Nanoparticulate immunotherapy for cancer

Enhancing Effector Jurkat Cell Activity and Increasing Cytotoxicity against A549 Cells Using Nivolumab as an Anti-PD-1 Agent Loaded on Gelatin Nanoparticles

The current research investigated the use of gelatin nanoparticles (GNPs) for enhancing the cytotoxic effects of nivolumab, an immune checkpoint inhibitor. The unique feature of GNPs is their biocompatibility and functionalization potential, improving the delivery and the efficacy of immunotherapeutic drugs with fewer side effects compared to traditional treatments. This exploration of GNPs represents an innovative direction in the advancement of nanomedicine in oncology. Nivolumab-loaded GNPs were prepared and characterized. The optimum formulation had a particle size of 191.9 ± 0.67 nm, a polydispersity index of 0.027 ± 0.02, and drug entrapment of 54.67 ± 3.51%. A co-culture experiment involving A549 target cells and effector Jurkat cells treated with free nivolumab solution, and nivolumab-loaded GNPs, demonstrated that the latter had significant improvements in inhibition rate by scoring 87.88 ± 2.47% for drug-loaded GNPs against 60.53 ± 3.96% for the free nivolumab solution. The nivolumab-loaded GNPs had a lower IC50 value, of 0.41 ± 0.01 µM, compared to free nivolumab solution (1.22 ± 0.37 µM) at 72 h. The results indicate that administering nivolumab-loaded GNPs augmented the cytotoxicity against A549 cells by enhancing effector Jurkat cell activity compared to nivolumab solution treatment.

Truncated PD1 Engineered Gas-Producing Extracellular Vesicles for Ultrasound Imaging and Subsequent Degradation of PDL1 in Tumor Cells

PDL1 blockade therapy holds great promise in cancer immunotherapy. Ultrasound imaging of PDL1 expression in the tumor is of great importance in predicting the therapeutic efficacy. As a proof-of-concept study, a novel ultrasound contrast agent has been innovated here to image and block PDL1 in the tumor tissue. Briefly, extracellular vesicles (EVs) are engineered to display truncated PD1 (tPD1) on the surface to bind PDL1 with high affinity by fusion to EV-abundant transmembrane protein PTGFRN. The engineered EVs are then encapsulated with Ca(HCO3)2 via electroporation and designated as Gp-EVtPD1, which would recognize PDL1 highly expressed cells and produce gas in the endosomes and lysosomes. On the one hand, the echogenic signal intensity correlates well with the PDL1 expression and immune response inhibition in the tumor. On the other hand, during the trajectory of Gp-EVtPD1 in the recipient cells, tPD1 on the EV binds PDL1 and triggers the PDL1 endocytosis and degradation in endosomes/lysosomes in a sequential manner, and thus boosts the anti-tumor immunity of cytotoxic T cells. In summary, Gp-EVtPD1 serves as a novel ultrasound contrast agent and blocker of PDL1, which might be of great advantage in imaging PDL1 expression and conquering immune checkpoint blocker resistance.

Tumor Vascular Destruction and cGAS-STING Activation Induced by Single Drug-Loaded Nano-Micelles for Multiple Synergistic Therapies of Cancer

Cancer and its metastasis/recurrence still threaten human health, despite various advanced treatments being employed. It is of great significance to develop simple drug formulations to enhance the efficacy and synergistic integration of various monotherapies. Herein, DMXAA, a vasodestructive agent with cGAS-STING stimulation capacity, is integrated with polyethylene glycol grafted poly (lactic-co-glycolic) acid co-polymer (PLGA-PEG), obtaining PLGA-PEG/DMXAA (PPD) nanoparticles to induce the tumor-specific vascular destruction for multiple synergistic therapies of cancer. PPD could induce the formation of blood clots in the tumor after intravenous injection, which subsequently mediate photothermal therapy and further promote the release of oxygen for enhanced radiotherapy. Meanwhile, the enhanced vascular injury can induce perfect starvation therapy of tumor. More importantly, PPD-mediated therapies could trigger potent systemic anti-tumor immunity via inducing the immunogenic death of tumor cells and activating the cGAS-STING pathway. Together with anti-PD-L1, PPD-mediated therapies could not only remove the primary tumors, but also effectively eliminate the distant tumors, metastasis, and recurrence. Therefore, the modulation of tumor composition induced by a single drug-loaded nano-micelle could be utilized to enhance the therapeutic effect of multiple treatments for synergistic and systemic antitumor response, providing a practical strategy for cancer therapy.

Driving natural killer cell-based cancer immunotherapy for cancer treatment: An arduous journey to promising ground

Immunotherapy represents one of the most effective strategies for cancer treatment. Recently, progress has been made in using natural killer (NK) cells for cancer therapy. NK cells can directly kill tumor cells without pre-sensitization and thus show promise in clinical applications, distinct from the use of T cells. Whereas, research and development on NK cell-based immunotherapy is still in its infancy, and enhancing the therapeutic effects of NK cells remains a key problem to be solved. An incompletely understanding of the mechanisms of action of NK cells, immune resistance in the tumor microenvironment, and obstacles associated with the delivery of therapeutic agents in vivo, represent three mountains that need to be scaled. Here, we firstly describe the mechanisms underlying the development, activity, and maturation of NK cells, and the formation of NK‑cell immunological synapses. Secondly, we discuss strategies for NK cell-based immunotherapy strategies, including adoptive transfer of NK cell therapy and treatment with cytokines, monoclonal antibodies, and immune checkpoint inhibitors targeting NK cells. Finally, we review the use of nanotechnology to overcome immune resistance, including enhancing the anti-tumor efficiency of chimeric antigen receptor-NK, cytokines and immunosuppressive-pathways inhibitors, promoting NK cell homing and developing NK cell-based nano-engagers.

Nanocarriers for cancer nano-immunotherapy

The host immune system possesses an intrinsic ability to target and kill cancer cells in a specific and adaptable manner that can be further enhanced by cancer immunotherapy, which aims to train the immune system to boost the antitumor immune response. Several different categories of cancer immunotherapy have emerged as new standard cancer therapies in the clinic, including cancer vaccines, immune checkpoint inhibitors, adoptive T cell therapy, and oncolytic virus therapy. Despite the remarkable survival benefit for a subset of patients, the low response rate and immunotoxicity remain the major challenges for current cancer immunotherapy. Over the last few decades, nanomedicine has been intensively investigated with great enthusiasm, leading to marked advancements in nanoparticle platforms and nanoengineering technology. Advances in nanomedicine and immunotherapy have also led to the emergence of a nascent research field of nano-immunotherapy, which aims to realize the full therapeutic potential of immunotherapy with the aid of nanomedicine. In particular, nanocarriers present an exciting opportunity in immuno-oncology to boost the activity, increase specificity, decrease toxicity, and sustain the antitumor efficacy of immunological agents by potentiating immunostimulatory activity and favorably modulating pharmacological properties. This review discusses the potential of nanocarriers for cancer immunotherapy and introduces preclinical studies designed to improve clinical cancer immunotherapy modalities using nanocarrier-based engineering approaches. It also discusses the potential of nanocarriers to address the challenges currently faced by immuno-oncology as well as the challenges for their translation to clinical applications.

