Nano-drug delivery systems for T cell-based immunotherapy

Anticancer Tetranuclear Cu(I) Complex Catalyzes a Click Reaction to Synthesize a Chemotherapeutic Agent in situ to Achieve Targeted Dual-Agent Combination Therapy for Cancer

To develop next-generation metal-based drugs and dual-drug combination therapy for cancer, we proposed to develop a copper (Cu) complex that exerts anticancer function by integrating chemotherapy, immunotherapy and catalyzes a click reaction for the in situ synthesis of a chemotherapeutic agent, thereby achieving targeted dual-agent combination therapy. We designed and synthesized a tetranuclear Cu(I) complex (Cu4) with remarkable cytotoxicity and notable catalytic ability for the in situ synthesis of a chemotherapeutic agent via Cu(I)-catalyzed azide-alkyne 1,3-cycloaddition (CuAAC). We also constructed an apoferritin (AFt)-Cu4 nanoparticles (NPs) delivery system. Aft-Cu4 NPs not only showed an enhanced performance of tumor growth inhibition, but also improved the targeting ability and reduced the systemic toxicity of Cu4 in vivo. Importantly, the anticancer effect was enhanced by combining the Aft-Cu4 NPs with the resveratrol analogue obtained from the CuAAC reaction in situ. Finally, we revealed the anticancer mechanism of the Cu4/Aft-Cu4 NPs, which involves both cuproptosis and cuproptosis-induced systemic immune response.

A stimulus responsive microneedle-based drug delivery system for cancer therapy

The intricate nature of the tumor microenvironment (TME) results in the inefficient delivery of anticancer drugs within tumor tissues, significantly compromising the therapeutic effect of cancer treatment. To address this issue, transdermal drug delivery microneedles (MNs) with high mechanical strength have emerged. Such MNs penetrate the skin barrier, enabling efficient drug delivery to tumor tissues. This approach enhances drug bioavailability, while also mitigating concerns such as liver and kidney toxicity associated with intravenous and oral drug administration. Notably, stimulus responsive MNs designed for drug delivery have the capacity to respond to various biological signals and pathological changes. This adaptability enables them to exert therapeutic effects within the TME, exploiting biochemical variations and tailoring treatment strategies to suit tumor characteristics. The present review surveys recent advancements in responsive MN systems. This comprehensive analysis serves as a valuable reference for the prospective application of smart MN drug delivery systems in cancer therapy.

Cobalt(III) prodrug-based nanomedicine for inducing immunogenic cell death and enhancing chemo-immunotherapy

Despite impressive advances in immune checkpoint blockade therapy, its efficacy as a standalone treatment remains limited. The influence of chemotherapeutic agents on tumor immunotherapy has progressively come to light in recent years, positioning them as promising contenders in the realm of combination therapy options for tumor immunotherapy. Herein, we present the rational design, synthesis, and biological evaluation of the first example of a Co(III) prodrug (Co2) capable of eliciting a localized cytotoxic effect while simultaneously inducing a systemic immune response via type II immunogenic cell death (ICD). To enhance its pharmacological properties, a glutathione-sensitive polymer was synthesized, and Co2 was encapsulated into polymeric nanoparticles (NP-Co2) to improve efficacy. Furthermore, NP-Co2 activates the GRP78/p-PERK/p-eIF2α/CHOP pathway, thereby inducing ICD in cancer cells. This facilitates the transformation of "cold tumors" into "hot tumors" and augments the effectiveness of the PD-1 monoclonal antibody (αPD-1). In essence, this nanomedicine, utilizing Co(III) prodrugs to induce ICD, provides a promising strategy to enhance chemotherapy and αPD-1 antibody-mediated cancer immunotherapy.

Glutathione-Scavenging Celastrol-Cu Nanoparticles Induce Self-Amplified Cuproptosis for Augmented Cancer Immunotherapy

Cuproptosis is a novel copper-dependent programmed cell death. The efficacy of cuproptosis is highly dependent on intracellular copper accumulation and counteracted by a high level of glutathione (GSH) in tumor cells. Here, this work develops a self-amplified cuproptosis nanoparticles (Cel-Cu NP) using celastrol (Cel), a natural product isolated from medical plant. In Cel-Cu NP, Cel serves as a versatile copper ionophore, exhibiting an ideal coordination capacity toward copper ions without compromising the cuproptosis induction. Notably, Cel can simultaneously scavenge GSH content to amplify cuproptosis. Moreover, this self-amplified cuproptosis further activates immunogenic cell death (ICD) to elicit robust immune response. Combining with immune checkpoint blockade, Cel-Cu NP effectively eradicates metastatic tumors in a mouse lung metastasis model. This study provides an efficient nanomedicine by inducing self-amplified cuproptosis for robust immunotherapy.

