Emerging Nano-/Microapproaches for Cancer Immunotherapy

End Group Dye-labeled Polycarbonate Block Copolymers for Micellar (immuno-)Drug Delivery

Defined conjugation of functional molecules to block copolymer end groups is a powerful strategy to enhance the scope of micellar carriers for drug delivery. In this study, we have established an approach to access well-defined polycarbonate-based block copolymers by labeling their end groups with single fluorescent dye molecules. Following controlled polymerization conditions, the block copolymers' primary hydroxy end group can be converted into activated pentafluorophenyl ester carbonates and subsequently aminolyzed with fluorescent dyes that are equipped with primary amines. During a solvent evaporation process, the resulting end group dye-labeled block copolymers self-assemble into narrowly dispersed 26 nm sized micelles and simultaneously encapsulate hydrophobic (immuno-)drugs. The covalently attached fluorescent tracer can be used to monitor both uptake into cells and stability under biologically relevant conditions, including incubation with blood plasma or during blood circulation in zebrafish embryos. By encapsulation of the TLR7/8 agonist CL075, immune stimulatory polymeric micelles are generated that get internalized by various antigen presenting dendritic cells and promote their maturation. Generally, such end group dye-labeled polycarbonate block copolymers display ideal features to permit targeted delivery of hydrophobic drugs to key immune cells for vaccination and cancer immunotherapy. This article is protected by copyright. All rights reserved.

Peptidic microarchitecture-trapped tumor vaccine combined with immune checkpoint inhibitor or PI3Kγ inhibitor can enhance immunogenicity and eradicate tumors

Background

With the rapid development of immune checkpoint inhibitors and neoantigen (NeoV)-based personalized tumor vaccines, tumor immunotherapy has shown promising therapeutic results. However, the limited efficacy of available tumor vaccines impedes the development of personalized tumor immunotherapy. In this study, we developed a novel tumor vaccine system and proposed combined therapeutic strategies for improving treatment effects.

Methods

We developed a novel tumor vaccine system comprising a newly synthesized peptidic microarchitecture (PMA) with high assembly efficacy. The PMA-trapped neoantigen vaccine was developed to codeliver tumor neoantigen and the Toll-like receptor 9 agonist CpG (NeoV), abbreviated as PMA-NeoV. A microfluidic chip was used to produce PMA particles in a uniform and precise manner. Vaccine effectiveness was investigated both in vitro and in vivo. The combined immunotherapeutic effect of PMA-NeoV with anti-programmed cell death ligand 1 antibody (aPD-L1) or with the phosphatidylinositol 3‑kinase γ (PI3Kγ) inhibitor IPI-549 was further tested in MC38 mouse tumor model.

Results

PMA-NeoV not only promoted codelivery of the tumor vaccine but also potentiated vaccine immunogenicity. Moreover, compared with free NeoV, PMA-NeoV significantly increased the number of tumor-infiltrating lymphocytes, promoted the neoantigen-specific systemic immune response, and suppressed murine colon MC38 tumor growth. Furthermore, PMA-NeoV increased the expression of programmed cell death receptor-1 on T lymphocytes, and in combination with aPD-L1 eradicated seven of eight MC38 tumors by rescuing exhausted T lymphocytes. Moreover, we combined the PMA-NeoV with the IPI-549, a molecular switch that controls immune suppression, and found that this combination significantly suppressed tumor growth and eradicated five of eight inoculated tumors, by switching suppressive macrophages to their active state and activating T cells to prime a robust tumor immune microenvironment.

Conclusions

We developed a tumor vaccine delivery system and presented a promising personalized tumor vaccine-based therapeutic regimen in which a tumor vaccine delivery system is combined with an aPD-L1 or PI3Kγ inhibitor to improve tumor immunotherapy outcomes.

Nano-immunotherapeutics: targeting approach as strategic regulation at tumor microenvironment for cancer treatment

Cancer is the leading cause of mortality worldwide, which necessitates our consideration related to novel treatment approach. Tumor cells at the tumor microenvironment (TME), regulate a plethora of key mechanistic signaling pathways that obstruct antitumor immune responses by immune suppression, immune resistance or acquired immune tolerance. The present therapeutic regimes are provided independently or in combination, or as immunotherapies for cancer immune targeting. Immunotherapy has altered the arena of oncology and patient care. By using the host immune system, the immunostimulatory molecules can exert a robust, personalized response against the patient’s own tumors. Alternatively, tumors may exploit these strategies to escape immune recognition, and accordingly, such mechanisms represent chances for immunotherapy intervention. Nonetheless, despite promising outcomes from immunotherapies in recurrent and metastatic cancers, immune-therapeutics in clinics has been limited owing to unpredictability in the produced immune response and reported instances of immune-related adverse effects. The unrealized potential of immunotherapies in cancer management maybe due to the obstacles such as heterogeneous nature, multiple targets, patients’ immune response, specificity for cancer or variability in response generation in toxicity levels, delivery and cost related to therapeutics etc. Further revolutionary trends related to immunotherapies are noticeable with slower progress for cancer management. Recent advances in nanomedicine strategize to ameliorate the lacuna of immunotherapy as it relies on the inherent biophysical characteristics of nanocarriers: size, shape, surface charge and multifunctionality and exploiting them as first line therapy for delivery of biomolecules, single checkpoint inhibitors and for imaging of TME. Therefore, nano-assisted immunotherapies can boost the immunotherapeutic approach, overcoming factors that are with imminent potential risks related to it, thereby significantly improving the survival rate associated with it in cancer patients. Nanotechnology is anticipated to overcome the confines of existing cancer immunotherapy and to successfully combine various cancer treatment modes.

Nanomaterial Technology and Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is a malignant breast cancer subtype that is prone to progression, with high associated metastasis and five-year mortality rates and an overall poor prognosis. Chemotherapy is usually administered to treat TNBC without additional targeted therapies. Novel nanomaterials have a variety of excellent physical and chemical properties and biological functions (including targeting specificity), and contrast agents and drug delivery vectors based on nanotechnology are progressing towards a more accurate and targeted direction. This review discusses the mechanisms of action and prospects for the use of nanotechnology in the treatment of TNBC, thus providing potential new strategies for the diagnosis and treatment of TNBC.

