Synergistic Cancer Immunotherapy Research Articles

A Pyroptosis-Inducing Arsenic(III) Nanomicelle Platform for Synergistic Cancer Immunotherapy.

Immunogenic cell death (ICD) could activate anti-tumor immune responses, which is highly attractive for improving cancer treatment effectiveness. Here, this work reports a multifunctional arsenic(III) allosteric inhibitor Mech02, which induces excessive accumulation of 1O2 through sensitized biocatalytic reactions, leading to cell pyroptosis and amplified ICD effect. After Mech02 is converted to Mech03, it could actualize stronger binding effects on the allosteric pocket of pyruvate kinase M2, further interfering with the anaerobic glycolysis pathway of tumors. The enhanced DNA damage triggered by Mech02 and the pyroptosis of cancer stem cells provide assurance for complete tumor clearance. In vivo experiments prove nanomicelle Mech02-HA NPs is able to activate immune memory effects and raise the persistence of anti-tumor immunity. In summary, this study for the first time to introduce the arsenic(III) pharmacophore as an enhanced ICD effect initiator into nitrogen mustard, providing insights for the development of efficient multimodal tumor therapy agents.

High-throughput screening identifies ibuprofen as an sEV PD-L1 inhibitor for synergistic cancer immunotherapy

Programmed death-ligand 1 (PD-L1) on tumor-derived small extracellular vesicles (sEVs) limits therapeutic effectiveness by interacting with the PD-1 receptor on host immune cells. Targeting the secretion of sEV PD-L1 has emerged as a promising strategy to enhance immunotherapy. However, the lack of small-molecule inhibitors poses a challenge for clinical translation. In this study, we developed a target and phenotype dual-driven high-throughput screening (TAP-HTS) strategy that combined virtual screening with nanoflow-based experimental verification. We identified ibuprofen (IBP) as a novel inhibitor that effectively targeted sEV PD-L1 secretion. IBP disrupted the biogenesis and secretion of PD-L1+ sEVs in tumor cells by physically interacting with a critical regulator of sEV biogenesis, hepatocyte growth factor-regulated tyrosine kinase substrate (HRS). Notably, the mechanism of action of IBP is distinct from its commonly known targets, cyclooxygenases (COX1 or COX2). Administration of IBP stimulated antitumor immunity and enhanced the efficacy of anti-PD-1 therapy in melanoma and oral squamous cell carcinoma (OSCC) mouse models. To address potential adverse effects, we further developed an IBP gel for topical application, which demonstrated remarkable therapeutic efficacy when combined with anti-PD-1 treatment. The discovery of this specific small inhibitor provides a promising avenue for establishing durable, systemic antitumor immunity.

Bimetallic phosphidethe nanoparticles as photo-enhanced nanozymes for synergistic cancer immunotherapy

<p class="MsoNormal" style="margin-top: 12pt; text-align: justify;"><span lang="EN-US" style="font-family: 'times new roman', times, serif; font-size: 14pt;">Nanozyme with biomimetic enzyme activity has the advantages of good catalytic performance, high stability, and is not easily affected by temperature. However, the application of tumor microenvironment (TME) in the tumor is limited due to its low catalytic activity. Herein, a multifunctional nanozyme based on CuCoP with multivalent metal ions (Cu+/Cu2+ and Co2+/ Co3+) provides an innovative strategy for constructing acid-responsive cancer therapy. CuCoP has excellent photothermal properties (photothermal conversion efficiency of 66.9%) as well as glutathione (GSH) peroxidase activity and high photo-enhanced peroxidase-like (POD) enzyme activity in weak acid TME. CuCoP can consume the overexpressed GSH, thus alleviating the antioxidant capacity of the tumor, and reduces Cu2+/ Co3+ to Cu+/ Co 2+. Subsequently, the generated Cu+/Co2+ will react with endogenous H2O2 to generate cytotoxic hydroxyl radical (•OH), which have high catalytic efficiency in weakly acidic TME. Crucially, the synergistic effect of PTT and the cascade reaction of bimetallic atoms with GSH and H2O2 can effectively reduce antioxidant capacity, inhibit tumors and trigger effective immune cell death (ICD) process, which caused a strong immune response and inhibit tumor recurrence and metastasis. As a novel bimetallic sulfide nanoenzyme triggered by TME, CuCoP has great research value in cancer therapy.</span></p>

