A transistor-like pH-sensitive nanodetergent for selective cancer therapy

Tumor microenvironment-activated polypeptide nanoparticles for oncolytic immunotherapy

Cationic oncolytic polypeptides have gained increasing attention owing to their ability to directly lyse cancer cells and activate potent antitumor immunity. However, the low tumor cell selectivity and inherent toxicity induced by positive charges of oncolytic polypeptides hinder their systemic application. Herein, a tumor microenvironment-responsive nanoparticle (DNP) is developed by the self-assembly of a cationic oncolytic polypeptide (PLP) with a pH-sensitive anionic polypeptide via electrostatic interactions. After the formation of DNP, the positive charges of PLP are shielded. DNPs can keep stable in physiological conditions (pH 7.4) but respond to acidic tumor microenvironment (pH 6.8) to release oncolytic PLP. As a result, DNPs evoke potent immunogenic cell death by disrupting cell membranes, damaging mitochondria and increasing intracellular levels of reactive oxygen species. In vivo results indicate that DNPs significantly improve the biocompatibility of PLP, and inhibit tumor growth, recurrence and metastasis by direct oncolysis and activation of antitumor immune responses. In summary, these results indicate that pH-sensitive DNPs represent a prospective strategy to improve the tumor selectivity and biosafety of cationic polymers for oncolytic immunotherapy.

Ultra-pH-sensitive nanoplatform for precise tumor therapy

The emergence of precision cancer treatment has triggered a paradigm shift in the field of oncology, facilitating the implementation of more effective and personalized therapeutic approaches that enhance patient outcomes. The pH of the tumor microenvironment (TME) plays a pivotal role in both the initiation and progression of cancer, thus emerging as a promising focal point for precision cancer treatment. By specifically targeting the acidic conditions inherent to the tumor microenvironment, innovative therapeutic interventions have been proposed, exhibiting significant potential in augmenting treatment efficacy and ameliorating patient prognosis. The concept of ultra-pH-sensitive (UPS) nanoplatform was proposed several years ago, demonstrating exceptional pH sensitivity and an adjustable pH transition point. Subsequently, diverse UPS nanoplatforms have been actively explored for biomedical applications, enabling the loading of fluorophores, therapeutic drugs, and photosensitizers. This review aims to elucidate the design strategy and response mechanism of the UPS nanoplatform, with a specific emphasis on its applications in surgical therapy, immunotherapy, drug delivery, photodynamic therapy, and photothermal therapy. The potential and challenges of translating in the clinic on UPS nanoplatforms are finally explored. Thanks to its responsive and easily modifiable nature, the integration of multiple functional units within a UPS nanoplatform holds great promise for future advancements in tumor precision theranositcs.

Tumor Microenvironment Responsive RNA Drug Delivery Systems: Intelligent Platforms for Sophisticated Release

Cancer is a significant health concern, increasingly showing insensitivity to traditional treatments, highlighting the urgent need for safer and more practical treatment options. Ribonucleic acid (RNA) gene therapy drugs have demonstrated promising potential in preclinical and clinical trials for antitumor therapy by regulating tumor-related gene expression. However, RNA's poor membrane permeability and stability restrict its effectiveness in entering and being utilized in cells. An appropriate delivery system is crucial for achieving targeted tumor effects. The tumor microenvironment (TME), characterized by acidity, hypoxia, enzyme overexpression, elevated glutathione (GSH) concentration, and excessive reactive oxygen species (ROS), is essential for tumor survival. Furthermore, these distinctive features can also be harnessed to develop intelligent drug delivery systems. Various nanocarriers that respond to the TME have been designed for RNA drug delivery, showing the advantages of tumor targeting and low toxicity. This Review discusses the abnormal changes of components in TME, therapeutic RNAs' roles, underlying mechanisms, and the latest developments in utilizing vectors that respond to microenvironments for treating tumors. We hope it provides insight into creating and optimizing RNA delivery vectors to improve their effectiveness.

Polysulfonium: Unveiling a Bioactive Polymer to Induce Immunogenic Cell Death for Anticancer Therapy

Here we report a brand-new bioactive polymer featuring sulfonium moieties that exhibits the capability of inducing immunogenic cell death (ICD) for anticancer therapy. The optimized polysulfonium presents a wide spectrum of potent anticancer activity and remarkable selectivity. In-depth mechanistic studies reveal that the polymer exerts its cytotoxic effects on cancer cells through a membrane-disrupting mechanism. This further initiates the release of a plethora of damage-associated molecular patterns, effectively triggering ICD and resulting in systemic anticancer immune responses. Notably, the compound demonstrated significant efficacy in suppressing tumor growth in the B16-F10 melanoma tumor model. Furthermore, it exhibits robust immune memory effects, effectively suppressing tumor recurrence and metastasis in both the rechallenge model and the lung metastatic tumor model. To the best of our knowledge, the study represents the pioneering exportation of cationic polysulfoniums, showcasing not only their remarkable safety and efficacy against primary tumors but also their unique ability in activating long-term immune memory.

Recent Advances in 3D Printing of Smart Scaffolds for Bone Tissue Engineering and Regeneration

The repair and functional reconstruction of bone defects resulting from severe trauma, surgical resection, degenerative disease, and congenital malformation pose significant clinical challenges. Bone tissue engineering (BTE) holds immense potential in treating these severe bone defects, without incurring prevalent complications associated with conventional autologous or allogeneic bone grafts. 3D printing technology enables control over architectural structures at multiple length scales and has been extensively employed to process biomimetic scaffolds for BTE. In contrast to inert and functional bone grafts, next-generation smart scaffolds possess a remarkable ability to mimic the dynamic nature of native extracellular matrix (ECM), thereby facilitating bone repair and regeneration. Additionally, they can generate tailored and controllable therapeutic effects, such as antibacterial or antitumor properties, in response to exogenous and/or endogenous stimuli. This review provides a comprehensive assessment of the progress of 3D-printed smart scaffolds for BTE applications. It begins with an introduction to bone physiology, followed by an overview of 3D printing technologies utilized for smart scaffolds. Notable advances in various stimuli-responsive strategies, therapeutic efficacy, and applications of 3D-printed smart scaffolds are discussed. Finally, the review highlights the existing challenges in the development and clinical implementation of smart scaffolds, as well as emerging technologies in this field.

Dendritic nanomedicine enhances chemo-immunotherapy by disturbing metabolism of cancer-associated fibroblasts for deep penetration and activating function of immune cells

Inefficient drug penetration hurdled by the stroma in the tumor tissue leads to a diminished therapeutic effect for drugs and a reduced infiltration level of immune cells. Herein, we constructed a PEGylated dendritic epirubicin (Epi) prodrug (Epi-P4D) to regulate the metabolism of cancer-associated fibroblasts (CAFs), thus enhancing Epi penetration into both multicellular tumor spheroids (MTSs) and tumor tissues in mouse colon cancer (CT26), mouse breast cancer (4T1) and human breast cancer (MDA-MB-231) models. Enhanced cytotoxicity against CT26 MTSs and remarkable antitumor efficacy of Epi-P4D were ascribed to reduced fibronectin, α-SMA, and collagen secretion. Besides, thinning of the tumor tissue stroma and efficient eradication of tumor cells promoted the immunogenic cell death effect for dendritic cell (DC) maturation and subsequent immune activation, including elevating the CD4+ T cell population, reducing CD4+ and CD8+ T cell hyperactivation and exhaustion, and amplifying the natural killer (NK) cell proportion and effectively activating them. As a result, this dendritic nanomedicine thinned the stroma of tumor tissues to enhance drug penetration and facilitate immune cell infiltration for elevated antitumor efficacy.

