Localized immunotherapy via liposome-anchored Anti-CD137 + IL-2 prevents lethal toxicity and elicits local and systemic antitumor immunity

Immunological nanomaterials to combat cancer metastasis

Metastasis causes greater than 90% of cancer-associated deaths, presenting huge challenges for detection and efficient treatment of cancer due to its high heterogeneity and widespread dissemination to various organs. Therefore, it is imperative to combat cancer metastasis, which is the key to achieving complete cancer eradication. Immunotherapy as a systemic approach has shown promising potential to combat metastasis. However, current clinical immunotherapies are not effective for all patients or all types of cancer metastases owing to insufficient immune responses. In recent years, immunological nanomaterials with intrinsic immunogenicity or immunomodulatory agents with efficient loading have been shown to enhance immune responses to eliminate metastasis. In this review, we would like to summarize various types of immunological nanomaterials against metastasis. Moreover, this review will summarize a series of immunological nanomaterial-mediated immunotherapy strategies to combat metastasis, including immunogenic cell death, regulation of chemokines and cytokines, improving the immunosuppressive tumour microenvironment, activation of the STING pathway, enhancing cytotoxic natural killer cell activity, enhancing antigen presentation of dendritic cells, and enhancing chimeric antigen receptor T cell therapy. Furthermore, the synergistic anti-metastasis strategies based on the combinational use of immunotherapy and other therapeutic modalities will also be introduced. In addition, the nanomaterial-mediated imaging techniques (e.g., optical imaging, magnetic resonance imaging, computed tomography, photoacoustic imaging, surface-enhanced Raman scattering, radionuclide imaging, etc.) for detecting metastasis and monitoring anti-metastasis efficacy are also summarized. Finally, the current challenges and future prospects of immunological nanomaterial-based anti-metastasis are also elucidated with the intention to accelerate its clinical translation.

A large-scale machine learning analysis of inorganic nanoparticles in preclinical cancer research

Owing to their distinct physical and chemical properties, inorganic nanoparticles (NPs) have shown promising results in preclinical cancer therapy, but designing and engineering them for effective therapeutic purposes remains a challenge. Although a comprehensive database of inorganic NP research is not currently available, it is crucial for developing effective cancer therapies. In this context, machine learning (ML) has emerged as a transformative tool, but its adaptation to nanomedicine is hindered by inexistent or small datasets. Here we assembled a large database of inorganic NPs, comprising experimental datasets from 745 preclinical studies in cancer nanomedicine. Using descriptive statistics and explainable ML models we mined this database to gain knowledge of inorganic NP design patterns and inform future NP research for cancer treatment. Our analyses suggest that NP shape and therapy type are prominent features in determining in vivo efficacy, measured as a percentage of tumour reduction. Moreover, our database provides a large-scale open-access resource for discriminative ML that the broader nanotechnology community can utilize. Our work blueprints data mining for translational cancer research and offers evidence for standardizing NP reporting to accelerate and de-risk inorganic NP-based drug delivery, which may help to improve patient outcomes in clinical settings.

Noncovalently particle-anchored cytokines with prolonged tumor retention safely elicit potent antitumor immunity

Preclinical studies have shown that immunostimulatory cytokines elicit antitumor immune responses but their clinical use is limited by severe immune-related adverse events upon systemic administration. Here, we report a facile and versatile strategy for noncovalently anchoring potent Fc-fused cytokine molecules to the surface of size-discrete particles decorated with Fc-binding peptide for local administration. Following intratumoral injection, particle-anchored Fc cytokines exhibit size-dependent intratumoral retention. The 1-micrometer particle prolongs intratumoral retention of Fc cytokine for over a week and has minimal systemic exposure, thereby eliciting antitumor immunity while eliminating systemic toxicity caused by circulating cytokines. In addition, the combination of these particle-anchored cytokines with immune checkpoint blockade antibodies safely promotes tumor regression in various syngeneic tumor models and genetically engineered murine tumor models and elicits systemic antitumor immunity against tumor rechallenge. Our formulation strategy renders a safe and tumor-agnostic approach that uncouples cytokines' immunostimulatory properties from their systemic toxicities for potential clinical application.

Nanoparticles in tumor microenvironment remodeling and cancer immunotherapy

Cancer immunotherapy and vaccine development have significantly improved the fight against cancers. Despite these advancements, challenges remain, particularly in the clinical delivery of immunomodulatory compounds. The tumor microenvironment (TME), comprising macrophages, fibroblasts, and immune cells, plays a crucial role in immune response modulation. Nanoparticles, engineered to reshape the TME, have shown promising results in enhancing immunotherapy by facilitating targeted delivery and immune modulation. These nanoparticles can suppress fibroblast activation, promote M1 macrophage polarization, aid dendritic cell maturation, and encourage T cell infiltration. Biomimetic nanoparticles further enhance immunotherapy by increasing the internalization of immunomodulatory agents in immune cells such as dendritic cells. Moreover, exosomes, whether naturally secreted by cells in the body or bioengineered, have been explored to regulate the TME and immune-related cells to affect cancer immunotherapy. Stimuli-responsive nanocarriers, activated by pH, redox, and light conditions, exhibit the potential to accelerate immunotherapy. The co-application of nanoparticles with immune checkpoint inhibitors is an emerging strategy to boost anti-tumor immunity. With their ability to induce long-term immunity, nanoarchitectures are promising structures in vaccine development. This review underscores the critical role of nanoparticles in overcoming current challenges and driving the advancement of cancer immunotherapy and TME modification.

Engineering approaches for innate immune-mediated tumor microenvironment remodeling

Cancer immunotherapy offers transformative promise particularly for the treatment of lethal cancers, since a correctly trained immune system can comprehensively orchestrate tumor clearance with no need for continued therapeutic intervention. Historically, the majority of immunotherapies have been T cell-focused and have included immune checkpoint inhibitors, chimeric antigen receptor T cells, and T-cell vaccines. Unfortunately T-cell-focused therapies have failed to achieve optimal efficacy in most solid tumors largely because of a highly immunosuppressed 'cold' or immune-excluded tumor microenvironment (TME). Recently, a rapidly growing treatment paradigm has emerged that focuses on activation of tumor-resident innate antigen-presenting cells, such as dendritic cells and macrophages, which can drive a proinflammatory immune response to remodel the TME from 'cold' or immune-excluded to 'hot'. Early strategies for TME remodeling centered on free cytokines and agonists, but these approaches have faced significant hurdles in both delivery and efficacy. Systemic toxicity from off-target inflammation is a paramount concern in these therapies. To address this critical gap, engineering approaches have provided the opportunity to add 'built-in' capabilities to cytokines, agonists, and other therapeutic agents to mediate improved delivery and efficacy. Such capabilities have included protective encapsulation to shield them from degradation, targeting to direct them with high specificity to tumors, and co-delivery strategies to harness synergistic proinflammatory pathways. Here, we review innate immune-mediated TME remodeling engineering approaches that focus on cytokines, innate immune agonists, immunogenic viruses, and cell-based methods, highlighting emerging preclinical approaches and strategies that are either being tested in clinical trials or already Food and Drug Administration approved.