Copper(II)-Based Nano-regulator Correlates Cuproptosis burst and Sequential Immunogenic Cell Death for Synergistic Cancer Immunotherapy

Copper(II)-Based Nano-regulator Correlates Cuproptosis burst and Sequential Immunogenic Cell Death for Synergistic Cancer Immunotherapy

Cancer cell-specific and pro-apoptotic SMAC peptide-doxorubicin conjugated prodrug encapsulated aposomes for synergistic cancer immunotherapy

BackgroundImmunogenic cell death (ICD) is a crucial approach to turn immunosuppressive tumor microenvironment (ITM) into immune-responsive milieu and improve the response rate of immune checkpoint blockade (ICB) therapy. However, cancer cells show resistance to ICD-inducing chemotherapeutic drugs, and non-specific toxicity of those drugs against immune cells reduce the immunotherapy efficiency.MethodsHerein, we propose cancer cell-specific and pro-apoptotic liposomes (Aposomes) encapsulating second mitochondria-derived activator of caspases mimetic peptide (SMAC-P)-doxorubicin (DOX) conjugated prodrug to potentiate combinational ICB therapy with ICD. The SMAC-P (AVPIAQ) with cathepsin B-cleavable peptide (FRRG) was directly conjugated to DOX, and the resulting SMAC-P-FRRG-DOX prodrug was encapsulated into PEGylated liposomes.ResultsThe SMAC-P-FRRG-DOX encapsulated PEGylated liposomes (Aposomes) form a stable nanostructure with an average diameter of 109.1 ± 5.14 nm and promote the apoptotic cell death mainly in cathepsin B-overexpressed cancer cells. Therefore, Aposomes induce a potent ICD in targeted cancer cells in synergy of SMAC-P with DOX in cultured cells. In colon tumor models, Aposomes efficiently accumulate in targeted tumor tissues via enhanced permeability and retention (EPR) effect and release the encapsulated prodrug of SMAC-P-FRRG-DOX, which is subsequently cleaved to SMAC-P and DOX in cancer cells. Importantly, the synergistic activity of inhibitors of apoptosis proteins (IAPs)-inhibitory SMAC-P sensitizing the effects of DOX induces a potent ICD in the cancer cells to promote dendritic cell (DC) maturation and stimulate T cell proliferation and activation, turning ITM into immune-responsive milieu.ConclusionsEventually, the combination of Aposomes with anti-PD-L1 antibody results in a high rate of complete tumor regression (CR: 80%) and also prevent the tumor recurrence by immunological memory established during treatments.Graphical

Metal-Phenolic Nanocloaks on Cancer Cells Potentiate STING Pathway Activation for Synergistic Cancer Immunotherapy.

Due to the presence of natural neoantigens, autologous tumor cells hold great promise as personalized therapeutic vaccines. Yet autologous tumor cell vaccines require multi-step production that frequently leads to the loss of immunoreactive antigens, causing insufficient immune activation and significantly hampering their clinical applications. Herein, we introduce a novel whole-cell cancer vaccine by cloaking cancer cells with lipopolysaccharide-decorated manganese(II)-phenolic networks (MnTA nanocloaks) to evoke tumor-specific immune response for highly efficacious synergistic cancer immunotherapy. The natural polyphenols coordinate with Mn2+ and immediately adhere to the surface of individual cancer cells, thereby forming a nanocloak and encapsulating tumor neoantigens. Subsequent decoration with lipopolysaccharide induces internalization by dendritic cells, where Mn2+ ions are released in the cytosol, further facilitating the activation of the stimulator of the interferon genes (STING) pathway. Highly effective tumor suppression was observed by combining the nanocloaked cancer cell treatment with anti-programmed cell death ligand 1 (anti-PD-L1) antibodies-mediated immune checkpoint blockade therapy. Our work demonstrates a universal yet simple strategy to engineer a cell-based nanobiohybrid system for enhanced cancer immunotherapy.

