Activating CD8+ T Cells by Pt(IV) Prodrug-Based Nanomedicine and aPD-L1 Antibody for Enhanced Cancer Immunotherapy

A Ruthenium(II)-DNA Nanophotosensitizer for cGAS-STING-Mediated Photodynamic Immunotherapy Against Hypoxic Cisplatin-Resistant Tumor Cells

Plasmid DNAs intercalated with Ru(II) complexes were encapsulated in liposomes to create nano-photosensitizers. Upon light exposure, the ruthenium complex photo-cleavages DNA. The DNA fragments specifically stimulate the cGAS-STING pathway and induce immunogenic death. This study presents a convenient strategy for photodynamic immunotherapy against cisplatin-resistant tumor cells under hypoxia.

The mechanism of action and therapeutic potential of tumor-associated macrophages in tumor immune evasion

Tumor-associated macrophages (TAMs) play a multifaceted role in tumor progression. As specialized immune cells, macrophages are capable of phagocytosis and digesting foreign substances, as well as removing harmful substances including cellular debris and tumor cells. Under specific pathological conditions, circulating monocytes can be recruited into the tumor microenvironment and differentiate into TAMs. Macrophages are generally polarized into two distinct subpopulations: classically activated macrophages (M1) and alternatively activated macrophages (M2). TAMs constitute a significant proportion of the mononuclear leukocyte population in solid tumors, exhibiting a complex and dualistic relationship with tumor cells. Substantial evidence indicates that TAMs can interact with tumor cells, facilitating their immune evasion while promoting invasion and metastasis. This review focuses on the mechanism and regulation of macrophages in the immune response to tumor cells, as well as various macrophage-based tumor-targeted therapeutic strategies. It will provide a reference for research on macrophage-centered therapy strategies and their application in clinical practice.

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.

Functional Materials Targeted Regulation of Gasdermins: From Fundamentals to Functionalities and Applications

Targeted regulation of pyroptosis to modulate the immune landscape has emerged as a novel design strategy for cancer immunotherapy and anti-inflammatory therapy. However, pyroptosis acts as a double-edged sword, making it important to optimize the design strategies of functional materials to appropriately activate pyroptosis for effective disease treatment. This paper summarizes and discusses the structure, pore formation, and molecular mechanisms of "executor" Gasdermins, as well as the events preceding and following these processes. Subsequently, the focus is on reviewing functional materials that directly regulate Gasdermin pore formation to target pyroptosis and those that indirectly regulate the events before and after Gasdermin pore formation to control pyroptosis activity. Finally, the advantages, disadvantages, and future prospects of designing such functional materials are provided, aiming to facilitate the precise design, pharmacological investigation, and clinical translation of pyroptosis-related functional materials.

PEGylation Effects on Amphiphilic Platinum(IV) Complexes: Influence on Uptake, Activation, and Cytotoxicity

Background/Objectives: The utilization of amphiphilic Pt(IV) complexes as prodrugs offers a promising strategy to revolutionize Pt-based cancer therapy by enhancing drug delivery and activation. While PEGylation is widely used to optimize drug properties, its impact on the biological behavior of amphiphilic Pt(IV) complexes remains unclear. This study systematically investigates how the PEGylation of varying molecular weights influences their cytotoxicity, cellular uptake, and activation. Methods: Pt(IV) complexes were synthesized with PEG chains of different molecular weights using HATU-catalyzed amide bond formation and copper-free click chemistry. Their biological properties were assessed through cell-based analyses, focusing on cytotoxicity, cellular uptake, and activation by biological reductants. Results: Small PEG modifications retained the potent cytotoxicity of amphiphilic Pt(IV) prodrugs, whereas large PEG chains significantly reduced efficacy. The decrease in potency was linked to impaired cellular uptake and mitochondrial accumulation. Additionally, large PEG modifications slowed the reduction and activation of Pt(IV) prodrugs by biological reductants, further limiting their anticancer activities. Conclusions: These findings underscore the critical role of PEGylation in metallodrug design and provide key insights into optimizing PEGylation strategies for enhancing platinum-based cancer therapies.