Locoregional drug delivery for cancer therapy: Preclinical progress and clinical translation

Systemic drug delivery is the current clinically preferred route for cancer therapy. However, challenges associated with tumor localization and off-tumor toxic effects limit the clinical effectiveness of this route. Locoregional drug delivery is an emerging viable alternative to systemic therapies. With the improvement in real-time imaging technologies and tools for direct access to tumor lesions, the clinical applicability of locoregional drug delivery is becoming more prominent. Theoretically, locoregional treatments can bypass challenges faced by systemic drug delivery. Preclinically, locoregional delivery of drugs has demonstrated enhanced therapeutic efficacy with limited off-target effects while still yielding an abscopal effect. Clinically, an array of locoregional strategies is under investigation for the delivery of drugs ranging in target and size. Locoregional tumor treatment strategies can be classified into two main categories: 1) direct drug infusion via injection or implanted port and 2) extended drug elution via injected or implanted depot. The number of studies investigating locoregional drug delivery strategies for cancer treatment is rising exponentially, in both preclinical and clinical settings, with some approaches approved for clinical use. Here, we highlight key preclinical advances and the clinical relevance of such locoregional delivery strategies in the treatment of cancer. Furthermore, we critically analyze 949 clinical trials involving locoregional drug delivery and discuss emerging trends.

Local delivery of cell surface-targeted immunocytokines programs systemic anti-tumor immunity

Cytokine therapies are potent immunotherapy agents but exhibit severe dose-limiting toxicities. One strategy to overcome this involves engineering cytokines for intratumoral retention following local delivery. Here, we develop a localized cytokine therapy that elicits profound anti-tumor immunity by engineered targeting to the ubiquitous leukocyte receptor CD45. We designed CD45-targeted immunocytokines (αCD45-Cyt) that, upon injection, decorated the surface of leukocytes in the tumor and tumor-draining lymph node (TDLN) without systemic exposure. αCD45-Cyt therapy eradicated both directly treated tumors and untreated distal lesions in multiple syngeneic mouse tumor models. Mechanistically, αCD45-Cyt triggered prolonged pSTAT signaling and reprogrammed tumor-specific CD8+ T cells in the TDLN to exhibit an anti-viral transcriptional signature. CD45 anchoring represents a broad platform for protein retention by host immune cells for use in immunotherapy.

Advanced Generation Therapeutics: Biomimetic Nanodelivery System for Tumor Immunotherapy

Tumor immunotherapy is a safe and effective strategy for precision medicine. However, immunotherapy for most cancer cases still ends in failure, with the root causes of the immunosuppressive and extraordinary heterogeneity of the solid tumors microenvironment. The emerging biomimetic nanodelivery system provides a promising tactic to improve the immunotherapy effect while reducing the adverse reactions on nontarget cells. Herein, we summarize the relationship between tumor occurrence and tumor immune microenvironment, mechanism of tumor immune escape, immunotherapy classification (including adoptive cellular therapy, cytokines, cancer vaccines, and immune checkpoint inhibitors) and recommend target cells for immunotherapy first, and then emphatically introduce the recent advances and applications of the latest biomimetic nanodelivery systems (e.g., immune cells, erythrocytes, tumor cells, platelets, bacteria) in tumor immunotherapy. Meanwhile, we separately summarize the application of tumor vaccines. Finally, the predictable challenges and perspectives in a forward exploration of biomimetic nanodelivery systems for tumor immunotherapy are also discussed.

Revitalizing Cytokine-Based Cancer Immunotherapy through Advanced Delivery Systems

Cytokines can coordinate robust immune responses, holding great promise as therapeutics against infections, autoimmune diseases, and cancers. In cancer treatment, numerous pro-inflammatory cytokines have displayed promising efficacy in preclinical studies. However, their clinical application is hindered by poor pharmacokinetics, significant toxicity and unsatisfactory anticancer efficacy. Thus, while IFN-α and IL-2 are approved for specific cancer treatments, other cytokines still remain subject of intense investigation. To accelerate the application of cytokines as cancer immunotherapeutics, strategies need to be directed to improve their safety and anticancer performance. In this regard, delivery systems could be used to generate innovative therapies by targeting the cytokines or nucleic acids, such as DNA and mRNA, encoding the cytokines to tumor tissues. This review centers on these innovative delivery strategies for cytokines, summarizing key approaches, such as gene delivery and protein delivery, and critically examining their potential and challenges for clinical translation.

Surface modification strategies in translocating nano-vesicles across different barriers and the role of bio-vesicles in improving anticancer therapy

Nanovesicles and bio-vesicles (BVs) have emerged as promising tools to achieve targeted cancer therapy due to their ability to overcome many of the key challenges currently being faced with conventional chemotherapy. These challenges include the diverse and often complex pathophysiology involving the progression of cancer, as well as the various biological barriers that circumvent therapeutic molecules reaching their target site in optimum concentration. The scientific evidence suggests that surface-functionalized nanovesicles and BVs camouflaged nano-carriers (NCs) both can bypass the established biological barriers and facilitate fourth-generation targeting for the improved regimen of treatment. In this review, we intend to emphasize the role of surface-functionalized nanovesicles and BVs camouflaged NCs through various approaches that lead to an improved internalization to achieve improved and targeted oncotherapy. We have explored various strategies that have been employed to surface-functionalize and biologically modify these vesicles, including the use of biomolecule functionalized target ligands such as peptides, antibodies, and aptamers, as well as the targeting of specific receptors on cancer cells. Further, the utility of BVs, which are made from the membranes of cells such as mesenchymal stem cells (MSCs), white blood cells (WBCs), red blood cells (RBCs), platelets (PLTs) as well as cancer cells also been investigated. Lastly, we have discussed the translational challenges and limitations that these NCs can encounter and still need to be overcome in order to fully realize the potential of nanovesicles and BVs for targeted cancer therapy. The fundamental challenges that currently prevent successful cancer therapy and the necessity of novel delivery systems are in the offing.