Metal‐Phenolic Nanocloaks on Cancer Cells Potentiate STING Pathway Activation for Synergistic Cancer Immunotherapy

AbstractDue to the presence of natural neoantigens, autologous tumor cells hold great promise as personalized therapeutic vaccines. Yet autologous tumor cell vaccines require multi‐step production that frequently leads to the loss of immunoreactive antigens, causing insufficient immune activation and significantly hampering their clinical applications. Herein, we introduce a novel whole‐cell cancer vaccine by cloaking cancer cells with lipopolysaccharide‐decorated manganese(II)‐phenolic networks (MnTA nanocloaks) to evoke tumor‐specific immune response for highly efficacious synergistic cancer immunotherapy. The natural polyphenols coordinate with Mn2+ and immediately adhere to the surface of individual cancer cells, thereby forming a nanocloak and encapsulating tumor neoantigens. Subsequent decoration with lipopolysaccharide induces internalization by dendritic cells, where Mn2+ ions are released in the cytosol, further facilitating the activation of the stimulator of the interferon genes (STING) pathway. Highly effective tumor suppression was observed by combining the nanocloaked cancer cell treatment with anti‐programmed cell death ligand 1 (anti‐PD‐L1) antibodies‐mediated immune checkpoint blockade therapy. Our work demonstrates a universal yet simple strategy to engineer a cell‐based nanobiohybrid system for enhanced cancer immunotherapy.

Tumor-Microenvironment-Activatable Nanoparticle Mediating Immunogene Therapy and M2 Macrophage-Targeted Inhibitor for Synergistic Cancer Immunotherapy.

Immunotherapy has achieved prominent clinical efficacy in combating cancer and has recently become a mainstream treatment strategy. However, achieving broad efficacy with a single modality is challenging, and the heterogeneity of the tumor microenvironment (TME) restricts the accuracy and effectiveness of immunotherapy strategies for tumors. Herein, a TME-responsive targeted nanoparticle to enhance antitumor immunity and reverse immune escape by codelivering interleukin-12 (IL-12) expressing gene and colony-stimulating factor-1 receptor (CSF-1R) inhibitor PLX3397 (PLX) is presented. The introduction of disulfide bonds and cyclo(Arg-Gly-Asp-d-Phe-Lys) (cRGD) peptides conferred reduction reactivity and tumor targeting to the nanoparticles, respectively. It is hypothesized that activating host immunity by the local expression of IL-12, while modulating the tumor-associated macrophages (TAM) function through blocking CSF-1/CSF-1R signaling, could constitute a feasible approach for cancer immunotherapy. The fabricated functional nanoparticle successfully ameliorated the TME by stimulating the proliferation and activation of T lymphocytes, promoting the repolarization of TAMs, reducing myeloid-derived suppressor cells (MDSCs), and promoting the maturation of dendritic cells (DC) as well as the secretion of antitumor cytokines, which efficiently suppressed tumor growth and metastasis. Finally, substantial changes in the TME were deciphered by single-cell analysis including infiltration of different cells, transcriptional states, secretory signaling and cell-cell communications. These findings provide a promising combinatorial immunotherapy strategy through immunomodulatory nanoparticles.

In Situ Vaccination with An Injectable Nucleic Acid Hydrogel for Synergistic Cancer Immunotherapy.

Recently, therapeutic cancer vaccines have emerged as promising candidates for cancer immunotherapy. Nevertheless, their efficacies are frequently impeded by challenges including inadequate antigen encapsulation, insufficient immune activation, and immunosuppressive tumor microenvironment. Herein, we report a three-in-one hydrogel assembled by nucleic acids (NAs) that can serve as a vaccine to in situ trigger strong immune response against cancer. Through site-specifically grafting the chemodrug, 7-ethyl-10-hydroxycamptothecin (also known as SN38), onto three component phosphorothioate (PS) DNA strands, a Y-shaped motif (Y-motif) with sticky ends is self-assembled, at one terminus of which an unmethylated cytosine-phosphate-guanine (CpG) segment is introduced as an immune agonist. Thereafter, programmed cell death ligand-1 (PD-L1) siRNA that performs as immune checkpoint inhibitor is designed as a crosslinker to assemble with the CpG- and SN38-containing Y-motif, resulting in the formation of final NA hydrogel vaccine. With three functional agents inside, the hydrogel can remarkably induce the immunogenic cell death to enhance the antigen presentation, promoting the dendritic cell maturation and effector T lymphocyte infiltration, as well as relieving the immunosuppressive tumor environment. When inoculated twice at tumor sites, the vaccine demonstrates a substantial antitumor effect in melanoma mouse model, proving its potential as a general platform for synergistic cancer immunotherapy.

