Stimuli-Responsive Polymer-Based Nanosystems for Cancer Theranostics

Prodrug-designed nanocarrier co-delivering chemotherapeutic and vascular disrupting agents with exceptionally high drug loading capacity

Chemotherapy remains a vital component of cancer treatment, with combination therapy widely used in clinical practice to overcome the limitations of single-drug administration. However, challenges persist including pharmacokinetic discrepancies among different pharmaceutical agents, and insufficient synergistic efficiency in small-molecule drug combinations. There is an urgent need to develop more efficient combination therapy strategies. Nanocarriers have been extensively used to address issues associated with free drugs, but achieving high delivery efficiency of small-molecular pharmaceuticals through traditional drug delivery methods remains difficult. Herein, we report an exceptionally efficient drug delivery strategy mediated by prodrug design. A prodrug composed of paclitaxel (PTX) and combretastatin A-4 (CA4) was developed to achieve synchronous and efficient delivery of both drugs. When the prodrug was encapsulated by a nanocarrier, the drug loading capacity (DLC) could reach as high as 99 %, almost achieving quantitative drug loading. The good biocompatibility and potent anti-tumor efficacy of the prodrug-loaded nanoparticles were confirmed through both in vitro and in vivo experiments. Our work provides valuable insights into the safe and efficient combination cancer therapy.

Harnessing nanoprodrugs to enhance cancer immunotherapy: overcoming barriers to precision treatment

Nanoprodrugs, leveraging advanced nanoparticle-based delivery systems, represent a promising strategy to enhance the efficacy of immunotherapy in cancer treatment. These systems offer precise tumor targeting, controlled drug release, and the potential to modulate the immune microenvironment, addressing several limitations of conventional therapeutic approaches. This review systematically evaluates the role of nanoprodrugs in improving immunotherapy outcomes, focusing on their ability to overcome challenges such as poor bioavailability, systemic toxicity, and limited tumor specificity. We also discuss the key advantages of these systems, including their ability to co-deliver immune checkpoint inhibitors and other immunomodulatory agents, potentially enabling more synergistic and effective treatment strategies. Despite their promise, several challenges remain, including achieving precise control over drug release, integrating multiple stimulus-responsive mechanisms, addressing tumor heterogeneity, and overcoming barriers to clinical translation. The review concludes with a perspective on future directions, emphasizing the need for further optimization of nanomaterial design, improved delivery strategies, and solutions to the complexities of the tumor microenvironment to maximize the clinical impact of nanoprodrugs in cancer immunotherapy.

HGF/c-Met Axis-Targeted Nanotherapy via GSH-Responsive Polymer Platforms Suppresses Uveal Melanoma Metastasis

Uveal melanoma (UM), a malignant tumor originating within the ocular, characterizes high metastasis and lethality among patients. Cancer stem cells (CSCs) distinguished by the c-Met protein are believed to mediate tumor metastasis in UM. However, the low bioavailability of c-Met inhibitors like Crizotilib (Criz) limits their clinical application. Herein, a GSH-responsive nanoparticle named NP@Oxa/Criz to precisely deliver Criz and Oxaliplatin (Oxa) is synthesized in this study. The dual-action mechanism of NP@Oxa/Criz inhibits the HGF/c-Met axis to prevent the nuclear translocation of β-Catenin, thereby reducing the transcription of metastasis-associated genes and undermining the stemness and metastasis of UM cells. Simultaneously, NP@Oxa/Criz induces immunogenic cell death to boost anti-tumor immunity. In vivo studies demonstrate that NP@Oxa/Criz can accumulate in tumor sites, significantly eradicating the primary UM in the ocular and suppressing the metastasis UM in the liver and peritoneal. The outcomes from this work illuminate the therapeutic mechanisms of NP@Oxa/Criz and provide a precise and potent nanotherapeutic strategy for clinical treatment and research in highly metastatic UM.

Raspberry-like gold nano-conjugates of block copolymer prodrug based bicontinuous nanoparticles for cancer theranostics

Theranostic nanoparticles like polymer conjugated gold nanoparticles are at the cutting edge of cancer therapy, offering an integrated platform for simultaneous diagnosis and treatment. In this study, we report a nanoconjugate (P2AuNPs) by combining doxorubicin (DOX) tethered polymeric prodrug based bicontinuous nanoparticles (P2NPs), developed recently by us, with gold nanoparticles (AuNPs). The AuNPs were generated by in situ reduction of HAuCl4, where different polymer functionalities served the role of reducing and stabilizing agents. The bicontinuous morphology of P2NPs provided a unique template for the growth of gold nanoparticles, resulting in an overall raspberry-like morphology. Compared to existing small-sized theranostic AuNPs, which often trigger systematic cytotoxicity, the synthesized P2AuNPs had an ideal size of ∼90 nm for passive targeting of cancer cells through leaky tumor blood vessels. Furthermore, the embedded gold nanoparticles in P2AuNPs nanoconjugate served as a nanometal surface energy transfer (NSET) pair with the covalently attached DOX molecules, resulting in the significant quenching of DOX (turned 'OFF' state) fluorescence at physiological pH (7.4) as confirmed through steady-state and time-resolved fluorescence measurements. It was also possible to recover the quenched DOX fluorescence (turned 'ON' state) with the release of DOX selectively in cancer cell lines, plausibly due to higher glutathione (GSH) levels and acidic pH. In vitro cellular studies asserted the safe nature of P2NPs against non-cancerous cells (HEK-293T) while exhibiting significantly higher drug-induced cytotoxicity against cancerous cells (MCF-7) compared to free DOX. Moreover, when P2AuNPs were incubated with HEK-293T and MCF-7 cells, a fluorescence turn 'ON' for DOX was observed only in MCF-7 cells after the release of DOX, thereby providing an opportunity to improve the sensitivity of imaging and real-time monitoring of drug release. Together, this integrated theranostic system not only has the potential to enhance the precision and effectiveness of cancer therapy but also offers improved monitoring capabilities, representing a significant advancement in tailored nanomedicine.

Harnessing nano-delivery systems to un-cover the challenges for cervical cancer therapy

Cervical cancer (CC) remains a prevalent malignancy among women, with current therapeutic strategies facing significant challenges in curbing its rising incidence. Nano-delivery systems have emerged as a promising approach to hinder CC progression. This review provides a comprehensive examination of CC pathogenesis and its physiological characteristics while focusing on applying various nano-delivery systems in CC therapy. Specifically, it highlights the potential of both internal (e.g., pH, reactive oxygen species, glutathione) and external (e.g., Photo, magnetism, sound waves, microwaves, electricity) stimuli-responsive nano-delivery platforms to enhance therapeutic efficacy. The challenges of nano-delivery systems in CC therapy, encompassing in vivo stability, biosafety, distribution, and metabolic processes, are addressed, along with potential remedies. Additionally, the review underscores recent preclinical advances in nano-delivery systems for CC therapy. By thoroughly exploring nanomaterial applications, this review provides valuable perspectives for advancing CC treatment and stimulating future research and innovation in this domain.

Nano-formulations in disease therapy: designs, advances, challenges, and future directions

Nano-formulations, as an innovative drug delivery system, offer distinct advantages in enhancing drug administration methods, improving bioavailability, promoting biodegradability, and enabling targeted delivery. By exploiting the unique size advantages of nano-formulations, therapeutic agents, including drugs, genes, and proteins, can be precisely reorganized at the microscale level. This modification not only facilitates the precise release of these agents but also significantly enhances their efficacy while minimizing adverse effects, thereby creating novel opportunities for treatment of a wide range of diseases. In this review, we discuss recent advancements, challenges, and future perspectives in nano-formulations for therapeutic applications. For this aim, we firstly introduce the development, design, synthesis, and action mechanisms of nano-formulations. Then, we summarize their applications in disease diagnosis and treatment, especially in fields of oncology, pulmonology, cardiology, endocrinology, dermatology, and ophthalmology. Furthermore, we address the challenges associated with the medical applications of nanomaterials, and provide an outlook on future directions based on these considerations. This review offers a comprehensive examination of the current applications and potential significance of nano-formulations in disease diagnosis and treatment, thereby contributing to the advancement of modern medical therapies.

Stimuli-Responsive Polymeric Nanoprobes for Bioimaging of Cancer Metastasis

Stimuli-responsive polymeric nanoprobes as a type of nanoscale probe can respond to the tumor microenvironment via specific stimuli inside tumors, such as pH, hypoxia, glutathione (GSH), enzymes, aberrant receptors, and high ATP concentration. The ingenious design of the nanoprobes can improve the specificity and sensitivity to distinguish the slight differences between normal tissues and tumors. Thus, the tiny tumor metastasis can be detected by bioimaging of the stimuli-responsive polymeric nanoprobes. This review summarizes the progress and applications of polymeric nanoprobes in the bioimaging of tumor metastasis. The design strategies for the nanoprobes targeting tumor tissues are discussed according to the stimulus types, including tumor pH, hypoxia, glutathione, enzymes, aberrant receptor, and ATP. Moreover, the challenges currently faced in this field are also discussed. This review will provide valuable insights for the design and optimization of stimuli-responsive polymeric nanoprobes to accelerate the development of bioimaging for tumor metastasis and promote the clinical translation.

