between their structural attributes and functional properties. This variability also introduces complexities in scaling the production processes and addressing safety considerations. Light and sound have firmly established their role in clinical applications as pivotal energy sources for minimally invasive therapeutic interventions. Given the limited penetration depth of light, photodynamic therapy (PDT) predominantly targets superficial conditions such as dermatological disorders, head and neck malignancies, ocular ailments, and early-stage esophageal cancer. Conversely, ultrasound-based sonodynamic therapy (SDT) capitalizes on its superior ability to propagate and focus ultrasound within biological tissues, enabling a diverse range of therapeutic applications, including the management of gliomas, breast cancer, hematological tumors, and modulation of the blood-brain barrier (BBB). Considering the advancements in theranostic and precision therapies, reevaluating these conventional energy sources and their associated sensitizers is imperative. This review introduces three prevalent treatment modalities that harness light and sound stimuli: PDT, SDT, and a synergistic approach that integrates PDT and SDT. This study delineated the therapeutic dynamics and contemporary designs of sensitizers tailored to these modalities. By exploring the historical context of the field and elucidating the latest design strategies, this review underscores the pivotal role of GQDs in propelling the evolution of PDT and SDT. This aspires to stimulate researchers to develop "multimodal" therapies integrating both light and sound stimuli.

Carbon Dots in the Pathological Microenvironment: ROS Producers or Scavengers?

Reactive oxygen species (ROS), as metabolic byproducts, play pivotal role in physiological and pathological processes. Recently, studies on the regulation of ROS levels for disease treatments have attracted extensive attention, mainly involving the ROS-induced toxicity therapy mediated by ROS producers and antioxidant therapy by ROS scavengers. Nanotechnology advancements have led to the development of numerous nanomaterials with ROS-modulating capabilities, among which carbon dots (CDs) standing out as noteworthy ROS-modulating nanomedicines own their distinctive physicochemical properties, high stability, and excellent biocompatibility. Despite progress in treating ROS-related diseases based on CDs, critical issues such as rational design principles for their regulation remain underexplored. The primary cause of these issues may stem from the intricate amalgamation of core structure, defects, and surface states, inherent to CDs, which poses challenges in establishing a consistent generalization. This review succinctly summarizes the recently progress of ROS-modulated approaches using CDs in disease treatment. Specifically, it investigates established therapeutic strategies based on CDs-regulated ROS, emphasizing the interplay between intrinsic structure and ROS generation or scavenging ability. The conclusion raises several unresolved key scientific issues and prominent technological bottlenecks, and explores future perspectives for the comprehensive development of CDs-based ROS-modulating therapy.

A Nanoreactor Based on Metal-Organic Frameworks With Triple Synergistic Therapy for Hepatocellular Carcinoma

The transformation of monotherapy into multimodal combined targeted therapy to fully exploit synergistic efficacy is of increasing interest in tumor treatment. In this work, a novel nanodrug-carrying platform based on iron-based MOFs, which is loaded with doxorubicin hydrochloride (DOX), dihydroartemisinin (DHA), and glucose oxidase (GOx), and concurrently covalently linked to the photosensitizer 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) in polydopamine (PDA)-encapsulated MIL-101(Fe) (denoted as MIL-101(Fe)-DOX-DHA@TCPP/GOx@PDA, MDDTG@P), is successfully developed. Upon entering the tumor microenvironment, MDDTG@P catalyzes the hydrogen peroxide (H2O2) into hydroxyl radicals (·OH) and depletes glutathione (GSH); thus, exerting the role of chemodynamic therapy (CDT). The reduced Fe2+ can also activate DHA, further expanding CDT and promoting tumor cell apoptosis. The introduced GOx will rapidly consume glucose and oxygen (O2) in the tumor; while, replenishing H2O2 for Fenton reaction, starving the cancer cells; and thus, realizing starvation and chemodynamic therapy. In addition, the covalent linkage of TCPP endows MDDTG@P with good photodynamic therapeutic (PDT) properties. Therefore, this study develops a nanocarrier platform for triple synergistic chemodynamic/photodynamic/starvation therapy, which has promising applications in the efficient treatment of tumors.

The influence of near-infrared carbon dots on the conformational variation and enzymatic activity of glucose oxidase: A multi-spectroscopic and biochemical study with molecular docking

In recent years, the exceptional biocatalytic properties of glucose oxidase (GOx) have spurred the development of various GOx-functionalized nanocatalysts for cancer diagnosis and treatment. Carbon dots, renowned for their excellent biocompatibility and distinctive fluorescence properties, effectively incorporate GOx. Given the paramount importance of GOx's enzymatic activity in therapeutic efficacy, this study conducts a thorough exploration of the molecular-level binding dynamics between GOx and near-infrared carbon dots (NIR-CDs). Utilizing various spectrometric and molecular simulation techniques, we reveal that NIR-CDs form a ground-state complex with GOx primarily via hydrogen bonds and van der Waals forces, interacting directly with amino acid residues in GOx's active site. This binding leads to conformational change and reduces thermal stability of GOx, slightly inhibiting its enzymatic activity and demonstrating a competitive inhibition effect. In vitro experiments demonstrate that NIR-CDs attenuate the GOx's capacity to produce H2O2 in HeLa cells, mitigating enzyme-induced cytotoxicity and cellular damage. This comprehensive elucidation of the intricate binding mechanisms between NIR-CDs and GOx provides critical insights for the design of NIR-CD-based nanotherapeutic platforms to augment cancer therapy. Such advancements lay the groundwork for innovative and efficacious cancer treatment strategies.

Comprehensive Overview of Controlled Fabrication of Multifunctional Fluorescent Carbon Quantum Dots and Exploring Applications

In recent years, carbon dots (CDs) have garnered increasing attention due to their simple preparation methods, versatile performances, and wide-ranging applications. CDs can manifest various optical, physical, and chemical properties including quantum yield (QY), emission wavelength (Em), solid-state fluorescence (SSF), room-temperature phosphorescence (RTP), material-specific responsivity, pH sensitivity, anti-oxidation and oxidation, and biocompatibility. These properties can be effectively regulated through precise control of the CD preparation process, rendering them suitable for diverse applications. However, the lack of consideration given to the precise control of each feature of CDs during the preparation process poses a challenge in obtaining the requisite features for various applications. This paper is to analyze existing research and present novel concepts and ideas for creating CDs with different distinct features and applications. The synthesis methods of CDs are discussed in the first section, followed by a comprehensive overview of the important properties of CDs and the modification strategy. Subsequently, the application of CDs and their requisite properties are reviewed. Finally, the paper outlines the current challenges in controlling CDs properties and their applications, discusses potential solutions, and offers suggestions for future research.