In Situ Vaccination with An Injectable Nucleic Acid Hydrogel for Synergistic Cancer Immunotherapy

AbstractRecently, therapeutic cancer vaccines have emerged as promising candidates for cancer immunotherapy. Nevertheless, their efficacies are frequently impeded by challenges including inadequate antigen encapsulation, insufficient immune activation, and immunosuppressive tumor microenvironment. Herein, we report a three‐in‐one hydrogel assembled by nucleic acids (NAs) that can serve as a vaccine to in situ trigger strong immune response against cancer. Through site‐specifically grafting the chemodrug, 7‐ethyl‐10‐hydroxycamptothecin (also known as SN38), onto three component phosphorothioate (PS) DNA strands, a Y‐shaped motif (Y‐motif) with sticky ends is self‐assembled, at one terminus of which an unmethylated cytosine‐phosphate‐guanine (CpG) segment is introduced as an immune agonist. Thereafter, programmed cell death ligand‐1 (PD‐L1) siRNA that performs as immune checkpoint inhibitor is designed as a crosslinker to assemble with the CpG‐ and SN38‐containing Y‐motif, resulting in the formation of final NA hydrogel vaccine. With three functional agents inside, the hydrogel can remarkably induce the immunogenic cell death to enhance the antigen presentation, promoting the dendritic cell maturation and effector T lymphocyte infiltration, as well as relieving the immunosuppressive tumor environment. When inoculated twice at tumor sites, the vaccine demonstrates a substantial antitumor effect in melanoma mouse model, proving its potential as a general platform for synergistic cancer immunotherapy.

Manganese-Enriched Zinc Peroxide Functional Nanoparticles for Potentiating Cancer Immunotherapy.

Immunotherapies have shown high clinical success, however, the therapeutical efficacy is largely restrained by insufficient immune activation and an immunosuppressive microenvironment. Herein, we report tumor microenvironment (TME)-responsive manganese-enriched zinc peroxide nanoparticles (MONPs) for synergistic cancer immunotherapy by inducing the immunogenic death (ICD) of cancer cells and activating the stimulator of the interferon gene (STING) pathway. MONPs especially disassociate upon exposure to acidic tumor tissue and in situ generate •OH for the ICD effect. Moreover, Mn2+ activated the STING and synergistically induced the secretion of type I interferon and inflammatory cytokines for specific T cell responses. Meanwhile, MONPs relieved the immunosuppression of TME through decreasing Tregs and polarizing M2 macrophages to the M1 type to unleash a cascade adaptive immune response. In combination with the anti-PD-1 antibody, MONPs showed superior efficacy in inhibiting tumor growth and preventing lung metastasis. Our study demonstrates the feasibility of functional nanoparticles to amplify STING innate stimulation, showing a prominent strategy for cancer immunotherapy.

Extracellular vesicles hybrid plasmid-loaded lipid nanovesicles for synergistic cancer immunotherapy

Combination immunotherapy of cancer vaccines with immune checkpoint inhibitors (ICIs) represents a promising therapeutic strategy for immunosuppressed and cold tumors. However, this strategy still faces challenges, including the limited therapeutic efficacy of cancer vaccines and immune-related adverse events associated with systematic delivery of ICIs. Herein, we demonstrate the antitumor immune response induced by outer membrane vesicle from Akkermansia muciniphila (Akk-OMV), which exhibites a favorable safety profile, highlighting the potential application as a natural and biocompatible self-adjuvanting vesicle. Utilizing tumor cell-derived exosome as an antigen source and Akk-OMV as a natural adjuvant, we construct a cancer vaccine formulation of extracellular vesicles hybrid lipid nanovesicles (Lipo@HEV) for enhanced prophylactic and therapeutic vaccination by promoting dendritic cell (DC) maturation in lymph node and activating cytotoxic T cell (CTL) response. The Lipo@HEV is further loaded with plasmid to enable gene therapy-mediated PD-L1 blockade upon peritumoral injection. Meanwhile, it penetrates into lymph node to initiate DC maturation and CTL activation, synergistically inhibiting the established tumor. The fabrication of extracellular vesicles hybrid plasmid-loaded lipid nanovesicles reveals a promising gene therapy-guided and vesicle-based hybrid system for therapeutic cancer vaccination and synergistic immunotherapy strategy.

