Advancing Cancer Immunotherapies with Nanotechnology

Recent advances in the development of poly(ester amide)s-based carriers for drug delivery

Biodegradable and biocompatible biomaterials have several important applications in drug delivery. The biomaterial family known as poly(ester amide)s (PEAs) has garnered considerable interest because it exhibits the benefits of both polyester and polyamide, as well as production from readily available raw ingredients and sophisticated synthesis techniques. Specifically, α-amino acid-based PEAs (AA-PEAs) are promising carriers because of their structural flexibility, biocompatibility, and biodegradability. Herein, we summarize the latest applications of PEAs in drug delivery systems, including antitumor, gene therapy, and protein drugs, and discuss the prospects of drug delivery based on PEAs, which provides a reference for designing safe and efficient drug delivery carriers.

Photodynamic and Photothermal Therapies: Synergy Opportunities for Nanomedicine

Tumoricidal photodynamic (PDT) and photothermal (PTT) therapies harness light to eliminate cancer cells with spatiotemporal precision by either generating reactive oxygen species or increasing temperature. Great strides have been made in understanding biological effects of PDT and PTT at the cellular, vascular and tumor microenvironmental levels, as well as translating both modalities in the clinic. Emerging evidence suggests that PDT and PTT may synergize due to their different mechanisms of action, and their nonoverlapping toxicity profiles make such combination potentially efficacious. Moreover, PDT/PTT combinations have gained momentum in recent years due to the development of multimodal nanoplatforms that simultaneously incorporate photodynamically- and photothermally active agents. In this review, we discuss how combining PDT and PTT can address the limitations of each modality alone and enhance treatment safety and efficacy. We provide an overview of recent literature featuring dual PDT/PTT nanoparticles and analyze the strengths and limitations of various nanoparticle design strategies. We also detail how treatment sequence and dose may affect cellular states, tumor pathophysiology and drug delivery, ultimately shaping the treatment response. Lastly, we analyze common experimental design pitfalls that complicate preclinical assessment of PDT/PTT combinations and propose rational guidelines to elucidate the mechanisms underlying PDT/PTT interactions.

Leveraging β-Adrenergic Receptor Signaling Blockade for Improved Cancer Immunotherapy Through Biomimetic Nanovaccine

The establishment of effective antitumor immune responses of vaccines is mainly limited by insufficient priming tumor infiltration of T cells and immunosuppressive tumor microenvironment (TME). Targeting β-adrenergic receptor (β-AR) signaling exerts promising benefits on reversing the suppressive effects directly on T cells, but it appears to have considerably limited antitumor performance when combined with vaccine-based immunotherapies. Herein, a tumor membrane-coated nanoplatform for codelivery of adjuvant CpG and propranolol (Pro), a β-AR inhibitor is designed. The biomimetic nanovaccine displayed an improved accumulation in lymph nodes and sufficient drug release, thereby inducing dendritic cell maturation and antigen presentation. Meanwhile, the integration of vaccination and blockade of β-AR signaling not only promoted the priming of the naive CD8+ T cells and effector T cell egress from lymph nodes, but also alleviated the immunosuppressive TME by decreasing the frequency of immunosuppressive cells and increasing the tumor infiltration of B cells and NK cells. Consequently, the biomimetic nanovaccines outperformed greater prophylactic and therapeutic efficacy than nanovaccines without Pro encapsulation in B16-F10 melanoma mice. Taken together, the work explored a biomimetic nanovaccine for priming tumor infiltration of T cells and immunosuppressive TME regulation, offering tremendous potential for a combined β-AR signaling-targeting strategy in cancer immunotherapy.

Role of Nanomedicine-Based Therapeutics in the Treatment of CNS Disorders

Central nervous system disorders, especially neurodegenerative diseases, are a public health priority and demand a strong scientific response. Various therapy procedures have been used in the past, but their therapeutic value has been insufficient. The blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier is two of the barriers that protect the central nervous system (CNS), but are the main barriers to medicine delivery into the CNS for treating CNS disorders, such as brain tumors, Parkinson's disease, Alzheimer's disease, and Huntington's disease. Nanotechnology-based medicinal approaches deliver valuable cargos targeting molecular and cellular processes with greater safety, efficacy, and specificity than traditional approaches. CNS diseases include a wide range of brain ailments connected to short- and long-term disability. They affect millions of people worldwide and are anticipated to become more common in the coming years. Nanotechnology-based brain therapy could solve the BBB problem. This review analyzes nanomedicine's role in medication delivery; immunotherapy, chemotherapy, and gene therapy are combined with nanomedicines to treat CNS disorders. We also evaluated nanotechnology-based approaches for CNS disease amelioration, with the intention of stimulating the immune system by delivering medications across the BBB.