Biomaterials Facilitating Dendritic Cell-Mediated Cancer Immunotherapy

Dendritic cell (DC)-based cancer immunotherapy has exhibited remarkable clinical prospects because DCs play a central role in initiating and regulating adaptive immune responses. However, the application of traditional DC-mediated immunotherapy is limited due to insufficient antigen delivery, inadequate antigen presentation, and high levels of immunosuppression. To address these challenges, engineered biomaterials have been exploited to enhance DC-mediated immunotherapeutic effects. In this review, vital principal components that can enhance DC-mediated immunotherapeutic effects are first introduced. The parameters considered in the rational design of biomaterials, including targeting modifications, size, shape, surface, and mechanical properties, which can affect biomaterial optimization of DC functions, are further summarized. Moreover, recent applications of various engineered biomaterials in the field of DC-mediated immunotherapy are reviewed, including those serve as immune component delivery platforms, remodel the tumor microenvironment, and synergistically enhance the effects of other antitumor therapies. Overall, the present review comprehensively and systematically summarizes biomaterials related to the promotion of DC functions; and specifically focuses on the recent advances in biomaterial designs for DC activation to eradicate tumors. The challenges and opportunities of treatment strategies designed to amplify DCs via the application of biomaterials are discussed with the aim of inspiring the clinical translation of future DC-mediated cancer immunotherapies.

Nanovaccines for cancer immunotherapy: Focusing on complex formation between adjuvant and antigen

As an interesting cancer immunotherapy approach, cancer vaccines have been developed to deliver tumor antigens and adjuvants to antigen-presenting cells (APCs). Although the safety and easy production shifted the vaccine designing platforms toward the subunit vaccines, their efficacy is limited due to inefficient vaccine delivery. Nanotechnology-based vaccines, called nanovaccines, address the delivery limitations through co-delivery of antigens and adjuvants into lymphoid organs and APCs and their intracellular release, leading to cross-presentation of antigens and induction of potent anti-tumor immune responses. Although the nanovaccines, either as encapsulating agents or biomimetic nanoparticles, exert the desired anti-tumor activities, there is evidence that the mixing formulation to form nanocomplexes between antigens and adjuvants based on the electrostatic interactions provokes high levels of immune responses owing to Ags' availability and faster release. Here, we summarized the various platforms for developing cancer vaccines and the advantages of using delivery systems. The cancer nanovaccines, including nanoparticle-based and biomimetic-based nanovaccines, are discussed in detail. Finally, we focused on the nanocomplexes formation between antigens and adjuvants as promising cancer nanovaccine platforms.

Targeted Nanophotoimmunotherapy Potentiates Cancer Treatment by Enhancing Tumor Immunogenicity and Improving the Immunosuppressive Tumor Microenvironment

Cancer immunotherapy, such as immune checkpoint blockade, chimeric antigen receptor, and cytokine therapy, has emerged as a robust therapeutic strategy activating the host immune system to inhibit primary and metastatic lesions. However, low tumor immunogenicity (LTI) and immunosuppressive tumor microenvironment (ITM) severely compromise the killing effect of immune cells on tumor cells, which fail to evoke a strong and effective immune response. As an exogenous stimulation therapy, phototherapy can induce immunogenic cell death (ICD), enhancing the therapeutic effect of tumor immunotherapy. However, the lack of tumor targeting and the occurrence of immune escape significantly reduce its efficacy in vivo, thus limiting its clinical application. Nanophotoimmunotherapy (nano-PIT) is a precision-targeted tumor treatment that co-loaded phototherapeutic agents and various immunotherapeutic agents by specifically targeted nanoparticles (NPs) to improve the effectiveness of phototherapy, reduce its phototoxicity, enhance tumor immunogenicity, and reverse the ITM. This review will focus on the theme of nano-PIT, introduce the current research status of nano-PIT on converting "cold" tumors to "hot" tumors to improve immune efficacy according to the classification of immunotherapy targets, and discuss the challenges, opportunities, and prospects.

Activation of cancer immunotherapy by nanomedicine

Cancer is one of the most difficult diseases to be treated in the world. Immunotherapy has made great strides in cancer treatment in recent years, and several tumor immunotherapy drugs have been approved by the U.S. Food and Drug Administration. Currently, immunotherapy faces many challenges, such as lacking specificity, cytotoxicity, drug resistance, etc. Nanoparticles have the characteristics of small particle size and stable surface function, playing a miraculous effect in anti-tumor treatment. Nanocarriers such as polymeric micelles, liposomes, nanoemulsions, dendrimers, and inorganic nanoparticles have been widely used to overcome deficits in cancer treatments including toxicity, insufficient specificity, and low bioavailability. Although nanomedicine research is extensive, only a few nanomedicines are approved to be used. Either Bottlenecks or solutions of nanomedicine in immunotherapy need to be further explored to cope with challenges. In this review, a brief overview of several types of cancer immunotherapy approaches and their advantages and disadvantages will be provided. Then, the types of nanomedicines, drug delivery strategies, and the progress of applications are introduced. Finally, the application and prospect of nanomedicines in immunotherapy and Chimeric antigen receptor T-cell therapy (CAR-T) are highlighted and summarized to address the problems of immunotherapy the overall goal of this article is to provide insights into the potential use of nanomedicines and to improve the efficacy and safety of immunotherapy.

Nanogels as target drug delivery systems in cancer therapy: A review of the last decade

Cancer is an important cause of morbidity and mortality worldwide, irrespective of the level of human development. Globally, it was estimated that there were 19.3 million new cases of cancer and almost 10 million deaths from cancer in 2020. The importance of prevention, early detection as well as effective cancer therapies cannot be over-emphasized. One of the important strategies in cancer therapy is targeted drug delivery to the specific tumor sites. Nanogels are among the several drug delivery systems (DDS) being explored as potential candidates for targeted drug delivery in cancer therapy. Nanogels, which are new generation, versatile DDS with the possession of dual characteristics of hydrogels and nanoparticles have shown great potential as targeted DDS in cancer therapy. Nanogels are hydrogels with a three-dimensional (3D) tunable porous structure and a particle size in the nanometre range, from 20 to 200 nm. They have been visualized as ideal DDS with enormous drug loading capacity, and high stability. Nanogels can be modified to achieve active targeting and enhance drug accumulation in disease sites. They can be designed to be stimulus-responsive, and react to internal or external stimuli such as pH, temperature, light, redox, thus resulting in the controlled release of loaded drug. This prevents drug accumulation in non-target tissues and minimizes the side effects of the drug. Drugs with severe adverse effects, short circulation half-life, and easy degradability by enzymes, such as anti-cancer drugs, and proteins, are suitable for delivery by chemically cross-linked or physically assembled nanogel systems. This systematic review summarizes the evolution of nanogels for targeted drug delivery for cancer therapy over the last decade. On-going clinical trials and recent applications of nanogels as targeted DDS for cancer therapy will be discussed in detail. The review will be concluded with discussions on safety and regulatory considerations as well as future research prospects of nanogel-targeted drug delivery for cancer therapy.