Expanded ROS Generation and Hypoxia Reversal: Excipient-free Self-assembled Nanotheranostics for Enhanced Cancer Photodynamic Immunotherapy

The efficacy of photodynamic therapy (PDT)-related cancer therapies is significantly restricted by two irreconcilable obstacles, i.e., low reactive oxygen species (ROS) generation capability and hypoxia which constrains the immune response. Herein, this work develops a self-assembled clinical photosensitizer indocyanine green (ICG) and the HSP90 inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) nanoparticles (ISDN) without any excipient. This work discovers that the hydrophobic interaction forces between ICG and 17-DMAG promote the photostability of ICG and its intersystem crossing (ISC) process, thereby improving the ROS quantum yield from 0.112 to 0.46. Augmented ROS generation enhances PDT efficacy and further enhances immunogenic cell death (ICD) effects. 17-DMAG inhibits the HSP90/hypoxia-inducible factor 1α (HIF-1α) axis to dramatically reverse the immunosuppressive tumor microenvironment caused by PDT-aggravated hypoxia. In a mouse model of pancreatic cancer, ISDN markedly improve cytotoxic T lymphocyte infiltration and MHC I and MHC II activation, demonstrating the superior ICD effects in situ tumor and the powerful systematic antitumor immunity generation, eventually achieving vigorous antitumor and recurrence resistance. This study proposes an unsophisticated and versatile strategy to significantly improve PDT efficacy for enhancing systemic antitumor immunity and potentially extending it to multiple cancers.

Recent Advances in Nanomedicine for Ocular Fundus Neovascularization Disease Management

As an indispensable part of the human sensory system, visual acuity may be impaired and even develop into irreversible blindness due to various ocular pathologies. Among ocular diseases, fundus neovascularization diseases (FNDs) are prominent etiologies of visual impairment worldwide. Intravitreal injection of anti-vascular endothelial growth factor drugs remains the primary therapy but is hurdled by common complications and incomplete potency. To renovate the current therapeutic modalities, nanomedicine emerged as the times required, which is endowed with advanced capabilities, able to fulfill the effective ocular fundus drug delivery and achieve precise drug release control, thus further improving the therapeutic effect. This review provides a comprehensive summary of advances in nanomedicine for FND management from state-of-the-art studies. First, the current therapeutic modalities for FNDs are thoroughly introduced, focusing on the key challenges of ocular fundus drug delivery. Second, nanocarriers are comprehensively reviewed for ocular posterior drug delivery based on the nanostructures: polymer-based nanocarriers, lipid-based nanocarriers, and inorganic nanoparticles. Thirdly, the characteristics of the fundus microenvironment, their pathological changes during FNDs, and corresponding strategies for constructing smart nanocarriers are elaborated. Furthermore, the challenges and prospects of nanomedicine for FND management are thoroughly discussed.

Detergent Chemistry Modulates the Transgression of Planetary Boundaries including Antimicrobial Resistance and Drug Discovery

Detergent chemistry enables applications in the world today while harming safe operating spaces that humanity needs for survival. Aim of this review is to support a holistic thought process in the design of detergent chemistry. We harness the planetary boundary concept as a framework for literature survey to identify progresses and knowledge gaps in context with detergent chemistry and five planetary boundaries that are currently transgressed, i.e., climate, freshwater, land system, novel entities, biosphere integrity. Our survey unveils the status of three critical challenges to be addressed in the years to come, including (i) the implementation of a holistically, climate-friendly detergent industry; (ii) the alignment of materialistic and social aspects in creating technical solutions by means of sustainable chemistry; (iii) the development of detergents that serve the purpose of applications but do not harm the biosphere in their role as novel entities. Specifically, medically relevant case reports revealed that even the most sophisticated detergent design cannot sufficiently accelerate drug discovery to outperform the antibiotic resistance development that detergents simultaneously promote as novel entities. Safe operating spaces that humanity needs for its survival may be secured by directing future efforts beyond sustainable chemistry, resource efficiency, and net zero emission targets.

Transition-Metal-Oxide-Based Nanozymes for Antitumor Applications

Transition metal oxide (TMO)-based nanozymes have appeared as hopeful tools for antitumor applications due to their unique catalytic properties and ability to modulate the tumor microenvironment (TME). The purpose of this review is to provide an overview of the latest progress made in the field of TMO-based nanozymes, focusing on their enzymatic activities and participating metal ions. These nanozymes exhibit catalase (CAT)-, peroxidase (POD)-, superoxide dismutase (SOD)-, oxidase (OXD)-, and glutathione oxidase (GSH-OXD)-like activities, enabling them to regulate reactive oxygen species (ROS) levels and glutathione (GSH) concentrations within the TME. Widely studied transition metals in TMO-based nanozymes include Fe, Mn, Cu, Ce, and the hybrid multimetallic oxides, which are also summarized. The review highlights several innovative nanozyme designs and their multifunctional capabilities. Despite the significant progress in TMO-based nanozymes, challenges such as long-term biosafety, targeting precision, catalytic mechanisms, and theoretical supports remain to be addressed, and these are also discussed. This review contributes to the summary and understanding of the rapid development of TMO-based nanozymes, which holds great promise for advancing nanomedicine and improving cancer treatment.

Enzyme-responsive oncolytic polypeptide for tumor therapy

Host defense peptide-mimicking cationic oncolytic polymers have attracted increasing attention for cancer treatment in recent years. However, polymers with large amounts of positive charge may cause rapid clearance and severe off-target toxicity. To facilitate in vivo application, an alkaline phosphatase (ALP)-responsive oncolytic polypeptide precursor (C12-PLL/PA) has been reported in this work. C12-PLL/PA could be hydrolyzed into the active form of the oncolytic polypeptide (C12-PLL) by the extracellular alkaline phosphatase within solid tumors, thereby resulting in the conversion of the negative charge to positive charge and restoring its membrane-lytic activity. Detailed mechanistic studies showed that C12-PLL/PA could effectively destroy cancer cell membranes and subsequently result in rapid necrosis of cancer cells. More importantly, C12-PLL/PA significantly inhibited the tumor growth in the 4T1 orthotopic breast tumor model with negligible side effects. In summary, these findings demonstrated that the shielding of the amino groups with phosphate groups represents a secure and effective strategy to develop cationic oncolytic polypeptide, which represents a valuable reference for the design of enzyme-activated oncolytic polymers. STATEMENT OF SIGNIFICANCE: Recently, there has been a growing interest in fabricating host defense peptide-mimicking cationic oncolytic polymers for cancer therapy. However, there remain concerns about the tumor selectivity and off-target toxicity of these cationic polymers. In this study, an alkaline phosphatase-responsive oncolytic polypeptide precursor (C12-PLL/PA) has been developed to selectively target cancer cells while sparing normal cells. Mechanistic investigations demonstrated that C12-PLL/PA effectively disrupted cancer cell membranes, leading to rapid necrosis. Both in vitro and in vivo experiments showed promising anticancer activity and reliable safety of C12-PLL/PA. The findings suggest that this synthetic enzyme-responsive polypeptide holds potential as a tumor-specific oncolytic polymer, paving the way for future applications in cancer therapy.

Dendritic Polymer-Based Nanomedicines Remodel the Tumor Stroma: Improve Drug Penetration and Enhance Antitumor Immune Response

The dense extracellular matrix (ECM) in solid tumors, contributed by cancer-associated fibroblasts (CAFs), hinders penetration of drugs and diminishes their therapeutic outcomes. A sequential treatment strategy of remodeling the ECM via a CAF modifier (dasatinib, DAS) is proposed to promote penetration of an immunogenic cell death (ICD) inducer (epirubicin, Epi) via apoptotic vesicles, ultimately enhancing the treatment efficacy against breast cancer. Dendritic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA)-based nanomedicines (poly[OEGMA-Dendron(G2)-Gly-Phe-Leu-Gly-DAS] (P-DAS) and poly[OEGMA-Dendron(G2)-hydrazone-Epi] (P-Epi)) are developed for sequential delivery of DAS and Epi, respectively. P-DAS reprograms CAFs to reduce collagen by downregulating collagen anabolism and energy metabolism, thereby reducing the ECM deposition. The regulated ECM can enhance tumor penetration of P-Epi to strengthen its ICD effect, leading to an amplified antitumor immune response. In breast cancer-bearing mice, this approach alleviates the ECM barrier, resulting in reduced tumor burden and increased cytotoxic T lymphocyte infiltration, and more encouragingly, synergizes effectively with anti-programmed cell death 1 (PD-1) therapy, significantly inhibiting tumor growth and preventing lung metastasis. Furthermore, systemic toxicity is barely detectable after sequential treatment with P-DAS and P-Epi. This approach opens a new avenue for treating desmoplastic tumors by metabolically targeting CAFs to overcome the ECM barrier.