Glucose Metabolism-Targeted Poly(amino acid) Nanoformulation of Oxaliplatin(IV)-Aspirin Prodrug for Enhanced Chemo-Immunotherapy

Inappropriate glucose metabolism in cancer cells is associated with immunosuppressive tumor microenvironments (TMEs). Although glycolysis inhibition enhances T cell-mediated immune responses, the integrated platforms combining glycolysis inhibition with immunotherapy remain underdeveloped. To address this gap, a glucose metabolism-targeted poly(amino acid) nanoformulation of oxaliplatin(IV)-aspirin prodrug (NP/OXA-ASP2) is developed to improve chemo-immunotherapy by suppressing tumor glycolysis. This poly(amino acid) nanoparticle exhibits selective release, discharging 90.0% of OXA-ASP2 under reductive conditions within 36 h. Furthermore, over 80% of the prodrug converts to OXA and ASP within 12 h, promoting mitochondrial damage and glycolysis inhibition, which amplifies immunogenic cell death induced by OXA. In addition, suppressing glycolytic flux reduces lactate leakage, mitigating the immunosuppressive TMEs. Together, these mechanisms contribute to stronger chemo-immunotherapy efficacy. Compared to the OXA plus ASP formulation, NP/OXA-ASP2 demonstrates superior performances, reducing lactate levels at the tumor site by 25.4%, increasing the proportion of cytotoxic T lymphocytes by 1.53 times, decreasing the proportion of regulatory T cells by 2.20 times, and improving 1.39-fold of the tumor inhibition rate. These findings underscore that NP/OXA-ASP2 is a promising platform for integrating tumor metabolic regulation with immunomodulation and holds significant potential for advancing clinical chemo-immunotherapy.

On-Demand Controlled Release Multi-Drugs Delivery System for Spatiotemporally Synergizing Antitumor Immunotherapy

Although cytotoxic T lymphocytes (CTLs) activation combined with programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) axis blockade have emerged as an effective strategy to improve immunotherapeutic potency, it remains challenging to realize the spatiotemporal synergy of these two components. Herein, the study reports an engineered bacterial-based delivery system that can simultaneously promote CTLs infiltration and control PD-L1 binding protein (PD-L1 trap) release on demand at tumor site. The drug release button of this tumor targeting system is the specific temperature, which is accomplished by dual-modified melanin nanoparticles with photothermal conversion capacity on the engineered bacterial. These dual-modified nanoparticles can form in situ reservoir of heat supplier and antitumor immunity activator once arriving at tumor microenvironment (TME). Importantly, the study establishes the personalized administration regimen according to TME changes, and perform local laser irradiation to trigger PD-L1 trap production only in TME when infiltrated CTLs reach the highest level. This work provides a flexible platform for optimizing cancer immunotherapy.

Activating the cGAS-STING Pathway by Manganese-Based Nanoparticles Combined with Platinum-Based Nanoparticles for Enhanced Ovarian Cancer Immunotherapy

Recent research has demonstrated that activating the cGAS-STING pathway can enhance interferon production and the activation of T cells. A manganese complex, called TPA-Mn, was developed in this context. The reactive oxygen species (ROS)-sensitive nanoparticles (NPMn) loaded with TPA-Mn are developed. NPMn activates the cGAS-STING pathway via cGAS activation (i.e., 1.6-fold enhancement of P-STING), which in turn increases the secretion of pro-inflammatory cytokines (e.g., TNF-α, IL-6, and IL-2). This promotes dendritic cell maturation, enhances the infiltration of cytotoxic T lymphocytes, and reduces the percentage of immunosuppressive regulatory T cells. In addition, it is crucial to emphasize that cisplatin-induced DNA damage can potentially trigger activation of the cGAS-STING pathway. NPMn, in combination with low-dose NPPt, a carrier of a Cis(IV) prodrug capable of causing DNA damage, augments the cGAS-STING pathway activation and significantly activates the tumor immune microenvironment (TIME). Furthermore, combined with anti-PD-1 antibody, NPPt+NPMn shows synergistic efficacy in both ovarian cancer peritoneal metastases and recurrence models. It not only effectively eliminates tumors but also induces a strong immune memory response, providing a promising strategy for the clinical management of ovarian cancer. This work offers a design of manganese-based nanoparticles for immunotherapy.