Spatiotemporally programming cytokine immunotherapies through protein engineering

Cytokines have long been considered promising cancer immunotherapy agents due to their endogenous role in activating and proliferating lymphocytes. However, since the initial FDA approvals of Interleukin-2 (IL-2) and Interferon-ɑ (IFNɑ) for oncology over 30 years ago, cytokines have achieved little success in the clinic due to narrow therapeutic windows and dose-limiting toxicities. This is attributable to the discrepancy between the localized, regulated manner in which cytokines are deployed endogenously versus the systemic, untargeted administration used to date in most exogenous cytokine therapies. Furthermore, cytokines' ability to stimulate multiple cell types, often with paradoxical effects, may present significant challenges for their translation into effective therapies. Recently, protein engineering has emerged as a tool to address the shortcomings of first-generation cytokine therapies. In this perspective, we contextualize cytokine engineering strategies such as partial agonism, conditional activation and intratumoral retention through the lens of spatiotemporal regulation. By controlling the time, place, specificity, and duration of cytokine signaling, protein engineering can allow exogenous cytokine therapies to more closely approach their endogenous exposure profile, ultimately moving us closer to unlocking their full therapeutic potential.

The exit of nanoparticles from solid tumours

Nanoparticles enter tumours through endothelial cells, gaps or other mechanisms, but how they exit is unclear. The current paradigm states that collapsed tumour lymphatic vessels impair the exit of nanoparticles and lead to enhanced retention. Here we show that nanoparticles exit the tumour through the lymphatic vessels within or surrounding the tumour. The dominant lymphatic exit mechanism depends on the nanoparticle size. Nanoparticles that exit the tumour through the lymphatics are returned to the blood system, allowing them to recirculate and interact with the tumour in another pass. Our results enable us to define a mechanism of nanoparticle delivery to solid tumours alternative to the enhanced permeability and retention effect. We call this mechanism the active transport and retention principle. This delivery principle provides a new framework to engineer nanomedicines for cancer treatment and detection.

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.

Reactive oxygen species-responsive dual-targeted nanosystem promoted immunogenic cell death against breast cancer

The development of an optimal treatment modality to improve the therapeutic outcome of breast cancer patients is still difficult. Poor antigen presentation to T cells is a major challenge in cancer immunotherapy. In this study, a synergistic immunotherapy strategy for breast cancer incorporating immune cell infiltration, immunogenic cell death (ICD), and dendritic cell (DC) maturation through a reactive oxygen species (ROS)-responsive dual-targeted smart nanosystem (anti-PD-L1-TKNP) for the simultaneous release of DOX, R848, and MIP-3α in the tumor microenvironment is reported. Following local injection, anti-PD-L1-DOX-R848-MIP-3α/thioketal nanoparticle (TKNP) converts tumor cells to a vaccine owing to the combinatorial effect of DOX-induced ICD, R848-mediated immunostimulatory properties, and MIP-3α-induced immune cell recruitment in the tumor microenvironment. Intratumoral injection of anti-PD-L1-DOX-R848-MIP-3α/TKNP caused significant regression of breast cancer. Mechanistic studies reveal that anti-PD-L1-DOX-R848-MIP-3α/TKNP specifically targets tumor tissue, resulting in maximum exposure of calreticulin (CRT) and HMGB1 in tumors, and significantly enhances intratumoral infiltration of CD4+ and CD8+ T cells in tumors. Therefore, a combined strategy using dual-targeted ROS-responsive TKNP highlights the significant application of nanoparticles in modulating the tumor microenvironment and could be a clinical treatment strategy for effective breast cancer management.

Lipid-based nanoparticles as drug delivery systems for cancer immunotherapy

Immune checkpoint inhibitors (ICIs) have shown remarkable success in cancer treatment. However, in cancer patients without sufficient antitumor immunity, numerous data indicate that blocking the negative signals elicited by immune checkpoints is ineffective. Drugs that stimulate immune activation-related pathways are emerging as another route for improving immunotherapy. In addition, the development of nanotechnology presents a promising platform for tissue and cell type-specific delivery and improved uptake of immunomodulatory agents, ultimately leading to enhanced cancer immunotherapy and reduced side effects. In this review, we summarize and discuss the latest developments in nanoparticles (NPs) for cancer immuno-oncology therapy with a focus on lipid-based NPs (lipid-NPs), including the characteristics and advantages of various types. Using the agonists targeting stimulation of the interferon genes (STING) transmembrane protein as an exemplar, we review the potential of various lipid-NPs to augment STING agonist therapy. Furthermore, we present recent findings and underlying mechanisms on how STING pathway activation fosters antitumor immunity and regulates the tumor microenvironment and provide a summary of the distinct STING agonists in preclinical studies and clinical trials. Ultimately, we conduct a critical assessment of the obstacles and future directions in the utilization of lipid-NPs to enhance cancer immunotherapy.

Nanoimmunoengineering strategies in cancer diagnosis and therapy

Cancer immunotherapy strategies in combination with engineered nanosystems have yielded beneficial results in the treatment of cancer and their application is increasing day by day. The pivotal role of stimuli-responsive nanosystems and nanomedicine-based cancer immunotherapy, as a subsidiary discipline in the field of immunology, cannot be ignored. Today, rapid advances in nanomedicine are used as a platform for exploring new therapeutic applications and modern smart healthcare management strategies. The progress of nanomedicine in cancer treatment has confirmed the findings of immunotherapy in the medical research phase. This study concentrates on approaches connected to the efficacy of nanoimmunoengineering strategies for cancer immunotherapies and their applications. By assessing improved approaches, different aspects of the nanoimmunoengineering strategies for cancer therapies are discussed in this study.

Cytokine Therapy Combined with Nanomaterials Participates in Cancer Immunotherapy

Immunotherapy has gradually become an emerging treatment modality for tumors after surgery, radiotherapy, and chemotherapy. Cytokine therapy is a promising treatment for cancer immunotherapy. Currently, there are many preclinical theoretical bases to support this treatment strategy and a variety of cytokines in clinical trials. When cytokines were applied to tumor immunotherapy, it was found that the efficacy was not satisfactory. As research on tumor immunity has deepened, the role of cytokines in the tumor microenvironment has been further explored. Meanwhile, the study of nanomaterials in drug delivery has been fully developed in the past 20 years. Researchers have begun to think about the possibility of combining cytokine therapy with nanomaterials. Herein, we briefly review various nano-delivery systems that can directly deliver cytokines or regulate the expression of cytokines in tumor cells for cancer immunotherapy. We further discussed the feasibility of the combination of various therapies. We looked forward to the main challenges, opportunities, and prospects of tumor immunotherapy with multiple cytokines and a nano-delivery system.