Bioengineered nanogels for cancer immunotherapy

Recent years have witnessed increasingly rapid advances in nanocarrier-based biomedicine aimed at improving treatment paradigms for cancer. Nanogels serve as multipurpose and constructed vectors formed via intramolecular cross-linking to generate drug delivery systems, which is attributed predominantly to their satisfactory biocompatibility, bio-responsiveness, high stability, and low toxicity. Recently, immunotherapy has experienced unprecedented growth and has become the preferred strategy for cancer treatment, and mainly involves the mobilisation of the immune system and an enhanced anti-tumour immunity of the tumour microenvironment. Despite the inspiring success, immunotherapeutic strategies are limited due to the low response rates and immune-related adverse events. Like other nanomedicines, nanogels are comparably limited by lower focal enrichment rates upon introduction into the organism via injection. Because nanogels are three-dimensional cross-linked aqueous materials that exhibit similar properties to natural tissues and are structurally stable, they can comfortably cope with shear forces and serum proteins in the bloodstream, and the longer circulation life increases the chance of nanogel accumulation in the tumour, conferring deep tumour penetration. The large specific surface area can reduce or eliminate off-target effects by introducing stimuli-responsive functional groups, allowing multiple physical and chemical modifications for specific purposes to improve targeting to specific immune cell subpopulations or immune organs, increasing the bioavailability of the drug, and conferring a low immune-related adverse events on nanogel therapies. The slow release upon reaching the tumour site facilitates long-term awakening of the host's immune system, ultimately achieving enhanced therapeutic effects. As an effective candidate for cancer immunotherapy, nanogel-based immunotherapy has been widely used. In this review, we mainly summarize the recent advances of nanogel-based immunotherapy to deliver immunomodulatory small molecule drugs, antibodies, genes and cytokines, to target antigen presenting cells, form cancer vaccines, and enable chimeric antigen receptor (CAR)-T cell therapy. Future challenges as well as expected and feasible prospects for clinical treatment are also highlighted.

In vitro and in vivo evaluation of DC-targeting PLGA nanoparticles encapsulating heparanase CD4+ and CD8+ T-cell epitopes for cancer immunotherapy

Heparanase has been identified as a universal tumor-associated antigen, but heparanase epitope peptides are difficult to recognize. Therefore, it is necessary to explore novel strategies to ensure efficient delivery to antigen-presenting cells. Here, we established a novel immunotherapy model targeting antigens to dendritic cell (DC) receptors using a combination of heparanase CD4⁺ and CD8⁺ T-cell epitope peptides to achieve an efficient cytotoxic T-cell response, which was associated with strong activation of DCs. First, pegylated poly(lactic-coglycolic acid) (PLGA) nanoparticles (NPs) were used to encapsulate a combined heparanase CD4⁺ and CD8⁺ T-cell epitope alone or in combination with Toll-like receptor 3 and 7 ligands as a model antigen to enhance immunogenicity. The ligands were then targeted to DC cell-surface molecules using a DEC-205 antibody. The binding and internalization of these PLGA NPs and the activation of DCs, the T-cell response and the tumor-killing effect were assessed. The results showed that PLGA NPs encapsulating epitope peptides (mHpa399 + mHpa519) could be targeted to and internalized by DCs more efficiently, stimulating higher levels of IL-12 production, T-cell proliferation and IFN-γ production by T cells in vitro. Moreover, vaccination with DEC-205-targeted PLGA NPs encapsulating combined epitope peptides exhibited higher tumor-killing efficacy both in vitro and in vivo. In conclusion, delivery of PLGA NP vaccines targeting DEC-205 based on heparanase CD4⁺ and CD8⁺ T-cell epitopes are suitable immunogens for antitumor immunotherapy and have promising potential for clinical applications.

Modification of Lipid-Based Nanoparticles: An Efficient Delivery System for Nucleic Acid-Based Immunotherapy

Lipid-based nanoparticles (LBNPs) are biocompatible and biodegradable vesicles that are considered to be one of the most efficient drug delivery platforms. Due to the prominent advantages, such as long circulation time, slow drug release, reduced toxicity, high transfection efficiency, and endosomal escape capacity, such synthetic nanoparticles have been widely used for carrying genetic therapeutics, particularly nucleic acids that can be applied in the treatment for various diseases, including congenital diseases, cancers, virus infections, and chronic inflammations. Despite great merits and multiple successful applications, many extracellular and intracellular barriers remain and greatly impair delivery efficacy and therapeutic outcomes. As such, the current state of knowledge and pitfalls regarding the gene delivery and construction of LBNPs will be initially summarized. In order to develop a new generation of LBNPs for improved delivery profiles and therapeutic effects, the modification strategies of LBNPs will be reviewed. On the basis of these developed modifications, the performance of LBNPs as therapeutic nanoplatforms have been greatly improved and extensively applied in immunotherapies, including infectious diseases and cancers. However, the therapeutic applications of LBNPs systems are still limited due to the undesirable endosomal escape, potential aggregation, and the inefficient encapsulation of therapeutics. Herein, we will review and discuss recent advances and remaining challenges in the development of LBNPs for nucleic acid-based immunotherapy.

Polyethylenimine-coated PLGA nanoparticles containing Angelica sinensis polysaccharide promote dendritic cells activation and associated molecular mechanisms

Cationic PLGA nanoparticles-based delivery systems have been extensively employed as nanocarriers for drugs and antigens in recent years. Herein, we investigated the effects of polyethylenimine-coated PLGA nanoparticles containing Angelica sinensis polysaccharide (ASP) system (ASP-PLGA-PEI) on dendritic cells (DCs) activation and maturation, and further explored the changes of transcriptome and underlying mechanism of DCs activation based on RNA-seq. Our results demonstrated that ASP-PLGA-PEI obviously promoted the activation and maturation of DCs. Meanwhile, RNA-seq analysis results exhibited 2812 differentially expressed genes (DEGs) between ASP-PLGA-PEI and control group, and the DCs activation by ASP-PLGA-PEI stimulation mainly related to phagosome, antigen processing and presentation, proteasome, lysosome, protein processing in endoplasmic reticulum and other pathways by KEGG pathways analysis. Furthermore, ASP-PLGA-PEI nanoparticles increased the levels of pJAK2 protein, and the expression of co-stimulatory molecules and cytokines induced by ASP-PLGA-PEI nanoparticles were decreased with the presence of the inhibitor of JAK2/STAT3 signaling pathway. In addition, the nanoparticles were internalized by DCs mainly through the clathrin-mediated endocytosis and micropinocytosis. These results suggested that the DCs activation and maturation stimulated by ASP-PLGA-PEI were regulated via a complex interaction network, in which the JAK2/STAT3 signaling pathway played a crucial role.