AIEgen-self-assembled nanoparticles with anti-PD-L1 antibody functionalization realize enhanced synergistic photodynamic therapy and immunotherapy against malignant melanoma

Immune checkpoint inhibitors (ICIs) become integral in clinical practice, yet their application in cancer therapy is constrained by low overall response rates and the primary resistance of cancers to ICIs. Herein, this study proposes aggregation-induced emission (AIE)-based nanoparticles (NPs) for a more effective and synergistic approach combining immunotherapy and photodynamic therapy (PDT) to achieve higher responses than anti-PD-L1 monotherapy. The TBP@aPD-L1 NPs are constructed by functionalizing azide group-modified TBP-2 (TBP-N3) with anti-PD-L1 antibodies via the DBCO-S-S-PEG2000-COOH linker. The anti-PD-L1 target the tumor cells and promote the TBP-N3 accumulation in tumors for enhanced PDT. Notably, the TBP-N3, featuring aggregation-induced emission, boosts reactive oxygen species (ROS) generation through both type I and type II processes for enhanced PDT. The TBP@aPD-L1-mediated PDT induces more powerful effects of direct tumor cell-killing and further elicits effective immunogenic cell death (ICD), which exerts anti-tumor immunity by activating T cells for ICI treatment and reshapes the tumor immune microenvironment (TIME), thereby enhancing the efficacy of PD-L1 blockade of anti-PD-L1. Consequently, TBP@aPD-L1 NPs demonstrated significantly enhanced inhibition of tumor growth in the mouse model of malignant melanoma (MM). Our NPs act as a facile and effective drug delivery platform for enhanced immunotherapy combined with enhanced PDT in treating MM.

Tricomponent immunoactivating nanomedicine to downregulate PD-L1 and polarize macrophage for photodynamic immunotherapy of colorectal cancer

The unsatisfactory immunotherapeutic responses are primarily attributed to the insufficient immune recognition and the presence of an immunosuppressive tumor microenvironment (ITM). This study focuses on the development of a tricomponent immunoactivating nanomedicine called TIN that combines a photosensitizer, an inhibitor of epidermal growth factor receptor (EGFR) and a CSF-1R inhibitor to enable photodynamic immunotherapy by downregulating PD-L1 expression and repolarizing tumor-associated macrophages (TAMs). TIN is designed to facilitate the drug delivery and target specific pathways involved in tumor progression. By inhibiting the activity of EGFR and CSF-1R, TIN reduces PD-L1 expression on tumor cells and induces the TAMs polarization to M1 phenotype, restoring the immune recognition of T cells and the phagocytosis of macrophage to reshape the immunosuppressive microenvironment. Additionally, the photodynamic therapy (PDT) of TIN can greatly destroy the primary tumor and trigger immunogenic cell death (ICD). Importantly, the immune checkpoint blockade effect of TIN can enhance the immune response of PDT-induced ICD for metastatic tumor treatment. This study presents a self-assembling strategy for the development of an all-in-one nanomedicine, effectively integrating multiple therapeutic modalities to provide a comprehensive and systemic approach for tumor suppression.

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.

Optically Controlled Drug Delivery Through Microscale Brain-Machine Interfaces Using Integrated Upconverting Nanoparticles

The aim of this work is to incorporate lanthanide-cored upconversion nanoparticles (UCNP) into the surface of microengineered biomedical implants to create a spatially controlled and optically releasable model drug delivery device in an integrated fashion. Our approach enables silicone-based microelectrocorticography (ECoG) implants holding platinum/iridium recording sites to serve as a stable host of UCNPs. Nanoparticles excitable in the near-infrared (lower energy) regime and emitting visible (higher energy) light are utilized in a study. With the upconverted higher energy photons, we demonstrate the induction of photochemical (cleaving) reactions that enable the local release of specific dyes as a model system near the implant. The modified ECoG electrodes can be implanted in brain tissue to act as an uncaging system that releases small amounts of substance while simultaneously measuring the evoked neural response upon light activation. In this paper, several technological challenges like the surface modification of UCNPs, the immobilization of particles on the implantable platform, and measuring the stability of integrated UCNPs in in vitro and in vivo conditions are addressed in detail. Besides the chemical, mechanical, and optical characterization of the ready-to-use devices, the effect of nanoparticles on the original electrophysiological function is also evaluated. The results confirm that silicone-based brain-machine interfaces can be efficiently complemented with UCNPs to facilitate local model drug release.