Nanotherapeutics for immune network modulation in tumor microenvironments

Immunotherapy has shown promise in cancer treatment, and is thus drawing increasing interest in this field. While the standard chemotherapy- and/or radiotherapy-based cancer treatments aim to directly kill cancer cells, immunotherapy uses host immune cell surveillance to fight cancer. In the tumor environment, there is a close relationship between tumor cells and the adjacent immune cells, which are largely suppressed by cancer-related regulation of immune checkpoints, immune-suppressive cytokines, and metabolic factors. The immune modulators currently approved for cancer treatment remain limited by issues with dose tolerance and insufficient efficacy. Researchers have developed and tested various nano-delivery systems with the goal of improving the treatment outcome of these drugs. By encapsulating immune modulators in particles and directing their tissue accumulation, some such systems have decreased immune-related toxicity while sharpening the antitumor response. Surface-ligand modification of nanoparticles has allowed drugs to be delivered to specific immune cells types. Researchers have also studied strategies for depleting or reprogramming the immune-suppressive cells to recover the immune environment. Combining a nanomaterial with an external stimulus has been used to induce immunogenic cell death; this favors the inflammatory environment found in tumor tissues to promote antitumor immunity. The present review covers the most recent strategies aimed at modulating the tumor immune environment, and discusses the challenges and future perspectives in developing nanoparticles for cancer immunotherapy.

Injectable Nanoparticle-Based Hydrogels Enable the Safe and Effective Deployment of Immunostimulatory CD40 Agonist Antibodies

When properly deployed, the immune system can eliminate deadly pathogens, eradicate metastatic cancers, and provide long-lasting protection from diverse diseases. Unfortunately, realizing these remarkable capabilities is inherently risky as disruption to immune homeostasis can elicit dangerous complications or autoimmune disorders. While current research is continuously expanding the arsenal of potent immunotherapeutics, there is a technological gap when it comes to controlling when, where, and how long these drugs act on the body. Here, this study explored the ability of a slow-releasing injectable hydrogel depot to reduce dose-limiting toxicities of immunostimulatory CD40 agonist (CD40a) while maintaining its potent anticancer efficacy. A previously described polymer-nanoparticle (PNP) hydrogel system is leveraged that exhibits shear-thinning and yield-stress properties that are hypothesized to improve locoregional delivery of CD40a immunotherapy. Using positron emission tomography, it is demonstrated that prolonged hydrogel-based delivery redistributes CD40a exposure to the tumor and the tumor draining lymph node (TdLN), thereby reducing weight loss, hepatotoxicity, and cytokine storm associated with standard treatment. Moreover, CD40a-loaded hydrogels mediate improved local cytokine induction in the TdLN and improve treatment efficacy in the B16F10 melanoma model. PNP hydrogels, therefore, represent a facile, drug-agnostic method to ameliorate immune-related adverse effects and explore locoregional delivery of immunostimulatory drugs.

Intratumorally anchored cytokine therapy

INTRODUCTION

On-target, off-tumor toxicity severely limits systemic dosing of cytokines and agonist antibodies for cancer. Intratumoral administration is increasingly being explored to mitigate this problem. Full exploitation of this mode of administration must include a mechanism for sustained retention of the drug; otherwise, rapid diffusion out of the tumor eliminates any advantage.

AREAS COVERED

We focus here on strategies for anchoring immune agonists in accessible formats. Such anchoring may utilize extracellular matrix components, cell surface receptor targets, or exogenously administered particulate materials. Promising alternative strategies not reviewed here include slow release from the interior of a material depot, expression following local transfection, and conditional proteolytic activation of masked molecules.

EXPERT OPINION

An effective mechanism for tissue retention is a critical component of intratumorally anchored cytokine therapy, as leakage leads to decreased tumor drug exposure and increased systemic toxicity. Matching variable drug release kinetics with receptor-mediated cellular uptake is an intrinsic requirement for the alternative strategies mentioned above. Bioavailability of an anchored form of the administered drug is key to obviating this balancing act.

Recent Advances in Polymer Additive Engineering for Diagnostic and Therapeutic Hydrogels

Hydrogels are hydrophilic polymer materials that provide a wide range of physicochemical properties as well as are highly biocompatible. Biomedical researchers are adapting these materials for the ever-increasing range of design options and potential applications in diagnostics and therapeutics. Along with innovative hydrogel polymer backbone developments, designing polymer additives for these backbones has been a major contributor to the field, especially for expanding the functionality spectrum of hydrogels. For the past decade, researchers invented numerous hydrogel functionalities that emerge from the rational incorporation of additives such as nucleic acids, proteins, cells, and inorganic nanomaterials. Cases of successful commercialization of such functional hydrogels are being reported, thus driving more translational research with hydrogels. Among the many hydrogels, here we reviewed recently reported functional hydrogels incorporated with polymer additives. We focused on those that have potential in translational medicine applications which range from diagnostic sensors as well as assay and drug screening to therapeutic actuators as well as drug delivery and implant. We discussed the growing trend of facile point-of-care diagnostics and integrated smart platforms. Additionally, special emphasis was given to emerging bioinformatics functionalities stemming from the information technology field, such as DNA data storage and anti-counterfeiting strategies. We anticipate that these translational purpose-driven polymer additive research studies will continue to advance the field of functional hydrogel engineering.

Inhibition of tumor recurrence and metastasis via a surgical tumor-derived personalized hydrogel vaccine

Tumor recurrence and metastasis have become thorny problems in clinical tumor therapy. Vaccine-mediated antitumor immune response has emerged as a significant postoperative inhibition for tumor recurrence and metastasis. However, limited tumor antigens are not conducive to trigger complete antigen-specific T cell-mediated immune responses. Herein, the design of a hydrogel vaccine system containing a granulocyte-macrophage colony stimulating factor (GM-CSF), based on surgically removed tumor cell lysates, was reported. The hydrogel was formed by crosslinking tumor cell lysates and alginate at low temperatures. The GM-CSF was released from the hydrogel to recruit dendritic cells (DCs), which provided a completely personalized tumor antigen pool. They were combined to foster the production of powerful antigen-specific T cells. The personalized hydrogel was implanted at the surgical site and it stimulated the antitumor immune response for the inhibition of residual tumor cells. Delightfully, the personalized hydrogel inhibited the tumor recurrence and metastasis well in a post-surgical mice tumor model, in combination with a programmed death-ligand 1 antibody (αPD-L1). The results demonstrated that the development of a personalized hydrogel and a combination of αPD-L1 provided a new strategy to prevent tumor recurrence and metastasis.