A Bioactive Injectable Hydrogel Regulates Tumor Metastasis and Wound Healing for Melanoma via NIR-Light Triggered Hyperthermia

Surgical resection remains the mainstream treatment for malignant melanoma. However, challenges in wound healing and residual tumor metastasis pose significant hurdles, resulting in high recurrence rates in patients. Herein, a bioactive injectable hydrogel (BG-Mngel) formed by crosslinking sodium alginate (SA) with manganese-doped bioactive glass (BG-Mn) is developed as a versatile platform for anti-tumor immunotherapy and postoperative wound healing for melanoma. The incorporation of Mn2+ within bioactive glass (BG) can activate the cGAS-STING immune pathway to elicit robust immune response for cancer immunotherapy. Furthermore, doping Mn2+ in BG endows system with excellent photothermal properties, hence facilitating STING activation and reversing the tumor immune-suppressive microenvironment. BG exhibits favorable angiogenic capacity and tissue regenerative potential, and Mn2+ promotes cell migration in vitro. When combining BG-Mngel with anti-PD-1 antibody (α-PD-1) for the treatment of malignant melanoma, it shows enhanced anti-tumor immune response and long-term immune memory response. Remarkably, BG-Mngel can upregulate the expression of genes related to blood vessel formation and promote skin tissue regeneration when treating full-thickness wounds. Overall, BG-MnGel serves as an effective adjuvant therapy to regulate tumor metastasis and wound healing for malignant melanoma.

Structural Optimization of Carboxy-Terminal Phenylalanine-Modified Dendrimers for T-Cell Association and Model Drug Loading

Dendrimers are potent nanocarriers in drug delivery systems because their structure can be precisely controlled. We previously reported that polyamidoamine (PAMAM) dendrimers that were modified with 1,2-cyclohexanedicarboxylic acid (CHex) and phenylalanine (Phe), PAMAM-CHex-Phe, exhibited an effective association with various immune cells, including T-cells. In this study, we synthesized various carboxy-terminal Phe-modified dendrimers with different linkers using phthalic acid and linear dicarboxylic acids to determine the association of these dendrimers with Jurkat cells, a T-cell model. PAMAM-n-hexyl-Phe demonstrated the highest association with Jurkat T-cells. In addition, dendri-graft polylysine (DGL) with CHex and Phe, DGL-CHex-Phe, was synthesized, and its association with Jurkat cells was investigated. The association of DGL-CHex-Phe with T-cells was higher than that of PAMAM-CHex-Phe. However, it was insoluble in water and thus it is unsuitable as a drug carrier. Model drugs, such as protoporphyrin IX and paclitaxel, were loaded onto these dendrimers, and the most model drug molecules could be loaded into PAMAM-CHex-Phe. PTX-loaded PAMAM-CHex-Phe exhibited cytotoxicity against Jurkat cells at a similar level to free PTX. These results suggest that PAMAM-CHex-Phe exhibited both efficient T-cell association and drug loading properties.

Stimulus-Responsive Copper Complex Nanoparticles Induce Cuproptosis for Augmented Cancer Immunotherapy

Cuproptosis, an emerging form of programmed cell death, has received tremendous attention in cancer therapy. However, the efficacy of cuproptosis remains limited by the poor delivery efficiency of copper ion carriers. Herein, copper complex nanoparticles (denoted as Cu(I) NP) are developed that can efficiently deliver copper complex into cancer cells to induce cuproptosis. Cu(I) NP demonstrate stimulus-responsive release of copper complexes, which results in mitochondrial dysfunction and promotes the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT), leading to cuproptosis. Notably, Cu(I) NP not only induce cuproptosis, but also elicit robust immune responses to suppress tumor growth. Overall, this study provides a promising strategy for cuproptosis-based cancer therapy.

Immunotherapy Study on Non-small-Cell Lung Cancer (NSCLC) Combined with Cytotoxic T Cells and miRNA34a