Intracellular Criegee's mechanism-based synergistic ozone therapy mediated by oleogels for cancer treatment

Broad cellular components-initiated efficient chemical reactions that occur in malignant cells may contribute to exploring emerging strategies for cancer treatment. Herein, an ozonated oleogel (OG(O)) was developed to achieve cancer ozone therapy (O3-T) based on intracellular Criegee's reaction. By integrating the chemo-drug, the ozone-loaded oleogel (Dox@OG(O)) was prepared as a chemotherapeutic agent for local O3-T, associated with chemotherapy (CT)/radiotherapy (RT)/immunotherapy and wound healing. The in vitro results showed that, Dox@OG(O) could achieve high ozone loading efficiency and ensure its stability. This Oleogel-mediated O3-T could directly destroy tumor cells via intracellular Criegee's reaction occurred on cell membranes, as well as the effects of tumor microenvironment (TME) regulation by the generation of oxygen/reactive oxygen species (ROS) and depletion of glutathione (GSH). Meanwhile, under the stimulation of X-ray, an accelerated free radical's production was observed, further combined with the radio-sensitivity after TME regulation, an effective anti-tumor effect would be achieved. Further on, in vivo results demonstrated that the locally implanted Dox@OG(O) could effectively inhibit the growth of both primary and secondary tumors. Considering these results above, it will serve as inspiration for future studies investigating of O3-T, especially for postoperative skin diseases.

Dendronized Polymer-Derived Nanomedicines for Mitochondrial Dynamics Regulation and Immune Modulation

The effects of dendron side chains in polymeric conjugates on tumor penetration and antigen presentation are systematically examined. Three polymer-gemcitabine (Gem) conjugates (pG0-Gem, pG1-Gem, pG2-Gem) are designed and prepared. The pG2-Gem conjugate uniquely binds to the mitochondria of tumor cells, thus regulating mitochondrial dynamics. The interaction between the pG2-Gem conjugate and the mitochondria promotes great penetration and accumulation of the conjugate at the tumor site, resulting in pronounced antitumor effects in an animal model. Such encouraging therapeutic effects can be ascribed to immune modulation since MHC-1 antigen presentation is significantly enhanced due to mitochondrial fusion and mitochondrial metabolism alteration after pG2-Gem treatment. Crucially, the drug-free dendronized polymer, pG2, is identified to regulate mitochondrial dynamics, and the regulation is independent of the conjugated Gem. Furthermore, the combination of pG2-Gem with anti-PD-1 antibody results in a remarkable tumor clearance rate of 87.5% and a prolonged survival rate of over 150 days, demonstrating the potential of dendronized polymers as an innovative nanoplatform for metabolic modulation and synergistic tumor immunotherapy.

Unveiling Interactions of Tumor-Targeting Nanoparticles with Lipid Bilayers Using a Titratable Martini Model

pH-responsive nanoparticles are ideal vehicles for drug delivery and are widely used in cell imaging in targeted therapy of cancer, which usually has a weakly acidic microenvironment. In this work, we constructed a titratable molecular model for nanoparticles grafted with ligands of pH-sensitive carboxylic acids and investigated the interactions between the nanoparticles and the lipid bilayer in varying pH environments. We mainly examined the effect of the grafting density of the pH-sensitive ligands of the nanoparticles on the interactions of the nanoparticles with the lipid bilayer. The results show that the nanoparticles can penetrate the lipid bilayer only when the pH value is lower than a critical value, which can be readily modulated to the specific pH value of the tumor microenvironment by changing the ligand grafting density. This work provides some insights into modulating the interactions between the pH-sensitive nanoparticles and cellular membranes to realize targeted drug delivery to tumors based on their specific pH environment.

Intelligent Biomaterialomics: Molecular Design, Manufacturing, and Biomedical Applications

Materialomics integrates experiment, theory, and computation in a high-throughput manner, and has changed the paradigm for the research and development of new functional materials. Recently, with the rapid development of high-throughput characterization and machine-learning technologies, the establishment of biomaterialomics that tackles complex physiological behaviors has become accessible. Breakthroughs in the clinical translation of nanoparticle-based therapeutics and vaccines have been observed. Herein, recent advances in biomaterials, including polymers, lipid-like materials, and peptides/proteins, discovered through high-throughput screening or machine learning-assisted methods, are summarized. The molecular design of structure-diversified libraries; high-throughput characterization, screening, and preparation; and, their applications in drug delivery and clinical translation are discussed in detail. Furthermore, the prospects and main challenges in future biomaterialomics and high-throughput screening development are highlighted.

Surface Bio-engineered Polymeric Nanoparticles

Surface bio-engineering of polymeric nanoparticles (PNPs) has emerged as a cornerstone in contemporary biomedical research, presenting a transformative avenue that can revolutionize diagnostics, therapies, and drug delivery systems. The approach involves integrating bioactive elements on the surfaces of PNPs, aiming to provide them with functionalities to enable precise, targeted, and favorable interactions with biological components within cellular environments. However, the full potential of surface bio-engineered PNPs in biomedicine is hampered by obstacles, including precise control over surface modifications, stability in biological environments, and lasting targeted interactions with cells or tissues. Concerns like scalability, reproducibility, and long-term safety also impede translation to clinical practice. In this review, these challenges in the context of recent breakthroughs in developing surface-biofunctionalized PNPs for various applications, from biosensing and bioimaging to targeted delivery of therapeutics are discussed. Particular attention is given to bonding mechanisms that underlie the attachment of bioactive moieties to PNP surfaces. The stability and efficacy of surface-bioengineered PNPs are critically reviewed in disease detection, diagnostics, and treatment, both in vitro and in vivo settings. Insights into existing challenges and limitations impeding progress are provided, and a forward-looking discussion on the field's future is presented. The paper concludes with recommendations to accelerate the clinical translation of surface bio-engineered PNPs.

A Bioinspired Immunostimulatory System for Inducing Powerful Antitumor Immune Function by Directly Causing Plasma Membrane Rupture

The Gasdermin protein is a membrane disruptor that can mediate immunogenic pyroptosis and elicit anti-tumor immune function. However, cancer cells downregulate Gasdermin and develop membrane repair mechanisms to resist pyroptosis. Therefore, an artificial membrane disruptor (AMD) that can directly mediate membrane rupture in pyroptosis-deficient cells and induce antitumor immune responses in a controllable manner will be valuable in preclinical and clinical research. A micron-scale Ce6-based AMD that can directly induce plasma membrane rupture (PMR) in gasdermin-deficient tumor cells is established. Micron-scale AMDs localize Ce6 specifically to the plasma membrane without labeling other organelles. Compared to free Ce6 molecules, the use of AMDs results in a higher degree of specificity for the plasma membrane. Due to this specificity, AMDs mediate fast and irreversible PMR under 660 nm red light. Furthermore, the AMDs are capable of inducing programmed cell death and lytic cell death in a catalytic manner, demonstrating that the amount of Ce6 used by AMDs is only one-fifth of that used by Ce6 alone when inducing 80% of cancer cell death. In vivo, the AMDs show specificity for tumor targeting and penetration, suggesting that light-driven programmed cell death is specific to tumors. AMDs are applied to antitumor therapy in gasdermin-deficient tumors, resulting in efficient tumor elimination with minimal damage to major organs when combined with anti-PD-1 therapy. Tumor regression is correlated with PMR-mediated inflammation and T-cell-based immune responses. This study provides new insights for designing bioinspired membrane disruptors for PMR and mediating anti-tumor immunotherapy. Additionally, AMD is a dependable tool for examining the immunogenicity of PMR both in vitro and in vivo.