User-Friendly Multifunctional Red-Emissive Carbon Dots for Rapid Cell Nucleus Staining via Targeting Nuclear Proteins

Cytoarchitectural staining is of great importance in disease diagnosis and cell biology research. This study developed user-friendly multifunctional red-emissive carbon dots (R-CDs) for rapid cell nucleus staining via targeting nuclear proteins. R-CDs, simply prepared by electrochemical treatment of 1,2,4-benzenetriamine, exhibit strong emission at 635 nm when excited at 507 nm. The R-CDs can rapidly stain the nucleus of human SH-SY5Y, HepG2, and HUH-7 cells with a high signal-to-noise ratio owing to fluorescence enhancement after entering the nucleus. Compared to conventional cytosolic dyes such as Hoechst and DAPI, R-CDs are cheaper, more highly dispersed in water, and more stable (requiring no stringent storage conditions). The R-CDs show stable optical properties with insignificant photobleaching over 7 days and salt resistance up to 2 M of NaCl. More importantly, R-CDs, possessing a positive charge, allow rapid staining of live cells (3 min) and dead cells (10 s) in saline. According to kinetic variation, R-CDs can distinguish live cells from dead cells. Staining exhibits high efficiency in onion epidermal cells, Aspergillus niger, Caenorhabditis elegans, and human spermatozoa. The mechanism for efficient staining is based on their fast accumulation in the nucleus due to their small size and positive charge and strong interaction with nuclear proteins at amino acid residues of histidine and arginine, resulting in fluorescence enhancement by dozens of times. The developed R-CDs do not bind to DNA and would not cause genetic damage and will find various safe applications in biological and medical fields.

Photothermal therapy: a novel potential treatment for prostate cancer

Prostate cancer (PCa) is a leading cause of cancer-related death in men, and most PCa patients treated with androgen deprivation therapy will progress to metastatic castration-resistant prostate cancer (mCRPC) due to the lack of efficient treatment. Recently, lots of research indicated that photothermal therapy (PTT) was a promising alternative that provided an accurate and efficient prostate cancer therapy. A photothermic agent (PTA) is a basic component of PPT and is divided into organic and inorganic PTAs. Besides, the combination of PTT and other therapies, such as photodynamic therapy (PDT), immunotherapy (IT), chemotherapy (CT), etc., provides an more efficient strategy for PCa therapy. Here, we introduce basic information about PTT and summarize the PTT treatment strategies for prostate cancer. Based on recent works, we think the combination of PPT and other therapies provides a novel possibility for PCa, especially CRPC clinical treatment.

Nanomaterials with Enzyme-like Properties for Combatting Foodborne Pathogen Infections: Classifications, Mechanisms, and Applications in Food Preservation

During the transportation and storage of food, foodborne spoilage caused by bacterial and biofilm infection is prone to occur, leading to issues such as short shelf life, economic loss, and sensory quality instability. Therefore, the development of novel and efficient antibacterial agents capable of efficiently inhibiting bacteria throughout various stages of food processing, transportation, and storage is strongly recommended by researchers. The emergence of nanozymes is considered to be an effective candidate for inhibiting foodborne bacteria agents in the food industry. As potent antibacterial agents, nanozymes have the advantages of low cost, high stability, strong broad-spectrum antibacterial ability, and biocompatibility. Herein, we aim to summarize the classification status of various nanozymes. Furthermore, the general catalytic bacteriostatic mechanism of nanozymes against intracellular bacteria, planktonic bacteria, and biofilm activities are highlighted, mainly concerning the destruction of cell walls and/or membranes, reactive oxygen species regulation, HOBr/Cl generation, damage of intracellular components, and so forth. In particular, the review focuses on the pivotal role of nanozymes as antibacterial agents and delivery vehicles in the fields of food preservation applications. We look forward to the future prospects, especially in the field of food preservation, to promote broader applications based on antimicrobial nanozymes.

Boosted photo-immunotherapy via near-infrared light excited phototherapy in tumor sites and photo-activation in sentinel lymph nodes

Phototherapy is a promising modality that could eradicate tumor and trigger immune responses via immunogenic cell death (ICD) to enhance anti-tumor immunity. However, due to the lack of deep-tissue-excitable phototherapeutic agents and appropriate excitation strategies, the utility of phototherapy for efficient activation of the immune system is challenging. Herein, we report functionalized ICG nanoparticles (NPs) with the capture capability of tumor-associated antigens (TAAs). Under near-infrared (NIR) light excitation, the ICG NPs exhibited high-performance phototherapy, i.e., synergistic photothermal therapy and photodynamic therapy, thereby efficiently eradicating primary solid tumor and inducing ICD and subsequently releasing TAAs. The ICG NPs also captured TAAs and delivered them to sentinel lymph nodes, and then the sentinel lymph nodes were activated with NIR light to trigger efficient T-cell immune responses through activation of dendritic cells with the assistance of ICG NP generated reactive oxygen species, inhibiting residual primary tumor recurrence and controlling distant tumor growth. The strategy of NIR light excited phototherapy in tumor sites and photo-activation in sentinel lymph nodes provides a powerful platform for active immune systems for anti-tumor photo-immunotherapy.

Logic "AND Gate Circuit"-Based Gasdermin Protein Expressing Nanoplatform Induces Tumor-Specific Pyroptosis to Enhance Cancer Immunotherapy

Pyroptosis mediated by gasdermin protein has shown great potential in cancer immunotherapies. However, the low expression of gasdermin proteins and the systemic toxicity of nonspecific pyroptosis limit its clinical application. Here, we designed a synthetic biology strategy to construct a tumor-specific pyroptosis-inducing nanoplatform M-CNP/Mn@pPHS, in which a pyroptosis-inducing plasmid (pPHS) was loaded onto a manganese (Mn)-doped calcium carbonate nanoparticle and wrapped in a tumor-derived cell membrane. M-CNP/Mn@pPHS showed an efficient tumor targeting ability. After its internalization by tumor cells, the degradation of M-CNP/Mn@pPHS in the acidic endosomal environment allowed the efficient endosomal escape of plasmid pPHS. To trigger tumor-specific pyroptosis, pPHS was designed according to the logic "AND gate circuit" strategy, with Hif-1α and Sox4 as two input signals and gasdermin D induced pyroptosis as output signal. Only in cells with high expression of Hif-1α and Sox4 simultaneously will the output signal gasdermin D be expressed. Since Hif-1α and Sox4 are both specifically expressed in tumor cells, M-CNP/Mn@pPHS induces the tumor-specific expression of gasdermin D and thus pyroptosis, triggering an efficient immune response with little systemic toxicity. The Mn2+ released from the nanoplatform further enhanced the antitumor immune response by stimulating the cGAS-STING pathway. Thus, M-CNP/Mn@pPHS efficiently inhibited tumor growth with 79.8% tumor regression in vivo. We demonstrate that this logic "AND gate circuit"-based gasdermin nanoplatform is a promising strategy for inducing tumor-specific pyroptosis with little systemic toxicity.