The use of supercytokines, immunocytokines, engager cytokines, and other synthetic cytokines in immunotherapy

Cytokines exert powerful immunomodulatory effects that are critical to physiology and pathology in humans. The application of natural cytokines in clinical studies has not been clearly established, and there are often problems associated with toxicity or lack of efficacy. The key reasons can be attributed to the pleiotropy of cytokine receptors and undesired activation of off-target cells. With a deeper understanding of the structural principles and functional signals of cytokine-receptor interactions, artificial modification of cytokine signaling through protein engineering and synthetic immunology has become an increasingly feasible and powerful approach. Engineered cytokines are designed to selectively target cells. Herein, the theoretical and experimental evidence of cytokine engineering is reviewed, and the "supercytokines" resulting from structural enhancement and the "immunocytokines" generated by antibody fusion are described. Finally, the "engager cytokines" formed by the crosslinking of cytokines and bispecific immune engagers and other synthetic cytokines formed by nonnatural analogs are also discussed.

Targeting immunoliposomes to EGFR-positive glioblastoma

Background

We assessed the capacity of epidermal growth factor receptor (EGFR)-targeted immunoliposomes to deliver cargo to brain tumor tissue in patients with relapsed glioblastoma harboring an EGFR amplification. We aimed to assess the tolerability and effectiveness of anti-EGFR immunoliposomes loaded with doxorubicin (anti-EGFR ILs-dox) in glioblastoma multiforme patients.

Patients and methods

Patients with EGFR-amplified, relapsed glioblastoma were included in this phase I pharmacokinetic trial. Patients received up to four cycles of anti-EGFR ILs-dox. Twenty-four hours later, plasma and cerebrospinal fluid (CSF) samples were obtained. In addition, we also treated three patients with anti-EGFR ILs-dox before resection of their relapsed glioblastoma. Doxorubicin concentrations were measured in plasma, CSF, and tumor tissue. Safety and efficacy parameters were also obtained.

Results

There were no or negligible levels of doxorubicin found in the CSF demonstrating that anti-EGFR ILs-dox are not able to cross the blood–brain barrier (BBB). However, significant levels were detected in glioblastoma tissue 24 h after the application, indicating that the disruption of BBB integrity present in high-grade gliomas might enable liposome delivery into tumor tissue. No new safety issues were observed. The median progression-free survival was 1.5 months and the median overall survival was 8 months. One patient undergoing surgery had a very long remission suggesting that neoadjuvant administration may have a positive effect on outcome.

Conclusions

We clearly demonstrate that anti-EGFR-immunoliposomes can be targeted to EGFR-amplified glioblastoma and cargo—in this case doxorubicin—can be delivered, although these immunoliposomes do not cross the intact BBB. (The GBM-LIPO trial was registered as NCT03603379).

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Human pharmacokinetic and pharmacodynamic data for EGFR-targeted immunoliposomes.

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Demonstration of delivery of immunoliposomes to glioblastoma tissue.

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EGFR as a target to deliver drug-containing nanoparticles to glioma tissue.

Smart biomaterials to enhance the efficiency of immunotherapy in glioblastoma: State of the art and future perspectives

Glioblastoma multiform (GBM) is considered as the most lethal tumor among CNS malignancies. Although immunotherapy has achieved remarkable advances in cancer treatment, it has not shown satisfactory results in GBM patients. Biomaterial science, along with nanobiotechnology, is able to optimize the efficiency of immunotherapy in these patients. They can be employed to provide the specific activation of immune cells in tumor tissue and combinational therapy as well as preventing systemic adverse effects resulting from hyperactivation of immune responses and off-targeting effect. Advance biomaterials in this field are classified into targeting nanocarriers and localized delivery systems. This review will offer an overview of immunotherapy strategies for glioblastoma and advance delivery systems for immunotherapeutics that may have a high potential in glioblastoma treatment.

Overcoming physical stromal barriers to cancer immunotherapy

Immunotherapy has emerged as an unprecedented hope for the treatment of notoriously refractory cancers. Numerous investigational drugs and immunotherapy-including combination regimens are under preclinical and clinical investigation. However, only a small patient subpopulation across different types of cancer responds to the therapy due to the presence of several mechanisms of resistance. There have been extensive efforts to overcome this limitation and to expand the patient population that could be benefited by this state-of-the-art therapeutic modality. Among various causes of the resistance, we here focus on physical stromal barriers that impede the access of immunotherapeutic drug molecules and/or native and engineered immune cells to cancer tissues and cells. Two primary stromal barriers that contribute to the resistance include aberrant tumor vasculatures and excessive extracellular matrix build-ups that restrict extravasation and infiltration, respectively, of molecular and cellular immunotherapeutic agents into tumor tissues. Here, we review the features of these barriers that limit the efficacy of immunotherapy and discuss recent advances that could potentially help immunotherapy overcome the barriers and improve therapeutic outcomes.

Transformable vesicles for cancer immunotherapy

Immunotherapy that utilizes the human immune system to fight cancer represents a revolutionary method for cancer treatment. Immunotherapeutic agents that trigger the immune response should be carefully delivered to the desired site to maximize immunotherapy effectiveness and minimize side effects. Vesicles offer the possibility of encapsulating both hydrophilic and hydrophobic drugs and thus serve as a promising delivery tool. As multiple irreconcilable requirements exist at different transport stages, developing vesicles transformable in response to given stimuli is of great significance. In this review, we first introduced various vesicle types used for immunotherapy. Furthermore, the typical stimuli that trigger vesicle transformation and the usually generated transformation styles were described. Focusing on three aspects of antigen-presenting cell (APC)/T cell activation, tumor microenvironment (TME) amelioration, and immunogenic cell death (ICD)-induced immunotherapy, we reviewed recently reported transformable vesicles for tumor treatment. Finally, we put forward possible directions for future research and clinical translation.

Nanoparticle delivery of recombinant IL-2 (BALLkine-2) achieves durable tumor control with less systemic adverse effects in cancer immunotherapy

Recent strategies in cancer immunotherapy based on interleukin-2 (IL-2) are generally focused on reducing regulatory T cell (Treg) development by modifying IL-2 receptor alpha (IL-2Rα) domain. However, the clinical utility of high-dose IL-2 treatment is mainly limited by severe systemic toxicity. We find that peritumorally injectable 'BALLkine-2', recombinant human IL-2 (rIL-2) loaded porous nanoparticle, dramatically reduces systemic side effects of rIL-2 by minimizing systemic IL-2 exposure. Notably, in cynomolgus monkeys, subcutaneous (SC)-injection of BALLkine-2 not only dramatically reduces systemic circulation of rIL-2 in the blood, but also increases half-life of IL-2 compared to IV- or SC-injection of free rIL-2. Peritumorally-injected BALLkine-2 enhances intratumoral lymphocyte infiltration without inducing Treg development and more effectively synergizes with PD-1 blockade than high-dose rIL-2 administration in B16F10 melanoma model. BALLkine-2 could be a highly potent therapeutic option due to higher anti-tumor efficacy with lower and fewer doses and reduced systemic toxicity compared to systemic rIL-2.