Doxorubicin-Loaded Metal-Organic Framework Nanoparticles as Acid-Activatable Hydroxyl Radical Nanogenerators for Enhanced Chemo/Chemodynamic Synergistic Therapy

Doxorubicin (DOX) is a widely used first-line antitumor agent; however, acquired drug resistance and side effects have become the main challenges to effective cancer therapy. Herein, DOX is loaded into iron-rich metal–organic framework/tannic acid (TA) nanocomplex to form a tumor-targeting and acid-activatable drug delivery system (MOF/TA-DOX, MTD). Under the acidic tumor microenvironment, MTD simultaneously releases DOX and ferrous ion (Fe²⁺) accompanied by degradation. Apart from the chemotherapeutic effect, DOX elevates the intracellular H₂O₂ levels through cascade reactions, which will be beneficial to the Fenton reaction between the Fe²⁺ and H₂O₂, to persistently produce hydroxyl radicals (•OH). Thus, MTD efficiently mediates chemodynamic therapy (CDT) and remarkably enhances the sensitivity of chemotherapy. More encouragingly, the cancer cell killing efficiency of MTD is up to ~86% even at the ultralow equivalent concentration of DOX (2.26 µg/mL), while the viability of normal cells remained >88% at the same concentration of MTD. Taken together, MTD is expected to serve as drug-delivery nanoplatforms and •OH nanogenerators for improving chemo/chemodynamic synergistic therapy and reducing the toxic side effects.

Cooperating minimalist nanovaccine with PD-1 blockade for effective and feasible cancer immunotherapy

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Facile antigen/adjuvant co-loaded nanovaccine made by convenient green preparation.

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The immunological activity of the antigen and adjuvant was maximally preserved.

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The minimalist nanovaccine had excellent stability and antitumor immune activation.

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Nanovaccine combined with PD-1 antibody synergistically enhanced therapy outcome.

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Good practicability for expanding clinical translation and personalized therapy.

Introduction

Tumor vaccine has been a research boom for cancer immunotherapy, while its therapeutic outcome is severely depressed by the vulnerable in vivo delivery efficiency. Moreover, tumor immune escape is also another intractable issue, which has badly whittled down the therapeutic efficiency.

Objectives

Our study aims to solve the above dilemmas by cooperating minimalist nanovaccine with PD-1 blockade for effective and feasible cancer immunotherapy.

Methods

The minimalist antigen and adjuvant co-delivery nanovaccine was developed by employing natural polycationic protamine (PRT) to carry the electronegative ovalbumin (OVA) antigen and unmethylated Cytosine-phosphorothioate-Guanine (CpG) adjuvant via convenient chemical bench-free “green” preparation without chemical-synthesis and no organic solvent was required, which could preserve the immunological activities of the antigens and adjuvants. On that basis, PD-1 antibody (aPD-1) was utilized to block the tumor immune escape and cooperate with the nanovaccine by maintaining the tumoricidal-activity of the vaccine-induced T cells.

Results

Benefited from the polycationic PRT, the facile PRT/CpG/OVA nanovaccine displayed satisfactory delivery performance, involving enhanced cellular uptake in dendritic cells (DCs), realizable endosomal escape and promoted stimulation for DCs’ maturation. These features would be helpful for the antitumor immunotherapeutic efficiency of the nanovaccine. Furthermore, the cooperation of the nanovaccine with aPD-1 synergistically improved the immunotherapy outcome, profiting by the cooperation of the “T cell induction” competency of the nanovaccine and the “T cell maintenance” function of the aPD-1.

Conclusion

This study will provide new concepts for the design and construction of facile nanovaccines, and contribute valuable scientific basis for cancer immunotherapy.

Bioinspired and Biomimetic Delivery Platforms for Cancer Vaccines

Cancer vaccines aim at eliciting tumor-specific responses for the immune system to identify and eradicate malignant tumor cells while sparing the normal tissues. Furthermore, cancer vaccines can potentially induce long-term immunological memory for antitumor responses, preventing metastasis and cancer recurrence, thus presenting an attractive treatment option in cancer immunotherapy. However, clinical efficacy of cancer vaccines has remained low due to longstanding challenges, such as poor immunogenicity, immunosuppressive tumor microenvironment, tumor heterogeneity, inappropriate immune tolerance, and systemic toxicity. Recently, bioinspired materials and biomimetic technologies have emerged to play a part in reshaping the field of cancer nanomedicine. By mimicking desirable chemical and biological properties in nature, bioinspired engineering of cancer vaccine delivery platforms can effectively transport therapeutic cargos to tumor sites, amplify antigen and adjuvant bioactivities, and enable spatiotemporal control and on-demand immunoactivation. As such, integration of biomimetic designs into delivery platforms for cancer vaccines can enhance efficacy while retaining good safety profiles, which contributes to expediting the clinical translation of cancer vaccines. Recent advances in bioinspired delivery platforms for cancer vaccines, existing obstacles faced, as well as insights and future directions for the field are discussed here.

Emerging Nanoparticle Strategies for Modulating Tumor-Associated Macrophage Polarization

Immunotherapy has made great progress in recent years, yet the efficacy of solid tumors remains far less than expected. One of the main hurdles is to overcome the immune-suppressive tumor microenvironment (TME). Among all cells in TME, tumor-associated macrophages (TAMs) play pivotal roles because of their abundance, multifaceted interactions to adaptive and host immune systems, as well as their context-dependent plasticity. Underlying the highly plastic characteristic, lots of research interests are focused on repolarizing TAMs from M2-like pro-tumor phenotype towards M1-like antitumoral ones. Nanotechnology offers great opportunities for targeting and modulating TAM polarization to mount the therapeutic efficacy in cancer immunotherapy. Here, this mini-review highlights those emerging nano-approaches for TAM repolarization in the last three years.

Improving the ability of CAR-T cells to hit solid tumors: Challenges and strategies

Chimeric antigen receptor T cell (CAR-T) therapy is a late-model of immune cell therapy that has been shown to be effective in refractory/recurrent B-cell leukemia and lymphoma. Compared with the traditional anti-tumor methods, CAR-T cell therapy has the advantages of higher specificity, stronger lethality and longer-lasting efficacy. Although CAR-T cells have made significant progress in the treatment of hematologic malignancies, diverse difficulties remain in the treatment of solid tumors, including immune escape due to tumor antigen heterogeneity, preventing entry or limiting the persistence of CAR-T cells by physical or cytokine barriers and along with other immunosuppressive molecule and cells in the tumor microenvironment (TME). Otherwise, the intracellular signaling of CAR also impact on CAR-T cells persistence. Appropriate modification of intracellular costimulatory molecular signal in the structure of CAR or coexpression of CAR and cytokines can provide a way to enhance CAR-T cells activity. Additionally, CAR-T cells dysfunction due to T cell exhaustion is associated with multi-factors, especially transcription factors, such as c-Jun, NR4A. Engineering CAR-T cells to coexpress or knockout transcription factors in favor of T_CM memory CAR-T cells differentiation was proved to prolonged the survival of CAR-T cells. Finally, combination of CAR-T cells with oncolytic viruses, nanoparticles or immune checkpoint inhibitors provides an effective measure to improve CAR-T cells function. Here, we discuss all of these advances and challenges and review promising strategies for treating solid tumors. In particular, we also highlight that CAR-T cells have enormous potential to be used in combination with other immunotherapies.