Enhanced Antibacterial Activity against Escherichia coli Based on Cationic Carbon Dots Assembling with 5-Aminolevulinic Acid

Carbon dots (CDs) with positive surface charges are considered one of the encouraging nanomedications for antibacterial applications. However, due to the distinctive membrane structure of Gram-negative bacteria, cationic CDs with relatively high concentrations are usually required for effective treatment, which might bring out serious safety issues at high doses. Therefore, it is of substantial significance to improve the killing efficiency of cationic CDs on Gram-negative bacteria at appropriately low concentrations. In this work, optimized cationic CDs (bPEI25 000-CDs) were prepared via a hydrothermal method with citric acid and branched PEI25000, which offered a positive surface potential, elimination abilities against Escherichia coli, and relatively high biosafety. The optimized bPEI25 000-CDs can further assemble with the clinical photodynamic therapy (PDT) drug 5-aminolevulinic acid (5-ALA) through electrostatic interaction. Moreover, compared with bPEI25 000-CDs and 5-ALA, the bacterial survival rate was significantly reduced by the ALA-bPEI25 000-CD-induced PDT effect. Even when the dose of bPEI25 000-CD carrier was halved, the bacterial survival could be reduced by 44.4% after light exposure compared to those incubated in the dark. The investigation of the bacterial morphology, membrane potential, and intracellular ROS production suggested that the enhanced antibacterial activity may be due to the membrane dysfunction and cell damage resulting from the high interaction between positively charged ALA-bPEI25 000-CDs and the bacterial cell membrane. Meanwhile, the cationic ALA-bPEI25 000-CDs may facilitate the cellular uptake of 5-ALA, resulting in a more efficient PDT effect. In summary, the antibacterial strategy proposed in this study will provide a novel approach for expanding the application of CD-based nanomedications.

The future of plant based green carbon dots as cancer Nanomedicine: From current progress to future Perspectives and beyond

BACKGROUND

The emergence of carbon dots (CDs) as anticancer agents had sparked a transformation in cancer research and treatment strategies. These fluorescent CDs, initially introduced in the early 2000 s, possess exceptional biocompatibility, tunable fluorescence, and surface modification capabilities, positioning them as promising tools in biomedical applications.

AIM OF REVIEW

The review encapsulates the transformative trajectory of green CDs as future anticancer nanomedicine, poised to redefine the strategies employed in the ongoing fight against cancer.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The versatility of CDs was rooted in their various synthesis approaches and sustainable strategies, enabling their adaptability for diverse therapeutic uses. In vitro studies had showcased CDs' selective cytotoxicity against cancer cells while sparing healthy counterparts, forming the basis for targeted therapeutic potential. This selectivity had been attributed to the reactive oxygen species (ROS) generation, which opened avenues for targeted interventions. The role of CDs in combination therapies, synergizing with chemotherapy, radiotherapy, and targeted approaches was then investigated to heighten their anticancer efficacy. Notably, in vivo studies highlight CDs' remarkable biocompatibility and minimal side effects, endorsing their translational promise. Integration with conventional cancer treatments such as chemotherapy, radiotherapy, and immunotherapy amplified the versatility and effectiveness of CDs. The exploration of CDs' applications in photo-induced treatments further solidified their significance, positioning them as photosensitizers (PS) in photodynamic therapy (PDT) and photothermal agents (PA) in photothermal therapy (PTT). In PDT, CDs triggered the generation of ROS upon light exposure, facilitating cancer cell elimination, while in PTT, they induced localized hyperthermia within cancer cells, enhancing therapeutic outcomes. In vitro and in vivo investigations validated CDs' efficacy in PDT and PTT, affirming their potential for integration into combination therapies. Looking ahead, the future of CDs in anticancer treatment encompasses bioavailability, biocompatibility, synergistic treatments, tumor targeting, artificial intelligence (AI) and robotics integration, personalized medicine, and clinical translation. This transformative odyssey of CDs as future anticancer agents is poised to redefine the paradigm of cancer treatment strategies.

Liposome-coated nanoparticle triggers prostate cancer ferroptosis through synergetic chemodynamic-gas therapy

Ferroptosis has attracted much attention for tumor treatment. It has been recently identified that castration-resistant prostate cancer (CRPC) is vulnerable to ferroptosis inducers. Notably, chemodynamic therapy (CDT), triggered by metal ions, could easily induce ferroptosis via a Fenton/Fenton-like reaction, but its efficiency was highly dependent on the intracellular H2O2 concentration, posing significant changes for its clinical translation. Herein, we attached glucose oxidase (GOx) onto the surface of manganese sulfide (MnS) and developed therapeutic nanocomposites (Lpo@MnS-GOx) after encapsulating with liposome. Upon internalization by cancer cells, the released GOx could transform glucose into gluconic acid (GA) and H2O2. Notably, the generated GA stimulates the degradation of MnS, followed by the promotion of the release of H2S and Mn2+, whereas the produced H2O2 can amplify the Fenton-like response initiated by Mn2+. The enhanced CDT combined with the gas therapy effect could simultaneously promote the accumulation of reactive oxygen species and finally induce ferroptosis and exhibit an excellent anti-tumor effect. Consequently, these Lpo@MnS-GOx NPs with enhanced ferroptosis-induced effect will find great potential for CRPC cancer treatment.

Metal-based nanoparticles in cancer therapy: Exploring photodynamic therapy and its interplay with regulated cell death pathways

Photodynamic therapy (PDT) represents a non-invasive treatment strategy currently utilized in the clinical management of selected cancers and infections. This technique is predicated on the administration of a photosensitizer (PS) and subsequent irradiation with light of specific wavelengths, thereby generating reactive oxygen species (ROS) within targeted cells. The cellular effects of PDT are dependent on both the localization of the PS and the severity of ROS challenge, potentially leading to the stimulation of various cell death modalities. For many years, the concept of regulated cell death (RCD) triggered by photodynamic reactions predominantly encompassed apoptosis, necrosis, and autophagy. However, in recent decades, further explorations have unveiled additional cell death modalities, such as necroptosis, ferroptosis, cuproptosis, pyroptosis, parthanatos, and immunogenic cell death (ICD), which helps to achieve tumor cell elimination. Recently, nanoparticles (NPs) have demonstrated substantial advantages over traditional PSs and become important components of PDT, due to their improved physicochemical properties, such as enhanced solubility and superior specificity for targeted cells. This review aims to summarize recent advancements in the applications of different metal-based NPs as PSs or delivery systems for optimized PDT in cancer treatment. Furthermore, it mechanistically highlights the contribution of RCD pathways during PDT with metal NPs and how these forms of cell death can improve specific PDT regimens in cancer therapy.