Immunotherapy has emerged as a promising approach for cancer treatment, and the use of microRNAs (miRNAs) as therapeutic agents has gained significant attention. In this study, we investigated the effectiveness of immunotherapy utilizing miRNA34a and Jurkat T cells in inducing cell death in non-small-cell lung cancer cells, specifically A549 cells. Moreover, we explored the impact of Jurkat T cell activation and miRNA34a delivery using iron oxide nanorods (IONRs) on the killing of cancer cells. A549 cells were cocultured with both activated and inactivated Jurkat T cells, both before and after the delivery of miRNA34a. Surprisingly, our results revealed that even inactive Jurkat T cells were capable of inducing cell death in cancer cells. This unexpected observation suggested the presence of alternative mechanisms by which Jurkat T cells can exert cytotoxic effects on cancer cells. We stimulated Jurkat T cells using anti-CD3/CD28 and analyzed their efficacy in killing A549 compared to that of the inactive Jurkat T cells in conjunction with miRNA34a. Our findings indicated that the activation of Jurkat T cells significantly enhanced their cytotoxic potential against cancer cells compared to their inactive counterparts. The combined treatment of A549 cells with activated Jurkat T cells and miRNA34a demonstrated the highest level of cancer cell death, suggesting a synergistic effect between Jurkat T cell activation and miRNA therapy. Besides the apoptosis mechanism for the Jurkat T cells' cytotoxic effects on A549 cells, we furthermore investigated the ferroptosis pathway, which was found to have an impact on the cancer cell killing due to the presence of miRNA34a and IONRs as the delivery agent inside the cancer cells.

Platinum Prodrug Nanoparticles with COX-2 Inhibition Amplify Pyroptosis for Enhanced Chemotherapy and Immune Activation of Pancreatic Cancer

Pyroptosis, an emerging mechanism of programmed cell death, holds great potential to trigger a robust antitumor immune response. Platinum-based chemotherapeutic agents can induce pyroptosis via caspase-3 activation. However, these agents also enhance cyclooxygenase-2 (COX-2) expression in tumor tissues, leading to drug resistance and immune evasion in pancreatic cancer and significantly limiting the effectiveness of chemotherapy-induced pyroptosis. Here, an amphiphilic polymer (denoted as PHDT-Pt-In) containing both indomethacin (In, a COX-2 inhibitor) and platinum(IV) prodrug (Pt(IV)) is developed, which is responsive to glutathione (GSH). This polymer self-assemble into nanoparticles (denoted as Pt-In NP) that can disintegrate in cancer cells due to the GSH responsiveness, releasing In to inhibit the COX-2 expression, hence overcoming the chemoresistance and amplifying cisplatin-induced pyroptosis. In a pancreatic cancer mouse model, Pt-In NP significantly inhibit tumor growth and elicit both innate and adaptive immune responses. Moreover, when combined with anti-programmed death ligand (α-PD-L1) treatment, Pt-In NP demonstrate the ability to completely suppress metastatic tumors, transforming "cold tumors" into "hot tumors". Overall, the sustained release of Pt(IV) and In from Pt-In NP amplifies platinum-drug-induced pyroptosis to elicit long-term immune responses, hence presenting a generalizable strategy for pancreatic cancer.

Combination of IDO inhibitors and platinum(IV) prodrugs reverses low immune responses to enhance cancer chemotherapy and immunotherapy for osteosarcoma

In recent years, immune checkpoint blockades (ICBs) have made great progress in the treatment of cancer. However, most ICBs have not yet been observed to be satisfactory in the treatment of osteosarcoma. Herein, we designed composite nanoparticles (NP-Pt-IDOi) from a reactive oxygen species (ROS) sensitive amphiphilic polymer (PHPM) with thiol-ketal bonds in the main chain to encapsulate a Pt(IV) prodrug (Pt(IV)-C12) and an indoleamine-(2/3)-dioxygenase (IDO) inhibitor (IDOi, NLG919). Once NP-Pt-IDOi enter the cancer cells, the polymeric nanoparticles could dissociate due to the intracellular ROS, and release Pt(IV)-C12 and NLG919. Pt(IV)-C12 induces DNA damage and activates the cGAS-STING pathway, increasing infiltration of CD8+ T cells in the tumor microenvironment. In addition, NLG919 inhibits tryptophan metabolism and enhances CD8+ T cell activity, ultimately activating anti-tumor immunity and enhancing the anti-tumor effects of platinum-based drugs. NP-Pt-IDOi were shown to have superior anti-cancer activity in vitro and in vivo in mouse models of osteosarcoma, providing a new clinical paradigm for combining chemotherapy with immunotherapy for osteosarcoma.

