Bioactive Peptide Nanodrugs Based on Supramolecular Assembly for Boosting Immunogenic Cell Death-Induced Cancer Immunotherapy

Necroptosis-inducing nanobubbles for effective oxygen delivery and enhanced sonodynamic immunotherapy of breast cancer via UTND

PURPOSE

Breast cancer (BC) is a global threat to female health. Sonodynamic therapy (SDT) has been shown to induce apoptosis in tumor cells and trigger immunogenic cell death, leading to the activation of antitumor immunity. However, the immunogenicity of this process may be compromised by oxidative stress and proteolysis. Necroptosis caused by ultrasound-targeted nanobubble destruction (UTND) could boost immunity. Therefore, we tested if necroptosis-inducible nanobubbles (NB) could enhance sonodynamic immunotherapy for BC. We also assessed whether O2-filled NB could address tumor hypoxia and enhance SDT efficacy.

METHODS

A novel multifunctional nano-system, comprising NB for UTND encapsulating chlorin e6 (Ce6) for SDT and O2 for hypoxia alleviation was established. Ce6-O2NB cytocompatibility and intracellular uptake was studied in vitro, as well as whether Ce6-O2NB could generated reactive oxygen species when exposed to ultrasound irradiation in order to induce apoptosis in tumor cells. In vivo pharmacokinetics, therapeutic efficacy, and immune activation after Ce6-O2NB treatment were studied in 4T1 tumor-bearing mice.

RESULTS

Ce6-O2NB had a well-designed core-shell structure and desirable biocompatibility and safe therapeutic effects. Ce6-O2NB was able to load both ce6 and oxygen to increase ce6 and oxygen accumulation in tumors. After triggering by ultrasound, Ce6-O2NB generated reactive oxygen species (ROS) and acted as sonosensitizers for SDT, promoting tumor cell death through apoptotic and/or necrotic mechanisms. Furthermore, antitumor immunity was activated by stimulation of spleen lymphocyte proliferation and cytotoxicity, and increasing cytotoxic T lymphocyte numbers. Combination of oxygen with SDT ultimately strengthened its antitumor effects. In addition, Ce6-O2NB alleviated tumor hypoxia, induced increased ROS generation, and improved immune responses and therapeutic efficacy of SDT. Ce6-O2NB also facilitated fluorescence and contrast-enhanced ultrasound imaging.

CONCLUSIONS

Ce6-O2NB can mitigate tumor hypoxia, enhance SDT, and activate antitumor immunity by inducing simultaneous immunogenic apoptosis and necroptosis, ultimately activating antitumor immunity and inhibiting breast tumor growth in mice.

Biomimetic Nanomaterials Based on Peptide In Situ Self-Assembly for Immunotherapy Applications

Cancer remains the leading cause of patient death worldwide and its incidence continues to rise. Immunotherapy is rapidly developing due to its significant differences in the mechanism of action from conventional radiotherapy and targeted antitumor drugs. In the past decades, many biomaterials have been designed and prepared to construct therapeutic platforms that modulate the immune system against cancer. Immunotherapeutic platforms utilizing biomaterials can markedly enhance therapeutic efficacy by optimizing the delivery of therapeutic agents, minimizing drug loss during circulation, and amplifying immunomodulatory effects. The intricate physiological barriers of tumors, coupled with adverse immune environments such as inadequate infiltration, off-target effects, and immunosuppression, have emerged as significant obstacles impeding the effectiveness of oncology drug therapy. However, most of the current studies are devoted to the development of complex immunomodulators that exert immunomodulatory functions by loading drugs or adjuvants, ignoring the complex physiological barriers and adverse immune environments of tumors. Compared with conventional biomaterials, biomimetic nanomaterials based on peptide in situ self-assembly with excellent functional characteristics of biocompatibility, biodegradability, and bioactivity have emerged as a novel and effective tool for cancer immunotherapy. This article presents a comprehensive review of the latest research findings on biomimetic nanomaterials based on peptide in situ self-assembly in tumor immunotherapy. Initially, we categorize the structural types of biomimetic peptide nanomaterials and elucidate their intrinsic driving forces. Subsequently, we delve into the in situ self-assembly strategies of these peptide biomimetic nanomaterials, highlighting their advantages in immunotherapy. Furthermore, we detail the applications of these biomimetic nanomaterials in antigen presentation and modulation of the immune microenvironment. In conclusion, we encapsulate the challenges and prospective developments of biomimetic nanomaterials based on peptide in situ self-assembly for clinical translation in immunotherapy.