Position-Scanning Peptide Libraries as Particle Immunogens for Improving CD8+ T-Cell Responses

Short peptides reflecting major histocompatibility complex (MHC) class I (MHC-I) epitopes frequently lack sufficient immunogenicity to induce robust antigen (Ag)-specific CD8+ T cell responses. In the current work, it is demonstrated that position-scanning peptide libraries themselves can serve as improved immunogens, inducing Ag-specific CD8+ T cells with greater frequency and function than the wild-type epitope. The approach involves displaying the entire position-scanning library onto immunogenic nanoliposomes. Each library contains the MHC-I epitope with a single randomized position. When a recently identified MHC-I epitope in the glycoprotein gp70 envelope protein of murine leukemia virus (MuLV) is assessed, only one of the eight positional libraries tested, randomized at amino acid position 5 (Pos5), shows enhanced induction of Ag-specific CD8+ T cells. A second MHC-I epitope from gp70 is assessed in the same manner and shows, in contrast, multiple positional libraries (Pos1, Pos3, Pos5, and Pos8) as well as the library mixture give rise to enhanced CD8+ T cell responses. The library mixture Pos1-3-5-8 induces a more diverse epitope-specific T-cell repertoire with superior antitumor efficacy compared to an established single mutation mimotope (AH1-A5). These data show that positional peptide libraries can serve as immunogens for improving CD8+ T-cell responses against endogenously expressed MHC-I epitopes.

Systematic Combination of Oligonucleotides and Synthetic Polymers for Advanced Therapeutic Applications

The potential of oligonucleotides is exceptional in therapeutics because of their high safety, potency, and specificity compared to conventional therapeutic agents. However, many obstacles, such as low in vivo stability and poor cellular uptake, have hampered their clinical success. Use of polymeric carriers can be an effective approach for overcoming the biological barriers and thereby maximizing the therapeutic efficacy of the oligonucleotides due to the availability of highly tunable synthesis and functional modification of various polymers. As loaded in the polymeric carriers, the therapeutic oligonucleotides, such as antisense oligonucleotides, small interfering RNAs, microRNAs, and even messenger RNAs, become nuclease-resistant by bypassing renal filtration and can be efficiently internalized into disease cells. In this review, we introduced a variety of systematic combinations between the therapeutic oligonucleotides and the synthetic polymers, including the uses of highly functionalized polymers responding to a wide range of endogenous and exogenous stimuli for spatiotemporal control of oligonucleotide release. We also presented intriguing characteristics of oligonucleotides suitable for targeted therapy and immunotherapy, which can be fully supported by versatile polymeric carriers.

Cancer nanotechnology: current status and perspectives

Modern medicine has been waging a war on cancer for nearly a century with no tangible end in sight. Cancer treatments have significantly progressed, but the need to increase specificity and decrease systemic toxicities remains. Early diagnosis holds a key to improving prognostic outlook and patient quality of life, and diagnostic tools are on the cusp of a technological revolution. Nanotechnology has steadily expanded into the reaches of cancer chemotherapy, radiotherapy, diagnostics, and imaging, demonstrating the capacity to augment each and advance patient care. Nanomaterials provide an abundance of versatility, functionality, and applications to engineer specifically targeted cancer medicine, accurate early-detection devices, robust imaging modalities, and enhanced radiotherapy adjuvants. This review provides insights into the current clinical and pre-clinical nanotechnological applications for cancer drug therapy, diagnostics, imaging, and radiation therapy.

Responsive Dual-Targeting Exosome as a Drug Carrier for Combination Cancer Immunotherapy

Recently, combination immunotherapy, which incorporates the activation of the immune system and inhibition of immune escape, has been proved to be a new powerful strategy for more efficient tumor suppression compared to monotherapy. However, the major challenge is how to integrate multiple immune drugs together and efficiently convey these drugs to tumor sites. Although a variety of nanomaterials have been exploited as carriers for targeting tumor issues and the delivery of multiple drugs, their potential toxicity, immune rejection, and stability are still controversial for clinical application. Here, we proposed endogenic exosomes as drug carriers to deliver two antibodies acting as tumor-targeting molecules and block checkpoint inhibitors with specific response to the tumor microenvironment and costimulatory molecules for further improvement of therapeutic effect. The versatile exosomes exhibit excellent biocompatibility and provide a combination immunotherapy platform with synergistic advantages of activation of immune response and inhibition of immune escape.

Emerging strategies based on nanomaterials for ionizing radiation-optimized drug treatment of cancer

Drug-radiotherapy is a common and effective combinational treatment for cancer. This study aimed to explore the ionizing radiation-optimized drug treatment based on nanomaterials so as to improve the synergistic efficacy of drug-radiotherapy against cancer and limit the adverse effect on healthy organs. In this review, these emerging strategies were divided into four parts. First, the delivery of the drug-loaded nanoparticles was optimized owing to the strengthened passive targeting process, active targeting process, and cell targeting process of nanoparticles after ionizing radiation exposure. Second, nanomaterials were designed to respond to the ionizing radiation, thus leading to the release of the loading drugs controllably. Third, radiation-activated pro-drugs were loaded onto nanoparticles for radiation-triggered drug therapy. In particular, nontoxic nanoparticles with radiosensitization capability and innocuous radio-dynamic contrast agents can be considered as radiation-activated drugs, which were discussed in this review. Fourth, according to the various synergetic mechanisms, radiotherapy could improve the drug response of cancer, obtaining optimized drug-radiotherapy. Finally, relative suggestions were provided to further optimize these aforementioned strategies. Therefore, a novel topic was selected and the emerging strategies in this region were discussed, aiming to stimulate the inspiration for the development of ionizing radiation-optimized drug treatment based on nanomaterials.

Nanomedicine-based cancer immunotherapy: recent trends and future perspectives

The combination of cancer immunotherapy with efficient functionalized nanosystems has emerged as a beneficial treatment strategy and its use has increased rapidly. The roles of stimuli-responsive nanosystems and nanomedicine-based cancer immunotherapy, a subsidiary discipline in the field of immunology, are pivotal. The present era is witnessing rapid advancements in the use of nanomedicine as a platform for investigating novel therapeutic applications and modern intelligent healthcare management strategies. The development of cancer nanomedicine has posthaste ratified the outcomes of immunotherapy to the subsequent stage in the current era of medical research. This review focuses on key findings with respect to the effectiveness of nanomedicine-based cancer immunotherapies and their applications, which include i) immune checkpoint inhibitors and nanomedicine, ii) CRISPR-Cas nanoparticles (NPs) in cancer immunotherapy, iii) combination cancer immunotherapy with core-shell nanoparticles, iv) biomimetic NPs for cancer immunotherapy, and v) CAR-T cells and cancer nanoimmunotherapy. By evaluating the state-of-the-art tools and taking the challenges involved into consideration, various aspects of the proposed nano-enabled therapeutic approaches have been discussed in this review.