Nanomaterials in anticancer applications and their mechanism of action - A review

The current challenges in cancer treatment using conventional therapies have made the emergence of nanotechnology with more advancements. The exponential growth of nanoscience has drawn to develop nanomaterials (NMs) with therapeutic activities. NMs have enormous potential in cancer treatment by altering the drug toxicity profile. Nanoparticles (NPs) with enhanced surface characteristics can diffuse more easily inside tumor cells, thus delivering an optimal concentration of drugs at tumor site while reducing the toxicity. Cancer cells can be targeted with greater affinity by utilizing NMs with tumor specific constituents. Furthermore, it bypasses the bottlenecks of indiscriminate biodistribution of the antitumor agent and high administration dosage. Here, we focus on the recent advances on the use of various nanomaterials for cancer treatment, including targeting cancer cell surfaces, tumor microenvironment (TME), organelles, and their mechanism of action. The paradigm shift in cancer management is achieved through the implementation of anticancer drug delivery using nano routes.

Metabolic signatures associated with oncolytic myxoma viral infections

Oncolytic viral therapy is a recent advance in cancer treatment, demonstrating promise as a primary treatment option. To date, the secondary metabolic effects of viral infection in cancer cells has not been extensively studied. In this work, we have analyzed early-stage metabolic changes in cancer cells associated with oncolytic myxoma virus infection. Using GC–MS based metabolomics, we characterized the myxoma virus infection induced metabolic changes in three cancer cell lines—small cell (H446) and non-small cell (A549) lung cancers, and glioblastoma (SFxL). We show that even at an early stage (6 and 12 h) myxoma infection causes profound changes in cancer cell metabolism spanning several important pathways such as the citric acid cycle, fatty acid metabolism, and amino acid metabolism. In general, the metabolic effects of viral infection across cell lines are not conserved. However, we have identified several candidate metabolites that can potentially serve as biomarkers for monitoring oncolytic viral action in general.

Immunization of Mice with Gold Nanoparticles Conjugated to Thermostable Cancer Antigens Prevents the Development of Xenografted Tumors

Gold nanoparticles as part of vaccines greatly increase antigen stability, antigen accumulation in the lymph nodes, and antigen uptake by antigen-presenting cells. The use of such particles as part of anticancer vaccines based on heat shock proteins to increase vaccine effectiveness is timely. We prepared and characterized nanoconjugates based on 15-nm gold nanoparticles and thermostable tumor antigens isolated from MH22a murine hepatoma cells. The whole-cell lysate of MH22a cells contained the main heat shock proteins. BALB/c mice were injected with the conjugates and then received transplants of MH22a cells. The highest titer was produced in mice immunized with the complex of gold nanoparticles + antigen with complete Freund's adjuvant. The immunized mice showed no signs of tumor growth for 24 days. They also showed a decreased production of the INF-γ, IL-6, and IL-1 proinflammatory cytokines compared to the mice immunized through other schemes. This study is the first to show that it is possible in principle to use gold nanoparticles in combination with thermostable tumor antigens for antitumor vaccination. Antitumor vaccines based on thermostable tumor antigens can be largely improved by including gold nanoparticles as additional adjuvants.

Monte Carlo Simulation-Guided Design of a Thorium-Based Metal-Organic Framework for Efficient Radiotherapy-Radiodynamic Therapy

High-Z metal-based nanoscale metal-organic frameworks (nMOFs) with photosensitizing ligands can enhance radiation damage to tumors via a unique radiotherapy-radiodynamic therapy (RT-RDT) process. Here we report Monte Carlo (MC) simulation-guided design of a Th-based nMOF built from Th6 -oxo secondary building units and 5,15-di(p-benzoato)porphyrin (DBP) ligands, Th-DBP, for enhanced RT-RDT. MC simulations revealed that the Th-lattice outperformed the Hf-lattice in radiation dose enhancement owing to its higher mass attenuation coefficient. Upon X-ray or γ-ray radiation, Th-DBP enhanced energy deposition, generated more reactive oxygen species, and induced significantly higher cytotoxicity to cancer cells over the previously reported Hf-DBP nMOF. With low-dose X-ray irradiation, Th-DBP suppressed tumor growth by 88 % in a colon cancer and 97 % in a pancreatic cancer mouse model.

Nanoparticle-Based Therapeutics to Overcome Obstacles in the Tumor Microenvironment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is still a main health concern around the world, with a rising incidence and high mortality rate. The tumor-promoting components of the tumor microenvironment (TME) play a vital role in the development and metastasis of HCC. TME-targeted therapies have recently drawn increasing interest in the treatment of HCC. However, the short medication retention time in TME limits the efficiency of TME modulating strategies. The nanoparticles can be elaborately designed as needed to specifically target the tumor-promoting components in TME. In this regard, the use of nanomedicine to modulate TME components by delivering drugs with protection and prolonged circulation time in a spatiotemporal manner has shown promising potential. In this review, we briefly introduce the obstacles of TME and highlight the updated information on nanoparticles that modulate these obstacles. Furthermore, the present challenges and future prospects of TME modulating nanomedicines will be briefly discussed.