Immunogenic cell death: A new strategy to enhancing cancer immunotherapy

Immunogenic cell death (ICD) is a distinct type of stress-induced regulated cell death that can lead to adaptive immune responses and the establishment of immunological memory. ICD exhibits both similarities and differences when compared to apoptosis and other non-apoptotic forms of regulated cell death (RCD). The interplay between ICD-mediated immunosurveillance against cancer and the ability of cancer cells to evade ICD influences the host-tumor immunological interaction. Consequently, the restoration of ICD and the development of effective strategies to induce ICD have emerged as crucial considerations in the treatment of cancer within the context of immunotherapy. To enhance comprehension of ICD in the setting of cancer, this paper examines the interconnected responsive pathways associated with ICD, the corresponding biomarkers indicative of ICD, and the mechanisms through which tumors subvert ICD. Additionally, this review explores strategies for reinstating ICD and the therapeutic potential of harnessing ICD in cancer immunotherapy.

Polymorphic Supramolecular Therapeutic Platforms with Precise Dye/Drug Ratio to Perform Synergistic Chemo-Photo Anti-Tumor Therapy and Long-Term Immune Protection

Malignant tumor has become one of the hellish killers threatening the health of people around the world, its diagnosis and treatment has become the concerns of public. However, the optimal therapeutic dose, undesired side-effect, and long-term immune activation were key and bottleneck problems in tumor treatment. Herein, different batches of supramolecular therapeutic platforms, including vesicles, spherical nanoparticles, and cylindrical nanorods, with precise ratios of dye to drug (1:2) and multiple stimulus responsiveness were constructed by host-guest complexation between cyanine-camptothecin conjugates (IR780-CPT2) and β-cyclodextrin (β-CD) pendent hydrophilic copolymers. The reduction responsiveness, near-infrared photothermal conversion and singlet oxygen (1O2) generation performances endowed these platforms excellent cancer cells killing effect in both of in vitro cellular experiments and in vivo mice models. More importantly, without affecting the weight of mice, the maturation of dendritic cells, proliferation of T cells, up-regulation of high mobility group protein B1, and reduction of immunosuppressive regulatory T cells were detected after employing a synergistic chemo-photo therapy, demonstrating the body's immune effect was successfully activated. Thus, during the treatment of primary tumor, the distal tumor was also inhibited. We believe this work could provide a distinctive way to fabricate supramolecular theranostic platforms with different morphologies and improve antitumor and antimetastasis capabilities.

Overcoming T Cell Exhaustion in Tumor Microenvironment via Immune Checkpoint Modulation with Nano-Delivery Systems for Enhanced Immunotherapy

Immune checkpoint blockade (ICB) therapy for tumors has arisen in growing interest. However, the low response rate of tumors to ICB is mainly attributed to the inhibitory infiltration of immune cells in the tumor microenvironment (TME). Despite the promising benefits of ICB, the therapeutic effects of antibodies are dependent on a high dose and long-term usage in the clinic, thereby leading to immune-related adverse effects. Accordingly, ICB combined with nano-delivery systems could be used to overcome T cell exhaustion, which reduces the side effects and the usage of antibodies with higher response rates in patients. In this review, the authors aim to overcome T cell exhaustion in TME via immune checkpoint modulation with nano-delivery systems for enhanced immunotherapy. Several strategies are summarized to combine ICB and nano-delivery systems to further enhance immunotherapy: a) expressing immune checkpoint on the surface of nano-delivery systems; b) loading immune checkpoint inhibitors into nano-delivery systems; c) loading gene-editing technology into nano-delivery systems; and d) nano-delivery systems mediated immune checkpoint modulation. Taken together, ICB combined with nano-delivery systems might be a promising strategy to overcome T cell exhaustion in TME for enhanced immunotherapy.