A novel self-assembled nucleobase-nanofiber platform of CDN to activate the STING pathway for synergistic cancer immunotherapy

2′, 3′-cGAMP (CDN) as cGAS-STING pathway agonist is extensively used in tumor treatment. However, due to its negatively charged nature (containing two phosphate groups) and high hydrophilicity, CDN faces challenges in crossing cell membranes, resulting in reduced efficiency of its use. Additionally, CDN is susceptible to inactivation through phosphodiesterase hydrolysis. Therefore, the development of a new drug delivery system for CDN is necessary to prevent hydrolysis and enhance targeted accumulation in tumors, as well as improve cellular uptake for STING activation. In this study, we have developed peptide-polymer nanofibers (PEG-Q11) that incorporate thymine (T) and arginine (R) residues to facilitate complexation with CDN through the principles of Watson-Crick base pairing with thymine and favorable electrostatic interactions and bidentate hydrogen bonding with arginine side chains. The entrapment efficiency (EE) of PEG-Q11T3R4@CDN was found to be 51% higher than that of PEG-Q11@CDN. Due to its favorable biocompatibility, PEG-Q11T3R4@CDN was employed for immunotherapy in mouse CT26 tumors. In local tumor treatment, the administration of PEG-Q11T3R4@CDN at a low dose and through a single injection exhibited inhibitory effects. Furthermore, the local injection of PEG-Q11T3R4@CDN resulted in systemic therapeutic responses, effectively suppressing tumor metastasis by activating CD8 + T cells to target distant tumors. This research not only underscores the potential of PEG-Q11T3R4@CDN as an efficient therapeutic agent but also highlights its ability to achieve long-lasting systemic therapeutic outcomes following local treatment. Consequently, PEG-Q11T3R4@CDN represents a promising strategy for immunization.

Gemcitabine nano-prodrug reprograms intratumoral metabolism and alleviates immunosuppression for hepatocellular carcinoma therapy

High-rate aerobic glycolysis and abnormal glutamine metabolism in tumor cells lead to their unlimited malignant proliferation and induce immune escape in the tumor microenvironment. In this study, the GLS1 inhibitor BPTES and the PDHC inhibitor CPI-613 were co-delivered by an ROS-sensitive GEM nano-prodrug (PD-G@BC), and a simultaneous inhibition of glycolysis and glutamine metabolism was achieved to deprive tumor cells of nutrient supply. In addition, this metabolism reprogramming effectively weakened the sources of glucose and glutamine in tumor cells, correspondingly thrived metabolism in antitumor immune cells, thereby increasing the intratumoral infiltration and functions of the immunogenic cells to alleviate the immunosuppressive responses. This multifunctional combination strategy will provide new insights into the design of synergistic cancer immunotherapy based on metabolic interventions.

Bionic immunoactivator copresenting autophagy promoting and costimulatory molecules for synergistic cancer immunotherapy

Bionic immunoactivator copresenting autophagy promoting and costimulatory molecules for synergistic cancer immunotherapy

Bispecific antibody targeting TGF-β and PD-L1 for synergistic cancer immunotherapy.

The PD-1/PD-L1 signaling pathway plays a crucial role in cancer immune evasion, and the use of anti-PD-1/PD-L1 antibodies represents a significant milestone in cancer immunotherapy. However, the low response rate observed in unselected patients and the development of therapeutic resistance remain major obstacles to their clinical application. Accumulating studies showed that overexpressed TGF-β is another immunosuppressive factor apart from traditional immune checkpoints. Actually, the effects of PD-1 and TGF-β pathways are independent and interactive, which work together contributing to the immune evasion of cancer cell. It has been verified that blocking TGF-β and PD-L1 simultaneously could enhance the efficacy of PD-L1 monoclonal antibody and overcome its treatment resistance. Based on the bispecific antibody or fusion protein technology, multiple bispecific and bifunctional antibodies have been developed. In the preclinical and clinical studies, these updated antibodies exhibited potent anti-tumor activity, superior to anti-PD-1/PD-L1 monotherapies. In the review, we summarized the advances of bispecific antibodies targeting TGF-β and PD-L1 in cancer immunotherapy. We believe these next-generation immune checkpoint inhibitors would substantially alter the cancer treatment paradigm, especially in anti-PD-1/PD-L1-resistant patients.