Nanotechnology for Boosting Cancer Immunotherapy and Remodeling Tumor Microenvironment: The Horizons in Cancer Treatment

Immunotherapy that harnesses the human immune system to fight cancer has received widespread attention and become a mainstream strategy for cancer treatment. Cancer immunotherapy not only eliminates primary tumors but also treats metastasis and recurrence, representing a major advantage over traditional cancer treatments. Recently with the development of nanotechnology, there exists much work applying nanomaterials to cancer immunotherapy on the basis of their excellent physiochemical properties, such as efficient tissue-specific delivery function, huge specific surface area, and controllable surface chemistry. Consequently, nanotechnology holds significant potential in improving the efficacy of cancer immunotherapy. Nanotechnology-based immunotherapy mainly manifests its inhibitory effect on tumors via two different approaches: one is to produce an effective anti-tumor immune response during tumorigenesis, and the other is to enhance tumor immune defense ability by modulating the immune suppression mechanism in the tumor microenvironment. With the success of tumor immunotherapy, understanding the interaction between the immune system and smart nanomedicine has provided vigorous vitality for the development of cancer treatment. This review highlights the application, progress, and prospect of nanomedicine in the process of tumor immunoediting and also discusses several engineering methods to improve the efficiency of tumor treatment.

Reinforcing the Combinational Immuno-Oncotherapy of Switching "Cold" Tumor to "Hot" by Responsive Penetrating Nanogels

Although immuno-oncotherapy in clinic has gained great success, the immunosuppressive tumor microenvironment (TME) existing in the "cold" tumor with insufficient and exhausted lymphocytes may result in a lower-than-expected therapeutic efficiency. Therefore, a properly designed synergistic strategy that can effectively turn the "cold" tumor to "hot" should be considered to improve the therapeutic effects of immuno-oncotherapy. Herein, TME-responsive penetrating nanogels (NGs) were developed, which can improve the delivery and penetration of the co-loaded resiquimod (R848) and green tea catechin (EGCG) in tumors by a nano-sized controlled releasing system of the soluble cyclodextrin-drug inclusion complex. Consequently, the NGs effectively promoted the maturation of dendritic cells, stimulated the cytotoxic T lymphocytes (CTLs), and decreased the PD-L1 expression in tumors. The combination of NGs with the OX40 agonist (αOX40) further synergistically enhanced the activation and infiltration of CTLs into the deep tumor and inhibited the suppression effects from the regulatory T cells (Tregs). As a result, an increased ratio of active CTLs to Tregs in tumors (20.66-fold) was achieved with a 91.56% tumor suppression effect, indicating a successful switch of "cold" tumors to "hot" for an immunologically beneficial TME with significantly improved anti-tumor immune therapeutics. This strategy could be tailored to other immuno-oncotherapeutic approaches to solve the urgent efficiency concerns of the checkpoint-based treatment in clinic.

Detachable Liposomes Combined Immunochemotherapy for Enhanced Triple-Negative Breast Cancer Treatment through Reprogramming of Tumor-Associated Macrophages

Triple-negative breast cancer (TNBC) is an aggressive disease with a high recurrence rate and poor outcomes in clinic. In this study, inspired by the enriched innate immune cell type tumor-associated macrophages (TAMs) in TNBC, we proposed a matrix metalloprotease 2 (MMP2) responsive integrated immunochemotherapeutic strategy to deliver paclitaxel (PTX) and anti-CD47 (aCD47) by detachable immune liposomes (ILips). In the TNBC microenvironment, the "two-in-one" ILips facilitated MMP2-responsive release of aCD47 to efficiently polarize M2 macrophages toward the M1 phenotype to enhance phagocytosis against tumor cells and activate the systemic T cell immune response. Together with the immune effect, the detached PTX-loaded liposomes were internalized in MDA-MB-231 cells to synergistically inhibit tumor cell proliferation and metastasis. In the TNBC-bearing mouse model, PTX-loaded ILips demonstrated superior antitumor efficacy against TNBC and inhibited tumor recurrence. Our integrated strategy represents a promising approach to synchronously enhance immune response and tumor-killing effects, improving the therapeutic efficacy against TNBC.

Dendritic Cell-Based Immunotherapies and their Potential use in Colorectal Cancer Immunotherapy

Dendritic cells (DCs) are professional antigen-presenting cells, which are resident or proliferating in organs. Major histocompatibility complex (MHC) Class I and II on DCs in normal steady conditions process and present antigens including cancer antigens. Many approaches are used to enhance antigen presentation process of DCs and capture cancer cells. DCs are harvested from cancer patients and manipulated ex vivo in DC-based cancer immunotherapy. In addition, DCs' vaccines and other anticancer therapy combinations were discussed to optimize DCs' efficiency for cancer immunotherapy. This review addressed the use of the human conventional type-1 DCs, OX40⁺ plasmacytoid DCs, and DCs-derived exosomes. In addition, different combinations with DCs therapy such as combination with the monoclonal antibody, cytokine-induced killer cells, adjuvants, chemotherapy (DCs-based chemoimmunotherapy), and nanoparticles were listed and explored for their effectiveness against cancer, and mainly against colorectal cancer.

Programmable Unlocking Nano-Matryoshka-CRISPR Precisely Reverses Immunosuppression to Unleash Cascade Amplified Adaptive Immune Response

Immune checkpoint blockade (ICB) is an attractive option in cancer therapy, but its efficacy is still less than expected due to the transient and incomplete blocking and the low responsiveness. Herein, an unprecedented programmable unlocking nano-matryoshka-CRISPR system (PUN) targeting programmed cell death ligand 1 (PD-L1) and protein tyrosine phosphatase N2 (PTPN2) is fabricated for permanent and complete and highly responsive immunotherapy. While PUN is inert at normal physiological conditions, enzyme-abundant tumor microenvironment and preternatural intracellular oxidative stress sequentially trigger programmable unlocking of PUN to realize a nano-matryoshka-like release of CRISPR/Cas9. The successful nucleus localization of CRISPR/Cas9 ensures the highly efficient disruption of PD-L1 and PTPN2 to unleash cascade amplified adaptive immune response via revoking the immune checkpoint effect. PD-L1 downregulation in tumor cells not only disrupts PD-1/PD-L1 interaction to attenuate the immunosurveillance evasion but also spurs potent immune T cell responses to enhance adaptive immunity. Synchronously, inhibition of JAK/STAT pathway is relieved by deleting PTPN2, which promotes tumor susceptibility to CD8+ T cells depending on IFN-γ, thus further amplifying adaptive immune responses. Combining these advances together, PUN exhibits optimal antitumor efficiency and long-term immune memory with negligible toxicity, which provides a promising alternative to current ICB therapy.