Nanoparticle-Mediated Immunotherapy in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype with the worst prognosis and highest recurrence rates. The treatment choices are limited due to the scarcity of endocrine and HER2 targets, except for chemotherapy. However, the side effects of chemotherapy restrict its long-term usage. Immunotherapy shows potential as a promising therapeutic strategy, such as inducing immunogenic cell death, immune checkpoint therapy, and immune adjuvant therapy. Nanotechnology offers unique advantages in the field of immunotherapy, such as improved delivery and targeted release of immunotherapeutic agents and enhanced bioavailability of immunomodulators. As well as the potential for combination therapy synergistically enhanced by nanocarriers. Nanoparticles-based combined application of multiple immunotherapies is designed to take the tactics of enhancing immunogenicity and reversing immunosuppression. Moreover, the increasing abundance of biomedical materials holds more promise for the development of this field. This review summarizes the advances in the field of nanoparticle-mediated immunotherapy in terms of both immune strategies for treatment and the development of biomaterials and presents challenges and hopes for the future.

Bioorthogonal In Situ Polymerization of Dendritic Agents for Hijacking Lysosomes and Enhancing Antigen Presentation in Cancer Cells

A low-generation lysine dendrimer, SPr-G2, responds to intracellular glutathione to initiate bioorthogonal in situ polymerization, resulting in the formation of large assemblies in mouse breast cancer cells. The intracellular large assemblies of SPr-G2 can interact with lysosomes to induce lysosome expansion and enhance lysosomal membrane permeabilization, leading to major histocompatibility complex class I upregulation on tumor cell surfaces and ultimately tumor cell death. Moreover, the use of the SPr-G2 dendrimer to conjugate the chemotherapeutic drug, camptothecin (CPT), can boost the therapeutic potency of CPT. Excellent antitumor effects in vitro and in vivo are obtained from the combinational treatment of the SPr-G2 dendrimer and CPT. This combinational effect also enhances antitumor immunity through promoting activation of cytotoxic T cells in tumor tissues and maturation of dendritic cells. This study can shed new light on the development of peptide dendritic agents for cancer therapy.

Advancing nanotechnology for neoantigen-based cancer theranostics

Neoantigens play a pivotal role in the field of tumour therapy, encompassing the stimulation of anti-tumour immune response and the enhancement of tumour targeting capability. Nonetheless, numerous factors directly influence the effectiveness of neoantigens in bolstering anti-tumour immune responses, including neoantigen quantity and specificity, uptake rates by antigen-presenting cells (APCs), residence duration within the tumour microenvironment (TME), and their ability to facilitate the maturation of APCs for immune response activation. Nanotechnology assumes a significant role in several aspects, including facilitating neoantigen release, promoting neoantigen delivery to antigen-presenting cells, augmenting neoantigen uptake by dendritic cells, shielding neoantigens from protease degradation, and optimizing interactions between neoantigens and the immune system. Consequently, the development of nanotechnology synergistically enhances the efficacy of neoantigens in cancer theranostics. In this review, we provide an overview of neoantigen sources, the mechanisms of neoantigen-induced immune responses, and the evolution of precision neoantigen-based nanomedicine. This encompasses various therapeutic modalities, such as neoantigen-based immunotherapy, phototherapy, radiotherapy, chemotherapy, chemodynamic therapy, and other strategies tailored to augment precision in cancer therapeutics. We also discuss the current challenges and prospects in the application of neoantigen-based precision nanomedicine, aiming to expedite its clinical translation.

Modulator of TMB-associated immune infiltration (MOTIF) predicts immunotherapy response and guides combination therapy

Patients with high tumor mutational burden (TMB) levels do not consistently respond to immune checkpoint inhibitors (ICIs), possibly because a high TMB level does not necessarily result in adequate infiltration of CD8+ T cells. Using bulk ribonucleic acid sequencing (RNA-seq) data from 9311 tumor samples across 30 cancer types, we developed a novel tool called the modulator of TMB-associated immune infiltration (MOTIF), which comprises genes that can determine the extent of CD8+ T cell infiltration prompted by a certain TMB level. We confirmed that MOTIF can accurately reflect the integrity and defects of the cancer-immunity cycle. By analyzing 84 human single-cell RNA-seq datasets from 32 types of solid tumors, we revealed that MOTIF can provide insights into the diverse roles of various cell types in the modulation of CD8+ T cell infiltration. Using pretreatment RNA-seq data from 13 ICI-treated cohorts, we validated the use of MOTIF in predicting CD8+ T cell infiltration and ICI efficacy. Among the components of MOTIF, we identified EMC3 as a negative regulator of CD8+ T cell infiltration, which was validated via in vivo studies. Additionally, MOTIF provided guidance for the potential combinations of programmed death 1 blockade with certain immunostimulatory drugs to facilitate CD8+ T cell infiltration and improve ICI efficacy.