Poly(Glutamic Acid)-Engineered Nanoplatforms for Enhanced Cancer Phototherapy

Phototherapies, including photothermal therapy and photodynamic therapy, have gained booming development over the past several decades for their attractive non-invasiveness nature, negligible adverse effects, minimal systemic toxicity, and high spatial selectivity. Phototherapy usually requires three components: light irradiation, photosensitizers, and molecular oxygen. Photosensitizers can convert light energy into heat or reactive oxygen species, which can be used in the tumor-killing process. The direct application of photosensitizers in tumor therapy is restricted by their poor water solubility, fast clearance, severe toxicity, and low cellular uptake. The encapsulation of photosensitizers into nanostructures is an attractive strategy to overcome these critical limitations. Poly(glutamic acid) (PGA) is a kind of poly(amino acid)s containing the repeating units of glutamic acid. PGA has superiority for cancer treatment because of its good biocompatibility, low immunogenicity, and modulated pH responsiveness. The hydrophilicity nature of PGA allows the physical entrapment of photosensitizers and anticancer drugs via the construction of amphiphilic polymers. Moreover, the pendent carboxyl groups of PGA enable chemical conjugation with therapeutic agents. In this mini-review, we highlight the stateof- the-art design and fabrication of PGA-based nanoplatforms for phototherapy. We also discuss the potential challenges and future perspectives of phototherapy, and clinical translation of PGA-based nanomedicines.

Arenobufagin-loaded PEG-PLA nanoparticles for reducing toxicity and enhancing cancer therapy

Arenobufagin (ArBu) is a natural anticancer drug with good anti-tumor effects, but its clinical applications and drug development potential are limited due to its toxicity. The purpose of this study is to reduce the toxic side effects of ArBu and improve the efficacy of tumor treatment by incorporating it into poly(ethylene glycol)-b-poly (lactide) co-polymer (PEG-PLA). ArBu@PEG-PLA micelles were prepared by a thin film hydration method. The optimized micelles were characterized by size, stability, drug loading, encapsulation rate, and drug release. The tumor-inhibition efficacy of the micelles was evaluated on A549 cells and tumor-bearing mice. The ArBu@PEG-PLA micelles have good drug-loading capacity, release performance, and stability. They can accumulate at the tumor site through the EPR effect. The micelles induce apoptosis through a mitochondrial apoptosis pathway. Compared with the free ArBu, the ArBu@PEG-PLA micelles had lower toxicity and higher safety in the acute toxicity evaluation experiment. The in vivo anti-tumor experiment with tumor-bearing mice showed that the tumor-inhibition rate of ArBu@PEG-PLA micelles was 72.9%, which was 1.28-fold higher than that of free ArBu (57.1%), thus showing a good tumor treatment effect. This study indicates that ArBu@PEG-PLA polymeric micelles can significantly improve the toxicity and therapeutic efficacy of ArBu. These can lead to a new therapeutic strategy to reduce the toxicity of ArBu and enhance tumor treatment.

Injectable glucose oxidase-immobilized gelatin hydrogel prevents tumor recurrence via oxidation therapy

In clinical practice, surgery is the preferred treatment for breast cancer; however, the high recurrence rate due to residual tumors after surgery remains a major issue. Hydrogels can reduce the side effects of residual tumors and exert strong anticancer effects, thereby showing potential as therapeutic agents for suppressing tumor recurrence after surgery. Glucose oxidase (GOD)-immobilized gelatin hydrogels (GOD-gelatin hydrogel) were prepared by bioorthogonal click chemistry. Then, the anticancer effect, tumor recurrence inhibition, and biodegradability of the resulting hydrogels were evaluated through cell and animal experiments. GOD-gelatin hydrogel showed cytotoxicity and anticancer effect via H2O2 generation. Unlike free GOD, GOD-gelatin hydrogel remained in the surgical site after implant and continued to suppress tumor recurrence over time. The proposed GOD-gelatin hydrogel system can be easily implanted at the surgical site after tumor surgery, representing a novel treatment to suppress tumor recurrence without any systemic toxicity.

An injectable, in situ forming and NIR-responsive hydrogel persistently reshaping tumor microenvironment for efficient melanoma therapy

BACKGROUND

Melanoma is a highly aggressive form of skin cancer with increasing incidence and mortality rates. Chemotherapy, the primary treatment for melanoma, is limited by hypoxia-induced drug resistance and suppressed immune response at the tumor site. Modulating the tumor microenvironment (TME) to alleviate hypoxia and enhance immune response has shown promise in improving chemotherapy outcomes.

METHODS

In this study, a novel injectable and in situ forming hydrogel named MD@SA was developed using manganese dioxide (MnO2) nanosheets pre-loaded with the chemotherapy drug doxorubicin (DOX) and mixed with sodium alginate (SA). The sustainable drug delivery, oxygen generation ability, and photothermal property of MD@SA hydrogel were characterized. The therapeutic efficacy of hydrogel was studied in B16F10 in vitro and B16F10 tumor-bearing mice in vivo. The immune effects on macrophages were analyzed by flow cytometry, real-time quantitative reverse transcription PCR, and immunofluorescence analyses.

RESULTS

The MD@SA hydrogel catalyzed the tumoral hydrogen peroxide (H2O2) into oxygen, reducing the hypoxic TME, down-regulating hypoxia-inducible factor-1 alpha (HIF-1α) and drug efflux pump P-glycoprotein (P-gp). The improved TME conditions enhanced the uptake of DOX by melanoma cells, enhancing its efficacy and facilitating the release of tumor antigens. Upon NIR irradiation, the photothermal effect of the hydrogel induced tumor apoptosis to expose more tumor antigens, thus re-educating the M2 type macrophage into the M1 phenotype. Consequently, the MD@SA hydrogel proposes an ability to constantly reverse the hypoxic and immune-inhibited TME, which eventually restrains cancer proliferation.

CONCLUSION

The injectable and in situ forming MD@SA hydrogel represents a promising strategy for reshaping the TME in melanoma treatment. By elevating oxygen levels and activating the immune response, this hydrogel offers a synergistic approach for TME regulation nanomedicine.