Genetic Alterations in Gliomas Remodel the Tumor Immune Microenvironment and Impact Immune-Mediated Therapies

High grade gliomas are malignant brain tumors that arise in the central nervous system, in patients of all ages. Currently, the standard of care, entailing surgery and chemo radiation, exhibits a survival rate of 14-17 months. Thus, there is an urgent need to develop new therapeutic strategies for these malignant brain tumors. Currently, immunotherapies represent an appealing approach to treat malignant gliomas, as the pre-clinical data has been encouraging. However, the translation of the discoveries from the bench to the bedside has not been as successful as with other types of cancer, and no long-lasting clinical benefits have been observed for glioma patients treated with immune-mediated therapies so far. This review aims to discuss our current knowledge about gliomas, their molecular particularities and the impact on the tumor immune microenvironment. Also, we discuss several murine models used to study these therapies pre-clinically and how the model selection can impact the outcomes of the approaches to be tested. Finally, we present different immunotherapy strategies being employed in clinical trials for glioma and the newest developments intended to harness the immune system against these incurable brain tumors.

Targeting the tumor microenvironment with amphiphilic near-infrared cyanine nanoparticles for potentiated photothermal immunotherapy

Despite the potential of photothermal therapy (PTT) for cancer treatments, PTT alone has limitations in treating metastatic tumors and preventing tumor recurrence, highlighting the need to combine PTT with immunotherapy. This study reports tumor microenvironment (TME)-targeting, near-infrared (NIR) dye derivative-based nanomedicine for effective combined PTT-immunotherapy. Amphiphilic NIR dye cyanine derivatives are used not only for constructing the nanoparticle mass, but also for creating a stable complex with CpG adjuvant; a peptide specific to fibronectin extra domain B (APT_EDB) is also introduced as a TME-targeting ligand, yielding the TME-targeting nanomedicine, APT_EDB-cyNP@CpG. APT_EDB-cyNP@CpG shows cancer-targeting ability in EDB-overexpressing CT26 colon tumor-bearing mice. When combined with laser irradiation, it induces immunogenic cell death (ICD) and subsequently leads to significant increase in CD8⁺ T cell population in the tumor, resulting in greater antitumor therapeutic efficacy than does cyNP@CpG lacking the TME-targeting ligand. Moreover, the combination of APT_EDB-cyNP@CpG-based PTT and an immune checkpoint blockade (ICB) antibody leads to remarkable antitumor efficacy against the laser-irradiated primary tumor as well as distant tumor through potentiation of systemic cancer cell-specific T cell immunity. Furthermore, the PTT-immunotherapy combination regimen is highly effective in inhibiting tumor recurrence and metastasis.

Nanotechnology: Breaking the Current Treatment Limits of Lung Cancer

Lung cancer is one of the most rapidly growing malignancies in terms of morbidity and mortality. Although traditional treatments have been used for more than 50 years, it is still far from solving the problems of postoperative risks and systemic toxicity. Emerging targeting and immunotherapy are developing continuously and are gaining recognition; eventually, they face the inevitable challenge of drug resistance. Nanotechnology has several important effects on lung cancer treatment, owing to its unique properties. Several nanoparticle-based treatments have successfully become cancer treatments. Good biocompatibility with higher specific surface area can carry substantial amounts of lung cancer treatment medications while avoiding medication toxicity; editable and modified characteristics give rise to multifunctional nanomedicines; excellent photoelectric effects make lung cancer a multimodal treatment. This article summarizes the breakthroughs achieved by nanotechnology, targeted therapy, and immunotherapy, reflecting the importance and necessity of nanotechnology in the treatment of lung cancer.

Low-Temperature Photothermal Therapy: Strategies and Applications

Although photothermal therapy (PTT) with the assistance of nanotechnology has been considered as an indispensable strategy in the biomedical field, it still encounters some severe problems that need to be solved. Excessive heat can induce treated cells to develop thermal resistance, and thus, the efficacy of PTT may be dramatically decreased. In the meantime, the uncontrollable diffusion of heat can pose a threat to the surrounding healthy tissues. Recently, low-temperature PTT (also known as mild PTT or mild-temperature PTT) has demonstrated its remarkable capacity of conquering these obstacles and has shown excellent performance in bacterial elimination, wound healing, and cancer treatments. Herein, we summarize the recently proposed strategies for achieving low-temperature PTT based on nanomaterials and introduce the synthesis, characteristics, and applications of these nanoplatforms. Additionally, the combination of PTT and other therapeutic modalities for defeating cancers and the synergistic cancer therapeutic effect of the combined treatments are discussed. Finally, the current limitations and future directions are proposed for inspiring more researchers to make contributions to promoting low-temperature PTT toward more successful preclinical and clinical disease treatments.

Engineering Nano-Therapeutics to Boost Adoptive Cell Therapy for Cancer Treatment

Although adoptive transfer of therapeutic cells to cancer patients is demonstrated with great success and fortunately approved for the treatment of leukemia and B-cell lymphoma, potential issues, including the unclear mechanism, complicated procedures, unfavorable therapeutic efficacy for solid tumors, and side effects, still hinder its extensive applications. The explosion of nanotechnology recently has led to advanced development of novel strategies to address these challenges, facilitating the design of nano-therapeutics to improve adoptive cell therapy (ACT) for cancer treatment. In this review, the emerging nano-enabled approaches, that design multiscale artificial antigen-presenting cells for cell proliferation and stimulation in vitro, promote the transducing efficiency of tumor-targeting domains, engineer therapeutic cells for in vivo imaging, tumor infiltration, and in vivo functional sustainability, as well as generate tumoricidal T cells in vivo, are summarized. Meanwhile, the current challenges and future perspectives of the nanostrategy-based ACT for cancer treatment are also discussed in the end.

Damaging Tumor Vessels with an Ultrasound-Triggered NO Release Nanosystem to Enhance Drug Accumulation and T Cells Infiltration

INTRODUCTION

Limited by tumor vascular barriers, restricted intratumoural T cell infiltration and nanoparticles accumulation remain major bottlenecks for anticancer therapy. Platelets are now known to maintain tumor vascular integrity. Therefore, inhibition of tumor-associated platelets may be an effective method to increase T cell infiltration and drug accumulation at tumor sites. Herein, we designed an ultrasound-responsive nitric oxide (NO) release nanosystem, SNO-HSA-PTX, which can release NO in response to ultrasound (US) irradiation, thereby inhibiting platelet function and opening the tumor vascular barrier, promoting drug accumulation and T cell infiltration.

METHODS

We evaluated the ability of SNO-HSA-PTX to release NO in response to US irradiation. We also tested the effect of SNO-HSA-PTX on platelet function. Plenty of studies including cytotoxicity, pharmacokinetics study, biodistribution, blood perfusion, T cell infiltration, in vivo antitumor efficacy and safety assessment were conducted to investigate the antitumor effect of SNO-HSA-PTX.

RESULTS

SNO-HSA-PTX with US irradiation inhibited tumor-associated platelets activation and induced openings in the tumor vascular barriers, which promoted the accumulation of SNO-HSA-PTX nanoparticles to the tumor sites. Meanwhile, the damaged vascular barriers allowed oxygen-carrying hemoglobin to infiltrate tumor regions, alleviating hypoxia of the tumor microenvironment. In addition, the intratumoral T cell infiltration was augmented, together with chemotherapy and NO therapy, which greatly inhibited tumor growth.