Cuproptosis Induced by ROS Responsive Nanoparticles with Elesclomol and Copper Combined with αPD‐L1 for Enhanced Cancer Immunotherapy (Adv. Mater. 22/2023)

Immunotherapy In article 2212267, Haihua Xiao, Nianzeng Xing, and co-workers present a novel therapeutic strategy to achieve synergistic cancer immunotherapy via cuproptosis induced by reactive oxygen species (ROS)-responsive nanomedicine loaded with elesclomol and copper ([email protected]). With this approach, the tumor microenvironment is reprogrammed, and the expression of PD-L1 is increased, which consequently improves responsiveness of immunotherapy.

Curvature-sensing peptide inhibits tumour-derived exosomes for enhanced cancer immunotherapy.

Tumour-derived exosomes (T-EXOs) impede immune checkpoint blockade therapies, motivating pharmacological efforts to inhibit them. Inspired by how antiviral curvature-sensing peptides disrupt membrane-enveloped virus particles in the exosome size range, we devised a broadly useful strategy that repurposes an engineered antiviral peptide to disrupt membrane-enveloped T-EXOs for synergistic cancer immunotherapy. The membrane-targeting peptide inhibits T-EXOs from various cancer types and exhibits pH-enhanced membrane disruption relevant to the tumour microenvironment. The combination of T-EXO-disrupting peptide and programmed cell death protein-1 antibody-based immune checkpoint blockade therapy improves treatment outcomes in tumour-bearing mice. Peptide-mediated disruption of T-EXOs not only reduces levels of circulating exosomal programmed death-ligand 1, but also restores CD8+ T cell effector function, prevents premetastatic niche formation and reshapes the tumour microenvironment in vivo. Our findings demonstrate that peptide-induced T-EXO depletion can enhance cancer immunotherapy and support the potential of peptide engineering for exosome-targeting applications.

Tumor microenvironment-modulated multiple nanotherapeutic system for potent cancer immunotherapy and metastasis inhibition

The hypoxic and immunosuppressive tumor microenvironment (TME) generally weaken the efficacy of immunotherapy in solid tumors. However, reversing TME remains a formidable challenge. Here, an elaborately multitasking nanotherapeutic system (PEG-PLGA-R848@GFCNs) is demonstrated to forceful remodel TME. This nanotherapeutic system could validly relieve tumor hypoxia and induce M2 to M1 polarization of tumor-associated macrophages (TAMs) to reverse immunosuppression, serving for TME reprogramming. Furthermore, PEG-PLGA-R848@GFCNs stimulates dendritic cells maturation, thereby initiating T-cell-mediated anti-tumor immune response. Of note, the nanotherapeutic system eliminates primary tumor that established by 4T1 tumor models in mice and efficiently inhibits B16F10 melanoma metastasis without obvious adverse effects. Importantly, PEG-PLGA-R848@GFCNs combined with anti-PD-L1 immune checkpoint inhibitor achieves superior synergistic cancer immunotherapy. Collectively, our work offers a reliable and safe strategy to fabricate a multitasking nanotherapeutic system for comprehensively modulating TME to achieve effective cancer immunotherapy and metastasis inhibition.

Cinnamaldehyde-based poly(thioacetal): A ROS-awakened self-amplifying degradable polymer for enhanced cancer immunotherapy

Although stimuli-responsive polymers have emerged as promising strategies for intelligent cancer therapy, limited polymer degradation and insufficient drug release remain a challenge. Here, we report a novel reactive oxygen species (ROS)-awakened self-amplifying degradable cinnamaldehyde (CA)-based poly(thioacetal) polymer. The polymer consists of ROS responsive thioacetal (TA) group and CA as the ROS generation agent. The self-amplified polymer degradation process is triggered by endogenous ROS-induced cleavage of the TA group to release CA. The CA released then promotes the generation of more ROS through mitochondrial dysfunction, resulting in amplified polymer degradation. More importantly, poly(thioacetal) itself can trigger immunogenic cell death (ICD) of the tumor cells and its side chains can be conjugated with indoleamine 2,3-dioxygenase 1 (IDO-1) inhibitor to reverse the immunosuppressive tumor microenvironment for synergistic cancer immunotherapy. The self-amplified degradable poly(thioacetal) developed in this work provides insights into the development of novel stimulus-responsive polymers for enhanced cancer immunotherapy.