Synergetic Photodynamic-Photothermal-Chemotherapy Dual Targeting Nanoplatform Effective Against Breast Cancer in-Mice Model

Introduction

Combined multimodal therapy for breast cancer is a promising therapeutic approach to increase treatment efficacy and reduce systemic toxicity. The present study aimed to develop a novel multifunctional drug release nanoplatform based on RGD-conjugated hyaluronic acid (HA)-functionalized copper sulfide (CuS) for activatable dual-targeted synergetic therapy against cancer.

Methods

The pH and NIR-responsive dual-targeting nanoplatform CuS:Ce6@HA:DOX@RGD was prepared, characterized, and evaluated for its stability and photodynamic and photothermal properties. The loading and release of the drug were measured at different pH values with or without laser radiation using the dialysis method. The cellular uptake of the platform specifically by the tumor cells treated with different formulations was investigated through fluorescence imaging. The in vitro and in vivo biosafety levels were assessed systematically. Finally, the antitumor efficiencies against breast cancer were assessed via in vitro and in vivo experiments.

Results

The spheroid CuS:Ce6@HA:DOX@RGD exhibited remarkable stability and monodispersity in solution. The photosensitive CuS and Ce6 could simultaneously absorb the near-infrared light efficiently to convert NIR light to fatal heat and to generate reactive oxygen species. The CuS:Ce6@HA:DOX@RGD dissociated under an acid environment, causing the release of DOX into the tumor to accelerate upon laser irradiation. The CuS:Ce6@HA:DOX@RGD exhibited target-specific and strong binding ability via a synergic CD44/αvβ3 receptor-mediated bimodal targeting, which led to improved therapeutic efficacy. The tumor growth was effectively inhibited using synergetic photodynamic/photothermal/chemo therapy. No evident systemic toxicity was noted during treatment.

Conclusion

The newly prepared CuS:Ce6@HA:DOX@RGD has great potential as an activatable theranostic nanoplatform for efficient dual-targeted synergistic therapy against breast cancer.

Coupling fermentation of glutamic acid and γ-polyglutamic acid and preparation of poly(amino acid) superabsorbent polymers

γ-polyglutamic acid (γ-PGA) is a biomarker that can be directly obtained by microbial fermentation. Poly(amino acid) superabsorbent polymers (SAPs) were prepared with purified γ-PGA as raw material and ethylene glycol diglycidyl ether (EGDGE) as a cross-linking agent. However, γ-PGA fermentation broth has a high viscosity, requires complex extraction and separation processes, and entails high energy consumption, resulting in the high cost of poly (amino acid) SAPs. Therefore, the coupling fermentation processes of glutamate polyglutamic acid, the process of using glutamate fermentation broth instead of pure glutamate powder for fermentation, and the process of treating the fermentation broth under conditions of centrifugation, UV irradiation, and high temperature, were studied. The results showed that the yield of γ-PGA after centrifugation decreased by 5%, but it did not affect the synthesis of hydrogels, and the addition of γ-PGA fermentation broth had a significant effect on the performance of γ-PGA-co-PASP SAPs. The proposed method not only helps avoid the separation of complex γ-PGA fermentation broth and reduces the cost, but it also helps improve the performance of the super-absorbent resin, which has great application potential.

Cascade strategy for glucose oxidase-based synergistic cancer therapy using nanomaterials

Nanomaterial-based cancer therapy faces significant limitations due to the complex nature of the tumor microenvironment (TME). Starvation therapy is an emerging therapeutic approach that targets tumor cell metabolism using glucose oxidase (GOx). Importantly, it can provide a material or environmental foundation for other diverse therapeutic methods by manipulating the properties of the TME, such as acidity, hydrogen peroxide (H2O2) levels, and hypoxia degree. In recent years, this cascade strategy has been extensively applied in nanoplatforms for ongoing synergetic therapy and still holds undeniable potential. However, only a few review articles comprehensively elucidate the rational designs of nanoplatforms for synergetic therapeutic regimens revolving around the conception of the cascade strategy. Therefore, this review focuses on innovative cascade strategies for GOx-based synergetic therapy from representative paradigms to state-of-the-art reports to provide an instructive, comprehensive, and insightful reference for readers. Thereafter, we discuss the remaining challenges and offer a critical perspective on the further advancement of GOx-facilitated cancer treatment toward clinical translation.

A cascade nanoplatform for the regulation of the tumor microenvironment and combined cancer therapy

Recently, disulfiram (DSF), an anti-alcoholism drug, has attracted increasing biomedical interest due to its anticancer effects. However, the anticancer activity of DSF is Cu(II)-dependent and it is extremely unstable, which severely hinders its clinical translation. Herein, we report the fabrication of a multifunctional nanoplatform (MCDGF) that can improve the stability of diethyldithiocarbamate (DTC), a main metabolite of DSF, by modifying the aryl boronic ester group to form a prodrug (DQ), and also realize the in situ generation of Cu(DTC)2, which relies on a cascade reaction. The delivered Cu/DQ induces immunogenic cell death (ICD) and powerfully enhances immune responses of cytotoxic T lymphocytes (CTLs) and the infiltration of dendritic cells as well as T cells. Furthermore, the grafted glucose oxidase (GOx) decomposes glucose, thus "starving" the cancer cells and providing H2O2 for the production of Cu(DTC)2. More importantly, H2O2 significantly promotes the polarization of macrophages to the anti-tumor subtype. The nano-carrier "mesoporous polydopamine (MPDA)" also displays a good photothermal therapeutic effect. The nanoplatform-integrated chemotherapy, starvation therapy, photothermal therapy, and immunotherapy synergistically stimulated CTL activation and M1 macrophage polarization. Taken together, the as-prepared nanoplatform could regulate the tumor immune microenvironment and eliminate cancer with combined cancer therapy, which will offer a promising strategy for cancer treatment and promote the clinical application of DSF in breast cancer.

Recent strategies of carbon dot-based nanodrugs for enhanced emerging antitumor modalities

Nanomaterial-based cancer therapy has recently emerged as a new therapeutic modality with the advantages of minimal invasiveness and negligible normal tissue toxicity over traditional cancer treatments. However, the complex microenvironment and self-protective mechanisms of tumors have suppressed the therapeutic effect of emerging antitumor modalities, which seriously hindered the transformation of these modalities to clinical settings. Due to the excellent biocompatibility, unique physicochemical properties and easy surface modification, carbon dots, as promising nanomaterials in the biomedical field, can effectively improve the therapeutic effect of emerging antitumor modalities as multifunctional nanoplatforms. In this review, the mechanism and limitations of emerging therapeutic modalities are described. Further, the recent advances related to carbon dot-based nanoplatforms in overcoming the therapeutic barriers of various emerging therapies are systematically summarized. Finally, the prospects and potential obstacles for the clinical translation of carbon dot-based nanoplatforms in tumor therapy are also discussed. This review is expected to provide a reference for nanomaterial design and its development for the efficacy enhancement of emerging therapeutic modalities.