DISCUSSION

Our research designed a simple strategy to open the vascular barrier by inhibiting the tumor-associated platelets, which provide new ideas for anti-tumor treatment.

Nanoparticles for Enhanced Adoptive T Cell Therapies and Future Perspectives for CNS Tumors

Adoptive T cell therapy has emerged as a revolutionary immunotherapy for treating cancer. Despite immense promise and clinical success in some hematologic malignancies, limitations remain that thwart its efficacy in solid tumors. Particularly in tumors of the central nervous system (CNS), T cell therapy is often restricted by the difficulty in intratumoral delivery across anatomical niches, suboptimal T cell specificity or activation, and intratumoral T cell dysfunction due to immunosuppressive tumor microenvironments (TMEs). Nanoparticles may offer several advantages to overcome these limitations of T cell therapy, as they can be designed to robustly and specifically activate T cells ex vivo prior to adoptive transfer, to encapsulate T cell stimulating agents for co-localized stimulation, and to be conjugated onto T cells for added functionality. This perspective highlights recent preclinical advances in using nanoparticles to enhance T cell therapy, and discusses the potential applicability and constraints of nanoparticle-enhanced T cells as a new platform for treating CNS tumors.

Recent Advancements in Nanomedicine for 'Cold' Tumor Immunotherapy

Although current anticancer immunotherapies using immune checkpoint inhibitors (ICIs) have been reported with a high clinical success rate, numerous patients still bear 'cold' tumors with insufficient T cell infiltration and low immunogenicity, responding poorly to ICI therapy. Considering the advancements in precision medicine, in-depth mechanism studies on the tumor immune microenvironment (TIME) among cold tumors are required to improve the treatment for these patients. Nanomedicine has emerged as a promising drug delivery system in anticancer immunotherapy, activates immune function, modulates the TIME, and has been applied in combination with other anticancer therapeutic strategies. This review initially summarizes the mechanisms underlying immunosuppressive TIME in cold tumors and addresses the recent advancements in nanotechnology for cold TIME reversal-based therapies, as well as a brief talk about the feasibility of clinical translation.

Emerging nanotechnological strategies to reshape tumor microenvironment for enhanced therapeutic outcomes of cancer immunotherapy

Immunotherapy was emerged as a novel cancer treatment in the last decade, however, efficacious responses to mono-immunotherapy have only been achieved in a relatively small portion of patients whereas combinational immunotherapies often lead to concurrent side effects. It has been proved that the tumor microenvironment (TME) is responsible for tumor immune escape and the ultimate treatment failure. Recently, both the understanding of the TME and the applications of nanotechnological strategies have achieved remarkable progresses, and reviewing the emerging immune-regulatory nanosystems may provide valuable information for specifically modulating the TME at different immune stages. In this review, we focus on comprehending the recently proposed T-cell-based tumor classification and identifying the most promising targets for different tumor phenotypes, and then summarizing the nanotechnological strategies to best target corresponding immune-related factors. For future precise personalized immunotherapy, the tailor-made TME modulation strategies conducted by well-designed nanosystems to alleviate the suppressive TME and then promote anti-tumor immune responses will significantly benefit the clinical outcomes of cancer patients.

Intelligent stimuli-responsive nano immunomodulators for cancer immunotherapy

Cancer immunotherapy is a revolutionary treatment method in oncology, which uses a human's own immune system against cancer. Many immunomodulators that trigger an immune response have been developed and applied in cancer immunotherapy. However, there is the risk of causing an excessive immune response upon directly injecting common immunomodulators into the human body to trigger an immune response. Therefore, the development of intelligent stimuli-responsive immunomodulators to elicit controlled immune responses in cancer immunotherapy is of great significance. Nanotechnology offers the possibility of designing smart nanomedicine to amplify the antitumor response in a safe and effective manner. Progress relating to intelligent stimuli-responsive nano immunomodulators for cancer immunotherapy is highlighted as a new creative direction in the field. Considering the clinical demand for cancer immunotherapy, we put forward some suggestions for constructing new intelligent stimuli-responsive nano immunomodulators, which will advance the development of cancer immunotherapy.

Traceable metallic antigen release for enhanced cancer immunotherapy

Tumor vaccine has shown outstanding advantages and good therapeutic effects in tumor immunotherapy. However, antigens in tumor vaccines can be easily cleared by the reticuloendothelium system in advance, which leads to poor therapeutic effect of tumor vaccines. Moreover, it was still hard to monitor the fate and distribution of antigens. To address these limitations, we synthesized a traceable nanovaccine based on gold nanocluster-labeled antigens and upconversion nanoparticles (UCNPs) for the treatment of melanoma in this study. PH-sensitive Schiff base bond is introduced between UCNPs and gold nanocluster-labeled ovalbumin antigens for monitoring antigens release. Our studies demonstrated that UCNPs conjugated metallic antigen showed excellent biocompatibility, pH-sensitive and therapeutic effect.

Sustained and targeted delivery of checkpoint inhibitors by metal-organic frameworks for cancer immunotherapy

The major impediments to the implementation of cancer immunotherapies are the sustained immune effect and the targeted delivery of these therapeutics, as they have life-threatening adverse effects. In this work, biomimetic metal-organic frameworks [zeolitic imidazolate frameworks (ZIFs)] are used for the controlled delivery of nivolumab (NV), a monoclonal antibody checkpoint inhibitor that was U.S. Food and Drug Administration-approved back in 2014. The sustained release behavior of NV-ZIF has shown a higher efficacy than the naked NV to activate T cells in hematological malignancies. The system was further modified by coating NV-ZIF with cancer cell membrane to enable tumor-specific targeted delivery while treating solid tumors. We envisage that such a biocompatible and biodegradable immunotherapeutic delivery system may promote the development and the translation of hybrid superstructures into smart and personalized delivery platforms.

Enhancing Combined Immunotherapy and Radiotherapy through Nanomedicine

Radiotherapy and immunotherapy are two key treatments for cancer. There is growing evidence that they are also synergistic, and combination treatments are being studied extensively in the clinical setting. In addition, there is emerging evidence that nanotechnology-enabled therapeutics can potentiate both radiotherapy and immunotherapy, in turn improving both treatments. This is an exciting new area of interdisciplinary science and has significant potential for major clinical impact. Some of the approaches in this area have already reached the clinical stage. In this review, we will discuss recent advances in the interface between radiotherapy, immunotherapy, and nanomedicine. We plan to review the many approaches to combine these three fields for cancer treatment.