Bioactive Assembly Cofactor-Assisted Ursolic Acid Helix for Enhanced Anticancer Efficacy via In Situ Virus-like Transition

Natural bioactive pentacyclic triterpenoids, such as ursolic acid (UA), hold significant potential as anticancer agents. However, their clinical application is limited by their poor solubility and bioavailability. Herein, we developed a novel polypeptoid assembly cofactor-assisted nanoplatform designed to enhance UA's therapeutic efficacy through in situ self-assembly within the tumor microenvironment (TME). Bioactive polypeptoid polyelectrolytes, inspired by natural molecular chaperones, were utilized as assembly cofactors to guide UA's co-assembly into stimuli-responsive nanostructures. These polypeptoids provide precise control over the assembly process, improving stability and enabling reversible, pH-responsive transformations. Acid-responsive groups and the target molecule lactobionic acid further promote the specificity and efficacy of UA delivery. Under neutral conditions, the assemblies retain a helical fibrous structure, while in the acidic TME, they transform into virus-like clusters composed of assembly subunits, facilitating deeper tumor penetration. Once internalized, these nanoparticles escape into the cytoplasm and accumulate around the mitochondria, where the oxidation of thioether bonds triggers the release of UA and polypeptoids, causing mitochondrial damage and apoptosis. Some nanoparticles reassemble into fibrous structures intracellularly, extending their retention in tumor cells and potentially leading to mitochondria damage. Notably, the nanoplatform demonstrates excellent synergistic effects, achieving significantly higher therapeutic efficiency compared with individual components, including UA and polypeptoids. In vivo studies further confirmed the effectiveness, demonstrating significant tumor growth suppression and reduced metastasis. By integrating the therapeutic UA with bioactive polypeptoids under precise control, this synergistic platform represents a highly efficient and targeted approach to cancer therapy, offering a promising new opportunity for natural compounds for advanced nanomedicine.

Peptide-based fluorescent probes for the diagnosis of tumor and image-guided surgery

Fluorescent contrast agents are instrumental in amplifying signals, thereby enhancing the sensitivity and accuracy of live optical imaging. However, a significant proportion of traditional fluorescent contrast agents exhibit drawbacks such as short half-life, suboptimal biocompatibility, and inadequate tumor targeting, all of which impede effective imaging guidance. Peptides, derived from natural structures, offer a flexible modular design that can be precisely engineered and adjusted using synthetic methods to achieve specific biological activity and pharmacokinetic properties. They bind with designated receptors to exert their effects, demonstrating high specificity. The development of fluorescent probes based on peptides significantly overcomes the limitations of conventional contrast agents, offering superior performance. This article provides a comprehensive review of three strategies for constructing peptide-based fluorescent probes, delving into their distinct design concepts, mechanisms of action, and innovative aspects. It also highlights the potential applications of peptide-based fluorescent probes in tumor diagnosis and image-guided surgery, offering insights into their future clinical transformation.

Nanocarrier-based targeted drug delivery for Alzheimer's disease: addressing neuroinflammation and enhancing clinical translation

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, amyloid-beta (Aβ) aggregation, tau pathology, and chronic neuroinflammation. Among these, neuroinflammation plays a crucial role in exacerbating disease progression, making it an attractive therapeutic target. However, the presence of the blood-brain barrier (BBB) significantly limits the effective delivery of therapeutic agents to the brain, necessitating novel drug delivery strategies. Nanocarrier-based delivery systems have emerged as a promising solution to these challenges, offering targeted drug transport, enhanced BBB penetration, and improved bioavailability while minimizing systemic toxicity. This review explores the current advancements in nanocarrier-mediated drug delivery for AD, focusing on the mechanisms of neuroinflammation, the role of nanocarriers in overcoming the BBB, and their ability to modulate inflammatory pathways. Furthermore, the review discusses preclinical validation strategies and key challenges, including safety concerns, large-scale production limitations, and regulatory hurdles that must be addressed to enable clinical translation. Future perspectives emphasize the integration of nanotechnology with precision medicine, gene therapy, and artificial intelligence to optimize nanocarrier design for individualized AD treatment. By overcoming these obstacles, nanocarriers hold the potential to revolutionize therapeutic approaches for AD and other neurodegenerative diseases.

Reverse Block Sequence in Self-Immolative Poly(benzyl ether)-Based Amphiphiles for Tailoring End Groups and Self-Assembly Behavior

This paper reports a modular design of self-immolative poly(benzyl ether) (PBE) amphiphiles that allows precise control over polymer chain structure, end-group placement, and degradation behavior. By tuning block sequences and exposing reactive end groups, these amphiphiles undergo efficient head-to-tail depolymerization upon external stimuli. Structural variations in the monomers enable micelle formation with end groups displayed on the surface, while the carboxylate content in the hydrophilic block influences global micelle morphology. The resulting micelles are degradable in aqueous environments and can transform into spherical structures when combined with conventional surfactants. As a proof of concept, small-molecule cargos were successfully loaded and released from the mixed micelles on demand. This design platform offers a versatile route to create functional, stimulus-responsive surfactants with tunable assembly, degradation, and controlled release capabilities.

Nanotechnology-Enhanced siRNA Delivery: Revolutionizing Cancer Therapy

RNA interference (RNAi) has emerged as a transformative approach for cancer therapy, enabling precise gene silencing through small interfering RNA (siRNA). However, the clinical application of siRNA-based treatments faces challenges such as rapid degradation, inefficient cellular uptake, and immune system clearance. Nanotechnology-enhanced siRNA delivery has revolutionized cancer therapy by addressing these limitations, improving siRNA stability, tumor-specific targeting, and therapeutic efficacy. Recent advancements in nanocarrier engineering have introduced innovative strategies to enhance the safety and precision of siRNA-based therapies, offering new opportunities for personalized medicine. This review highlights three key innovations in nanotechnology-enhanced siRNA delivery: artificial intelligence (AI)-driven nanocarrier design, multifunctional nanoparticles for combined therapeutic strategies, and biomimetic nanocarriers for enhanced biocompatibility. AI-driven nanocarriers utilize machine learning algorithms to optimize nanoparticle properties, improving drug release profiles and minimizing off-target effects. Multifunctional nanoparticles integrate siRNA with chemotherapy, immunotherapy, or photothermal therapy, enabling synergistic treatment approaches that enhance therapeutic outcomes and reduce drug resistance. Biomimetic nanocarriers, including exosome-mimicking systems and cell-membrane-coated nanoparticles, improve circulation time, immune evasion, and targeted tumor delivery. These innovations collectively enhance the precision, efficiency, and safety of siRNA-based cancer therapies. The scope and novelty of these advancements lie in their ability to overcome the primary barriers of siRNA delivery while paving the way for clinically viable solutions. This review provides a comprehensive analysis of the latest developments in nanocarrier fabrication, preclinical and clinical studies, and safety assessments. By integrating AI-driven design, multifunctionality, and biomimicry, nanotechnology-enhanced siRNA delivery holds immense potential for the future of precision cancer therapy.

Next-Generation Transformable Nanomedicines: Revolutionizing Cancer Drug Delivery and Theranostics

Nanomedicine has significantly advanced the treatment of various cancer phenotypes, addressing numerous challenges associated with conventional therapies. Researchers have extensively investigated the physicochemical properties of nanocarriers, such as charge, morphology, and surface chemistry, to optimize drug delivery systems. In the context of transformable nanomedicine, these properties are particularly critical for overcoming existing limitations, including suboptimal blood circulation times, sequestration by the reticuloendothelial system and mononuclear phagocyte system, and inefficient targeting of the tumor microenvironment (TME). Alterations in nanocarrier geometry, surface charge, and hydrophilicity have shown potential in mitigating these barriers, offering improved therapeutic outcomes and enhanced biomedical applications. This review explores controlled modulation of these properties in the context of anticancer therapy, offering an in-depth exploration of transformable strategies activated by both internal and external stimuli. We analyze the implications of these tunable characteristics on pharmacokinetics, biodistribution, and targeted delivery to the TME. Additionally, we address the current challenges in the clinical translation of these advanced nanocarriers and propose strategies to overcome these obstacles to enhance the clinical feasibility of nanomedicine-based cancer therapies.