Recent advances in glucose oxidase-based nanocarriers for tumor targeting therapy

Glucose oxidase (GOx) can specifically catalyze the conversion of β-d-glucose into gluconic acid and hydrogen peroxide (H2O2) in the presence of oxygen, making it promising for tumor starvation therapy and oxidative therapy. However, GOx's immunogenicity, poor in vivo stability, short half-life, and potential systemic toxicity, limit its application in cancer therapy. Nanocarriers are capable of improving the pharmacological properties of therapeutic drugs (e.g. stability, circulating half-life, and tumor accumulation) and lower toxicity, hence resolving GOx issues and enhancing its efficacy. Although the application of targeted nanocarriers based on GOx has recently flourished, this field has not yet been reviewed and evaluated. Herein, we initially examined the mechanism of GOx-based nanocarriers for enhanced tumor therapy. Also, we present a comprehensive and up-to-date review that highlights GOx-based nanocarriers for tumor targeting therapy. This review expands on GOx-based nano-targeted combination therapies from both passive and active targeting perspectives, meanwhile, active targeting is further classified into ligand-mediated targeting and physical-mediated targeting. Furthermore, this review also emphasizes the present challenges and promising advancements.

Luminescence of carbon quantum dots and their application in biochemistry

Similar to fullerenes, carbon nanotubes and graphene, carbon dots (CDs) are causing a lot of research work in their own right. CDs are a type of surface-passivated quantum dot that contain carbon atoms. Their distinctive characteristics, such as luminescent emission that varies with size and wavelength, resistance to photobleaching, easy biological binding, lack of toxicity, and economical production without the need for intricate synthetic processes, have led to a noteworthy surge in attention within the research community. Different techniques can be utilized to create these CDs, spanning from basic candle burning to laser ablation. This review article delves into the principles of fluorescence technology, providing insights into how different synthesis methods of quantum dots impact their luminescent properties. Additionally, it highlights the latest applications of quantum dots in catalysis and biomedical fields, with special emphasis on the current status of luminescent properties in biology and chemistry. Towards the end, the article discusses the limitations of quantum dots in current practical applications, pointing out that CDs hold promising potential for future applications.

Nanoparticle-Based Photothermal Therapy for Breast Cancer Noninvasive Treatment

Rapid advancements in materials science and nanotechnology, intertwined with oncology, have positioned photothermal therapy (PTT) as a promising noninvasive treatment strategy for cancer. The breast's superficial anatomical location and aesthetic significance render breast cancer a particularly pertinent candidate for the clinical application of PTT following melanoma. This review comprehensively explores the research conducted on the various types of nanoparticles employed in PTT for breast cancer and elaborates on their specific roles and mechanisms of action. The integration of PTT with existing clinical therapies for breast cancer is scrutinized, underscoring its potential for synergistic outcomes. Additionally, the mechanisms underlying PTT and consequential modifications to the tumor microenvironment after treatment are elaborated from a medical perspective. Future research directions are suggested, with an emphasis on the development of integrative platforms that combine multiple therapeutic approaches and the optimization of nanoparticle synthesis for enhanced treatment efficacy. The goal is to push the boundaries of PTT toward a comprehensive, clinically applicable treatment for breast cancer.

Recent advances on hyperthermia therapy applications of carbon-based nanocomposites

Generally, hyperthermia is referred to the composites capability to increase local temperature in such a way that the generated heat would lead to cancerous or bacteria cells destruction, with minimum damage to normal tissue cells. Many different materials have been utilized for hyperthermia application via different heat generating methods. Carbon-based nanomaterials consisting of graphene oxide (GO), carbon nanotube (CNT), carbon dot (CD) and carbon quantum dot (CQD), nanodiamond (ND), fullerene and carbon fiber (CF), have been studied significantly for different applications including hyperthermia due to their biocompatibility, biodegradability, chemical and physical stability, thermal and electrical conductivity and in some cases photothermal conversion. Therefore, in this comprehensive review, a structure-based view on carbon nanomaterials application in hyperthermia therapy of cancer and bacteria via various methods such as optical, magnetic, ultrasonic and radiofrequency-induced hyperthermia is presented.

Cu-MOFs based photocatalyst triggered antibacterial platform for wound healing: 2D/2D Schottky junction and DFT calculation

Herein, we developed a multimodal antibacterial nanoplatform via synergism effect including knife-effect, photothermal, photocatalytic induced reactive oxygen species (ROS), and Cu²⁺ inherent attribute. Typically, 0.8-TC/Cu-NS possesses higher photothermal property with the higher photothermal conversion efficiency of 24% and the moderate temperature up to 97 °C. Meanwhile, 0.8-TC/Cu-NS exhibits the more active ROS, ¹O₂ and ·O₂^-. Hence, 0.8-TC/Cu-NS possesses best antibacterial properties against S. aureus and E. coli in vitro with efficiency of 99.94%/99.97% under near-infrared (NIR) light, respectively. In the therapeutic practical use for wound healing of Kunming mice, this system exhibits outstanding curing capacity and good biocompatibility. Based on the electron configuration measurement and density functional theory (DFT) simulation, it is confirmed that the electrons on CB of Cu-TCPP flow fleetingly to MXene trough the interface, with redistribution of charge and band upward bending over Cu-TCPP. As a result, the self-assembled 2D/2D interfacial Schottky junction have made great favor to accelerate photogenerated charges mobility, hamper charge recombination, and increases the photothermal/photocatalytic activity. This work gives us a hint to mostly design the multimodal synergistic nanoplatform under NIR light in biological applications without drug resistance.

An AIEgen-based "turn-on" probe for sensing cancer cells and tiny tumors with high furin expression

Peptide-aggregation-induced emission (AIE) luminogen (AIEgen) conjugates are widely used in the bioimaging field for their good resistance to photobleaching, red and near-infrared light emission, good biocompatibility, etc. However, their peptides are mainly negatively charged and the positively charged peptide-AIEgen conjugates are rarely used in in vivo imaging due to their high non-specific interaction with protein to cause "false-positive" results and their potential risk of triggering hemolysis. Herein, we introduce a black hole quencher 3 (BHQ3) to RVRRGFF-AIE (FA) to build a "turn-on" probe, named BHQ3-RVRRGFF-AIE (BFA). Compared with FA, BFA has advantages in the anti-interference ability for different proteins and many solution environments. But, both BFA and FA have high risks of inducing hemolysis, which restricts their further application. Through co-assembly with poly-γ-glutamic acid (γ-PGA), molecular probes BFA and FA are formed into PGA-BFA and PGA-FA nanoparticles with high biocompatibility and suppressed phototoxicity. Cell studies show that PGA-BFA can discriminate cancer cells with high furin expression from low furin-expressed cancer cells and normal cells. In vivo studies show that PGA-BFA can light up tiny tumors in the abdominal cavity with a better tumor-to-intestine ratio (3.14) than that of PGA-FA (1.47), which is helpful for the accurate excision of tiny tumors. This study will advance the development of constructing good biosafety probes with a high signal-to-noise ratio for fluorescence image-guided cancer surgery.