Targeted Anti-Cancer Provascular Therapy Using Ultrasound, Microbubbles, and Nitrite to Increase Radiotherapy Efficacy

Hypoxia is an important mechanism of resistance to radiation therapy in many human malignancies including prostate cancer. It has been recently shown that ultrasound targeted microbubble cavitation (UTMC) can increase blood perfusion in skeletal muscle by triggering nitric oxide signaling. Interestingly, this effect was amplified with a sodium nitrite coinjection. Since sodium nitrite has been shown to synergize with radiotherapy (RT), we hypothesized that UTMC with a sodium nitrite coinjection could further radiosensitize solid tumors by increasing blood perfusion and thus reduce tumor hypoxia. We evaluated (1) the ability of UTMC with and without nitrite to increase perfusion in muscle (mouse hindlimbs) and human prostate tumors using different pulse lengths and pressure; (2) the efficacy of this approach as a provascular therapy given directly before RT in the human prostate subcutaneous xenografts PC3 tumor model. Using long pulses with various pressures, in muscle, the provascular response following UTMC was strong (6.61 ± 4.41-fold increase in perfusion post-treatment). In tumors, long pulses caused an increase in perfusion (2.42 ± 1.38-fold) at lower mechanical index (MI = 0.25) but not at higher MI (0.375, 0.5, and 0.750) when compared to control (no UTMC). However, when combined with RT, UTMC with long pulses (MI = 0.25) did not improve tumor growth inhibition. With short pulses, in muscle, the provascular response following UTMC (SONOS) + nitrite was strong (13.74 ± 8.60-fold increase in perfusion post-treatment). In tumors, UTMC (SONOS) + nitrite also caused a provascular response (1.94 ± 1.20-fold increase in perfusion post-treatment) that lasted for at least 10 min, but not with nitrite alone. Interestingly, the blunted provascular response observed for long pulses at higher MI without nitrite was reversed with the addition of nitrite. UTMC (SONOS) with and without nitrite caused an increase in perfusion in tumors. The provascular response observed for UTMC (SONOS) + nitrite was confirmed by histology. Finally, there was an improved growth inhibition for the 8 Gy RT dose + nitrite + UTMC group vs 8 Gy RT + nitrite alone. This effect was not significant with mice treated by UTMC + nitrite and receiving doses of 0 or 2 Gy RT. In conclusion, UTMC + nitrite increased blood flow leading to an increased efficacy of higher doses of RT in our tumor model, warranting further study of this strategy.

Teleost Fish as an Experimental Model for Vaccine Development

Advances in vaccine development depend on animal models to test innovative therapies. Recent studies have reported the successful introduction of teleost fish as a new vertebrate model in scientific research, with emphasis on the species Danio rerio (zebrafish). This chapter aims to give an overview of important aspects related to the immune system of fish, as well as the current progress of the successful use of these animals in studies for the development of vaccines, assisting in the determination of efficacy and clinical safety. Among the advantages of using fish for the development of vaccines and immunomodulatory drugs, it is worth highlighting the reproductive capacity of these animals resulting in a high number of individuals belonging to the same spawning, transparent embryos, low cost of breeding and high genetic similarity that favor translational responses to vertebrate organisms like humans.

Jug-PLGA-NPs, a New Form of Juglone with Enhanced Efficiency and Reduced Toxicity on Melanoma

OBJECTIVE

To verrify the anti-tumor efficacy and toxicity between juglone (Jug) and Jug-loaded PLGA nanoparticles (Jug-PLGA-NPs).

METHODS

Jug-PLGA-NPs were prepared by ultrasonic emulsification. The anti-tumor activity of Jug (2, 3, 4 µg/mL) and Jug-PLGA-NPs (Jug: 2, 3, 4 µg/mL) in vitro was measured by MTT assay and cell apoptosis analysis. The distribution, anti-tumor effect and biological safety in vivo was evaluated on A375 nude mice.

RESULTS

With the advantage of good penetration and targeting properties, Jug-PLGA-NPs significantly inhibited proliferation and migration of melanoma cells both in vitro and in vivo (P<0.05 or P<0.01) with acceptable biocompatibility.

CONCLUSIONS

Jug can inhibit the growth of melanoma but is highly toxic. With the advantage of sustained release, tumor targeting, anti-tumor activity and acceptable biological safety, Jug-PLGA-NPs provide a new pharmaceutical form for future application of Jug.

Nanofibrous drug delivery systems for breast cancer: a review

Breast cancer is the most common type of cancer among women. Breast-conserving surgery (BCS) is one of the preferred approaches for treating non-invasive or early-stage breast cancers. However, local-regional recurrence (LRR) is one of the critical risk factors after BCS. As many as 10%-20% of BCS cases may show LRR within 5 years and almost 50% within 10 years after surgery. Radiation therapy is one of the preferred treatments used to prevent LRR after BCS. However, because of possible side-effects of radiation therapy, targeted drug delivery systems (DDS) based on nanofibers loaded with anti-cancer drugs have been explored in recent years to control LRR. This paper aims to review different polymers and anti-cancer drugs used for developing nanofibrous DDS against various breast cancer cell lines for their efficacy and advantages. It was observed that the utilization of nanofibers scaffolds after mastectomy could decrease the recurrence of breast cancer cells to a great extent as these nanofibrous scaffolds release drugs in a sustained manner for a prolonged time eliminating the need for radiations. Besides, the side effects of chemotherapy or other aggressive anticancer treatment on healthy cells could also be avoided.

Natural killer (NK) cell-based immunotherapies and the many faces of NK cell memory: A look into how nanoparticles enhance NK cell activity

Natural killer (NK) cells are lymphocytes able to exert potent antitumor and antiviral functions by different means. Besides their classification as innate lymphoid cells (ILCs), NK cells exhibit memory-like and memory responses after cytokine preactivation, viral infections and hapten exposure. Multiple NK cell-based immunotherapies have been developed and are currently being tested, including the possibility to translate the NK cell memory responses into the clinic. Nevertheless, still there is a need to improve these therapies, especially for the treatment of solid tumors, and nanotechnology represents an attractive option to increase NK cell effector functions against transformed cells. In this article, we review the basis of NK cell activity, the diversity of the NK cell memory responses and the current NK cell-based immunotherapies that are being used in the clinic. Furthermore, we take a look into nanotechnology-based strategies targeting NK cells to modulate their responses for effective immunotherapy.

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.