T Lymphocyte-Captured DNA Network for Localized Immunotherapy

The efficient isolation of immune cells with high purity and low cell damage is important for immunotherapy and remains highly challenging. We herein report a cell capture DNA network containing polyvalent multimodules for the specific isolation and in situ incubation of T lymphocytes (T-cells). Two ultralong DNA chains synthesized by an enzymatic amplification process were rationally designed to include functional multimodules as cell anchors and immune adjuvants. Mutually complementary sequences facilitated the formation of a DNA network and encapsulation of T-cells, as well as offering cutting sites of a restriction enzyme for the responsive release of T-cells and immune adjuvants. The purity of captured tumor-infiltrating T-cells reached 98%, and the viability of T-cells maintained ∼90%. The T-cells-containing DNA network was further administrated to a tumor lesion for localized immunotherapy. Our work provides a robust nanobiotechnology for efficient isolation of immune cells and other biological particles.

Nanotechnology-based products for cancer immunotherapy

Abstract

Currently, nanoscale materials and scaffolds carrying antitumor agents to the tumor target site are practical approaches for cancer treatment. Immunotherapy is a modern approach to cancer treatment in which the body’s immune system adjusts to deal with cancer cells. Immuno-engineering is a new branch of regenerative medicine-based therapies that uses engineering principles by using biological tools to stimulate the immune system. Therefore, this branch’s final aim is to regulate distribution, release, and simultaneous placement of several immune factors at the tumor site, so then upgrade the current treatment methods and subsequently improve the immune system’s handling. In this paper, recent research and prospects of nanotechnology-based cancer immunotherapy have been presented and discussed. Furthermore, different encouraging nanotechnology-based plans for targeting various innate and adaptive immune systems will also be discussed. Due to novel views in nanotechnology strategies, this field can address some biological obstacles, although studies are ongoing.

Graphic abstract

The application of immune checkpoint blockade in breast cancer and the emerging role of nanoparticle

Breast cancer is the most common malignancy in the female population with a high mortality rate. Despite the satisfying depth of studies evaluating the contributory role of immune checkpoints in this malignancy, few articles have reviewed the pros and cons of immune checkpoint blockades (ICBs). In the current review, we provide an overview of immune-related inhibitory molecules and also discuss the original data obtained from international research laboratories on the aberrant expression of T and non-T cell-associated immune checkpoints in breast cancer. Then, we especially focus on recent studies that utilized ICBs as the treatment strategy in breast cancer and provide their efficiency reports. As there are always costs and benefits, we discuss the limitations and challenges toward ICB therapy such as adverse events and drug resistance. In the last section, we allocate an overview of the recent data concerning the application of nanoparticle systems for cancer immunotherapy and propose that nano-based ICB approaches may overcome the challenges related to ICB therapy in breast cancer. In conclusion, it seems it is time for nanoscience to more rapidly move forward into clinical trials and illuminates the breast cancer treatment area with its potent features for the target delivery of ICBs.

Switchable immune modulator for tumor-specific activation of anticancer immunity

Immune stimulatory antibodies and cytokines elicit potent antitumor immunity. However, the dose-limiting systemic toxicity greatly hinders their clinical applications. Here, we demonstrate a chemical approach, termed “switchable” immune modulator (Sw-IM), to limit the systemic exposure and therefore ameliorate their toxicities. Sw-IM is a biomacromolecular therapeutic reversibly masked by biocompatible polymers through chemical linkers that are responsive to tumor-specific stimuli, such as high reducing potential and acidic pH. Sw-IMs stay inert (switch off) in the circulation and healthy tissues but get reactivated (switch on) selectively in tumor via responsive removal of the polymer masks, thus focusing the immune boosting activities in the tumor microenvironment. Sw-IMs applied to anti–4-1BB agonistic antibody and IL-15 cytokine led to equivalent antitumor efficacy to the parental IMs with markedly reduced toxicities. Sw-IM provides a highly modular and generic approach to improve the therapeutic window and clinical applicability of potent IMs in mono- and combinational immunotherapies.

Nanotechnology-based immunotherapies to combat cancer metastasis

Emerging concepts in nanotechnology have gained particular attention for their clinical translation of immunotherapies of cancer, autoimmune and infectious diseases. Several nanoconstructs have been engineered with unique structural, physicochemical, and functional features as robust alternatives for conventional chemotherapies. Traditional cancer therapies like chemotherapy, radiotherapy, and ultimately surgery are the most widely practiced in biomedical settings. Biomaterials and nanotechnology have introduced vehicles for drug delivery and have revolutionized the concept of the modern immunotherapeutic paradigm. Various types of nanomaterials, such as nanoparticles and, more specifically, drug-loaded nanoparticles are becoming famous for drug delivery applications because of safety, patient compliance, and smart action. Such therapeutic modalities have acknowledged regulatory endorsement and are being used in twenty-first-century clinical settings. Considering the emerging concepts and landscaping potentialities, herein, we spotlight and discuss nanoparticle-based immunotherapies as a smart and sophisticated drug delivery approach to combat cancer metastasis. The introductory part of this manuscript discusses a broad overview of cancer immunotherapy to understand better the tumor microenvironment and nanotechnology-oriented immunomodulatory strategies to cope with advanced-stage cancers. Following that, most addressable problems allied with conventional immunotherapies are given in comparison to nanoparticle-based immunotherapies. The later half of this work comprehensively highlights the requisite delivery of various bioactive entities with particular cases and examples. Finally, this review also encompasses a comprehensive concluding overview and future standpoints to strengthen a successful clinical translation of nanoparticle-based immunotherapies as a smart and sophisticated drug delivery approach.

Intratumoural administration and tumour tissue targeting of cancer immunotherapies

Immune-checkpoint inhibitors and chimeric antigen receptor (CAR) T cells are revolutionizing oncology and haematology practice. With these and other immunotherapies, however, systemic biodistribution raises safety issues, potentially requiring the use of suboptimal doses or even precluding their clinical development. Delivering or attracting immune cells or immunomodulatory factors directly to the tumour and/or draining lymph nodes might overcome these problems. Hence, intratumoural delivery and tumour tissue-targeted compounds are attractive options to increase the in situ bioavailability and, thus, the efficacy of immunotherapies. In mouse models, intratumoural administration of immunostimulatory monoclonal antibodies, pattern recognition receptor agonists, genetically engineered viruses, bacteria, cytokines or immune cells can exert powerful effects not only against the injected tumours but also often against uninjected lesions (abscopal or anenestic effects). Alternatively, or additionally, biotechnology strategies are being used to achieve higher functional concentrations of immune mediators in tumour tissues, either by targeting locally overexpressed moieties or engineering 'unmaskable' agents to be activated by elements enriched within tumour tissues. Clinical trials evaluating these strategies are ongoing, but their development faces issues relating to the administration methodology, pharmacokinetic parameters, pharmacodynamic end points, and immunobiological and clinical response assessments. Herein, we discuss these approaches in the context of their historical development and describe the current landscape of intratumoural or tumour tissue-targeted immunotherapies.