Fluorine assembly nanocluster breaks the shackles of immunosuppression to turn the cold tumor hot

Clinical investigations have shown that a nonimmunogenic "cold" tumor is usually accompanied by few immunopositive cells and more immunosuppressive cells in the tumor microenvironment (TME), which is still the bottleneck of immune activation. Here, a fluorine assembly nanocluster was explored to break the shackles of immunosuppression, reawaken the immune system, and turn the cold tumor "hot." Once under laser irradiation, FS@PMPt produces sufficient reactive oxygen species (ROS) to fracture the ROS-sensitive linker, thus releasing the cisplatin conjugated PMPt to penetrate into the tumors and kill the regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). Meanwhile, ROS will induce potent immunogenic cell death (ICD) and further promote the accumulation of dendritic cells (DCs) and T cells, therefore not only increasing the infiltration of immunopositive cells from the outside but also reducing the immunosuppressive cells from the inside to break through the bottleneck of immune activation. The FS@PMPt nanocluster regulates the immune process in TME from negative to positive, from shallow to deep, to turn the cold tumor into a hot tumor and provoke a robust antitumor immune response.

Fundamentals to clinical application of nanoparticles in cancer immunotherapy and radiotherapy

Cancer immunotherapy has made rapid progress over the past decade leading to high enthusiasm and interest worldwide. Codelivery of immunomodulators with chemotherapeutic agents and radioisotopes has been shown to elicit a strong and sustained immune response in animal models. Despite showing promising results in metastatic and recurrent cancers, the utilisation of immunotherapy in clinical settings has been limited owing to uncertainties in elicited immune response and occurrence of immune-related adverse events. These uncertainties can be overcome with the help of nanoparticles possessing unique properties for the effective delivery of targeted agents to specific sites. Nanoparticles play a crucial role in the effective delivery of cancer antigens and adjuvants, modulation of tumour microenvironment, production of long-term immune response and development of cancer vaccines. Here, we provide a comprehensive summary of nanotechnology-based cancer immunotherapy and radiotherapy including basics of nanotechnology, properties of nanoparticles and various methods of employing nanoparticles in cancer treatment. Thus, nanotechnology is anticipated to overcome the limitations of existing cancer immunotherapy and to effectively combine various cancer treatment modalities.

Synthetic Particles for Cancer Vaccines: Connecting the Inherent Supply Chain

Cancer vaccines have opened a new paradigm for safe and effective antitumor therapy, but they still suffer from shortcomings such as insufficient immunogenicity and immune tolerance, which seldom makes them the first choice in clinic. In fact, similar to providing a high-end product, a robust antitumor effect depends on the inherent supply chain, which attains, processes, and presents tumor-associated antigens via antigen presenting cells to T cells, which then leads to lysis of the cancer cells to release more antigens to complete the supply chain. Under these circumstances, the failure of cancer vaccines can be treated as a blockade or chain rupture. Thus, for effective tumor treatment, the key is to rationally design logistic systems to restore the supply chain.Under these circumstances, this Account summarizes our recent attempts to exploit the immunogenic trait of synthetic particles to enhance the distribution, presentation, and immune activations of the whole priming process in cancer vaccines: (1) Raw material (tumor antigen/signals) procurement: We illustrated the efforts to deliver antigens to antigen presenting cells (APCs) and draining lymph nodes for potent internalizations, and put more emphasis on the structural effect of sizes, charges, shapes, and assembly strategies for the antigen depot, lymph node transfer, and APC endocytosis. (2) Manufacture of cytotoxic T lymphocytes (CTLs) via APC recognition and presentation: We centered on exploiting the softness of two-dimensional graphene and Pickering emulsions to dynamically potentiate the immune recognition, and demonstrating the recent advances in lysosome escape strategies for enhanced antigen cross-presentations. (3) Marketing the accumulations of CTLs and the reversal of an immunosuppressive microenvironment within the tumor: We demonstrated the previous attempts to inherently cultivate the tumor tropism of the T cells via the multiantigenic repertoire and discussed the advances and challenges of combinatory cancer vaccines with an immune checkpoint blockade to reinforce the antitumor efficacy. Collectively, this Account aims to illustrate the potential of the particulate cancer vaccines to recapitalize the inherent host immune responses for the maximum antitumor effect. And by integrating the antitumor supply chain, optimized synthetic particles may shed light on the development of safe and effective particulate cancer vaccines.

Polyanhydride Nanoparticles Induce Low Inflammatory Dendritic Cell Activation Resulting in CD8+ T Cell Memory and Delayed Tumor Progression

Introduction

Adjuvants and immunotherapies designed to activate adaptive immunity to eliminate infectious disease and tumors have become an area of interest aimed at providing a safe and effective strategy to prevent or eliminate disease. Existing approaches would benefit from the development of immunization regimens capable of inducing efficacious cell-mediated immunity directed toward CD8⁺ T cell-specific antigens. This goal is critically dependent upon appropriate activation of antigen-presenting cells (APCs) most notably dendritic cells (DCs). In this regard, polyanhydride particles have been shown to be effectively internalized by APCs and induce activation.

Methods

Here, a prophylactic vaccine regimen designed as a single-dose polyanhydride nanovaccine encapsulating antigen is evaluated for the induction of CD8⁺ T cell memory in a model system where antigen-specific protection is restricted to CD8⁺ T cells. Bone marrow-derived dendritic cells (BMDCs) are used as an in vitro model system to evaluate the magnitude and phenotype of APC activation. Primary DCs, particularly those with described ability to activate CD8⁺ T cells, are also evaluated for their in vitro responses to polyanhydride nanoparticles.

Results

Herein, polyanhydride nanoparticles are shown to induce potent in vitro upregulation of costimulatory molecules on the cell surface of BMDCs. In contrast to the classically used TLR agonists, nanoparticles did not induce large amounts of pro-inflammatory cytokines, did not induce characteristic metabolic response of DCs, nor produce innate antimicrobial effector molecules, such as nitric oxide (NO). The polyanhydride nanovaccine results in protective CD8⁺ T cell responses as measured by inhibition of tumor progression and survival.

Discussion

Together, these results suggest that the use of a polyanhydride-based nanovaccine can be an effective approach to inducing antigen-specific CD8⁺ T cell memory by providing antigen delivery and DC activation while avoiding overt inflammatory responses typically associated with traditional adjuvants.

Nanomedicines based on nanoscale metal-organic frameworks for cancer immunotherapy

Cancer immunotherapy, with an aim to enhance host immune responses, has been recognized as a promising therapeutic treatment for cancer. A diversity of immunomodulatory agents, including tumor-associated antigens, adjuvants, cytokines and immunomodulators, has been explored for their ability to induce a cascading adaptive immune response. Nanoscale metal-organic frameworks (nMOFs), a class of crystalline-shaped nanomaterials formed by the self-assembly of organic ligands and metal nodes, are attractive for cancer immunotherapy because they feature tunable pore size, high surface area and loading capacity, and intrinsic biodegradability. In this review we summarize recent progress in the development of nMOFs for cancer immunotherapy, including cancer vaccine delivery and combination of in situ vaccination with immunomodulators to reverse immune suppression. Current challenges and future perspectives for rational design of nMOF-based cancer immunotherapy are also discussed.