Application of Nanomaterials in the Diagnosis and Treatment of Retinal Diseases

In recent years, nanomaterials have demonstrated broad prospects in the diagnosis and treatment of retinal diseases due to their unique physicochemical properties, such as small-size effects, high biocompatibility, and functional surfaces. Retinal diseases are often accompanied by complex pathological microenvironments, where conventional diagnostic and therapeutic approaches face challenges such as low drug delivery efficiency, risks associated with invasive procedures, and difficulties in real-time monitoring. Nanomaterials hold promise in addressing these limitations of traditional therapies, thereby improving treatment precision and efficacy. The applications of nanomaterials in diagnostics are summarized, where they enable high-resolution retinal imaging by carrying fluorescent probes or contrast agents or act as biosensors to sensitively detect disease-related biomarkers, facilitating early diagnosis and dynamic monitoring. In therapeutics, functionalized nanocarriers can precisely deliver drugs, genes, or antioxidant molecules to retinal target cells, significantly enhancing therapeutic outcomes while reducing systemic toxicity. Additionally, nanofiber materials possess unique properties that make them particularly suitable for retinal regeneration in tissue engineering. By loading neurotrophic factors into nanofiber scaffolds, their regenerative effects can be amplified, promoting the repair of retinal neurons. Despite their immense potential, clinical translation of nanomaterials still requires addressing challenges such as long-term biosafety, scalable manufacturing processes, and optimization of targeting efficiency.

A Mechanistic Understanding of Reactive Oxygen Species (ROS)-Responsive Bio-Polymeric Nanoparticles: Current State, Challenges and Future Toward Precision Therapeutics

Inflammation is a hallmark of various pathological conditions, including cancer, cardiovascular diseases, neurodegenerative disorders, and autoimmune diseases. Reactive oxygen species (ROS) are crucial mediators in the inflammatory microenvironment, playing a pivotal role in both normal cellular processes and disease progression. Targeting ROS overproduction in inflamed tissues has emerged as a promising therapeutic strategy. Polymeric nanoparticles (NPs) responsive to ROS levels in pathological tissues have gained substantial attention as precision drug delivery systems, capable of ensuring controlled, site-specific drug release. This review provides a comprehensive mechanistic insight into ROS-responsive polymeric nanoparticles, examining their structural design, functionalization strategies, drug release mechanisms, and potential for targeted therapies in inflammatory conditions. Furthermore, we discuss recent advancements, challenges, and future directions in utilizing ROS-responsive polymeric nanoparticles for precision therapeutics, highlighting their transformative potential in clinical applications.

pH-responsive photothermal effect and heterojunction formation for tumor-specific pyroelectrodynamic and nanozyme-catalyzed starvation therapy

Pyroelectrodynamic therapy (PEDT) integrates photothermal ablation and catalytic generation of reactive oxygen species (ROS), yet tumor-specific PEDT remains unexplored. Herein, pyroelectric tetragonal BaTiO3 (tBT) nanoparticles (NPs) were capped with polyaniline (PANI) via a Pickering emulsion-masking method, followed by in situ deposition of MnO2 nanodots on PANI caps to synthesize Janus tBT@PANI-MnO2 NPs. PANI emeraldine salts (PANI-ES) at pH 6.5 display strong near-infrared II (NIR-II) absorption and 4.67-fold higher photothermal conversion efficiency than that of PANI emeraldine base at pH 7.4. MnO2 nanodots exhibit self-propagating glucose oxidase (GOx), peroxidase (POD), and catalase (CAT) catalytic activities, remodeling the tumor microenvironment and enhancing PTT and PEDT efficacy. Heterojunction formation with PANI-ES generates 1.63-fold higher pyroelectric potentials compared to pristine tBT NPs. The pyroelectric field selectively alters tumor cell membrane potential and, along with the self-propelled motion by asymmetrical thermophoresis from the Janus structure, promotes cellular uptake of NPs. Tumor accumulation of NPs increases 3.2 folds with broad intratumoral distributions of NPs and ROS. Synergistic toxicities to tumor cells arise from PANI-mediated photothermal effect, ROS generation from tBT-PANI heterojunctions, and MnO2 nanozymes-catalyzed glucose depletion. Integration of PEDT, mild PTT and MnO2-catalyzed starvation therapy completely inhibits tumor growth, extends animal survival, elevated intratumoral O2 levels, and suppressed adenosine triphosphate productions. Thus, this Janus NP design represents the first attempt to develop pH-responsive heterojunctions and enables tumor-specific PTT, PEDT and nanozyme-catalyzed starvation therapy. STATEMENT OF SIGNIFICANCE: Although phototherapy achieves light localization for tumor suppression, inevitable toxicities usually occur when light penetrates healthy tissues with accumulation of photoactive agents. Extensive efforts have been dedicated to exploring tumor microenvironment-responsive drug delivery systems, aiming to enhance tumor-targeting efficiency and treatment selectivity of anticancer agents. However, to date, no efforts have been made to develop a method that can achieve tumor-specific temperature elevation and pyroelectrodynamic therapy while simultaneously minimizing exposure to normal tissues. To address these challenges, a concise strategy is proposed to generate pyroelectric heterojunctions in response to the slightly acidic tumor microenvironment, taking advantages of reversible protonation and deprotonation properties of polyaniline. The tumor-specific conversion into polyaniline emeraldine salts triggers strong NIR-II absorptions and pyroelectric effect, and the self-propagated catalytic reactions of MnO2 nanozymes reinforce photothermal, pyroelectrodynamic and starvation therapies of tumors.

NIR-II D-A-D-Type Small-Molecule Coordination with Carboxylatopillar[5]Arene: a Multifunctional Phototheranostic for Low-Temperature NIR-II Photothermal/Platinum-Based/Chemodynamic Combination Cancer Immunotherapy

Low-temperature second near-infrared region (NIR-II) photothermal therapy (PTT) has shown significant potential in minimizing damage to normal tissues and reducing inflammation. However, it still faces challenge of insufficient immune response. Thus, a multifunctional phototheranostic nanoparticle (BDPB/Pt/Fe@P[5]) is developed by co-loading BDPB, CDHPt, and Fe2⁺ with a pH-sensitive lipid DSPE-PEOz2K. The carboxylatopillar[5]arene (CP[5]) used to construct this nanoparticle exhibits strong host-guest recognition with pyridine salts, alleviating aggregation caused quench (ACQ) effect and enhancing the NIR-II emission of the donor-acceptor-donor (D-A-D)-type organic small molecule (BDPB). CP[5] provides suitable vehicles for encapsulating platinum (IV) prodrugs (CDHPt) and Fe2⁺ ions via metal coordination for controllable reactive oxygen species (ROS) release. Under low-intensity NIR-II laser irradiation and an acidic tumor microenvironment, the nanoparticles degrade, releasing CDHPt and Fe2⁺ ions for platinum-based therapy and chemodynamic therapy (CDT). CDHPt facilitates the direct production of superoxide anions (O₂·⁻) from O₂ and partially converts it into the highly cytotoxic hydroxyl radicals, thereby promoting the Fenton reaction process. The therapeutic efficacy is further synergized by immunogenic cell death (ICD) effect.

A biotin guided PtIV amphiphilic prodrug synergized with CDK4/6 inhibition for enhanced tumor targeted therapy

Platinum-based chemotherapy has been the first-line treatment for advanced bladder cancer for decades, but its durability and safety remain important challenges. Targeted delivery and other precision medicine bring hope to fight cancer. In this study, we present a novel targeted therapy utilizing a biotin receptor-targeting lipid PtIV prodrug amphiphile, which encapsulates a CDK4/6 inhibitor into BPtIV@Rib. CDK4/6 inhibitors have the potential to combat breast cancer and enhance sensitivity to cisplatin, thereby improving its therapeutic efficacy. Our findings demonstrate that BPtIV@Rib also exhibits excellent bladder tumor-targeting capability, resulting in increased accumulation of Pt and ribociclib (Rib) at the tumor site. The combination of PtIV and Rib leads to substantial tumor growth suppression while minimizing synergistic toxicity compared to conventional therapies. In conclusion, this combination therapy represents a promising strategy for enhanced targeted treatment of bladder cancer, potentially improving patient outcomes while reducing adverse effects.