Nanovaccine-Based Strategies to Overcome Challenges in the Whole Vaccination Cascade for Tumor Immunotherapy

Nanovaccine-based immunotherapy (NBI) has received greater attention recently for its potential to prime tumor-specific immunity and establish a long-term immune memory that prevents tumor recurrence. Despite encouraging results in the recent studies, there are still numerous challenges to be tackled for eliciting potent antitumor immunity using NBI strategies. Based on the principles that govern immune response, here it is proposed that these challenges need to be addressed at the five critical cascading events: Loading tumor-specific antigens by nanoscale drug delivery systems (L); Draining tumor antigens to lymph nodes (D); Internalization by dendritic cells (DCs) (I); Maturation of DCs by costimulatory signaling (M); and Presenting tumor-peptide-major histocompatibility complexes to T cells (P) (LDIMP cascade in short). This review provides a detailed and objective overview of emerging NBI strategies to improve the efficacy of nanovaccines in each step of the LDIMP cascade. It is concluded that the balance between each step must be optimized by delicate designing and modification of nanovaccines and by combining with complementary approaches to provide a synergistic immunity in the fight against cancer.

Systemic Immunotherapy with Micellar Resiquimod-Polymer Conjugates Triggers a Robust Antitumor Response in a Breast Cancer Model

Resiquimod is an immunopotent toll-like receptor 7/8 agonist with antitumor activity. Despite being potent against skin cancers, it is poorly tolerated systemically due to toxicity. Integrating resiquimod into nanoparticles presents an avenue to circumvent the toxicity problem. Herein, the preparation of degradable nanoparticles with covalently bound resiquimod and their systemic application in cancer immunotherapy is reported. Dispersion in water of amphiphilic constructs integrating resiquimod covalently bound via degradable amide or ester linkages yields immune-activating nanoparticles. The degradable agonist-nanoparticle bonds allow the release of resiquimod from the carrier nanoparticles. In vitro assays with antigen presenting cells demonstrate that the nanoparticles retain the immunostimulatory activity of resiquimod. Systemic administration of the nanoparticles and checkpoint blockade (aPD-1) to a breast cancer mouse model with multiple established tumors triggers antitumor activity evidenced by suppressed tumor growth and enhanced CD8+ T-cell infiltration. Nanoparticles with ester links, which hydrolyze more readily, yield a stronger immune response with 75% of tumors eliminated when combined with aPD-1. The reduced tumor growth and the presence of activated CD8+ T-cells across multiple tumors suggest the potential for treating metastatic cancer.

Administration Routes of Polyethylenimine-Coated PLGA Nanoparticles Encapsulating Angelica Sinensis Polysaccharide Vaccine Delivery System Affect Immune Responses

Nanoparticle vaccine delivery systems have been emerging strategies for inducing potent immune responses to prevent and treat infectious diseases and cancers. The properties of nanoparticle vaccine delivery systems, such as nanoparticle size, surface charge, and antigen release kinetics, have been extensively studied and proven to effectively influence the efficacy of vaccine responses. However, a few types of research have focused on the influence of administration routes of nanoparticle vaccines on immune responses. Herein, to investigate how the administration routes affect the immune responses of nanoparticles vaccines, we developed a nanoparticles system (NPs), in which the ovalbumin (OVA) and Angelica sinensis polysaccharide (ASP) were incorporated into poly(lactic-co-glycolic acid) (PLGA) nanoparticles and the polyethylenimine (PEI) was coated on the surface of nanoparticles. The NPs vaccine was intramuscularly and subcutaneously injected (im and sc) into mice, and the immune responses induced by these two delivery routes were compared. The results showed that both im and sc administration of NPs vaccines elicited strong antigen-specific IgG, IgG1, and IgG2a antibody responses, with no significant difference. In contrast, NP vaccines with sc administration significantly enhanced immune responses, such as enhancing the recruitment and activation of dendritic cells (DCs) in lymph nodes (LNs), promoting the antigen transport into draining lymph nodes, increasing the secretion of cytokines, improving the ratio of CD4⁺T cells to CD8⁺ T cells, activating cytotoxic T lymphocyte response, and inducing a strong cellular immune response. These results may provide a new insight onto the development of vaccine delivery systems.

Codelivery of STAT3 and PD-L1 siRNA by hyaluronate-TAT trimethyl/thiolated chitosan nanoparticles suppresses cancer progression in tumor-bearing mice

Immunotherapy methods using potential tumor microenvironment modulators have elicited durable therapeutic responses in cancer treatment. Immune checkpoint molecule programmed cell death-ligand 1 (PD-L1) and oncogenic transcription factor STAT3 (signal transducer and activator of transcription-3) assigned as inhibitory targets of our study and particular delivery system designed to deliver small interfering RNAs (siRNAs) to silence the targeted genes. Generated trimethyl chitosan (TMC) and thiolated chitosan (TC) nanoparticles (NPs) conjugated with HIV-1-derived TAT peptide and HA (hyaluronic acid) exhibited eligible physicochemical characteristics, notable siRNA encapsulation, serum stability, non-toxicity, controlled siRNA release, and extensive cellular uptake by cancer cells. Dual inhibition with STAT3/PD-L1 siRNA-loaded HA-TAT-TMC-TC NPs led to promising results, including significant downregulation of PD-L1 and STAT3 genes, striking suppressive effects on proliferation, migration, and angiogenesis of breast and melanoma cancer cell lines, and restrained tumor growth in vivo. These findings infer the capability of HA-TAT-TMC-TC NPs containing STAT3/PD-L1 siRNAs as a novel tumor-suppressive candidate in cancer treatment.

A Review on Nano-Based Drug Delivery System for Cancer Chemoimmunotherapy

Although notable progress has been made on novel cancer treatments, the overall survival rate and therapeutic effects are still unsatisfactory for cancer patients. Chemoimmunotherapy, combining chemotherapeutics and immunotherapeutic drugs, has emerged as a promising approach for cancer treatment, with the advantages of cooperating two kinds of treatment mechanism, reducing the dosage of the drug and enhancing therapeutic effect. Moreover, nano-based drug delivery system (NDDS) was applied to encapsulate chemotherapeutic agents and exhibited outstanding properties such as targeted delivery, tumor microenvironment response and site-specific release. Several nanocarriers have been approved in clinical cancer chemotherapy and showed significant improvement in therapeutic efficiency compared with traditional formulations, such as liposomes (Doxil®, Lipusu®), nanoparticles (Abraxane®) and micelles (Genexol-PM®). The applications of NDDS to chemoimmunotherapy would be a powerful strategy for future cancer treatment, which could greatly enhance the therapeutic efficacy, reduce the side effects and optimize the clinical outcomes of cancer patients. Herein, the current approaches of cancer immunotherapy and chemoimmunotherapy were discussed, and recent advances of NDDS applied for chemoimmunotherapy were further reviewed.