Engineering Strategies for Immunomodulatory Cytokine Therapies - Challenges and Clinical Progress

Cytokines are immunoregulatory proteins involved in many pathological states with promising potential as therapeutic agents. A diverse array of cytokines have been studied in preclinical disease models since the 1950s, some of which became successful biopharmaceutical products with the advancement of recombinant protein technology in the 1980s. However, following these early approvals, clinical translation of these natural immune signaling molecules has been limited due to their pleiotropic action in many cell types, and the fact that they have evolved to act primarily locally in tissues. These characteristics, combined with poor pharmacokinetics, have hindered the delivery of cytokines via systemic administration routes due to dose-limiting toxicities. However, given their clinical potential and recent clinical successes in cancer immunotherapy, cytokines continue to be extensively pursued in preclinical and clinical studies, and a range of molecular and formulation engineering strategies are being applied to reduce treatment toxicity while maintaining or enhancing therapeutic efficacy. This review provides a brief background on the characteristics of cytokines and their history as clinical therapeutics, followed by a deeper discussion on the engineering strategies developed for cytokine therapies with a focus on the translational relevance of these approaches.

From Design to Clinic: Engineered Nanobiomaterials for Immune Normalization Therapy of Cancer

The tumor immune microenvironment (TIME) is comprised of a complex milieu that contributes to stunting antitumor immune responses by restricting T cells to accumulate in the vicinity of the tumor. Nanomedicine-based strategies are being proposed as a salvage effort to reinvigorate antitumor immunity. Various strategies, however, often fail to unleash the antitumor immune response because of the paucity of appropriate therapeutic targets in the complex TIME, invigorating a fervor of investigation into mechanisms underlying the TIME to resist nanomedicines. In this review article, effective nano/biomaterial-based delivery and TIME normalization approaches that promote T cell-mediated antitumor immune response will be discussed, with a focus on emerging preclinical and clinical strategies for immune normalization. Based on currently available evidence, it seems as if the ultimate success of cancer immunotherapy and nanomedicine hinges on the capacity to normalize the TIME. Here, how nanomedicines target immunosuppressive cells and signaling pathways to broaden the impact of cancer immunotherapy are explored. Acquisition of the urgently needed knowledge of nanomedicine-mediated immune normalization will guide researchers and scientists towards clinical applications of cancer immunotherapy.

Engineering Nanoparticles toward the Modulation of Emerging Cancer Immunotherapy

Cancer immunotherapy is a new therapeutic strategy to fight cancer by activating the patients' own immune system. At present, immunotherapy approaches such as cancer vaccines, immune checkpoint blockade (ICB), adoptive cell transfer (ACT), monoclonal antibodies (mAbs) therapy, and cytokines therapy have therapeutic potential in preclinical and clinical applications. However, the intrinsic limitations of conventional immunotherapy are difficulty of precise dosage control, insufficient enrichment in tumor tissues, partial immune response silencing or hyperactivity, and high cost. Engineering nanoparticles (NPs) have been emerging as a promising multifunctional platform to enhance conventional immunotherapy due to their intrinsic immunogenicity, convenient delivery function, controlled surface chemistry activity, multifunctional modifying potential, and intelligent targeting. This review presents the recent progress reflected by engineering NPs, including the diversified selection of functionalized NPs, the superiority of engineering NPs for enhancing conventional immunotherapy, and NP-mediated multiscale strategies for synergistic therapy consisting of compositions and their mechanism. Finally, the perspective on multifunctional NP-based cancer immunotherapy for boosting immunomodulation is discussed, which reveals the expanding landscape of engineering NPs in clinical translation.

Emerging advances in cationic liposomal cancer nanovaccines: opportunities and challenges

Advancements in the field of cancer therapeutics have witnessed a recent surge in the use of liposomes. The physicochemical characteristics of the liposomes and their components, including the lipid phase transition temperature, vesicular size and size distribution, surface properties, and route of administration, play a significant role in the modulation of the immune response as an adjuvant and for loaded antigen (Ag). Cationic liposomes, concerning their potential ability to amplify the immunogenicity of the loaded Ag/adjuvant, have received enormous interest as a promising vaccine delivery platform for cancer immunotherapy. In the present review, the physicochemical considerations for the development of Ag/adjuvant-loaded liposomes and the cationic liposomes' effectiveness for promoting cancer immunotherapy have been summarized.

CD137+ T-Cells: Protagonists of the Immunotherapy Revolution

Simple Summary

The CD137 receptor is expressed by activated antigen-specific T-cells. CD137⁺ T-cells were identified inside TILs and PBMCs of different tumor types and have proven to be the naturally occurring antitumor effector cells, capable of expressing a wide variability in terms of TCR specificity against both shared and neoantigenic tumor-derived peptides. The aim of this review is thus summarizing and highlighting their role as drivers of patients’ immune responses in anticancer therapies as well as their potential role in future and current strategies of immunotherapy.

Abstract

The CD137 receptor (4-1BB, TNF RSF9) is an activation induced molecule expressed by antigen-specific T-cells. The engagement with its ligand, CD137L, is capable of increasing T-cell survival, proliferation, and cytokine production. This allowed to identify the CD137⁺ T-cells as the real tumor-specific activated T-cell population. In fact, these cells express various TCRs that are specific for a wide range of tumor-derived peptides, both shared and neoantigenic ones. Moreover, their prevalence in sites close to the tumor and their unicity in killing cancer cells both in vitro and in vivo, raised particular interest in studying their potential role in different strategies of immunotherapy. They indeed showed to be a reliable marker able to predict patient’s outcome to immune-based therapies as well as monitor their response. In addition, the possibility of isolating and expanding this population, turned promising in order to generate effector antitumor T-cells in the context of adoptive T-cell therapies. CD137-targeting monoclonal antibodies have already shown their antitumor efficacy in cancer patients and a number of clinical trials are thus ongoing to test their possible introduction in different combination approaches of immunotherapy. Finally, the intracellular domain of the CD137 receptor was introduced in the anti-CD19 CAR-T cells that were approved by FDA for the treatment of pediatric B-cell leukemia and refractory B-cell lymphoma.