Tumor microenvironment-responsive precise delivery nanocarrier potentiating synchronous radionuclide therapy and chemotherapy against cancer

To achieve better therapeutic outcomes in cancer treatment, the combination of radionuclide and chemotherapy is commonly employed in clinical practice. However, the primary challenge lies in achieving precise drug delivery to tumor tissues, often leading to suboptimal therapeutic efficacy. This study presents a novel, tumor microenvironment-responsive drug delivery carrier that integrates real-time MRI/SPECT dual-modal imaging for precise diagnosis and treatment monitoring. The carrier comprised is based on a hybrid structure composed of hyaluronic acid (HA) and human serum albumin (HSA), encapsulating the metal-organic framework MIL-100(Fe). It was loaded with the chemotherapeutic drug doxorubicin (DOX) and modified with the radionuclide 131I, designed to precise diagnosis and treatment of tumors. HA binds specifically to the overexpressed CD44 receptor on the tumor surface, ensuring that the carrier targets tumors selectively. The incorporated 131I emits β rays, which deliver ionizing radiation to eradicate tumor cells. Concurrently, the carrier could release DOX in response to the tumor microenvironment, inhibiting DNA synthesis and sensitizing the tumor cells to radiation. This combined approach results in synchronous radionuclide therapy (RNT) and chemotherapy, maximizing therapeutic impact. In vitro and in vivo experiments demonstrated that the carrier exhibited favorable biocompatibility, stable radionuclide labeling, tumor-specific accumulation, and controlled release of DOX within the tumor microenvironment. Furthermore, MRI/SPECT dual-modal imaging enabled real-time tumor localization and monitoring of the carrier in vivo biodistribution. Experimental outcomes confirmed that this innovative carrier, combining RNT and chemotherapy, significantly inhibited tumor growth. This strategy offers a promising approach for precision radio-chemotherapy guided by dual-modal imaging, providing valuable insights for integrated targeted diagnosis and treatment of tumors.

Biotin Receptor-Targeting PtIV Oxygen Carrying Prodrug Amphiphile for Alleviating Tumor Hypoxia Induced Immune Chemotherapy Suppression

Platinum (Pt)-based chemotherapeutic agents, known for their potent cytotoxicity, are extensively used in clinical oncology. However, their therapeutic efficacy is severely limited by a variety of factors, particularly the hypoxic tumor microenvironment (TME), which not only impedes effective drug delivery but also triggers immune suppression, further diminishing the antitumor effects of Pt drugs. In response to these challenges, we have developed a biotin receptor (BR)-targeting oxaliplatin (OXA)-based PtIV prodrug, named Lipo-OPtIV-BT, which could encapsulate hemoglobin (Hb) as an oxygen carrier, forming PtIV-loaded lipid nanoparticles (Hb@BTOPtIV). The design of the Hb@BTOPtIV aims to address the dual issues of poor drug delivery and immune suppression by effectively increasing local oxygen tension in the TME. Notably, our findings demonstrate that the cytotoxic effects of the BR-targeting PtIV prodrug and increased oxygen levels synergistically reverse the tumor immune microenvironment, leading to improved antitumor efficacy. We observed that Hb@BTOPtIV significantly improved the biodistribution of the drug, enabling it to preferentially accumulate in tumor regions. Importantly, the enhanced oxygenation within the TME also plays a critical role in reshaping the immune landscape of the tumor, promoting a more favorable immune environment for effective chemotherapy. This reversal of immune suppression is evidenced by increased infiltration of cytotoxic T cells and reduced levels of regulatory T cells (Tregs) within the tumor. These findings highlight the promising potential of using BR-targeting lipid PtIV prodrug amphiphiles to improve drug accumulation at tumor sites and counteract immunosuppression induced by tumor hypoxia.

Understanding the interplay between pH and charges for theranostic nanomaterials

Nanotechnology has emerged as a highly promising platform for theranostics, offering dual capabilities in targeted imaging and therapy. Interactions between the nanomaterial and biological components determine the in vivo fate of these materials which makes the control of their surface properties of utmost importance. Nanoparticles with neutral or negative surface charge have a longer circulation time while positively charged nanoparticles have higher affinity to cells and better cellular uptake. This trade-off presents a key challenge in optimizing surface charge for theranostic applications. A sophisticated solution is an on-demand switch of surface charge, enabled by leveraging the distinct pH conditions at the target site. In this review, we explore the intricate relationship between pH and charge modulation, summarizing recent advances in pH-induced charge-switchable nanomaterials for theranostics over the past five years. Additionally, we discuss how these innovations enhance targeted drug delivery and imaging contrast and provide perspectives on future directions for this transformative field.

Diselenide-based nanoparticles enhancing the radioprotection to the small intestine of mice

The widespread application of ionizing radiation (IR) in medicine, while beneficial, also poses potential risks that necessitate effective countermeasures. Both 2-(3-aminopropylamino) ethanethiol (WR-1065) and curcumin are recognized as radioprotective agents; however, their clinical utility is hindered by notable shortcomings that could be addressed through reactive oxygen species (ROS)-responsive amphiphilic nanomaterials. We introduced a newly synthesized poly (ethylene glycol) (PEG)-polycaprolactone (PCL) polymer integrated with diselenide bonds and curcumin (HOOC-SeSe-Cur-PEG-SeSe-Cur-PCL, PEG-Cur-SeSe-PCL). The resulting spherical nanoparticles (NPs), which self-assembled from this polymer, were uniform with an average diameter of 118 nm. As a carrier for WR-1065, these NPs demonstrated a loading capacity of 30.9% and an efficacy of 56.7%. Importantly, the degradation of WR-1065 within the NPs was minimal in gastric fluid, decreasing by only approximately 20% over a 6-hour period. The innovative aspect of these NPs is their design to destabilize in ROS-rich environments, facilitating the release of WR-1065 and curcumin. Indeed, the survival rate of mice increased to 50% when these NPs were orally administered prior to exposure to a lethal dose of whole-body irradiation (8 Gy). The radioprotective impact of WR-1065-loaded NPs was evident in the small intestine of irradiated mice, characterized by the amelioration of radiation-induced epithelial damage, reduction of DNA damage, and inhibition of the apoptotic pathway. Collectively, this oral nanocarrier system for WR-1065 and curcumin holds promise as a potential candidate for the prophylaxis and treatment of acute intestinal injuries induced by IR.

Responsive Surfactant-Driven Morphology Transformation of Block Copolymer Microparticles

Block copolymer (BCP) microparticles, which exhibit rapid change of morphology and physicochemical property in response to external stimuli, represent a promising avenue for the development of programmable smart materials. Among the methods available for generating BCP microparticles with adjustable morphologies, the confined assembly of BCPs within emulsions has emerged as a particularly facile and versatile approach. This review provides a comprehensive overview of the role of responsive surfactants in modulating interfacial interactions at the oil-water interface, which facilitates controlled BCP microparticle morphology. We elucidate how variations in the properties of responsive surfactants, activated by external stimuli, influence BCP chain arrangement and interfacial selectivity. Additionally, this review explores the applications of shape-switchable microparticles in advanced technologies such as smart display, fluorescence modulation, magnetic resonance imaging, drug delivery, and photonic crystal. Finally, the challenges and prospective future directions in this rapidly evolving field are discussed.

Folate-targeted nanoparticles for glutamine metabolism inhibition enhance anti-tumor immunity and suppress tumor growth in ovarian cancer

Ovarian cancer (OC) is a highly malignant gynecological tumor, and its effective treatment is frequently impeded by drug resistance and recurrent tumor growth. The reprogramming of glutamine metabolism in ovarian cancer is closely associated with tumor progression and the immunosuppressive tumor microenvironment. Recently, targeting metabolic reprogramming has emerged as a promising approach for cancer therapy. However, the application of such therapies is often constrained by their significant toxicity to normal tissues. In this study, we fabricated folate-targeted nanoparticles (FA-DCNPs) that co-encapsulate the glutamine metabolism inhibitor 6-diazo-5-oxo-L-norleucine (DON) and calcium carbonate (CaCO3). These nanoparticles alleviate damage to normal tissues by specifically targeting tumor cells via folate receptors (FOLR) mediation. Under acidic conditions, the FA-DCNPs release DON and Ca2+, generating a synergistic anti-tumor effect by impeding glutamine metabolism and inducing calcium overload. Additionally, FA-DCNPs target M2 phenotype tumor-associated macrophages (TAMs) via FOLR2, attenuating M2-TAMs activity. When partially phagocytosed by M0-TAMs, the nanoparticles restrict glutamate production, inhibiting polarization towards the M2 phenotype. This resulted in an increased proportion of M1-TAMs, thereby improving the tumor immune microenvironment. Our study explores a nanotherapeutic strategy that enhances the biosafety of anti-glutamine metabolism therapy through folate targeting, effectively suppresses tumor cell proliferation, and enhances the anti-tumor immune response.

Supramolecular polyrotaxane-based nano-theranostics enable cancer-cell stiffening for enhanced T-cell-mediated anticancer immunotherapy

Despite the tremendous therapeutic promise of activating stimulators of interferon genes (STING) enable to prime robust de novo T-cell responses, biomechanics-mediated immune inhibitory pathways hinder the cytotoxicity of T cells against tumor cells. Blocking cancer cell biomechanics-mediated evasion provides a feasible strategy for augmenting STING activation-mediated anti-tumor therapeutic efficacy. Here, we fabricate a redox-responsive Methyl-β-cyclodextrin (MeβCD)-based supramolecular polyrotaxanes (MSPs), where the amphiphilic diselenide-bridged axle polymer loads MeβCD by the host-guest interaction and end-caping with two near-infrared (NIR) fluorescence probes IR783. The MSPs self-assemble with STING agonists diABZIs into nanoparticles (RDPNs@diABZIs), which enable simultaneous release of MeβCD and diABZIs in the redox tumor microenvironment. After the released diABZIs activate STING on antigen-presenting cells (APCs), de novo T-cell responses are initiated. Meanwhile, the released MeβCD depletes membrane cholesterol to overcome cancer-cell mechanical softness, which enhances the CTL-mediated killing of cancer cells. In the female tumor-bearing mouse model, we demonstrate that RDPNs@diABZIs lead to effective tumor regression and generate long-term immunological memory. Furthermore, RDPNs@diABZIs can achieve significant tumor eradication, with these mice remaining survival for at least 2 months.