GSH-responsive bithiophene Aza-BODIPY@HMON nanoplatform for achieving triple-synergistic photoimmunotherapy

Photoimmunotherapy represents an innovative approach to enhancing the efficiency of immunotherapy in cancer treatment. This approach involves the fusion of immunotherapy and phototherapy (encompassing techniques like photodynamic therapy (PDT) and photothermal therapy (PTT)). Boron-dipyrromethene (BODIPY) has the potential to trigger immunotherapy owing to its excellent PD and PT efficiency. However, the improvements in water solubility, bioavailability, PD/PT combined efficiency, and tumor tissue targeting of BODIPY require introduction of suitable carriers for potential practical application. Herein, a disulfide bond-based hollow mesoporous organosilica (HMON) with excellent biocompatibility and GSH-responsive degradation properties was used as a carrier to load a bithiophene Aza-BODIPY dye (B5), constructing a sample chemotherapy reagent-free B5@HMON nanoplatform achieving triple-synergistic photoimmunotherapy. HMON, involving disulfide bond, is utilized to improve water solubility, tumor tissue targeting, and PD efficiency by depleting GSH and enhancing host-guest interaction between B5 and HMO. The study reveals that HMON's large specific surface area and porous properties significantly enhance the light collection and oxygen adsorption capacity. The HMON's rich mesoporous structure and internal cavity achieved a loading rate of B5 at 11 %. It was found that the triple-synergistic nanoplatform triggered a stronger anti-tumor immune response, including tumor invasion, cytokine production, calreticulin translocation, and dendritic cell maturation, eliciting specific tumor-specific immunological responses in vivo and in vitro. The BALB/c mouse model with 4T1 tumors was used to assess tumor suppression efficiency in vivo, showing that almost all tumors in the B5@HMON group disappeared after 14 days. Such a simple chemotherapy reagent-free B5@HMON nanoplatform achieved triple-synergistic photoimmunotherapy.

Hydroxyethyl starch conjugates co-assembled nanoparticles promote photodynamic therapy and antitumor immunity by inhibiting antioxidant systems

Photodynamic therapy (PDT) can produce high levels of reactive oxygen species (ROS) to kill tumor cells and induce antitumor immunity. However, intracellular antioxidant systems, including glutathione (GSH) system and thioredoxin (Trx) system, limit the accumulation of ROS, resulting in compromised PDT and insufficient immune stimulation. Herein, we designed a nanomedicine PtHPs co-loading photosensitizer pyropheophorbide a (PPa) and cisplatin prodrug Pt-COOH(IV) (Pt (IV)) based on hydroxyethyl starch (HES) to inhibit both GSH and Trx antioxidant systems and achieve potent PDT as well as antitumor immune responses. Specifically, HES-PPa and HES-Pt were obtained by coupling HES with PPa and Pt (IV), and assembled into nanoparticle PtHPs by emulsification method to achieve the purpose of co-delivery of PPa and Pt (IV). PtHPs improved PPa photostability while retaining PPa photodynamic properties. In vitro experiments showed that PtHPs reduced GSH, inhibited Trx system and had better cell-killing effect and ROS generation ability. Subcutaneous tumor models showed that PtHPs had good safety and tumor inhibition effect. Bilateral tumor models suggested that PtHPs promoted the release of damage-associated molecular patterns and the maturation of dendritic cells, induced T cell-mediated immune responses, and thus suppressed the growth of both primary and distal tumors. This study reports a novel platinum-based nanomedicine and provides a new strategy for boosting PDT therapy-mediated antitumor immunity by overcoming intrinsic antioxidant systems.

Innovative Formulation Platform: Paving the Way for Superior Protein Therapeutics with Enhanced Efficacy and Broadened Applications

Protein therapeutics offer high therapeutic potency and specificity; the broader adoptions and development of protein therapeutics, however, have been constricted by their intrinsic limitations such as inadequate stability, immunogenicity, suboptimal pharmacokinetics and biodistribution, and off-target effects. This review describes a platform technology that formulates individual protein molecules with a thin formulation layer of crosslinked polymers, which confers the protein therapeutics with high activity, enhanced stability, controlled release capability, reduced immunogenicity, improved pharmacokinetics and biodistribution, and ability to cross the blood brain barriers. Based on currently approved protein therapeutics, this formulating platform affords the development of a vast family of superior protein therapeutics with improved efficacy and broadened indications at significantly reduced cost.

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.