Tumor-Targeted Nanomedicine for Immunotherapy

Therapeutic manipulation of the immune system against cancer has revolutionized the treatment of several advanced-stage tumors. While many have benefited from these treatments, the proportion of patients responding to immunotherapies is still low. Nanomedicines have promise to revolutionize tumor treatments through spatiotemporal control of drug activity. Such control of drug function could allow enhanced therapeutic actions of immunotherapies and reduced side effects. However, only a handful of formulations have been able to reach human clinical studies so far, and even fewer systems are being used in the clinic. Among translatable formulations, self-assembled nanomedicines have shown unique and versatile features for dealing with the heterogeneity and malignancy of tumors in the clinic. Such nanomedicines can be designed to promote antitumor immune responses through a series of immunopotentiating functions after being directly injected into tumors, or achieving selective tumor accumulation upon intravenous administration. Thus, tumor-targeted nanomedicines can enhance antitumor immunity by several mechanisms, such as inducing immunogenic damage to cancer cells, altering the tumor immune microenvironment by delivering immunomodulators, or eliminating or reprogramming immunosuppressive cells, enhancing the exposure of tumor-associated antigens to antigen presenting cells, stimulating innate immunity mechanisms, and facilitating the infiltration of antitumor immune cells and their interaction with cancer cells. Moreover, nanomedicines can be engineered to sense intratumoral stimuli for activating specific immune responses or installed with ligands for increasing drug levels in tumors, granting subcellular delivery, and triggering immune signals and proliferation of immune cells. Thus, the ability of nanomedicines to exert immunomodulatory functions selectively in tumor and tumor-associated tissues, such as draining lymph nodes, increases the efficiency of the treatments, while avoiding systemic immunosuppressive toxicities and the exacerbation of adverse immune responses. Moreover, the compartmentalized structure of self-assembled nanomedicines offers the possibility to coload a variety of drugs for controlled pharmacokinetics, enhanced tumor delivery, and synergistic therapeutic output. Also, by integrating imaging functionalities into nanomedicines, it is possible to develop theranostic platforms reporting the immune settings of tumors as well as the effects of nanomedicines on the tumor immune microenvironment. Herein, we critically reviewed significant strategies for developing nanomedicines capable of potentiating antitumor immune responses by surmounting biological barriers and modulating antitumor immune signals. Moreover, the potential of these nanomedicines for developing innovative anticancer treatments by targeting particular cells is discussed. Finally, we present our perspectives on the awaiting challenges and future directions of nanomedicines in the age of immunotherapy.

Immunoliposomes bearing lymphocyte activation gene 3 fusion protein and P5 peptide: A novel vaccine for breast cancer

LAG3-Ig as an immune adjuvant has elicited potent anti-tumor immune responses in several preclinical and clinical studies, but the full potential immunostimulatory of LAG3-Ig has yet to be achieved. We hypothesized that by anchoring LAG3-Ig to the surface of liposomes, the adjuvant activity of LAG3-Ig could be improved. We also investigated the immunotherapy by co-delivery of liposome-coupled LAG3-Ig and P5 tumor antigen in mice model of TUBO breast cancer. We prepared and characterized novel PEGylated liposomes bearing surface conjugated LAG3-Ig and P5. Consistent with our hypothesis, liposomes-conjugated LAG3-Ig via multivalent binding to MHC class II molecules exerted immunostimulatory of LAG3-Ig and markedly induced maturation of dendritic cells more efficiently than free LAG3-Ig. LAG3-Ig-P5-immunoliposomes effectively elicited protective anti-tumor responses more than locally injected soluble LAG3-Ig + P5. The higher percentage of CD4⁺ and CD8⁺ T cells in the spleen and more rapid and pronounced infiltration of these effector cells into the site of the tumor were seen following immunoliposome therapy. Finally, anti-tumor immunity induced by LAG3-Ig-P5-immunoliposomes translated into the more tumor regression and prolonged survival of treated mice, compared to soluble immunotherapy. Taken together, our findings suggest that LAG3-Ig-P5-immunoliposomes can be considered as a valuable candidate for developing a liposome-based therapeutic cancer vaccine in treating HER2/ neu⁺ breast cancer patients.

Liposome-Based Drug Delivery Systems in Cancer Immunotherapy

Cancer immunotherapy has shown remarkable progress in recent years. Nanocarriers, such as liposomes, have favorable advantages with the potential to further improve cancer immunotherapy and even stronger immune responses by improving cell type-specific delivery and enhancing drug efficacy. Liposomes can offer solutions to common problems faced by several cancer immunotherapies, including the following: (1) Vaccination: Liposomes can improve the delivery of antigens and other stimulatory molecules to antigen-presenting cells or T cells; (2) Tumor normalization: Liposomes can deliver drugs selectively to the tumor microenvironment to overcome the immune-suppressive state; (3) Rewiring of tumor signaling: Liposomes can be used for the delivery of specific drugs to specific cell types to correct or modulate pathways to facilitate better anti-tumor immune responses; (4) Combinational therapy: Liposomes are ideal vehicles for the simultaneous delivery of drugs to be combined with other therapies, including chemotherapy, radiotherapy, and phototherapy. In this review, different liposomal systems specifically developed for immunomodulation in cancer are summarized and discussed.

Lymphatic immunomodulation using engineered drug delivery systems for cancer immunotherapy

Though immunotherapy has revolutionized the treatment of cancer to improve disease outcomes, an array of challenges remain that limit wider clinical success, including low rate of response and immune-related adverse events. Targeting immunomodulatory drugs to therapeutically relevant tissues offers a way to overcome these challenges by potentially enabling enhanced therapeutic efficacy and decreased incidence of side effects. Research highlighting the importance of lymphatic tissues in the response to immunotherapy has increased interest in the application of engineered drug delivery systems (DDSs) to enable specific targeting of immunomodulators to lymphatic tissues and cells that they house. To this end, a variety of DDS platforms have been developed that enable more efficient uptake into lymphatic vessels and lymph nodes to provide targeted modulation of the immune response to cancer. This can occur either by delivery of immunotherapeutics to lymphatics tissues or by direct modulation of the lymphatic vasculature itself due to their direct involvement in tumor immune processes. This review will highlight DDS platforms that, by enabling the activities of cancer vaccines, chemotherapeutics, immune checkpoint blockade (ICB) antibodies, and anti- or pro-lymphangiogenic factors to lymphatic tissues through directed delivery and controlled release, augment cancer immunotherapy.