Mitochondria-targeting nanostructures from enzymatically degradable fluorescent amphiphilic polyesters

Water-soluble π-conjugated luminescent bioprobes have been broadly used in biomedical research but are limited by the nonbiodegradability associated with their rigid C-C backbones. In the present work, we introduced three naphthalene monoimide (NMI)-functionalized amphiphilic fluorescent polyesters (P1, P2, and P3) prepared by transesterification of functional diols with an activated diester monomer of adipic acid. These polyesters featured a side-chain NMI fluorophore, imparting the required hydrophobicity for self-assembly in water and endowing the polymeric nanoassemblies with green fluorescence. Two polymers (P1 and P2) were intrinsically cationic at physiological pH (7.4), while neutral P3 exhibited pH-triggered (pH ∼6.2) cationic features due to the protonation of the tertiary amine groups present in its backbone. These biocompatible polymers revealed around 85% cellular uptake after 1 hour of incubation. However, the initial uptake for the cationic polymers (P1 and P2) within 15 minutes was significantly greater than that of the neutral P3 because of their stronger electrostatic interactions with the negatively charged cell membranes. Notably, cationic P1 and P2 could specifically target mitochondria in cancerous HeLa cells by escaping the initial endosome/lysosome trap. In contrast, neutral P3 exhibited cell-selective mitochondria targeting in cancerous (HeLa) cells over non-cancerous (NKE) cells. This is attributed to P3's protonation-induced positive charge accumulation in the acidic environment of cancer cells, unlike in the non-acidic environment of non-cancerous cells. This possibly causes P3 nanoassemblies to behave similarly to P1 and P2 in HeLa cells despite P3 being intrinsically neutral. The insights gained from this work may be relevant for future development of cell-specific, mitochondria-targeted drug delivery systems from enzymatically degradable polyester backbones.

Recent Updates on Blood Purification: Use of Smart Polymer Materials

Blood purification is indispensable in addressing various conditions such as liver dysfunction, autoimmune diseases, and renal failure whereby toxins have to be cleared from the bloodstream effectively. Conventional methods that involve hemoperfusion, hemodialysis, and hemofiltration possess several weaknesses, including loss of plasma components and inefficient clearance of high molecular weight solutes. This review explores current developments in blood purification techniques particularly stimuli-responsive polymers for use in extracorporeal therapy among other applications. Many aspects of engineering stimuli-responsive polymers are described in terms of their role in the removal of small soluble molecules and toxins in blood purification techniques. The development of stimuli-responsive systems has introduced a new paradigm in blood purification by enabling selective, on-demand control of polymer parameters in response to external stimuli such as temperature, pH, electrolytes, and light. Such advanced materials have been demonstrated potential for toxin clearance, minimizing thrombosis, and improving blood compatibility and antifouling, which are far much better than traditional approaches. Furthermore, the review presents a perspective on stimuli-responsive polymers that could be used in developing novel extracorporeal systems for future medical purposes.

Stimuli-Responsive Nano Drug Delivery Systems for the Treatment of Neurological Diseases

Nanomaterials with unparalleled physical and chemical attributes have become a cornerstone in the field of nanomedicine delivery. These materials can be engineered into various functionalized nanocarriers, which have become the focus of research. Stimulus-responsive nanodrug delivery systems (SRDDS) stand out as a sophisticated class of nanocarriers that can release drugs in response to environmental cues. Due to the complex pathogenesis and the multifaceted pathological environment of the nervous system, developing accurate and effective drug therapy with low side-effects is a formidable task. In recent years, SRDDS have been widely used in the treatment of neurological diseases. By customizing SRDDS to align with the specific microenvironment of the nervous system tissues or external stimulation, the efficacy of drug delivery can be enhanced. This review provides an in-depth look at the characteristics of the microenvironment of neurological diseases and highlights case studies of SRDDS tailored to treat these disorders based on the unique stimulation criteria of nervous system tissues or external triggers. Additionally, this review provides a comprehensive overview of the progress and future prospects of SRDDS technology in the treatment of neurological diseases, providing valuable guidance for its transition from fundamental research to clinical application.

Chemical and biological investigations on modified gemcitabine by nanoliposome structured on cholesterol, pectin, and phosphatidylcholine as an anticancer drug via a drug delivery system

Gemcitabine hydrochloride (GEM) mimics one of the building blocks of DNA and RNA, so it indicates possible chemotherapeutic effects. It prevents cancer cells from producing DNA and proteins, which ultimately leads to their death. The goal of this work is to modify the GEM medication by nanoforming nanoliposomes based on the composition of Cholesterol, pectin nanoparticles, and phosphatidylcholine (PhC). The drug in nanoliposome form is made using the precipitation method, and several approaches are employed to characterize it. UV-Vis spectroscopy is used to measure the release process of GEM from the lipids and its integration with them. Results of the combination efficiency for PhC.Pectin@GEM, PhC.GEM@Pectin, and PhC@Cholestrol.GEM were recorded at 78.8 %, 83 %, and 80 %, respectively. A UV-Vis spectrophotometer was used to determine the release efficiency of the nanoliposomes, which was measured at pH values of 3, 6.8, and 7.4. The in-vitro investigation employed SRB (Routine analysis IC50) to determine the modified drug's toxicity on breast adenocarcinoma (MCF-7) cells, while the in-vitro study assessed the produced nanoliposomes' capacity to do so. The conclusion is that to ascertain whether GEM medicine's nanoliposomes can effectively treat breast cancer in place of GEM medication, clinical trials are necessary to prove the ability for treatment.

Metal-organic framework-based smart stimuli-responsive drug delivery systems for cancer therapy: advances, challenges, and future perspectives

Cancer treatment is currently one of the most critical healthcare issues globally. A well-designed drug delivery system can precisely target tumor tissues, improve efficacy, and reduce damage to normal tissues. Stimuli-responsive drug delivery systems (SRDDSs) have shown promising application prospects. Intelligent nano drug delivery systems responsive to endogenous stimuli such as weak acidity, complex redox characteristics, hypoxia, active energy metabolism, as well as exogenous stimuli like high temperature, light, pressure, and magnetic fields are increasingly being applied in chemotherapy, radiotherapy, photothermal therapy, photodynamic therapy, and various other anticancer approaches. Metal-organic frameworks (MOFs) have become promising candidate materials for constructing SRDDSs due to their large surface area, tunable porosity and structure, ease of synthesis and modification, and good biocompatibility. This paper reviews the application of MOF-based SRDDSs in various modes of cancer therapy. It summarizes the key aspects, including the classification, synthesis, modifications, drug loading modes, stimuli-responsive mechanisms, and their roles in different cancer treatment modalities. Furthermore, we address the current challenges and summarize the potential applications of artificial intelligence in MOF synthesis. Finally, we propose strategies to enhance the efficacy and safety of MOF-based SRDDSs, ultimately aiming at facilitating their clinical translation.

Biomimetic metal-phenolic nanocarrier for co-delivery of multiple phytomedical bioactive components for anti-atherosclerotic therapy

Atherosclerosis, a major cause of cardiovascular diseases, involves complex pathophysiological processes. The co-delivery of multiple bioactive components derived from phytomedicine to atherosclerotic plaque is challenging, especially for those with varied solubilities. This study introduces a novel metal-phenolic network-based core-shell recombinant high-density lipoprotein nanocarrier (SSPH-MPN@rHDL) for co-delivering multiple bioactive components from Salvia miltiorrhiza and Carthamus tinctorius, including salvianic acid A (SAA), salvianolic acid B (SAB), protocatechuic aldehyde (PCA), hydroxysafflor yellow A (HSYA), and tanshinone IIA (TS-IIA). These components have varied solubilities, presenting challenges for achieving synergistic therapeutic effects. The SSPH-MPN@rHDL system encapsulates the four hydrophilic components (i.e. SAA, SAB, PCA, HSYA) within a quaternary metal-phenolic network and a hydrophobic component (i.e. TS-IIA) in an outer lipid layer, facilitating targeted plaque delivery. In vitro and in vivo experimental results demonstrated that SSPH-MPN@rHDL enhanced anti-atherosclerotic efficacy through combined antioxidant, anti-inflammatory, and lipid-lowering actions. This approach offers new perspectives on using nanotechnology to optimize the delivery of phytomedicinal compounds for cardiovascular therapy.