Injectable carboxymethyl chitosan-based hydrogel for simultaneous anti-tumor recurrence and anti-bacterial applications

The postoperative recurrence has adversely affected the treatment of tumors. Besides, the potential bacterial infection at the wound site may lead to a series of tissue necrosis. Here, we developed an injectable γ-polyglutamic acid/carboxymethyl chitosan/polydopamine hydrogel (PCP) for simultaneously reducing the postoperative infection and preventing the tumor recurrence. On the one hand, the aqueous solution of carboxymethyl chitosan oxidized the dopamine into polydopamine; on the other, the carboxymethyl chitosan was cross-linked with the activated γ-polyglutamic acid to form a hydrogel. After local implantation, the PCP hydrogel effectively killed tumor cells and bacteria under 808 nm laser irradiation. In addition, carboxymethyl chitosan rendered the hydrogel with anti-bacterial properties as well as anti-tumor efficiencies. The anti-tumor recurrence and anti-bacterial efficiencies of PCP hydrogel were proved on a tumor-removed mouse model and a Staphylococcus aureus-infected mouse model, respectively. Moreover, the hydrogel has the advantages of good biocompatibility and simple preparation, and thus has potential application prospects in the prevention of tumor recurrence and wound bacterial infection.

Recent Advances of Photoactive Near-Infrared Carbon Dots in Cancer Photodynamic Therapy

Photodynamic therapy (PDT) is a treatment that employs exogenously produced reactive oxygen species (ROS) to kill cancer cells. ROS are generated from the interaction of excited-state photosensitizers (PSs) or photosensitizing agents with molecular oxygen. Novel PSs with high ROS generation efficiency is essential and highly required for cancer photodynamic therapy. Carbon dots (CDs), the rising star of carbon-based nanomaterial family, have shown great potential in cancer PDT benefiting from their excellent photoactivity, luminescence properties, low price, and biocompatibility. In recent years, photoactive near-infrared CDs (PNCDs) have attracted increasing interest in this field due to their deep therapeutic tissue penetration, superior imaging performance, excellent photoactivity, and photostability. In this review, we review recent progress in the designs, fabrication, and applications of PNCDs in cancer PDT. We also provide insights of future directions in accelerating the clinical progress of PNCDs.

Recent progress of biocompatible carbon dots in hypoxia-related fields

Almost all eukaryotes need oxygen to maintain regular physiological activities. When the organism is under hypoxic situation for a persistent or periodic, it will induce irreversible physiological disorders and even pathological results. Hypoxia is closely related to the pathogenesis of metabolic diseases, cancer, chronic heart disease and kidney disease, myocardial ischemia, as well as reproductive diseases like preeclampsia and endometriosis. Therefore, monitoring and treatment of hypoxia have important implications for the pathophysiology of human-related diseases. Carbon dots (CDs) are emerging nanomaterials developed after 2004 with excellent performance, and have broad application potential in variousdomains likeoptical, biomedicine, energy. Advanced hypoxia therapeutics should be integrated with monitoring and treatment, and CDs with excellent performance are good potential options when sensing is combined with various therapeutic methods. Some researchers have also begun to carry out research in related fields and achieved some results. This article aims to clarify the various applications of CDs in hypoxia-related fields in recent years, including hypoxia sensing and hypoxia tumor theranostics. Finally, the possible challenges and prospects for the application of CDs in hypoxia-related fields are discussed.

Nanomedicines for Overcoming Cancer Drug Resistance

Clinically, cancer drug resistance to chemotherapy, targeted therapy or immunotherapy remains the main impediment towards curative cancer therapy, which leads directly to treatment failure along with extended hospital stays, increased medical costs and high mortality. Therefore, increasing attention has been paid to nanotechnology-based delivery systems for overcoming drug resistance in cancer. In this respect, novel tumor-targeting nanomedicines offer fairly effective therapeutic strategies for surmounting the various limitations of chemotherapy, targeted therapy and immunotherapy, enabling more precise cancer treatment, more convenient monitoring of treatment agents, as well as surmounting cancer drug resistance, including multidrug resistance (MDR). Nanotechnology-based delivery systems, including liposomes, polymer micelles, nanoparticles (NPs), and DNA nanostructures, enable a large number of properly designed therapeutic nanomedicines. In this paper, we review the different mechanisms of cancer drug resistance to chemotherapy, targeted therapy and immunotherapy, and discuss the latest developments in nanomedicines for overcoming cancer drug resistance.

Tumor microenvironment responsive polypeptide-based supramolecular nanoprodrugs for combination therapy

Tumor microenvironment responsive nanomedicine has drawn considerable attention for combination therapy, but still remains a significant challenge for less side effects and enhanced anti-tumor efficiency. Herein, we develop a pH/ROS dual-responsive supramolecular polypeptide nanoprodrug (PFW-DOX/GOD) by using pillar[5]arene-based host-guest strategy for combined glucose degradation, chemodynamic therapy (CDT), and chemotherapy (CT). The PFW-DOX/GOD consists of a pH-responsive ferrocene/pillar[5]arene-containing polypeptide, a ROS-responsive polyprodrug, and encapsulated glucose oxidase (GOD). Upon into intracellular acidic environment, PFW-DOX/GOD exhibits rapid pH-triggered disassembly behavior. Simultaneously, the released GOD can catalyze intratumoral glucose into massive H₂O₂, which are further converted into highly toxic hydroxyl radicals (•OH) by the catalysis of ferrocene via the Fenton reaction. Thereafter, induced by the ROS-responsive cleavage of thioketal linkage, the conjugated DOX prodrug was released and activated. The combined glucose degradation, chemodynamic therapy (CDT), and chemotherapy (CT) of PFW-DOX/GOD present anti-tumor effect with 96% of tumor inhibitory rate (TIR). Therefore, such tumor microenvironment-responsive supramolecular polypeptide nanoprodrugs represent a potential candidate for combination therapy with minimal side effects. STATEMENT OF SIGNIFICANCE: In this work, a tumor microenvironment-responsive supramolecular polypeptide nanoprodrug (PFW-DOX/GOD) was prepared via pillar[5]arene-based host-guest interactions, and presented low side effects and high tumor accumulation owing to the diameters of about 200 nm and surface PEG segment. After pH-responsive release of GOD in the intracellular acidic environment, the cascade catalytic reactions including GOD-catalyzed degradation of intratumoral glucose and Fenton reaction, effectively happened to generate •OH for chemodynamic therapy (CDT), which subsequently induced the cleavage of thioketal linkage to activate free DOX for chemotherapy (CT). Collectively, this supramolecular polypeptide nanoprodrugs provide a promising strategy for combination therapy with synergetic anti-tumor effect.