Nanomedomics

Nanomaterials have attractive physicochemical properties. A variety of nanomaterials such as inorganic, lipid, polymers, and protein nanoparticles have been widely developed for nanomedicine via chemical conjugation or physical encapsulation of bioactive molecules. Superior to traditional drugs, nanomedicines offer high biocompatibility, good water solubility, long blood circulation times, and tumor-targeting properties. Capitalizing on this, several nanoformulations have already been clinically approved and many others are currently being studied in clinical trials. Despite their undoubtful success, the molecular mechanism of action of the vast majority of nanomedicines remains poorly understood. To tackle this limitation, herein, this review critically discusses the strategy of applying multiomics analysis to study the mechanism of action of nanomedicines, named nanomedomics, including advantages, applications, and future directions. A comprehensive understanding of the molecular mechanism could provide valuable insight and therefore foster the development and clinical translation of nanomedicines.

A Polymeric Nanoparticle to Co-Deliver Mitochondria-Targeting Peptides and Pt(IV) Prodrug: Toward High Loading Efficiency and Combination Efficacy

Developing combination chemotherapy systems with high drug loading efficiency at predetermined drug ratios to achieve a synergistic effect is important for cancer therapy. Herein, a polymeric dual-drug nanoparticle composed of a Pt(IV) prodrug derived from oxaliplatin and a mitochondria-targeting cytotoxic peptide is constructed through emulsion interfacial polymerization, which processes high drug loading efficiency and high biocompatibility. The depolymerization of polymeric dual-drug nanoparticle and the activation of Pt prodrug can be effectively triggered by the acidic tumor environment extracellularly and the high levels of glutathione intracellularly in cancer cells, respectively. The utilization of mitochondria-targeting peptide can inhibit ATP-dependent processes including drug efflux and DNA damage repair. This leads to increased accumulation of Pt-drugs within cancer cells. Eventually, the polymeric dual-drug nanoparticle demonstrates appreciable antitumor effects on both cell line derived and patient derived xenograft lung cancer model. It is highly anticipated that the polymeric dual-or multi-drug systems can be applied for combination chemotherapy to achieve enhanced anticancer activity and reduced side effects.

Reversing Anticancer Drug Resistance by Synergistic Combination of Chemotherapeutics and Membranolytic Antitumor β-Peptide Polymer

Multidrug resistance is the main obstacle to cancer chemotherapy. Overexpression of drug efflux pumps causes excessive drug efflux from cancer cells, ultimately leading to drug resistance. Hereby, we raise an effective strategy to overcome multidrug resistance using a synergistic combination of membranolytic antitumor β-peptide polymer and chemotherapy drugs. This membrane-active β-peptide polymer promotes the transmembrane transport of chemotherapeutic drugs by increasing membrane permeability and enhances the activity of chemotherapy drugs against multidrug-resistant cancer cells. As a proof-of-concept demonstration, the synergistic combination of β-peptide polymer and doxorubicin (DOX) is substantially more effective than DOX alone against drug-resistant cancer both in vitro and in vivo. Notably, the synergistic combination maintains a potent anticancer activity after continuous use. Collectively, this combination therapy using membrane lytic β-peptide polymer appears to be an effective strategy to reverse anticancer drug resistance.

Mesoporous nanoperforators as membranolytic agents via nano- and molecular-scale multi-patterning

Plasma membrane lysis is an effective anticancer strategy, which mostly relying on soluble molecular membranolytic agents. However, nanomaterial-based membranolytic agents has been largely unexplored. Herein, we introduce a mesoporous membranolytic nanoperforators (MLNPs) via a nano- and molecular-scale multi-patterning strategy, featuring a spiky surface topography (nanoscale patterning) and molecular-level periodicity in the spikes with a benzene-bridged organosilica composition (molecular-scale patterning), which cooperatively endow an intrinsic membranolytic activity. Computational modelling reveals a nanospike-mediated multivalent perforation behaviour, i.e., multiple spikes induce nonlinearly enlarged membrane pores compared to a single spike, and that benzene groups aligned parallelly to a phospholipid molecule show considerably higher binding energy than other alignments, underpinning the importance of molecular ordering in phospholipid extraction for membranolysis. Finally, the antitumour activity of MLNPs is demonstrated in female Balb/c mouse models. This work demonstrates assembly of organosilica based bioactive nanostructures, enabling new understandings on nano-/molecular patterns co-governed nano-bio interaction.

Engineering Logic DNA Nanoprobes on Live Cell Membranes for Simultaneously Monitoring Extracellular pH and Precise Drug Delivery

It remains a challenge to use a single probe to simultaneously detect extracellular pH fluctuations and specifically recognize cancer cells for precise drug delivery. Here, we engineered a tetrahedral framework nucleic acid-based logic nanoprobe (isgc8-tFNA) on live cell membranes for simultaneously monitoring extracellular pH and targeted drug delivery. Isgc8-tFNA was anchored stably on the cell surface through three cholesterol molecules inserting into the bilayer of the cell membrane. Once responding to the acidic tumor microenvironment, isgc8-tFNA formed an i-motif structure, leading to turn-on FRET signals for monitoring changes of extracellular pH. The nanoprobe exhibited a narrow pH-response window and excellent reversibility. Moreover, the nanoprobe could execute logic identification on the cell surface for precise drug delivery. Only if both in the acidic microenvironment and aptamer-targeting marker are present on the cell surface, the sgc8-ASO-chimera strand, carrying an antisense oligonucleotide drug, was released from the nanoprobe and entered into targeted cancer cells for gene silence. Additionally, the in situ drug release facilitated the uptake of drugs mediated by the interaction between sgc8 aptamer and membrane proteins, resulting in enhanced inhibition of cancer cell migration and proliferation. This logic nanoprobe will provide inspiration for designing smart devices for diagnosis of pH-related diseases and targeted drug delivery.

Enhancing drug penetration in solid tumors via nanomedicine: Evaluation models, strategies and perspectives

Effective tumor treatment depends on optimizing drug penetration and accumulation in tumor tissue while minimizing systemic toxicity. Nanomedicine has emerged as a key solution that addresses the rapid clearance of free drugs, but achieving deep drug penetration into solid tumors remains elusive. This review discusses various strategies to enhance drug penetration, including manipulation of the tumor microenvironment, exploitation of both external and internal stimuli, pioneering nanocarrier surface engineering, and development of innovative tactics for active tumor penetration. One outstanding strategy is organelle-affinitive transfer, which exploits the unique properties of specific tumor cell organelles and heralds a potentially transformative approach to active transcellular transfer for deep tumor penetration. Rigorous models are essential to evaluate the efficacy of these strategies. The patient-derived xenograft (PDX) model is gaining traction as a bridge between laboratory discovery and clinical application. However, the journey from bench to bedside for nanomedicines is fraught with challenges. Future efforts should prioritize deepening our understanding of nanoparticle-tumor interactions, re-evaluating the EPR effect, and exploring novel nanoparticle transport mechanisms.

pH-Responsive Protein Conformation Transistor

Analogous to electronic transistors, transistor-like responsive materials undergo sharp structural transitions in response to a very narrow range of microenvironment signals. This kind of material is typically limited to synthetic polymer-derived nanoscale assembly or disassembly and has profound implications for modern high-tech applications. Herein, we evolve this system from synthetic polymers to biopolymers and extend the corresponding assembly scale from the nanoscale to meso/macro-scale. We develop unique protein nanocrystals with core-shell structures through a two-step nucleation process. The protein nanocrystals exhibit exceptional transistor-like pH-responsive mesoscale assembly through the formation of inter-particle β-sheet linkers. This allows ultrasensitive cross-linking behavior, such as self-coacervation at a water/water interface, ultrafast gelation in seconds, and ultrasensitive swelling for detection of basic vapors at extremely low concentrations. This breakthrough has great promise for broader applications such as drug encapsulation and delivery, biosensing, cytomimetic materials, and microfluidic chemistry.