Invasion and metastasis in cancer: molecular insights and therapeutic targets

The progression of malignant tumors leads to the development of secondary tumors in various organs, including bones, the brain, liver, and lungs. This metastatic process severely impacts the prognosis of patients, significantly affecting their quality of life and survival rates. Research efforts have consistently focused on the intricate mechanisms underlying this process and the corresponding clinical management strategies. Consequently, a comprehensive understanding of the biological foundations of tumor metastasis, identification of pivotal signaling pathways, and systematic evaluation of existing and emerging therapeutic strategies are paramount to enhancing the overall diagnostic and treatment capabilities for metastatic tumors. However, current research is primarily focused on metastasis within specific cancer types, leaving significant gaps in our understanding of the complex metastatic cascade, organ-specific tropism mechanisms, and the development of targeted treatments. In this study, we examine the sequential processes of tumor metastasis, elucidate the underlying mechanisms driving organ-tropic metastasis, and systematically analyze therapeutic strategies for metastatic tumors, including those tailored to specific organ involvement. Subsequently, we synthesize the most recent advances in emerging therapeutic technologies for tumor metastasis and analyze the challenges and opportunities encountered in clinical research pertaining to bone metastasis. Our objective is to offer insights that can inform future research and clinical practice in this crucial field.

Transcytosis-Triggering Nanoparticles for Overcoming Stromal Barriers and Reversing Immunosuppression in Pancreatic Cancer Combinatorial Therapy

In pancreatic ductal adenocarcinoma (PDAC), stromal cells and matrix proteins form a dense physical barrier that, while preventing the outward spread of tumor cells, also limits the penetration of drugs and CD8+ T cells inward. Additionally, the overactivated TGF-β/SMAD signaling pathway further promotes matrix proliferation and immune suppression. Therefore, crossing the stromal barrier while preserving the integrity of the stroma, releasing drugs intratumorally, remodeling the stroma, and activating the immune system is a promising drug delivery strategy. In this work, a type of enamine N-oxides modified nanoparticle was prepared, with stearic acid-modified gemcitabine prodrug (GemC18) and pSMAD2/3 inhibitor galunisertib encapsulated. The peripheral enamine N-oxides can trigger transcytosis and then respond to hypoxia and acidic microenvironments, turning the surface charge of the nanoparticles to a positive charge and enhancing penetration. The released galunisertib inhibits the TGF-β/SMAD signaling pathway, reshapes the matrix, activates antitumor immunity, and combines with gemcitabine (Gem) to kill tumor cells.

A novel cyanine photosensitizer for sequential dual-site GSH depletion and ROS-potentiated cancer photodynamic therapy

The efficacy of photodynamic therapy (PDT) is often limited by the reductive microenvironment in tumor cells due to the high level of glutathione (GSH) and glutathione peroxidase 4 (GPX4), which maintain redox homeostasis. Therefore, designing a GSH-responsive photosensitizer that depletes intracellular GSH is a promising strategy to enhance PDT selectivity and efficacy. Herein, we present a GSH-selective sequentially responsive theranostic photosensitizer, Cy-Res. This cyanine agent targeting mitochondria effectively depletes two GSH molecules, leading to the generation of abundant ROS and exacerbating oxidative stress. Additionally, it achieves an 80-fold fluorescence enhancement upon response to GSH, enabling selective imaging of tumor cells. By mitigating GSH's impact on PDT, Cy-ResNPs achieves synergistic and efficient PDT treatment of invasive melanoma under low-power irradiation (808 nm, 80 mW/cm2). The inhibitory processes downregulate GPX4, increase apoptotic proteins like Bax, and promote mixed cell death involving both ferroptosis and apoptosis. Overall, this study offers new insights and strategies for the development of GSH-responsive theranostic agents, highlighting their potential for application in tumor diagnosis and therapy.

Hypoxia-Responsive Covalent Organic Framework Nanoplatform for Breast-Cancer-Targeted Cocktail Immunotherapy via Triple Therapeutic Switch Mechanisms

Covalent organic frameworks (COFs), known for their exceptional in situ encapsulation and precise release capabilities, are emerging as pioneering drug delivery systems. This study introduces a hypoxia-responsive COF designed to encapsulate the chemotherapy drug gambogic acid (GA) in situ. Bimetallic gold-palladium islands were grown on UiO-66-NH2 (UiO) to form UiO@Au-Pdislands (UAPi), which were encapsulated with GA through COF membrane formation, resulting in a core-shell structure (UAPiGC). Further modification with hyaluronic acid (HA) created UiO@Au-Pdislands@GA-COF@HA (UAPiGCH) for enhanced tumor targeting. In the hypoxic tumor microenvironment, the COF collapses, releasing GA and UAPi, initiating a triple therapeutic response: nanozyme-catalyzed therapy, near-infrared II (NIR-II) mild photothermal therapy (mild-PTT), and chemotherapy. UAPi exhibits catalase (CAT)-like and peroxidase (POD)-like activities, generating oxygen to alleviate hypoxia and reactive oxygen species (ROS) for tumor destruction. GA acts as a chemotherapeutic agent and inhibits heat shock protein 90 (HSP90), enhancing photothermal sensitivity. In vitro and in vivo studies confirm UAPiGCH's ability to induce pyroptosis, stimulate dendritic cell maturation, and boost T cell infiltration, demonstrating its potential as a precise therapeutic nanoplatform. This strategy integrates multiple therapies into a hypoxia-responsive system, offering promising applications in cancer treatment.

Bioengineering stimuli-responsive organic-inorganic nanoarchitetures based on carboxymethylcellulose-poly-l-lysine nanoplexes: Unlocking the potential for bioimaging and multimodal chemodynamic-magnetothermal therapy of brain cancer cells

Regrettably, glioblastoma multiforme (GBM) remains the deadliest form of brain cancer, where the early diagnosis plays a pivotal role in the patient's therapy and prognosis. Hence, we report for the first time the design, synthesis, and characterization of new hybrid organic-inorganic stimuli-responsive nanoplexes (NPX) for bioimaging and killing brain cancer cells (GBM, U-87). These nanoplexes were built through coupling two nanoconjugates, produced using a facile, sustainable, green aqueous colloidal process ("bottom-up"). One nanocomponent was based on cationic epsilon-poly-l-lysine polypeptide (εPL) conjugated with ZnS quantum dots (QDs) acting as chemical ligand and cell-penetrating peptide (CPP) for bioimaging of cancer cells (QD@εPL). The second nanocomponent was based on anionic carboxymethylcellulose (CMC) polysaccharide surrounding superparamagnetic magnetite "nanozymes" (MNZ) behaving as a capping macromolecular shell (MNZ@CMC) for killing cancer cells through chemodynamic therapy (CDT) and magnetohyperthermia (MHT). The results demonstrated the effective production of supramolecular aqueous colloidal nanoplexes (QD@εPL_MNZ@CMC, NPX) integrated into single nanoplatforms, mainly electrostatically stabilized by εPL/CMC biomolecules with anticancer activity against U-87 cells using 2D and 3D spheroid models. They displayed nanotheranostics (i.e., diagnosis and therapy) behavior credited to the photonic activity of QD@εPL with luminescent intracellular bioimaging, amalgamated with a dual-mode killing effect of GBM cancer cells through CDT by nanozyme-induced biocatalysis and as "nanoheaters" by magnetically-responsive hyperthermia therapy.

Advanced Polymeric Nanoparticles for Cancer Immunotherapy: Materials Engineering, Immunotherapeutic Mechanism and Clinical Translation

Cancer immunotherapy, which leverages immune system components to treat malignancies, has emerged as a cornerstone of contemporary therapeutic strategies. Yet, critical concerns about the efficacy and safety of cancer immunotherapies remain formidable. Nanotechnology, especially polymeric nanoparticles (PNPs), offers unparalleled flexibility in manipulation-from the chemical composition and physical properties to the precision control of nanoassemblies. PNPs provide an optimal platform to amplify the potency and minimize systematic toxicity in a broad spectrum of immunotherapeutic modalities. In this comprehensive review, the basics of polymer chemistry, and state-of-the-art designs of PNPs from a physicochemical standpoint for cancer immunotherapy, encompassing therapeutic cancer vaccines, in situ vaccination, adoptive T-cell therapies, tumor-infiltrating immune cell-targeted therapies, therapeutic antibodies, and cytokine therapies are delineated. Each immunotherapy necessitates distinctively tailored design strategies in polymeric nanoplatforms. The extensive applications of PNPs, and investigation of their mechanisms of action for enhanced efficacy are particularly focused on. The safety profiles of PNPs and clinical research progress are discussed. Additionally, forthcoming developments and emergent trends of polymeric nano-immunotherapeutics poised to transform cancer treatment paradigms into clinics are explored.