Stimuli-responsive ultra-small vanadate prodrug nanoparticles with NIR photothermal properties to precisely inhibit Na/K-ATPase for enhanced cancer therapy

Inhibition of Na/K-ATPase is a promising cancer treatment owing to the essential role of Na/K-ATPase in maintaining various cellular functions. The potent Na/K-ATPase inhibitor, vanadate(V) (termed as V(V)), has exhibited efficient anticancer effects. However, nonspecific inhibition using V(V) results in serious side effects, which hinder its clinical application. Here, bovine serum albumin (BSA)-modified ultra-small vanadate prodrug nanoparticles (V(IV) NPs) were synthesized via a combined reduction-coordination strategy with a natural polyphenol tannic acid (TA). A lower systemic toxicity of V(IV) NPs is achieved by strong metal-polyphenol coordination interactions. An efficient V(V) activation is realized by reactive oxygen species (ROS) at the tumor site. Furthermore, V(IV) NPs show excellent photothermal properties in the near-infrared (NIR) region. By NIR irradiation at the tumor site for mild hyperthermia, selective enhancement of the interactions between V(V) and Na/K-ATPase achieves stronger inhibition of Na/K-ATPase for robust cell killing effect. Altogether, V(IV) NPs specifically inhibit Na/K-ATPase in cancer cells with negligible toxicity to normal tissues, thus making them a promising candidate for clinical applications of Na/K-ATPase inhibition.

NIR-II light evokes DNA cross-linking for chemotherapy and immunogenic cell death

As a DNA damaging agent, oxaliplatin (OXA) can induce immunogenic cell death (ICD) in tumors to activate the immune system. However, the DNA damage induced by OXA is limited and the ICD effect is not strong enough to enhance anti-tumor efficacy. Here, we propose a strategy to maximize the ICD effect of OXA through the mild hyperthermia generated by nanoparticles with a platinum (IV) prodrug of OXA (Pt(IV)-C16) and a near-infrared-II (NIR-II) photothermal agent IR1061 upon the irradiation of NIR-II light. The mild hyperthermia (43 °C) holds advantages in two aspects: 1) increase the Pt-DNA cross-linking, leading to enhanced DNA damage and apoptosis; 2) induce stronger ICD effects for cancer immunotherapy. We demonstrated that, compared with OXA and photothermal therapy of IR1061 alone, these nanoparticles under NIR-II light irradiation can significantly improve the anti-cancer efficacy against triple-negative breast cancer 4T1 tumor. This new strategy provides an effective way to improve the therapeutic outcome of OXA. STATEMENT OF SIGNIFICANCE: OXA could induce immunogenic cell death (ICD) via stimulating immune responses by increasing tumor cell stress and death, which triggers tumor-specific immune responses to achieve immunotherapy. However, due to the insufficient Pt-DNA crosslinks, the ICD effect triggered by OXA cannot induce robust immune response. Mild hyperthermia has great potential to maximize the therapeutic outcome of oxaliplatin by increasing the Pt-DNA cross-linking to augment the immunoresponse for enhanced cancer immunotherapy.

Fibrous dressing containing bioactive glass with combined chemotherapy and wound healing promotion for post-surgical treatment of melanoma

Surgery is the mainstream treatment for melanoma. However, inappropriate post-surgical treatment could result in the tumor recurrence and sever tissue damage, which ultimately leads to the failure of therapy and significantly compromises the therapeutic outcome of surgery. Herein, taking advantages of the co-axial electrospinning technology, we construct a dual-function nanofibrous wound dressing for the post-surgical treatment of melanoma. Si-Ca-P-based mesoporous bioactive glass (MBG) was prepared by the template-sol-gel process, with the compositions being set as 60 SiO₂: 36 CaO: 4 P₂O₅ in mol%. Through rational design, 5-fluorouracil (5-FU)-loaded MBG nanoparticles (MBG-U) are successfully incorporated into the fiber core with biodegradable poly(lactic-co-glycolic acid) (PLGA) as the cladding layer to form the core-shell nanofibers (MBG-U CSF), which achieves sustained releases of chemotherapeutic drug (i.e.,5-FU) and wound healing promotion function. Thereafter, the post-surgical melanoma model was established to evaluate the in-situ anti-cancer and wound healing effect of MBG-U CSF. Thereafter, the post-surgical melanoma model was established to evaluate the anti-cancer and wound healing effect. The results demonstrated that the core-shell nanofibrous dressing almost complete suppressed tumor growth, and simultaneously promoted skin regeneration, which provides a promising strategy for the post-surgical treatment for melanoma.

Glutathione-Responsive Nanoparticles of Camptothecin Prodrug for Cancer Therapy

Camptothecin (CPT) is a potent chemotherapeutic agent for various cancers, but the broader application of CPT is still hindered by its poor bioavailability and systemic toxicity. Here, a prodrug that releases CPT in response to glutathione (GSH), which is commonly overexpressed by cancer cells is reported. Through assembling with PEGylated lipids, the prodrug is incorporated within as-assembled nanoparticles, affording CPT with a prolonged half-life in blood circulation, enhanced tumor targetingability, and improved therapeutic efficacy. Furthermore, such prodrug nanoparticles can also promote dendritic cell maturation and tumor infiltration of CD8⁺ T cells, providing a novel strategy to improve the therapeutic efficacy of CPT.