Dendritic Nanomedicine with Boronate Bonds for Augmented Chemo-Immunotherapy via Synergistic Modulation of Tumor Immune Microenvironment

Unsatisfied tumor accumulation of chemotherapeutic drugs and a complicated immunosuppressive microenvironment diminish the immune response rate and the therapeutic effect. Surface modification of these drugs with target ligands can promote their cellular internalization, but the modified drugs may be subjected to unexpected immune recognition and clearance. Herein, a phenylboronic acid (PBA) group-shieldable dendritic nanomedicine that integrates an immunogenic cell death (ICD)-inducing agent (epirubicin, Epi) and an indoleamine 2,3-dioxgenase 1 (IDO1) inhibitor (NLG919) is reported for tumor chemo-immunotherapy. This NLG919-loaded Epi-conjugated PEGylated dendrimers bridged with boronate bonds (NLG919@Epi-DBP) maintains a stable nanostructure during circulation. Under a moderate acidic condition, the PBA group exposes to the sialic acid residue on the tumor cell membrane to enhance the internalization and penetration of NLG919@Epi-DBP. At pH 5.0, NLG919@Epi-DBP rapidly disassembles to release the incorporated Epi and NLG919. Epi triggers robust ICD of tumor cells that evokes strong immune response. In addition, inhibition of the IDO1 activity downregulates the metabolism of L-tryptophan to kynurenine, leading to a reduction in the recruitment of immunosuppressive cells and modulation of the tumor immune microenvironment. Collectively, this promising strategy has been demonstrated to evoke robust immune response as well as remodel the immunosuppressive microenvironment for an enhanced chemo-immunotherapeutic effect.

Fully Active Delivery of Nanodrugs In Vivo via Remote Optical Manipulation

The active delivery of nanodrugs has been a bottleneck problem in nanomedicine. While modification of nanodrugs with targeting agents can enhance their retention at the lesion location, the transportation of nanodrugs in the circulation system is still a passive process. The navigation of nanodrugs with external forces such as magnetic field has been shown to be effective for active delivery, but the existing techniques are limited to specific materials like magnetic nanoparticles. In this study, an alternative actuation method is proposed based on optical manipulation for remote navigation of nanodrugs in vivo, which is compatible with most of the common drug carriers and exhibits significantly higher manipulation precision. By the programmable scanning of the laser beam, the motion trajectory and velocity of the nanodrugs can be precisely controlled in real time, making it possible for intelligent drug delivery, such as inverse-flow transportation, selective entry into specific vascular branch, and dynamic circumvention across obstacles. In addition, the controlled mass delivery of nanodrugs can be realized through indirect actuation by the microflow field. The developed optical manipulation method provides a new solution for the active delivery of nanodrugs, with promising potential for the treatment of blood diseases such as leukemia and thrombosis.

From oncolytic peptides to oncolytic polymers: A new paradigm for oncotherapy

Traditional cancer therapy methods, especially those directed against specific intracellular targets or signaling pathways, are not powerful enough to overcome tumor heterogeneity and therapeutic resistance. Oncolytic peptides that can induce membrane lysis-mediated cancer cell death and subsequent anticancer immune responses, has provided a new paradigm for cancer therapy. However, the clinical application of oncolytic peptides is always limited by some factors such as unsatisfactory bio-distribution, poor stability, and off-target toxicity. To overcome these limitations, oncolytic polymers stand out as prospective therapeutic materials owing to their high stability, chemical versatility, and scalable production capacity, which has the potential to drive a revolution in cancer treatment. This review provides an overview of the mechanism and structure-activity relationship of oncolytic peptides. Then the oncolytic peptides-mediated combination therapy and the nano-delivery strategies for oncolytic peptides are summarized. Emphatically, the current research progress of oncolytic polymers has been highlighted. Lastly, the challenges and prospects in the development of oncolytic polymers are discussed.

Multistage Self-Assembled Nanomaterials for Cancer Immunotherapy

Advances in nanotechnology have brought innovations to cancer therapy. Nanoparticle-based anticancer drugs have achieved great success from bench to bedside. However, insufficient therapy efficacy due to various physiological barriers in the body remains a key challenge. To overcome these biological barriers and improve the therapeutic efficacy of cancers, multistage self-assembled nanomaterials with advantages of stimuli-responsiveness, programmable delivery, and immune modulations provide great opportunities. In this review, we describe the typical biological barriers for nanomedicines, discuss the recent achievements of multistage self-assembled nanomaterials for stimuli-responsive drug delivery, highlighting the programmable delivery nanomaterials, in situ transformable self-assembled nanomaterials, and immune-reprogramming nanomaterials. Ultimately, we perspective the future opportunities and challenges of multistage self-assembled nanomaterials for cancer immunotherapy.

Hydrophobicity-Adaptive Polymers Trigger Fission of Tumor-Cell-Derived Microparticles for Enhanced Anticancer Drug Delivery

Tumor-cell-derived microparticles (MPs) can function as anticancer drug-delivery carriers. However, short blood circulation time, large-size-induced insufficient tumor accumulation and penetration into tumor parenchyma, as well as limited cellular internalization by tumor cells and cancer stem cells (CSCs), and difficult intracellular drug release restrict the anticancer activity of tumor-cell-derived MP-based drug-delivery systems. In this work, hydrophobicity-adaptive polymers based on poly(N-isopropylacrylamide) are anchored to tumor-cell-derived MPs for enhanced delivery of the anticancer drug doxorubicin (DOX). The polymers are hydrophilic in blood to prolong the circulation time of DOX-loaded MPs (DOX@MPs), while rapidly switching to hydrophobic at the tumor acidic microenvironment. The hydrophobicity of polymers drives the fission of tumor-cell-derived MPs to form small vesicles, facilitating tumor accumulation, deep tumor penetration, and efficient internalization of DOX@MPs into tumor cells and CSCs. Subsequently, the hydrophobicity of polymers in acidic lysosomes further promotes DOX release to nuclei for strong cytotoxicity against tumor cells and CSCs. The work provides a facile and simple strategy for improved anticancer drug delivery of tumor-cell-derived MPs.

Dendritic polymer-functionalized nanomedicine potentiates immunotherapy via lethal energy crisis-induced PD-L1 degradation

The advent of immune checkpoint inhibitors ushers in a new era of anti-tumor immunity. However, current clinical anti-PD-L1 antibodies only interdict PD-L1 on the membrane, which cannot diminish the complex cancer-promoting effects of intracellular PD-L1. Therefore, directly reducing the PD-L1 abundance of cancer cells might be a potential PD-L1 inhibitory strategy to circumvent the issues of current anti-PD-L1 antibodies. Herein, we develop a dendritic polymer-functionalized nanomedicine with a potent cellular energy depletion effect on colon cancer cells. Treatment with the nanomedicine significantly promotes phosphorylation of AMPK, which in turn leads to PD-L1 degradation and eventual T cell activation. Meanwhile, the nanomedicine can potently induce immunogenic cell death (ICD) to enhance the anti-cancer immunity. Moreover, the combination of the nanomedicine with PD-1 blockade further enhances the activity of cytotoxic T lymphocytes, and dramatically inhibits tumor growth in vivo without distinct side effects. Overall, this study provides a promising nanoplatform to induce lethal energy crisis and ICD, and suppress PD-L1 expression, thus potentiating cancer immunotherapy.