Personalized neoantigen vaccination with synthetic long peptides: recent advances and future perspectives

Therapeutic cancer vaccines are one of the most promising strategies of immunotherapy. Traditional vaccines consisting of tumor-associated antigens have met with limited success. Recently, neoantigens derived from nonsynonymous mutations in tumor cells have emerged as alternatives that can improve tumor-specificity and reduce on-target off-tumor toxicity. Synthetic peptides are a common platform for neoantigen vaccines. It has been suggested that extending short peptides into long peptides can overcome immune tolerance and induce both CD4⁺ and CD8⁺ T cell responses. This review will introduce the history of long peptide-based neoantigen vaccines, discuss their advantages, summarize current preclinical and clinical developments, and propose future perspectives.

Clinical significance of expression of MEG8 and TGM2 genes in gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the common malignant tumors, and its incidence and mortality rates are among the highest in China and even the world, posing an important threat to human health. There is still a lack of early diagnosis, treatment, and prognosis-related gene targets for GC.

AIM

To investigate the expression of maternally expressed gene 8 (MEG8) and transglutaminase-2 (TGM2) in GC and analyze their clinical significance.

METHODS

The expression of MEG8 and TGM2 in 30 pairs of GC and tumor-adjacent tissues was detected by fluorescence quantitative polymerase chain reaction. The correlation between MEG8 and TGM2 expression and clinicopathological features of GC patients was analyzed. The difference of TGM2 expression and its correlation with the survival status of GC patients were analyzed by employing the relevant research data in Oncomine database.

RESULTS

The expression of MEG8 in GC tissues was significantly lower than that in tumor-adjacent tissues (0.462 ± 0.082 vs 1.048 ± 0.149, P < 0.05), and the expression of TGM2 in GC tissues was significantly higher than that in tumor-adjacent tissues (1.202 ± 0.143 vs 0.742 ± 0.083, P < 0.05). The expression of MEG8 was correlated with age and clinical stage, and the expression of TGM2 was correlated with clinical stage (P < 0.05). The expression of TGM2 was not related to the survival status of patients with GC (P > 0.05).

CONCLUSION

MEG8 and TGM2 may be involved in the occurrence and development of GC and can be used as potential targets for the diagnosis and prognosis of GC.

Synergistic anti-tumor efficacy by combination therapy of a self-assembled nanogel vaccine with an immune checkpoint anti-PD-1 antibody

Therapeutic strategies for cancer involving immune checkpoint inhibitors (ICIs) have been gaining widespread attention, but their efficacy remains limited. Thus, combination of ICI therapies with other therapeutic modalities may be required to improve their outcomes. In this study, we examined the improved efficacy of a CHP nanogel-based vaccine delivery system after combination with ICI therapy. For this, we evaluated the therapeutic efficacy of combining an anti-PD-1 antibody as an ICI with an OVA antigen-complexed CHP nanogel vaccine delivery system in a mouse E.G7-OVA tumor model. Mice were subcutaneously inoculated with E.G7-OVA tumor cells on one side of the back, and subcutaneously injected with OVA or the OVA/CHP nanogel vaccine on the other side of the back. Anti-PD-1 antibody was administered at defined intervals. Tumor volume, immune responses, and tumor-infiltrating cells were evaluated. Mice treated with OVA vaccine alone showed weak tumor suppression compared with untreated control mice. Mice receiving combined OVA/CHP nanogel vaccine and anti-PD-1 antibody therapy exhibited strong tumor growth suppression and markedly improved survival, suggesting that PD-1 signaling blockade by the anti-PD-1 antibody enhanced the anti-tumor efficacy of the OVA vaccine. Furthermore, tumor-infiltrating cells and immune responses were increased in the combined therapy group. No serious side effects were observed for any of the treatments. Taken together, the immune system activation induced by the CHP nanogel vaccine was synergistically enhanced by the anti-PD-1 antibody. The present findings suggest the potential for enhanced therapeutic efficacy by combining the CHP nanogel vaccine delivery system with ICI therapy for various cancer types.

Combination therapy of OVA/CHP nanogel vaccine with anti-PD-1 antibody synergistically improved anti-tumor effect and survival rate without side effects.

Nanomedicine and Immunotherapy: A Step Further towards Precision Medicine for Glioblastoma

Owing to the advancement of technology combined with our deeper knowledge of human nature and diseases, we are able to move towards precision medicine, where patients are treated at the individual level in concordance with their genetic profiles. Lately, the integration of nanoparticles in biotechnology and their applications in medicine has allowed us to diagnose and treat disease better and more precisely. As a model disease, we used a grade IV malignant brain tumor (glioblastoma). Significant improvements in diagnosis were achieved with the application of fluorescent nanoparticles for intraoperative magnetic resonance imaging (MRI), allowing for improved tumor cell visibility and increasing the extent of the surgical resection, leading to better patient response. Fluorescent probes can be engineered to be activated through different molecular pathways, which will open the path to individualized glioblastoma diagnosis, monitoring, and treatment. Nanoparticles are also extensively studied as nanovehicles for targeted delivery and more controlled medication release, and some nanomedicines are already in early phases of clinical trials. Moreover, sampling biological fluids will give new insights into glioblastoma pathogenesis due to the presence of extracellular vesicles, circulating tumor cells, and circulating tumor DNA. As current glioblastoma therapy does not provide good quality of life for patients, other approaches such as immunotherapy are explored. To conclude, we reason that development of personalized therapies based on a patient's genetic signature combined with pharmacogenomics and immunogenomic information will significantly change the outcome of glioblastoma patients.

Emerging Prospects for Nanoparticle-Enabled Cancer Immunotherapy

One of the standards for cancer treatment is cancer immunotherapy which treats both primary and metastasized tumors. Although cancer immunotherapeutics show better outcomes as compared with conventional approaches of cancer treatment, the currently used cancer immunotherapeutics have limited application in delivering cancer antigens to immune cells. Conversely, in solid tumors, tumor microenvironment suppresses the immune system leading to the evasion of anticancer immunity. Some promising attempts have been made to overcome these drawbacks by using different approaches, for instance, the use of biomaterial-based nanoparticles. Accordingly, various studies involving the application of nanoparticles in cancer immunotherapy have been discussed in this review article. This review not only describes the modes of cancer immunotherapy to reveal the importance of nanoparticles in this modality but also narrates nanoparticle-mediated delivery of cancer antigens and therapeutic supplements. Moreover, the impact of nanoparticles on the immunosuppressive behavior of tumor environment has been discussed. The last part of this review deals with cancer immunotherapy using a combination of traditional interventional oncology approach and image-guided local immunotherapy against cancer. According to recent studies, cancer therapy can potentially be improved through nanoparticle-based immunotherapy. In addition, drawbacks associated with the currently used cancer immunotherapeutics can be fixed by using nanoparticles.