Advances on Delivery of Cytotoxic Enzymes as Anticancer Agents

Cancer is one of the most serious human diseases, causing millions of deaths worldwide annually, and, therefore, it is one of the most investigated research disciplines. Developing efficient anticancer tools includes studying the effects of different natural enzymes of plant and microbial origin on tumor cells. The development of various smart delivery systems based on enzyme drugs has been conducted for more than two decades. Some of these delivery systems have been developed to the point that they have reached clinical stages, and a few have even found application in selected cancer treatments. Various biological, chemical, and physical approaches have been utilized to enhance their efficiencies by improving their delivery and targeting. In this paper, we review advanced delivery systems for enzyme drugs for use in cancer therapy. Their structure-based functions, mechanisms of action, fused forms with other peptides in terms of targeting and penetration, and other main results from in vivo and clinical studies of these advanced delivery systems are highlighted.

Aggregation-Induced Emission Nanoparticles for Single Near-Infrared Light-Triggered Photodynamic and Photothermal Antibacterial Therapy

Phototheranostics is a potential area for precision medicine, which has received increasing attention for antibacterial applications. Integrating all phototheranostic modalities in a single molecule and achieving precise spatial colocalization is a challenging task because of the complexity of energy dissipation and molecular design. Here, a type of quaternary amine functionalized aggregation-induced emission (AIE), AIEgen, was synthesized and used to produce singlet oxygen (¹O₂) and heat, which were used to eradicate the bacteria. With the introduction of the positive charge in AIEgen, AIE nanoparticles (AIE NPs) could selectively target bacteria. Notably, the AIE NPs displayed obvious antibacterial performance against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The antibacterial rates of AIE NPs were as high as 99.9% and 99.8% for S. aureus and E. coli, respectively. Therefore, our results suggested the potential of AIE NPs acting as broad-spectrum antimicrobial materials, which provided a strategy for treating different microorganisms.

Multifunctional metal-organic framework-based nanoreactor for starvation/oxidation improved indoleamine 2,3-dioxygenase-blockade tumor immunotherapy

Inhibited immune response and low levels of delivery restrict starvation cancer therapy efficacy. Here, we report on the co-delivery of glucose oxidase (GOx) and indoleamine 2,3-dioxygenase (IDO) inhibitor 1-methyltryptophan using a metal-organic framework (MOF)-based nanoreactor, showing an amplified release for tumor starvation/oxidation immunotherapy. The nanosystem significantly overcomes the biobarriers associated with tumor penetration and improves the cargo bioavailability owing to the weakly acidic tumor microenvironment-activated charge reversal and size reduction strategy. The nanosystem rapidly disassembles and releases cargoes in response to the intracellular reactive oxygen species (ROS). GOx competitively consumes glucose and generates ROS, further inducing the self-amplifiable MOF disassembly and drug release. The starvation/oxidation combined IDO-blockade immunotherapy not only strengthens the immune response and stimulates the immune memory through the GOx-activated tumor starvation and recruitment of effector T cells, but also effectively relieves the immune tolerance by IDO blocking, remarkably inhibiting the tumor growth and metastasis in vivo.

Inhibited immune response and low levels of delivery inhibit starvation cancer therapies. Here, the authors report on the co-delivery of glucose oxidase and IDO inhibitor 1-methyltryptophan using metal organic frameworks and show amplified release in response to starvation therapy along with immune modulatory effects.

Nanococktail Based on Supramolecular Glyco-Assembly for Eradicating Tumors In Vivo

The development of robust phototherapeutic strategies for eradicating tumors remains a significant challenge in the transfer of cancer phototherapy to clinical practice. Here, a phototherapeutic nanococktail atovaquone/17-dimethylaminoethylamino-17-demethoxygeldanamycin/glyco-BODIPY (ADB) was developed to enhance photodynamic therapy (PDT) and photothermal therapy (PTT) via alleviation of hypoxia and thermal resistance that was constructed using supramolecular self-assembly of glyco-BODIPY (BODIPY-SS-LAC, BSL-1), hypoxia reliever atovaquone (ATO), and heat shock protein inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG). Benefiting from a glyco-targeting and glutathione (GSH) responsive units BSL-1, ADB can be rapidly taken up by hepatoma cells, furthermore the loaded ATO and 17-DMAG can be released in original form into the cytoplasm. Using in vitro and in vivo results, it was confirmed that ADB enhanced the synergetic PDT and PTT upon irradiation using 685 nm near-infrared light (NIR) under a hypoxic tumor microenvironment where ATO can reduce O₂ consumption and 17-DMAG can down-regulate HSP90. Moreover, ADB exhibited good biosafety, and tumor eradication in vivo. Hence, this as-developed phototherapeutic nanococktail overcomes the substantial obstacles encountered by phototherapy in tumor treatment and offers a promising approach for the eradication of tumors.

Acid-Sensitive Nanoparticles Based on Molybdenum Disulfide for Photothermal-Chemo Therapy

The combination of multiple treatments has recently been investigated for tumor treatment. In this study, molybdenum disulfide (MoS₂) with excellent photothermal conversion performance was used as the core, and manganese dioxide (MnO₂), which responds to the tumor microenvironment, was loaded on its surface by liquid deposition to form a mesoporous core-shell structure. Then, the chemotherapeutic drug Adriamycin (DOX) was loaded into the hole. To further enhance its water solubility and stability, the surface of MnO₂ was modified with mPEG-NH₂ to prepare the combined antitumor nanocomposite MoS₂@DOX/MnO₂-PEG (MDMP). The results showed that MDMP had a diameter of about 236 nm, its photothermal conversion efficiency was 33.7%, and the loading and release rates of DOX were 13 and 65%, respectively. During in vivo and in vitro studies, MDMP showed excellent antitumor activity. Under the combined treatment, the tumor cell viability rate was only 11.8%. This nanocomposite exhibits considerable potential for chemo-photothermal combined antitumor therapy.