A dual drug-loaded peptide system with morphological transformation prolongs drug retention and inhibits breast cancer growth

The treatment of breast cancer relies heavily on chemotherapy, but chemotherapy is limited by the disadvantages of poor targeting, susceptibility to extracellular matrix (ECM) interference and a short duration of action in tumor cells. To address these limitations, we developed an amphipathic peptide containing an RGD motif, Pep1, that encapsulated paclitaxel (PTX) and losartan potassium (LP) to form the drug-loaded peptide PL/Pep1. PL/Pep1 self-assembled into spherical nanoparticles (NPs) under normal physiological conditions and transformed into aggregates containing short nanofibers at acidic pH. The RGD peptide facilitated tumor targeting and the aggregates prolonged drug retention in the tumor, which allowed more drug to reach and accumulate in the tumor tissue to promote apoptosis and remodel the tumor microenvironment. The results of in vitro and in vivo experiments confirmed the superiority of PL/Pep1 in terms of targeting, prolonged retention and facilitated penetration for antitumor therapy. In conclusion, amphipathic peptides as coloaded drug carriers are a new platform and strategy for breast cancer chemotherapy.

Bimetallic Ions Functionalized Metal-Organic-Framework Nanozyme for Tumor Microenvironment Regulating and Enhanced Photodynamic Therapy for Hypoxic Tumor

Photodynamic therapy (PDT), as a light irradiation inducing reactive oxygen species (ROS) generation for cancer treatment, offers facile and promising solutions with respect to spatiotemporal control of ROS generation, and minimizes the systemic toxicity and side effects for highly precise tumor therapy. However, the PDT efficiency is often severely compromised by the complex tumor microenvironment (TME), such as the hypoxic condition and overexpressed antioxidants. Here, for the first time, a bimetallic ion-modified metal-organic framework nanozyme (Zr4+ -MOF-Ru3+ /Pt4+ -Ce6@HA, ZMRPC@HA) is designed. ZMRPC@HA with catalase (CAT) and glutathione oxidase (GSHOx) mimetic activities, can efficiently regulate TME by generation of O2 and deplete the GSH synergistically for enhancing the long-term PDT efficacy toward the hypoxic tumor. The in vitro cell inhibition and in vivo on tumor xenograft evaluations demonstrate the PDT strategy by using ZMRPC@HA can successfully inhibit the differentiation and proliferation of tumor cells under a 660 nm laser irradiation in deep tissues. These findings open a new avenue for the design of multimetallic ions functionalized MOF-based nanozymes with multienzyme mimetic activities toward the antitumor and various other biological applications.

Synthetic lipo-polylysine with anti-cancer activity

Development of novel therapeutic agents that possess different anticancer mechanisms from the traditional antitumor drugs is highly attractive as no medication can cure all types of cancers. Herein, we report a rational design of antitumor lipo-polylysine polymers as synthetic mimics of biosynthetic lipopeptide surfactants featuring antimicrobial or cytotoxic activities for cancer therapy. The optimal polymer shows a wide range of anticancer activities against multiple cancer cells, including highly metastatic and drug-resistant ones, but low toxicity to normal cells. Mechanism studies show that the optimal polymer can interact with the membrane of cancer cells and induce cell necrosis by triggering cell membrane perforation, which is different from the therapeutic mechanisms of traditional anticancer drugs. In vivo studies imply that the optimal polymer efficiently inhibits tumor growth without causing obvious side effects on a C26 graft tumor model. Overall, the lipopeptide-mimicking lipo-polylysine with the advantages of easy synthesis and low cost provides a new anticancer strategy with high efficacy and biocompatibility.

A cytotoxic T cell inspired oncolytic nanosystem promotes lytic cell death by lipid peroxidation and elicits antitumor immune responses

Lytic cell death triggers an antitumour immune response. However, cancer cells evade lytic cell death by several mechanisms. Moreover, a prolonged and uncontrolled immune response conversely leads to T-cell exhaustion. Therefore, an oncolytic system capable of eliciting an immune response by killing cancer cells in a controlled manner is needed. Here, we establish a micro-scale cytotoxic T-cell-inspired oncolytic system (TIOs) to precisely lyse cancer cells by NIR-light-controlled lipid peroxidation. Our TIOs present antigen-based cell recognition, tumour-targeting and catalytic cell-lysis ability; thus, the TIOs induce oncolysis in vivo. We apply TIOs to preclinical cancer models, showing anti-tumor activity with negligible side-effects. Tumour regression is correlated with a T-cell based anti-tumour immune response and TIOs also improve responses to anti-PD-1 therapy or STING activation. Our study provides insights to design oncolytic systems for antitumour immunity. Moreover, activation of STING can reverse T-cell exhaustion in oncolysis.

Enzyme-triggered deep tumor penetration of a dual-drug nanomedicine enables an enhanced cancer combination therapy

Cancer cells could be eradicated by promoting generation of excessive intracellular reactive oxygen species (ROS) via emerging nanomedicines. However, tumor heterogeneity and poor penetration of nanomedicines often lead to diverse levels of ROS production in the tumor site, and ROS at a low level promote tumor cell growth, thus diminishing the therapeutic effect of these nanomedicines. Herein, we construct an amphiphilic and block polymer-dendron conjugate-derived nanomedicine (Lap@pOEGMA-b-p(GFLG-Dendron-Ppa), GFLG-DP/Lap NPs) that incorporates a photosensitizer, Pyropheophorbide a (Ppa), for ROS therapy and Lapatinib (Lap) for molecular targeted therapy. Lap, an epidermal growth factor receptor (EGFR) inhibitor that plays a role in inhibiting cell growth and proliferation, is hypothesized to synergize with ROS therapy for effectively killing cancer cells. Our results suggest that the enzyme-sensitive polymeric conjugate, pOEGMA-b-p(GFLG-Dendron-Ppa) (GFLG-DP), releases in response to cathepsin B (CTSB) after entering the tumor tissue. Dendritic-Ppa has a strong adsorption capacity to tumor cell membranes, which promotes efficient penetration and long-term retention. Lap can also be efficiently delivered to internal tumor cells to play its role due to the increased vesicle activity. Laser irradiation of Ppa-containing tumor cells results in production of intracellular ROS that is sufficient for inducing cell apoptosis. Meanwhile, Lap efficiently inhibits proliferation of remaining viable cells even in deep tumor regions, thus generating a significant synergistic anti-tumor therapeutic effect. This novel strategy can be extended to the development of efficient membrane lipid-based therapies to effectively combat tumors.

Impairing Tumor Metabolic Plasticity via a Stable Metal-Phenolic-Based Polymeric Nanomedicine to Suppress Colorectal Cancer

Targeting metabolic vulnerability of tumor cells is a promising anticancer strategy. However, the therapeutic efficacy of existing metabolism-regulating agents is often compromised due to tolerance resulting from tumor metabolic plasticity, as well as their poor bioavailability and tumor-targetability. Inspired by the inhibitive effect of N-ethylmaleimide on the mitochondrial function, a dendronized-polymer-functionalized metal-phenolic nanomedicine (pOEG-b-D-SH@NP) encapsulating maleimide-modified doxorubicin (Mal-DOX) is developed to enable improvement in the overall delivery efficiency and inhibition of the tumor metabolism via multiple pathways. It is observed that Mal-DOX and its derived nanomedicine induces energy depletion of CT26 colorectal cancer cells more efficiently than doxorubicin, and shifts the balance of programmed cell death from apoptosis toward necroptosis. Notably, pOEG-b-D-SH@NP simultaneously inhibits cellular oxidative phosphorylation and glycolysis, thus potently suppressing cancer growth and peritoneal intestinal metastasis in mouse models. Overall, the study provides a promising dendronized-polymer-derived nanoplatform for the treatment of cancers through impairing metabolic plasticity.