Versatile Peptide-Based Nanosystems for Photodynamic Therapy

Photodynamic therapy (PDT) has become an important therapeutic strategy because it is highly controllable, effective, and does not cause drug resistance. Moreover, precise delivery of photosensitizers to tumor lesions can greatly reduce the amount of drug administered and optimize therapeutic outcomes. As alternatives to protein antibodies, peptides have been applied as useful targeting ligands for targeted biomedical imaging, drug delivery and PDT. In addition, other functionalities of peptides such as stimuli responsiveness, self-assembly, and therapeutic activity can be integrated with photosensitizers to yield versatile peptide-based nanosystems for PDT. In this article, we start with a brief introduction to PDT and peptide-based nanosystems, followed by more detailed descriptions about the structure, property, and architecture of peptides as background information. Finally, the most recent advances in peptide-based nanosystems for PDT are emphasized and summarized according to the functionalities of peptide in the system to reveal the design and development principle in different therapeutic circumstances. We hope this review could provide useful insights and valuable reference for the development of peptide-based nanosystems for PDT.

Supramolecular self-assembly of EGCG-selenomethionine nanodrug for treating osteoarthritis

Osteoarthritis (OA) has emerged as a significant health concern among the elderly population, with increasing attention paid to ferroptosis-induced OA in recent years. However, the prolonged use of nonsteroidal anti-inflammatory drugs or corticosteroids can lead to a series of side effects and limited therapeutic efficacy. This study aimed to employ the Mannich condensation reaction between epigallocatechin-3-gallate (EGCG) and selenomethionine (SeMet) to efficiently synthesize polyphenol-based nanodrugs in aqueous media for treating OA. Molecular biology experiments demonstrated that EGCG-based nanodrugs (ES NDs) could effectively reduce glutathione peroxidase 4 (GPX4) inactivation, abnormal Fe2+ accumulation, and lipid peroxidation induced by oxidative stress, which ameliorated the metabolic disorder of chondrocytes and other multiple pathological processes triggered by ferroptosis. Moreover, imaging and histopathological analysis of the destabilization of the medial meniscus model in mice confirmed that ES NDs exhibiting significant therapeutic effects in relieving OA. The intra-articular delivery of ES NDs represents a promising approach for treating OA and other joint inflammatory diseases.

Nanoreactor based on single-atom nanoenzymes promotes ferroptosis for cancer immunotherapy

Immunotherapy is a promising mainstream approach in anti-tumor therapy. It boasts advantages such as durable responses and lower side effects. However, there are still some limitations to be addressed. Current cancer immunotherapy has shown low response rates due to inadequate immunogenicity of certain tumor cells. To address these challenges, an acid-specific nanoreactor was developed, designed to induce immunogenicity by triggering ferroptosis in tumor cells. The nanoreactor integrates glucose oxidase (GOx) with a single-atom nanoenzyme (SAE), which exhibits high peroxidase (POD)-like activity in the acidic tumor microenvironment (TME). This specific acid-sensitivity transforms endogenous hydrogen peroxide (H2O2) into cytotoxic hydroxyl radicals (•OH). GOx enhances the POD-like SAE activity in the nanoreactor by metabolizing glucose in tumor cells, producing gluconic acid and H2O2. This nanoreactor induces high levels of oxidative stress within tumor cells through the synergistic action of SAE and GOx, leading to depletion of GSH and subsequently triggering ferroptosis. The resulting nanoreactor-induced ferroptosis leads to immunogenic cell death (ICD) and significantly recruits T lymphocyte infiltration in tumor tissues. This study was designed with the concept of triggering ferroptosis-dependent ICD mechanism in bladder cancer cells, and developed an acid-specific nanoreactor to enhance the immunotherapy efficacy for bladder cancer, which introduces a novel approach for immunotherapy of bladder cancer.