A covalent organic framework as a nanocarrier for synergistic phototherapy and immunotherapy

As traditional cancer treatment methods, photodynamic therapy (PDT) and photothermal therapy (PTT) can eliminate primary tumors, but they cannot inhibit extensive tumor metastasis and local recurrence.

A Multifunctional Cascade Bioreactor Based on Hollow-Structured Cu2 MoS4 for Synergetic Cancer Chemo-Dynamic Therapy/Starvation Therapy/Phototherapy/Immunotherapy with Remarkably Enhanced Efficacy

The unique tumor microenvironment (TME) facilitates cancer proliferation and metastasis, and it is hard to cure cancer completely via monotherapy. Herein, a multifunctional cascade bioreactor based on hollow mesoporous Cu₂ MoS₄ (CMS) loaded with glucose oxidase (GOx) is constructed for synergetic cancer therapy by chemo-dynamic therapy (CDT)/starvation therapy/phototherapy/immunotherapy. The CMS harboring multivalent elements (Cu^1+/2+ , Mo^4+/6+ ) exhibit Fenton-like, glutathione (GSH) peroxidase-like and catalase-like activity. Once internalized into the tumor, CMS could generate ·OH for CDT via Fenton-like reaction and deplete overexpressed GSH in TME to alleviate antioxidant capability of the tumors. Moreover, under hypoxia TME, the catalase-like CMS could react with endogenous H₂ O₂ to generate O₂ for activating the catalyzed oxidation of glucose by GOx for starvation therapy accompanied with the regeneration of H₂ O₂ . The regenerated H₂ O₂ can devote to Fenton-like reaction for realizing GOx-catalysis-enhanced CDT. Meanwhile, the CMS under 1064 nm laser irradiation shows remarkable tumor-killing ability by phototherapy due to its excellent photothermal conversion efficiency (η = 63.3%) and cytotoxic superoxide anion (·O₂ ^- ) generation performance. More importantly, the PEGylated CMS@GOx-based synergistic therapy combined with checkpoint blockade therapy could elicit robust immune responses for both effectively ablating primary tumors and inhibiting cancer metastasis.

Nanotechnology platforms for cancer immunotherapy

Various cancer therapies have advanced remarkably over the past decade. Unlike the direct therapeutic targeting of tumor cells, cancer immunotherapy is a new strategy that boosts the host's immune system to detect specific cancer cells for efficient elimination. Nanoparticles incorporating immunomodulatory agents can activate immune cells and modulate the tumor microenvironment to enhance antitumor immunity. Such nanoparticle-based cancer immunotherapies have received considerable attention and have been extensively studied in recent years. This review thus focuses on nanoparticle-based platforms (especially naturally derived nanoparticles and synthetic nanoparticles) utilized in recent advances; summarizes delivery systems that incorporate various immune-modulating agents, including peptides and nucleic acids, immune checkpoint inhibitors, and other small immunostimulating agents; and introduces combinational cancer immunotherapy with nanoparticles, especially nanoparticle-based photo-immunotherapy and nanoparticle-based chemo-immunotherapy. Undoubtedly, the recent studies introduced in this review prove that nanoparticle-incorporated cancer immunotherapy is a highly promising treatment modality for patients with cancer. Nonetheless further research is needed to solve safety concerns and improve efficacy of nanoplatform-based cancer immunotherapy for future clinical application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Recent advances in nanotheranostics for triple negative breast cancer treatment

Triple-negative breast cancer (TNBC) is the most complex and aggressive type of breast cancer encountered world widely in women. Absence of hormonal receptors on breast cancer cells necessitates the chemotherapy as the only treatment regime. High propensity to metastasize and relapse in addition to poor prognosis and survival motivated the oncologist, nano-medical scientist to develop novel and efficient nanotherapies to solve such a big TNBC challenge. Recently, the focus for enhanced availability, targeted cellular uptake with minimal toxicity is achieved by nano-carriers. These smart nano-carriers carrying all the necessary arsenals (drugs, tracking probe, and ligand) designed in such a way that specifically targets the TNBC cells at site. Articulating the targeted delivery system with multifunctional molecules for high specificity, tracking, diagnosis, and treatment emerged as theranostic approach. In this review, in addition to classical treatment modalities, recent advances in nanotheranostics for early and effective diagnostic and treatment is discussed. This review highlighted the recently FDA approved immunotherapy and all the ongoing clinical trials for TNBC, in addition to nanoparticle assisted immunotherapy. Futuristic but realistic advancements in artificial intelligence (AI) and machine learning not only improve early diagnosis but also assist clinicians for their workup in TNBC. The novel concept of Nanoparticles induced endothelial leakiness (NanoEL) as a way of tumor invasion is also discussed in addition to classical EPR effect. This review intends to provide basic insight and understanding of the novel nano-therapeutic modalities in TNBC diagnosis and treatment and to sensitize the readers for continue designing the novel nanomedicine. This is the first time that designing nanoparticles with stoichiometric definable number of antibodies per nanoparticle now represents the next level of precision by design in nanomedicine.

Drug Delivery for Cancer Immunotherapy and Vaccines

Cancer cells are able to avoid immune surveillance and exploit the immune system to grow and metastasize. With the development of nano- and micro-particles, there has been a growing number of immunotherapy delivery systems developed to elicit innate and adaptive immune responses to eradicate cancer cells. This can be accomplished by training resident immune cells to recognize and eliminate cells with tumor-associated antigens or by providing external stimuli to enhance tumor cell apoptosis in the immunosuppressive tumor microenvironment (TME). In this review we will focus on nano- and micro-particle (NP and MP) based immunotherapies and vaccines used to elicit a potent and sustained antitumor immune response.

Biohybrid Vaccines for Improved Treatment of Aggressive Melanoma with Checkpoint Inhibitor

Recent approaches in the treatment of cancer focus on involving the immune system to control the tumor growth. The administration of immunotherapies, like checkpoint inhibitors, has shown impressive results in the long term survival of patients. Cancer vaccines are being investigated as further tools to prime tumor-specific immunity. Biomaterials show potential as adjuvants in the formulation of vaccines, and biomimetic elements derived from the membrane of tumor cells may widen the range of antigens contained in the vaccine. Here, we show how mice presenting an aggressive melanoma tumor model treated twice with the complete nanovaccine formulation showed control on the tumor progression, while in a less aggressive model, the animals showed remission and control on the tumor progression, with a modification in the immunological profile of the tumor microenvironment. We also prove that co-administration of the nanovaccine together with a checkpoint inhibitor increases the efficacy of the treatment (87.5% of the animals responding, with 2 remissions) compared to the checkpoint inhibitor alone in the B16.OVA model. Our platform thereby shows potential applications as a cancer nanovaccine in combination with the standard clinical care treatment for melanoma cancers.