A Native Drug-Free Macromolecular Therapeutic to Trigger Mutual Reinforcing of Endoplasmic Reticulum Stress and Mitochondrial Dysfunction for Cancer Treatment

Drug-free macromolecular therapeutics are promising alternatives to traditional drugs. Nanomedicines with multiple organelles targeting can potentially increase the efficacy. Herein, a drug-free macromolecular therapeutic was designed to formulate endoplasmic reticulum (ER) and mitochondria dual-targeting nanoparticles (EMT-NPs), which can synergistically elicit ER stress and mitochondrial dysfunction. In vitro experiments indicated that EMT-NPs could effectively enter ER and mitochondria at an approximate ratio of 2 to 3. Subsequently, EMT-NPs could upregulate ER stress-related protein expression (IRE1α, CHOP), boosting calcium ion (Ca²⁺) efflux and activating the caspase-12 signaling cascade in cancer cells. In addition, EMT-NPs induced direct oxidative stress in mitochondria; some mitochondrial-related apoptotic events such as decreased mitochondrial membrane potential (MMP), upregulation of Bax, cytochrome c release, and caspase-3 activation were also observed for tumor cells upon incubation with EMT-NPs. Furthermore, the leaked Ca²⁺ from ER could induce mitochondrial Ca²⁺ overloading to further augment cancer cell apoptosis. In brief, mitochondrial and ER signaling networks collaborated well to promote cancer cell death. Extended photoacoustic and fluorescence imaging served well for the treatment of in vivo patient-derived xenografts cancer model. This drug-free macromolecular strategy with multiple subcellular targeting provides a potential paradigm for cancer theranostics in precision nanomedicine.

pH Window for High Selectivity of Ionizable Antimicrobial Polymers toward Bacteria

Antimicrobial polymers exhibit great potential for treating drug-resistant bacteria; however, designing antimicrobial polymers that can selectively kill bacteria and cause relatively low toxicity to normal tissues/cells remains a key challenge. Here, we report a pH window for ionizable polymers that exhibit high selectivity toward bacteria. Ionizable polymer PC6A showed the greatest selectivity (131.6) at pH 7.4, exhibiting low hemolytic activity and high antimicrobial activity against bacteria, whereas a very high or low protonation degree (PD) produced relatively low selectivity (≤35.6). Bactericidal mechanism of PC6A primarily comprised membrane lysis without inducing drug resistance even after consecutive incubation for 32 passages. Furthermore, PC6A demonstrated synergistic effects in combination with antibiotics at pH 7.4. Hence, this study provides a strategy for designing selective antimicrobial polymers.

Fabrication of Molecular Blocks with High Responsiveness to the Cancer Microenvironment by Ursodeoxycholic Acid

In cancer therapy, a drug delivery system (DDS) has been widely studied to achieve selective drug accumulation at the tumor site. However, DDS still has a major drawback in that it requires multistep processes for intracellular delivery, resulting in low efficiency of drug delivery. To overcome this problem, we recently reported a molecular block (MB) that disrupts cancer cell membranes in the cancer microenvironment using deoxycholic acid (DCA). However, the MB showed considerable cytotoxicity even at neutral pH, possibly due to the structural hydrophobic property of DCA. Herein, we focused on selecting the most suitable bile acid for an MB that possessed high responsiveness to the cancer microenvironment without cytotoxicity at neutral pH. Cell viabilities of the free bile acids such as DCA, chenodeoxycholic acid (CDCA), cholic acid (CA), and ursodeoxycholic acid (UDCA) were evaluated at neutral pH (pH = 7.4) and a cancer acidic environment (pH = 6.3-6.5). The half-maximal inhibition concentration (IC₅₀) value of UDCA at pH = 7.4 showed an approximately 7.5-fold higher IC₅₀ value than that at pH = 6.3, whereas the other bile acids yielded less than a 4-fold IC₅₀ value difference between the same pHs. Biocompatible poly(vinyl alcohol) (PVA) was functionalized with UDCA (PVA-UDCA) for the synthesis of higher responsiveness to the cancer microenvironment without cytotoxicity at neutral pH. Importantly, 56% pancreatic cancer cell death was observed at pH = 6.5, whereas only 10% was detected at neutral pH by the PVA-UDCA treatment. However, PVA-DCA indicated almost the same cancer cell death property, independent of pH conditions. These results suggest PVA-UDCA shows great potential for a new class of MB.

Charge-conversional click polyprodrug nanomedicine for targeted and synergistic cancer therapy

Polyprodrug nanomedicines hold great potential for combating tumors. However, the functionalization of polyprodrug nanomedicines to improve therapeutic efficacy is restricted by conventional polymerization methods. Herein, we fabricated a charge-conversional click polyprodrug nanomedicine system by metal-free azide-alkyne cycloaddition click polymerization (AACCP) for targeted and synergistic cancer therapy. Specifically, Pt(IV) prodrug-backboned diazide monomer, DMC prodrug-pendent diazide monomer, dialkyne-terminated PEG monomer and azide-modified folate were click polymerized to obtain the target polyprodrug (P1). P1 could self-assemble into nano-micelles (1-NM), where PEG was the hydrophilic shell with folate on the surface, Pt(IV) and DMC prodrugs as the hydrophobic core. Taking advantage of PEGylation and folate-mediated tumor cell targeting, 1-NM achieved prolonged blood circulation time and high tumor accumulation efficiency. Tumor acidic microenvironment-responsive cleavage and cascade activation of pendant DMC prodrug induced surface charge conversion of 1-NM from negative to positive, which promoted tumor penetration and cellular internalization of the remaining 1-NM. After internalization into tumor cells, the reduction-responsive activation of Pt(IV) prodrug to Pt(II) further showed synergetic effect with DMC for enhanced apoptosis. This first designed charge-conversional click polyprodrug nanomedicine exhibited targeted and synergistic efficacy to suppress tumor proliferation in living mice bearing human ovarian tumor model.

Modulating tumor-stromal crosstalk via a redox-responsive nanomedicine for combination tumor therapy

Interaction between carcinoma-associated fibroblasts (CAFs) and tumor cells leads to the invasion and metastasis of breast cancer. Herein, we prepared a redox-responsive chondroitin sulfate (CS)-based nanomedicine, in which hydrophobic cabazitaxel (CTX) was conjugated to the backbone of CS via glutathione (GSH)-sensitive dithiomaleimide (DTM) to form an amphipathic CS-DTM-CTX (CDC) conjugate, and dasatinib (DAS) co-assembled with the CDC conjugate to obtain DAS@CDC. After CD44 receptor-mediated internalization by CAFs, the nanomedicine could reverse CAFs to normal fibroblasts, blocking their crosstalk with tumor cells and reducing synthesis of major tumor extracellular matrix proteins, including collagen and fibronectin. Meanwhile, the nanomedicine internalized by tumor cells could effectively inhibit tumor proliferation and metastasis, leading to shrinkage of the tumor volume and inhibition of lung metastasis in a subcutaneous 4T1 tumor model with low side effects. Collectively, the nanomedicine showed a remarkably synergistic therapy effect against breast cancer by modulating tumor-stromal crosstalk.

Membrane-disruptive homo-polymethacrylate with both hydrophobicity and pH-sensitive protonation for selective cancer therapy

The membrane-disruptive strategy, which involves host defense peptides and their mimetics, is a revolutionary cancer treatment based on broad-spectrum anticancer activities. However, clinical application is limited by low selectivity towards tumors. In this context, we have established a highly selective anticancer polymer, i.e. poly(ethylene glycol)-poly(2-azepane ethyl methacrylate) (PEG-PAEMA), that can mediate the membrane-disruptive activity via a subtle pH change between physiological pH and tumor acidity for selective cancer treatment. Specifically, the resulting PEG-PAEMA can assemble into neutral nanoparticles and silence the membrane-disruptive activity at physiological pH and disassemble into cationic free-chains or smaller nanoparticles with potent membrane-disruptive activity after the protonation of the PAEMA block due to tumor acidity, resulting in high selectivity towards tumors. Dramatically, PEG-PAEMA exhibited a >200-fold amplification in hemolysis and <5% in IC₅₀ against Hepa1-6, SKOV3 and CT-26 cells at pH 6.7 as compared to those at pH 7.4, thanks to the selective membrane-disruptive mechanism. Moreover, mid- and high-dose PEG-PAEMA demonstrated higher anticancer efficacy than an optimal clinical prescription (bevacizumab plus PD-1) and, significantly, had few side effects on major organs in the tumor-bearing mice model, agreeing with the highly selective membrane-disruptive activity in vivo. Collectively, this work showcases the latent anticancer pharmacological activity of the PAEMA block, and also brings new hope for selective cancer therapy.