Biomedical Application of Porphyrin-Based Amphiphiles and Their Self-Assembled Nanomaterials

Porphyrins have been vastly explored and applied in many cutting-edge fields with plenty of encouraging achievements because of their excellent properties. As important derivatives of porphyrins, porphyrin-based amphiphiles (PBAs) not only maintain the advanced properties of porphyrins (catalysis, imaging, and energy transfer) but also possess self-assembly and encapsulation capability in aqueous solution. Accordingly, PBAs and their self-assembles have had important roles in diagnosing and treating tumors and inflammation lesions in vivo, but not limited to these. In this article, we introduce the research progress of PBAs, including their constitution, structure design strategies, and performances in tumor and inflammation lesion diagnosis and treatments. On that basis, the defects of synthesized PBAs during their application and the possible effective strategies to overcome the limitations are also proposed. Finally, perspectives on PBAs exploration are updated based on our knowledge. We hope this review will bring researchers from various domains insights about PBAs.

Photozyme-Catalyzed ATP Generation Based on ATP Synthase-Reconstituted Nanoarchitectonics

We demonstrate that ATP synthase-reconstituted proteoliposome coatings on the surface of microcapsules can realize photozyme-catalyzed oxidative phosphorylation. The microcapsules were assembled through layer-by-layer deposition of semiconducting graphitic carbon nitride (g-C3N4) nanosheets and polyelectrolytes. It is found that electrons from polyelectrolytes are transferred to g-C3N4 nanosheets, which enhances the separation of photogenerated electron-hole pairs. Thus, the encapsulated g-C3N4 nanosheets as the photozyme accelerate oxidation of glucose into gluconic acid to yield protons under light illumination. The outward transmembrane proton gradient is established to drive ATP synthase to synthesize adenosine triphosphate. With such an assembled system, light-driven oxidative phosphorylation is achieved. This indicates that an assembled photozyme can be used for oxidative phosphorylation, which creates an unusual way for chemical-to-biological energy conversion. Compared to conventional oxidative phosphorylation systems, such an artificial design enables higher energy conversion efficiency.

Potential targets and applications of nanodrug targeting myeloid cells in osteosarcoma for the enhancement of immunotherapy

Targeted immunotherapies have emerged as a transformative approach in cancer treatment, offering enhanced specificity to tumor cells, and minimizing damage to healthy tissues. The targeted treatment of the tumor immune system has become clinically applicable, demonstrating significant anti-tumor activity in both early and late-stage malignancies, subsequently enhancing long-term survival rates. The most frequent and significant targeted therapies for the tumor immune system are executed through the utilization of checkpoint inhibitor antibodies and chimeric antigen receptor T cell treatment. However, when using immunotherapeutic drugs or combined treatments for solid tumors like osteosarcoma, challenges arise due to limited efficacy or the induction of severe cytotoxicity. Utilizing nanoparticle drug delivery systems to target tumor-associated macrophages and bone marrow-derived suppressor cells is a promising and attractive immunotherapeutic approach. This is because these bone marrow cells often exert immunosuppressive effects in the tumor microenvironment, promoting tumor progression, metastasis, and the development of drug resistance. Moreover, given the propensity of myeloid cells to engulf nanoparticles and microparticles, they are logical therapeutic targets. Therefore, we have discussed the mechanisms of nanomedicine-based enhancement of immune therapy through targeting myeloid cells in osteosarcoma, and how the related therapeutic strategies well adapt to immunotherapy from perspectives such as promoting immunogenic cell death with nanoparticles, regulating the proportion of various cellular subgroups in tumor-associated macrophages, interaction with myeloid cell receptor ligands, activating immunostimulatory signaling pathways, altering myeloid cell epigenetics, and modulating the intensity of immunostimulation. We also explored the clinical implementations of immunotherapy grounded on nanomedicine.

Immunotherapy: cancer immunotherapy and its combination with nanomaterials and other therapies

Immunotherapy is a new type of tumor treatment after surgery, radiotherapy and chemotherapy, and can be used to manage and destroy tumor cells through activating or strengthening the immune response. Immunotherapy has the benefits of a low recurrence rate and high specificity compared to traditional treatment methods. Immunotherapy has developed rapidly in recent years and has become a research hotspot. Currently, chimeric antigen receptor T-cell immunotherapy and immune checkpoint inhibitors are the most effective tumor immunotherapies in clinical practice. While tumor immunotherapy brings hope to patients, it also faces some challenges and still requires continuous research and progress. Combination therapy is the future direction of anti-tumor treatment. In this review, the main focus is on an overview of the research progress of immune checkpoint inhibitors, cellular therapies, tumor vaccines, small molecule inhibitors and oncolytic virotherapy in tumor treatment, as well as the combination of immunotherapy with other treatments.