Protein Transduction Domain Mimics Facilitate Rapid Antigen Delivery into Monocytes

Delivering peptides and proteins with intracellular function represents a promising avenue for therapeutics, but remains a challenge due to the selective permeability of the plasma membrane. The successful delivery of cytosolically active proteins would enable many opportunities, including improved vaccine development through major histocompatibility complex (MHC) class I antigen display. Extended research using cell-penetrating peptides (CPPs) has aimed to facilitate intracellular delivery of exogenous proteins with some success. A new class of polymer-based mimics termed protein transduction domain mimics (PTDMs), which maintain the positive charge and amphiphilic nature displayed by many CPPs, was developed using a poly-norbornene-based backbone. Herein, we use a previously characterized PTDM to investigate delivery of the model antigen SIINFEKL into leukocytes. Peptide delivery into over 90% of CD14+ monocytes was detected in less than 15 min with nominal inflammatory cytokine response and high cell viability. The co-delivery of a TLR9 agonist and antigen using the PTDM into antigen-presenting cells in vitro showed presentation of SIINFEKL in association with MHC class I molecules, in addition to upregulation of classical differentiation markers revealing the ability of the PTDM to successfully deliver cargo intracellularly and show application in the field of immunotherapy.

Combined strategies for tumor immunotherapy with nanoparticles

A brief review of tumor immunotherapies shows significant advancements in academic research and preclinical studies. Analysis of different immune cell pathways, including macrophage activation, natural killer cells, and dendritic cell presentation show promising clinical results when targeted with different nanoparticle polymer and gold materials. Following a brief discussion on immuno-oncology successes, detailed results are discussed in macrophage activation, dendritic cell presentation, and lysis of tumor cells with natural killer cells. Common targets include tumor-associated macrophages and induction of the proinflammatory phenotype, dual targeting of cell and humoral immunity with dendritic cells, and creating chimeric antigen receptors on natural killer cells. An analysis of the results shows a variety of nanoparticle synthesis methods are required depending on drug type and tissue type affected by tumors. Future research is discussed in conjunction with a brief analysis of completed clinical trial data on cancer therapies using nanoparticles to date. Although paclitaxel-loaded albumin nanoparticles are most frequently studied, academic research shows there may be additional mechanisms of action to elicit anti-tumor activity.

Emerging Nano-/Microapproaches for Cancer Immunotherapy

Cancer immunotherapy has achieved remarkable clinical efficacy through recent advances such as chimeric antigen receptor-T cell (CAR-T) therapy, immune checkpoint blockade (ICB) therapy, and neoantigen vaccines. However, application of immunotherapy in a clinical setting has been limited by low durable response rates and immune-related adverse events. The rapid development of nano-/microtechnologies in the past decade provides potential strategies to improve cancer immunotherapy. Advances of nano-/microparticles such as virus-like size, high surface to volume ratio, and modifiable surfaces for precise targeting of specific cell types can be exploited in the design of cancer vaccines and delivery of immunomodulators. Here, the emerging nano-/microapproaches in the field of cancer vaccines, immune checkpoint blockade, and adoptive or indirect immunotherapies are summarized. How nano-/microparticles improve the efficacy of these therapies, relevant immunological mechanisms, and how nano-/microparticle methods are able to accelerate the clinical translation of cancer immunotherapy are explored.

Efficient ovalbumin delivery using a novel multifunctional micellar platform for targeted melanoma immunotherapy

Cancer immunotherapy is considered to be one of the alternatives to traditional chemotherapy. It's known that foreign antigen, such as ovalbumin (OVA), can label tumor cells, leading to neoantigen recognition by cytotoxic T lymphocytes. Herein, a novel multifunctional micelle coated with PEGylated hyaluronic acid (HA) was prepared through self-assembly and electrostatic interaction. The OVA-loaded micelle with uniform size (132.1 ± 0.2 nm in diameter) exhibited favorable stability and sustained release profiles. The HA-coated micelle could target CD44-overexpressed cells and enhance the cellular uptake of OVA by 11.9 fold compared to free OVA. In vitro studies revealed that the cationic polymer, polyethyleneimine, could facilitate endosomal escape of OVA to label a tumor cell. After treatment with the OVA-loaded micelle, tumor growth in mice was significantly inhibited by 70% compared to the group treated with free OVA. All these results suggest the potential application of the immunotherapeutic micellar platform for melanoma treatment.

SPIO Enhance the Cross-Presentation and Migration of DCs and Anionic SPIO Influence the Nanoadjuvant Effects Related to Interleukin-1β

Superparamagnetic iron oxide nanoparticles (SPIO) have been synthesized and explored for use as carriers of various nanoadjuvants via loading into dendritic cells (DCs). In our study, homogeneous and superparamagnetic nanoparticles are susceptible to internalization by DCs and SPIO-pulsed DCs showed excellent biocompatibility and capacity for ovalbumin (OVA) cross-presentation. Herein, we found that SPIO-loaded DCs can promote the maturation and migration of DCs in vitro. SPIO coated with 3-aminopropyltrimethoxysilane (APTS) and meso-2,3-dimercaptosuccinic acid (DMSA), which present positive and negative charges, respectively, were prepared. We aimed to investigate whether the surface charge of SPIO can affect the antigen cross-presentation of the DCs. Additionally, the formation of interleukin-1β (IL-1β) was examined after treatment with oppositely charged SPIO to identify the nanoadjuvants mechanism. In conclusion, our results suggest that SPIO are biocompatible and can induce the migration of DCs into secondary lymph nodes. SPIO coated with APTS (SPIO/A⁺) exhibited excellent adjuvant potentials for the promotion of antigen cross-presentation and T cell activation and surpassed that of DMSA-coated nanoparticles (SPIO/D^-). This process may be related to the secretion of IL-1β. Our study provides insights into the predictive modification of nanoadjuvants, which will be valuable in DC vaccine design and could lead to the creation of new adjuvants for applications in vaccines for humans.

Unimicellar hyperstars as multi-antigen cancer nanovaccines displaying clustered epitopes of immunostimulating peptides

Unimicellar hyperstar macromolecular chimeras displaying multiple melanoma peptide antigens were prepared primarily via a combination of click chemistry and esterification reactions starting from a biodegradable hyperbranched polymer template. Solubilization of the hyperstars in aqueous solution afforded a multi-antigen unimicellar cancer nanovaccine of about 20 nm. The nanovaccine showed good biocompatibility and uptake by dendritic cells in vitro. An in vivo evaluation of the nanovaccine therapeutic efficacy against melanoma in mice implanted with B16OVA tumors revealed significantly greater T-cell recruitment and improved survival rates for mice treated with nanovaccine and adjuvant compared to non-treated mice.