Tumor-Targeted Catalytic Immunotherapy

Cancer immunotherapy holds significant promise for improving cancer treatment efficacy; however, the low response rate remains a considerable challenge. To overcome this limitation, advanced catalytic materials offer potential in augmenting catalytic immunotherapy by modulating the immunosuppressive tumor microenvironment (TME) through precise biochemical reactions. Achieving optimal targeting precision and therapeutic efficacy necessitates a thorough understanding of the properties and underlying mechanisms of tumor-targeted catalytic materials. This review provides a comprehensive and systematic overview of recent advancements in tumor-targeted catalytic materials and their critical role in enhancing catalytic immunotherapy. It highlights the types of catalytic reactions, the construction strategies of catalytic materials, and their fundamental mechanisms for tumor targeting, including passive, bioactive, stimuli-responsive, and biomimetic targeting approaches. Furthermore, this review outlines various tumor-specific targeting strategies, encompassing tumor tissue, tumor cell, exogenous stimuli-responsive, TME-responsive, and cellular TME targeting strategies. Finally, the discussion addresses the challenges and future perspectives for transitioning catalytic materials into clinical applications, offering insights that pave the way for next-generation cancer therapies and provide substantial benefits to patients in clinical settings.

Strategy and Design of In Situ Activated Protein Hydrolysis Targeted Chimeras

Protein hydrolysis targeted chimeras (PROTACs) represent a different therapeutic approach, particularly relevant for overcoming challenges associated with traditional small molecule inhibitors. These challenges include targeting difficult proteins that are often deemed "undruggable" and addressing issues of acquired resistance. PROTACs employ the body's own E3 ubiquitin ligases to induce the degradation of specific proteins of interest (POIs) through the ubiquitin-proteasome pathway. This process is cyclical, allowing for broad applicability, potent protein degradation, and selective targeting. Despite their effectiveness, PROTACs can inadvertently target and degrade nonspecific proteins, potentially resulting in significant side effects and off-target toxicity. To address this concern, researchers have created stimuli-activated PROTACs that enhance targeted protein degradation while minimizing potential harm to healthy cells. These advanced PROTACs aim to improve the precision of degradation in both time and space. This article reviews the strategies for in situ activated PROTACs, highlighting key compounds and research advancements associated with various mechanisms of action. The insights presented here aim to guide further exploration in the field of activated PROTACs.

Bioresponsive Polymeric Nanoparticles: From Design, Targeted Therapy to Cancer Immunotherapy

Bioresponsive polymeric nanoparticles (NPs) that are capable of delivering and releasing therapeutics and biotherapeutics to target sites have attracted vivid interest in cancer therapy and immunotherapy. In contrast to enthusiastic evolution in the academic world, the clinical translation of these smart systems is scarce, partly due to concerns about safety, stability, complexity, and scalability. The moderate targetability, responsivity, and benefits are other concerns. In the past 17 years, we have devoted ourselves to exploring elegant strategies to address the above basic and translational problems by introducing diverse functional groups and/or targeting ligands to safe biomedical materials, such as biodegradable polymers and water-soluble polymers. This minimal modification is critical for further clinical translation. We have tailor-made various bioresponsive NPs including shell-sheddable and/or acid-sensitive biodegradable NPs, disulfide-cross-linked biodegradable micelles and polymersomes, and blood-brain barrier (BBB)-permeable NPs, to target different tumors. This perspective provides an overview of our work path toward targeted nanomedicines and personalized vaccines, which might inspire clinical translation and future research on cancer therapy.

Regulating Triplet Excitons of Organic Luminophores for Promoted Bioimaging

Afterglow materials with organic room temperature phosphorescence (RTP) or thermally activated delayed fluorescence (TADF) exhibit significant potential in biological imaging due to their long lifetime. By utilizing time-resolved technology, interference from biological tissue fluorescence can be mitigated, enabling high signal-tobackground ratio imaging. Despite the continued emergence of individual reports on RTP or TADF in recent years, comprehensive reviews addressing these two materials are rare. Therefore, this review aims to provide a comprehensive overview of several typical molecular designs for organic RTP and TADF materials. It also explores the primary methods through which triplet excitons resist quenching by water and oxygen. Furthermore, we analyze the principal challenges faced by afterglow materials and discuss key directions for future research with the hope of inspiring developments in afterglow imaging.

Cascade-Activatable Nanoprodrug System Augments Sonochemotherapy of Bladder Cancer

Sonochemotherapy (SCT) has emerged as a powerful modality for cancer treatment by triggering excessive production of reactive oxygen species (ROS) and controlled release of chemotherapeutic agents under ultrasound. However, achieving spatiotemporally controlled release of chemotherapeutic agents during ROS generation is still an enormous challenge. In this work, we developed a cascade-activated nanoprodrug (CAN) system that utilizes a reversible covalent Schiff base mixed with a hypoxia-activatable camptothecin (CPT) prodrug. Briefly, the designed fluorinated CAN system is self-assembled into nanoparticles under aqueous conditions, which could penetrate deep tumors to offer sufficient oxygen for ultrasound-triggered ROS production. Consequently, the nanoparticles substantially exacerbated the hypoxia of the tumor microenvironment (TME) by elevating oxygen consumption. The aggravated hypoxia in turn served as a positive amplifier to boost the tumor-specific CPT release of Azo-CPT prodrug, which made up for the insufficient treatment efficacy of sonodynamic therapy (SDT). On this basis, we observed a substantial reduction, approximately 3.5-fold, in the half-maximal inhibitory concentration (IC50) of the CAN system compared to that of free CPT in bladder cancer cell lines (T24). Furthermore, the CAN system demonstrated potent antitumor efficacy with reduced side effects, resulting in regression and eradication of T24 tumors in various mouse models. In summary, the CAN system can be easily extended by incorporating different chemotherapeutic agents, showing great potential to revolutionize the clinical management paradigm of bladder cancer.

Cyanobacteria-probiotics symbionts for modulation of intestinal inflammation and microbiome dysregulation in colitis

Inflammatory bowel disease (IBD) is often associated with excessive inflammatory response and highly dysregulated gut microbiota. Traditional treatments utilize drugs to manage inflammation, potentially with probiotic therapy as an adjuvant. However, current standard practices often suffer from detrimental side effects, low bioavailability, and unsatisfactory therapeutic outcomes. Microbial complexes characterized by mutually beneficial symbiosis hold great promise for IBD therapy. Here, we aggregated Synechocystis sp. PCC6803 (Sp) with Bacillus subtilis (BS) by biomimetic mineralization to form cyanobacteria-probiotics symbionts (ASp@BS), which reshaped a healthy immune system and gut microbiota in a murine model of acute colitis. The symbionts exhibited excellent tolerance to the harsh environment of the gastrointestinal tract. Importantly, probiotics within the symbionts created a local anaerobic environment to activate the [NiFe]-hydrogenase enzyme of cyanobacteria, facilitating the production of hydrogen gas (H2) to persistently scavenge elevated reactive oxygen species and alleviate inflammatory factors. The resulting reduced inflammation improves the viability of the probiotics to efficiently regulate the gut microbiota and reshape the intestinal barrier functions. Our research elucidates that ASp@BS leverages the synergistic interaction between Sp and BS to create a therapeutic platform that addresses multiple aspects of IBD, offering a promising and comprehensive solution for IBD treatment.

Functionalities of pH-responsive DNA nanostructures in tumor-targeted strategies

Nanostructures integrating pH-sensitive DNA motifs have emerged as versatile platforms for active tumor targeting, owing to their ability to undergo conformation changes in response to the common acidic environment of the tumor extracellular matrix and endocytosis pathway. This review summarizes the latest advances in the design and application of various pH-responsive DNA nanostructures for tumor-targeted strategies, including tumor recognition, cell imaging, dynamic nanocarrier construction, and controlled drug release. A comprehensive framework for pH-controlled multi-stage tumor targeting is introduced, addressing the divergences in targeting strategies for extracellular and intracellular environments. The unique attributes, practical performance and application challenges of pH-responsive DNA nanostructures are also critically discussed to provide guidance for future development in this field.

A Thin Polymer Layer Enables Peptide-Polycation Complexes with Ultrahigh Efficient Encapsulation

A monolayer encapsulation is a new opportunity for engineering a system with high drug loading, but immobilizing polymer molecules on the surface of individual peptide nanoparticles is still an ongoing challenge. Herein, an individual peptide nanoparticle encapsulation strategy is proposed via surface adsorption, in which peptide molecules undergo granulation and subsequently aggregate with polymer molecules, forming a network via electrostatic interactions. Under the water phase, surplus polymer molecules dissolve, leading to a single nanoparticle encapsulation with a core-shell structure. As expected, the dense interfacial layer on the peptide nanoparticle surface achieves a superior loading degree of up to 95.4%. What's more, once the core-shell structure is established, the peptide mass fraction in individual encapsulation always exceeds 90% even under fierce external force. Following the individual nanoparticle encapsulation, the insulin-polycation complex (InsNp@PEI) reduces the inflammation from polymer and displays an effective glycemic control in type 1 diabetes. Overall, the newly developed single surface decoration encapsulates peptides with ultrahigh efficiency and opens up the possibility for further encapsulation.