Attenuating Metabolic Competition of Tumor Cells for Favoring the Nutritional Demand of Immune Cells by a Branched Polymeric Drug Delivery System

Tumor cells are dominant in the nutritional competition in the tumor microenvironment, and their metabolic abnormalities often lead to microenvironmental acidosis and nutrient deprivation, thereby impairing the function of immune cells and diminishing the antitumor therapeutic effect. Herein, a branched polymeric conjugate and its efficacy in attenuating the metabolic competition of tumor cells are reported. Compared with the control nanoparticles prepared from its linear counterpart, the branched-conjugate-based nanoparticles can more efficiently accumulate in the tumor tissue and interfere with the metabolic processes of tumor cells to increase the concentration of essential nutrients and reduce the level of immunosuppressive metabolites in the TME, thus creating a favorable environment for infiltrated immune cells. Its combined treatment with an immune checkpoint inhibitor (ICI) achieves an enhanced antitumor effect. The work presents a promising approach for targeting metabolic competition in the TME to enhance the chemo-immunotherapeutic effect against cancers.

A helical oncolytic polypeptide with potent membranolytic activity for cancer therapy

Oncolytic peptides (OLPs) with membranolytic activity show great potential to combat multidrug-resistant cancer cells. Herein, we report a cationic helical oncolytic polypeptide (OLPP) with potent membranolytic activity for cancer therapy. The OLPP was synthesized by ring-opening polymerization of N-carboxyanhydrides (NCAs) and thiol-ene reaction. The OLPP was resistant to protease, showed high cytotoxicity to a series of cancer cells and caused cancer cell necrosis by quickly lysing cancer cell membrane independent of classic death-related intracellular pathways. Intra-tumoral injection of the OLPP effectively suppressed tumor growth in mice through the direct oncolytic effect. The OLPP represents a potential oncolytic chemotherapeutics for cancer therapy.

Controlled Cascade-Release and High Selective Sterilization by Core-Shell Nanogels for Microenvironment Regulation of Aerobic Vaginitis

Aerobic vaginitis (AV) is a gynecological disease associated with vaginal flora imbalance. The nonselective bactericidal nature of antibiotics and low customization rate of probiotic supplementation in existing treatments lead to AV recurrence. Here, a drug delivery strategy is proposed that works with the changing dynamics of the bacterial flora. In particular, a core-shell nanogel (CSNG) is designed to encapsulate prebiotic inulin and antimicrobial peptide Cath 30. The proposed strategy allows for the sequential release of both drugs using gelatinase produced by AV pathogenic bacteria, initially selectively killing pathogenic bacteria and subsequently promoting the proliferation of beneficial bacteria in the vagina. In a simulated infection environment in vitro, the outer layer of CSNGs, Cath 30 is rapidly degraded and potently killed the pathogenic bacterium Staphylococcus aureus at 2-6 h. CSNGs enhances proliferation of the beneficial bacterium Lactobacillus crispatus by more than 50% at 24 h. In a rat AV model, the drug delivery strategy precisely regulated the bacterial microenvironment while controlling the inflammatory response of the vaginal microenvironment. This new treatment approach, configured on demand and precisely controlled, offers a new strategy for the treatment of vaginal diseases.

Acid-switchable nanoparticles induce self-adaptive aggregation for enhancing antitumor immunity of natural killer cells

Deficiency of natural killer (NK) cells shows a significant impact on tumor progression and failure of immunotherapy. It is highly desirable to boost NK cell immunity by upregulating active receptors and relieving the immunosuppressive tumor microenvironment. Unfortunately, mobilization of NK cells is hampered by poor accumulation and short retention of drugs in tumors, thus declining antitumor efficiency. Herein, we develop an acid-switchable nanoparticle with self-adaptive aggregation property for co-delivering galunisertib and interleukin 15 (IL-15). The nanoparticles induce morphology switch by a decomposition-metal coordination cascade reaction, which provides a new methodology to trigger aggregation. It shows self-adaptive size-enlargement upon acidity, thus improving drug retention in tumor to over 120 h. The diameter of agglomerates is increased and drug release is effectively promoted following reduced pH values. The nanoparticles activate both NK cell and CD8⁺ T cell immunity in vivo. It significantly suppresses CT26 tumor in immune-deficient BALB/c mice, and the efficiency is further improved in immunocompetent mice, indicating that the nanoparticles can not only boost innate NK cell immunity but also adaptive T cell immunity. The approach reported here provides an innovative strategy to improve drug retention in tumors, which will enhance cancer immunotherapy by boosting NK cells.

Development of stimuli responsive polymeric nanomedicines modulating tumor microenvironment for improved cancer therapy

The complexity of the tumor microenvironment (TME) severely hinders the therapeutic effects of various cancer treatment modalities. The TME differs from normal tissues owing to the presence of hypoxia, low pH, and immune-suppressive characteristics. Modulation of the TME to reverse tumor growth equilibrium is considered an effective way to treat tumors. Recently, polymeric nanomedicines have been widely used in cancer therapy, because their synthesis can be controlled and they are highly modifiable, and have demonstrated great potential to remodel the TME. In this review, we outline the application of various stimuli responsive polymeric nanomedicines to modulate the TME, aiming to provide insights for the design of the next generation of polymeric nanomedicines and promote the development of polymeric nanomedicines for cancer therapy.

Artificial intelligence aids in development of nanomedicines for cancer management

Over the last decade, the nanomedicine has experienced unprecedented development in diagnosis and management of diseases. A number of nanomedicines have been approved in clinical use, which has demonstrated the potential value of clinical transition of nanotechnology-modified medicines from bench to bedside. The application of artificial intelligence (AI) in development of nanotechnology-based products could transform the healthcare sector by realizing acquisition and analysis of large datasets, and tailoring precision nanomedicines for cancer management. AI-enabled nanotechnology could improve the accuracy of molecular profiling and early diagnosis of patients, and optimize the design pipeline of nanomedicines by tuning the properties of nanomedicines, achieving effective drug synergy, and decreasing the nanotoxicity, thereby, enhancing the targetability, personalized dosing and treatment potency of nanomedicines. Herein, the advances in AI-enabled nanomedicines in cancer management are elaborated and their application in diagnosis, monitoring and therapy as well in precision medicine development is discussed.

Nanomedicine embraces cancer radio-immunotherapy: mechanism, design, recent advances, and clinical translation

Cancer radio-immunotherapy, integrating external/internal radiation therapy with immuno-oncology treatments, emerges in the current management of cancer. A growing number of pre-clinical studies and clinical trials have recently validated the synergistic antitumor effect of radio-immunotherapy, far beyond the "abscopal effect", but it suffers from a low response rate and toxicity issues. To this end, nanomedicines with an optimized design have been introduced to improve cancer radio-immunotherapy. Specifically, these nanomedicines are elegantly prepared by incorporating tumor antigens, immuno- or radio-regulators, or biomarker-specific imaging agents into the corresponding optimized nanoformulations. Moreover, they contribute to inducing various biological effects, such as generating in situ vaccination, promoting immunogenic cell death, overcoming radiation resistance, reversing immunosuppression, as well as pre-stratifying patients and assessing therapeutic response or therapy-induced toxicity. Overall, this review aims to provide a comprehensive landscape of nanomedicine-assisted radio-immunotherapy. The underlying working principles and the corresponding design strategies for these nanomedicines are elaborated by following the concept of "from bench to clinic". Their state-of-the-art applications, concerns over their clinical translation, along with perspectives are covered.