Targeting antigen-presenting cells by anti-PD-1 nanoparticles augments antitumor immunity

Recent studies in cancer research have focused intensely on the antineoplastic effects of immune checkpoint inhibitors. While the development of these inhibitors has progressed successfully, strategies to further improve their efficacy and reduce their toxicity are still needed. We hypothesized that the delivery of anti-PD-1 antibody encapsulated in PLGA nanoparticles (anti-PD-1 NPs) to the spleen would improve the antitumor effect of this agent. Unexpectedly, we found that mice treated with a high dose of anti-PD-1 NPs exhibited significantly higher mortality compared with those treated with free anti-PD-1 antibody, due to the overactivation of T cells. Administration of anti-PD-1 NPs to splenectomized LT-α-/- mice, which lack both lymph nodes and spleen, resulted in a complete reversal of this increased mortality and revealed the importance of secondary lymphoid tissues in mediating anti-PD-1-associated toxicity. Attenuation of the anti-PD-1 NPs dosage prevented toxicity and significantly improved its antitumor effect in the B16-F10 murine melanoma model. Furthermore, we found that anti-PD-1 NPs undergo internalization by DCs in the spleen, leading to their maturation and the subsequent activation of T cells. Our findings provide important clues that can lead to the development of strategies to enhance the efficacy of immune checkpoint inhibitors.

Self-Assembled, Adjuvant/Antigen-Based Nanovaccine Mediates Anti-Tumor Immune Response against Melanoma Tumor

Malignant melanoma is a highly aggressive type of cancer that requires radical treatment strategies to inhibit the cancer cell progression and metastasis. In recent years, preclinical research and clinical trials on melanoma treatment have been considerably focused on the adjuvant-based immunotherapy for enhancing the immune response of innate immune cells against cancer cells. However, the clinical outcome of these adjuvant-based treatments is inadequate due to an improper delivery system for these immune activators to reach the target site. Hence, we developed a vaccine formulation containing tumor lysate protein (TL) and poly I:C (PIC) complexed with positively charged poly (sorbitol-co-polyethylenimine (PEI) (PSPEI). The resulting ionic PSPEI-polyplexed antigen/adjuvant (PAA) (PSPEI-PAA) nanocomplexes were stable at the physiological condition, are non-toxic, and have enhanced intracellular uptake of antigen and adjuvant in immature dendritic cells leading to dendritic cell maturation. In the murine B16F10 tumor xenograft model, PSPEI-PAA nanocomplexes significantly suppressed tumor growth and did not exhibit any noticeable sign of toxicity. The level of matured dendritic cells (CD80+/CD86+ cells) in the tumor draining lymph node of PSPEI-PAA treated tumor mice were enhanced and therefore CD8+ T cells infiltration in the tumor were enriched. Additionally, the cytotoxic T lymphocytes (CTLs) assay involving co-culturing of splenocytes isolated from the PSPEI-PAA-treated mice with that of B16F10 cells significantly revealed enhanced cancer killing by the TL-reactivated CTLs compared to untreated control mice bearing tumor. Therefore, we strongly believe that PSPEI-PAA nanocomplexes could be an efficient antigen/adjuvant delivery system and enhance the antitumor immune response against melanoma tumor in the future clinical trials.

Ultrasound-mediated microbubble destruction: a new method in cancer immunotherapy

Immunotherapy provides a new treatment option for cancer. However, it may be therapeutically insufficient if only using the self-immune system alone to attack the tumor without any aiding methods. To overcome this drawback and improve the efficiency of therapy, new treatment methods are emerging. In recent years, ultrasound-mediated microbubble destruction (UMMD) has shown great potential in cancer immunotherapy. Using the combination of ultrasound and targeted microbubbles, molecules such as antigens or genes encoding antigens can be efficiently and specifically delivered into the tumor tissue. This review focuses on the recent progress in the application of UMMD in cancer immunotherapy.

Integration of nano drug-delivery system with cancer immunotherapy

Immune checkpoint therapy represents a new, revolutionary type of cancer therapy, but emerging evidence indicates that only a minority of patients will benefit from it. The issue of how to improve and widen the clinical response is a pivotal issue, and combining other types of therapy with immune checkpoint inhibitors is currently under development. A nanotechnology-based drug-delivery system (nano DDS) could be an important contribution to the development of an effective combination therapy. In this document, we review recent findings in the field of tumor immunology, which provide a strategy for an efficient combination therapy, and discuss nano DDS that are associated with cancer immunotherapy and nano DDS strategies based on the immune status in tumor microenvironments.

Modulating T-cell-based cancer immunotherapy via particulate systems

Immunotherapy holds tremendous promise for improving cancer treatment in which an appropriate stimulator may naturally trigger the immune system to control cancer. Up-to-date, adoptive T-cell therapy has received two new FDA approvals that provide great hope for some cancer patient groups. Nevertheless, expense and safety-related issues require further study to obtain insight into targets for efficient immunotherapy. The development of material science was largely responsible for providing a promising horizon to strengthen immunoengineering. In this review, we focus on T-cell characteristics in the context of the immune system against cancer and discuss several approaches of exploiting engineered particles to manipulate the responses of T cells and the tumour microenvironment.

Immunocompetence and mechanism of the DRibble-DCs vaccine for oral squamous cell carcinoma

Background

Due to the high-quality immunogenicity of tumor-derived autophagosomes (DRibbles), we aimed to explore the antitumor ability and mechanism of DRibble-loaded dendritic cells (DRibble-DCs).

Materials and methods

DRibbles extracted from the oral squamous cell carcinoma cell line SCC7 express specific LC3-II and ubiquitination marker. Immunization of mice with the DRibble-DCs vaccine led to the proliferation and differentiation of CD3⁺CD4⁺IFN-γ⁺ and CD3⁺CD8⁺IFN-γ⁺ T cells. The expression of proteins in endoplasmic reticulum stress (ERS) pathways was determined by Western blotting. Additionally, the functional properties of the DRibble-DCs were examined in mice, and regulatory T cells were measured by flow cytometry.

Results

Excellent biocompatibility was observed in vitro when DCs were loaded with DRibbles. T cells of lymph nodes and spleens from mice immunized with DRibble-DCs had cytotoxic effects on SCC7 cells. DCs homeostasis and ERS-related proteins were affected by DRibbles. Moreover, the DRibble-DCs vaccine achieved significantly better antitumor efficacy than DRibbles and tumor cell lysate-loaded DCs.

Conclusion

The results validated the antitumor immune responses to the DRibble-DCs vaccine in vivo and in vitro. The ERS pathway can be affected by DRibbles.

Nanotechnology Approaches to Improving Cancer Immunotherapy

Cancer immunotherapy is a powerful, growing treatment approach to cancer that can be combined with chemotherapy, radiotherapy, and oncosurgery. Modulating the immune system to enhance anticancer response by several strategies has yielded improved cancer survival. Despite this progress, the success rate for immunotherapy has been below expectations due to unpredictable efficacy and off-target side effects from systemic dosing. Nanotechnology offers numerous different materials and targeting properties to overcome many of these challenges in immunotherapy. In this chapter, we review current immunotherapy and its challenges as well as the latest nanotechnology applications in cancer immunotherapy.