NIR-II Fluorescent Nanotheranostics with a Switchable Irradiation Mode for Immunogenic Sonodynamic Therapy

Nanotheranostics, which integrate diagnostic and therapeutic functionalities, offer significant potential for tumor treatment. However, current nanotheranostic systems typically involve multiple molecules, each providing a singular diagnostic or therapeutic function, leading to challenges such as complex structural composition, poor targeting efficiency, lack of spatiotemporal control, and dependence on a single therapeutic modality. This study introduces NPRBOXA, a nanoparticle functionalized with surface-bound cRGD for targeted delivery to αvβ3/αvβ5 receptors on tumor cells, achieving theranostic integration by sequentially switching its irradiation modes. Under 808 nm laser irradiation, NPRBOXA emits NIR-II fluorescence, which aids in identifying the nanoparticle's location and fluorescence intensity, thereby determining the optimal treatment window. Following this, the irradiation mode switches to ultrasound irradiation at the optimal treatment window. Ultrasound irradiation induces NPRBOXA to generate reactive oxygen species, promoting the reduction of OXA-IV to OXA-II, which in turn triggers immunogenic cell death. This mechanism enables a combination of sonodynamic therapy, chemotherapy, and immunotherapy for tumor treatment. The versatile design of NPRBOXA holds promise for advancing precision oncology through enhanced therapeutic efficacy and real-time imaging guidance.

Recent advances in reactive oxygen species (ROS)-responsive drug delivery systems for photodynamic therapy of cancer

Reactive oxygen species (ROS)-responsive drug delivery systems (DDSs) have garnered significant attention in cancer research because of their potential for precise spatiotemporal drug release tailored to high ROS levels within tumors. Despite the challenges posed by ROS distribution heterogeneity and endogenous supply constraints, this review highlights the strategic alliance of ROS-responsive DDSs with photodynamic therapy (PDT), enabling selective drug delivery and leveraging PDT-induced ROS for enhanced therapeutic efficacy. This review delves into the biological importance of ROS in cancer progression and treatment. We elucidate in detail the operational mechanisms of ROS-responsive linkers, including thioether, thioketal, selenide, diselencide, telluride and aryl boronic acids/esters, as well as the latest developments in ROS-responsive nanomedicines that integrate with PDT strategies. These insights are intended to inspire the design of innovative ROS-responsive nanocarriers for enhanced cancer PDT.

Preparation of Disulfide/Trisulfide Core-Cross-Linked Polycarbonate Nanocarriers for Intracellular Reduction-Triggered Drug Release

Polymeric nanocarriers have attracted significant attention in the field of anticancer drug delivery due to their unique advantages. However, designing nanocarriers that can maintain stability in the bloodstream while achieving specific drug release within tumor cells remains a major challenge. To address this issue, constructing reversible cross-linked polymeric nanocarriers that are sensitive to the intracellular reducible glutathione (GSH) characteristic of the tumor microenvironment is a promising strategy. Based on this, we designed and synthesized two novel six-membered bicyclic carbonate monomers containing disulfide (DSBC) and trisulfide (TSBC) bonds. Through a one-step ring-opening polymerization, a series of reduction-sensitive polycarbonate copolymers (i.e., PEG-PDSBC and PEG-PTSBC) were prepared, and doxorubicin (DOX)-loaded nanoparticles were fabricated using a nanoprecipitation method. The in vitro drug release behaviors of these nanoparticles were systematically investigated. The results showed that these polymers, due to the cross-linked structure formed by the ring-opening polymerization of their bicyclic monomers, could self-assemble into stable nanoparticles. Under different concentrations of glutathione, DOX-loaded PEG-PTSBC nanoparticles demonstrated faster drug release, indicating more optimized intracellular drug release properties. Further cytotoxicity experiments revealed that both types of blank nanoparticles exhibited good biocompatibility with the 4T1 and NIH-3T3 cells. Fluorescence microscopy and flow cytometry results further indicated that DOX-loaded PEG-PTSBC nanoparticles released more drugs in 4T1 cells, significantly inhibiting tumor cell growth compared with DOX-loaded PEG-PDSBC nanoparticles, with no noticeable difference in NIH-3T3 normal cells. In conclusion, this study suggests that trisulfide cross-linked polycarbonate-based nanocarriers hold promise as an anticancer drug delivery system that combines stability in the bloodstream with specific intracellular drug release, offering new insights for the development of novel, efficient, and safe anticancer nanomedicines.

Enhanced Synergistic Efficacy Against Breast Cancer Cells Promoted by Co-Encapsulation of Piplartine and Paclitaxel in Acetalated Dextran Nanoparticles

Malignant breast tumors constitute the most frequent cancer diagnosis among women. Notwithstanding the progress in treatments, this condition persists as a major public health issue. Paclitaxel (PTX) is a first-line classical chemotherapeutic drug used as a single active pharmaceutical ingredient (API) or in combination therapy for breast cancer (BC) treatment. Adverse effects, poor water solubility, and inevitable susceptibility to drug resistance seriously limit its therapeutic efficacy in the clinic. Piplartine (PPT), an alkaloid extracted from Piper longum L., has been shown to inhibit cancer cell proliferation in several cell lines due to its pro-oxidant activity. However, PPT has low water solubility and bioavailability in vivo, and new strategies should be developed to optimize its use as a chemotherapeutic agent. In this context, the present study aimed to synthesize a series of acetalated dextran nanoparticles (Ac-Dex NPs) encapsulating PPT and PTX to overcome the limitations of PPT and PTX, maximizing their therapeutic efficacy and achieving prolonged and targeted codelivery of these anticancer compounds into BC cells. Biodegradable, pH-responsive, and biocompatible Ac-Dex NPs with diameters of 100-200 nm and spherical morphologies were formulated using a single emulsion method. Selected Ac-Dex NPs containing only PPT or PTX as well as those coloaded with PPT and PTX achieved excellent drug-loading capabilities (PPT, ca. 11-33%; PTX, ca. 2-14%) and high encapsulation efficiencies (PPT, ∼57-98%; PTX, ∼80-97%). Under physiological conditions (pH 7.4), these NPs exhibited excellent colloidal stability and were capable of protecting drug release, while under acidic conditions (pH 5.5) they showed structural collapse, releasing the therapeutics in an extended manner. Cytotoxicity results demonstrated that the encapsulation in Ac-Dex NPs had a positive effect on the activities of both PPT and PTX against the MCF-7 human breast cancer cell line after 48 h of treatment, as well as toward MDA-MB-231 triple-negative BC cells. PPT/PTX@Ac-Dex NPs were significantly more cytotoxic (IC50/PPT = 0.25-1.77 μM and IC50/PTX = 0.07-0.75 μM) and selective (SI = 2.9-6.7) against MCF-7 cells than all the control therapeutic agents: free PPT (IC50 = 4.57 μM; SI = 1.2), free PTX (IC50 = 0.97 μM; SI = 1.0), the single-drug-loaded Ac-Dex NPs, and the physical mixture of both free drugs. All combinations of PPT and PTX resulted in pronounced synergistic antiproliferative effects in MCF-7 cells, with an optimal molar ratio of PPT to PTX of 2.3:1. PPT/PTX-2@Ac-Dex NPs notably promoted apoptosis, cell cycle arrest at the G2/M, accumulation of intracellular reactive oxygen species (ROS), and combined effects from both PPT and PTX on the microtubule network of MCF-7 cells. Overall, the combination of PTX and PPT in pH-responsive Ac-Dex NPs may offer great potential to improve the therapeutic efficacy, overcome the limitations, and provide effective simultaneous delivery of these therapeutics for BC treatment.

The advance of ultrasound-enabled diagnostics and therapeutics

Point-of-care ultrasound demonstrates significant potential in biomedical research due to its noninvasive, real-time visualization, cost-effectiveness, and other biological benefits. Ultrasound irradiation can precisely control the mechanical and physicochemical effects on pathogenic lesions, enabling real-time visualization, tunable tissue penetration depth, and therapeutic applications. This review summarizes recent advancements in ultrasound-enabled diagnostics and therapeutics, focusing on mechanochemical effects that can be directly integrated into biomedical applications. Additionally, the structure-functionality relationships of sonotheranostic nanoplatforms are systematically discussed, providing insights into the underlying biological effects. Finally, the limitations of current ultrasonic medicine are discussed, along with potential expansions to facilitate patient-centered translations.