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

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

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

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

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

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The minimalist nanovaccine had excellent stability and antitumor immune activation.

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

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Good practicability for expanding clinical translation and personalized therapy.

Introduction

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

Objectives

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

Methods

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

Results

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

Conclusion

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

Preparation and Anti-tumor Study of Dextran 70,000-Selenium Nanoparticles and Poloxamer 188-Selenium Nanoparticles

The anti-tumor effect of selenium nanoparticles (SeNPs) has received more and more attention. However, the clinical application of SeNPs is not optimistic due to the poor stability. To improve the stability of SeNPs, many polymers are used to modify the SeNPs. However, most of the polymers are not approved by FDA. It is significant to develop a SeNPs product with good stability for clinic application. Dextran 70,000 (T70) and poloxamer 188 (P188) are FDA-approved pharmaceutical injection excipients. In this study, we decorate SeNPs with T70 and P188 and assess the physicochemical characterization, storage stability, and anti-tumor activities of T70-SeNPs and P188-SeNPs. Transmission electron microscopy (TEM) shows that T70-SeNPs and P188-SeNPs are spherical particles with particle sizes of 110 nm and 60 nm respectively. Fourier-Transform Infrared Spectra (FT-IR) show that T70 or P188 can interact with SeNPs through hydrogen bonding. Stability study shows that P188-SeNPs freeze-dried powder and T70-SeNPs freeze-dried powder remain stable at 4℃ for 6 months. T70-SeNPs and P188-SeNPs can aggregate in cell matrix and play an anti-tumor role to HepG2 by promoting apoptosis, increasing reactive oxygen species (ROS) content and reducing mitochondrial membrane potential (MMP). This study can provide reference for industrial production of SeNPs products.

Ferroptosis in cancer therapeutics: a materials chemistry perspective

Ferroptosis, distinct from apoptosis, is a regulated form of cell death caused by lipid peroxidation that has attracted extensive research interest since it was first defined in 2012. Over the past five years, an increasing number of studies have revealed the close relationship between ferroptosis and materials chemistry, in particular nanobiotechnology, and have concluded that nanotechnology-triggered ferroptosis is an efficient and promising antitumor strategy that provides an alternative therapeutic approach, especially for apoptosis-resistant tumors. In this review, we summarize recent advances in ferroptosis-induced tumor therapy at the intersection of materials chemistry, redox biology, and tumor biology. The biological features and molecular mechanisms of ferroptosis are first outlined, followed by a summary of the feasible strategies to induce ferroptosis using nanomaterials and the applications of ferroptosis in combined tumor therapy. Finally, the existing challenges and future development directions in this emerging field are discussed, with the aim of promoting the progress of ferroptosis-based oncotherapy in materials science and nanoscience and enriching the antitumor arsenal.

Multifunctional lipidic nanocarriers for effective therapy of glioblastoma: recent advances in stimuli-responsive, receptor and subcellular targeted approaches

Background

Glioblastoma, or glioblastoma multiforme (GBM), remains a fatal cancer type despite the remarkable progress in understanding the genesis and propagation of the tumor. Current treatment modalities, comprising mainly of surgery followed by adjuvant chemoradiation, are insufficient for improving patients' survival owing to existing hurdles, including the blood–brain barrier (BBB). In contemporary practice, the prospect of long-term survival or cure continues to be a challenge for patients suffering from GBM. This review provides an insight into the drug delivery strategies and the significant efforts made in lipid-based nanoplatform research to circumvent the challenges in optimal drug delivery in GBM.

Area covered

Owing to the unique properties of lipid-based nanoplatforms and advancements in clinical translation, this article describes the application of various stimuli-responsive lipid nanocarriers and tumor subcellular organelle-targeted therapy to give an idea about the strategies that can be applied to enhance site-specific drug delivery for GBM. Furthermore, active targeting of drugs via surface-modified lipid-based nanostructures and recent findings in alternative therapeutic platforms such as gene therapy, immunotherapy, and multimodal therapy have also been overviewed.

Expert opinion

Lipid-based nanoparticles stand out among the other nanocarriers explored for GBM drug delivery, as they support both passive and active drug targeting by crossing/bypassing the BBB at the same time minimizing toxicity and projects better pharmacological parameters. Although these nanocarriers could be a plausible choice for treating GBM, in-depth research is essential to advance neuro-oncology research and enhance outcomes in patients with brain tumors.

Molecular Perspective of Nanoparticle Mediated Therapeutic Targeting in Breast Cancer: An Odyssey of Endoplasmic Reticulum Unfolded Protein Response (UPRER) and Beyond

Breast cancer (BC) is the second most frequent cause of death among women. Representing a complex and heterogeneous type of cancer, its occurrence is attributed by both genetic (gene mutations, e.g., BRCA1, BRCA2) and non-genetic (race, ethnicity, etc.) risk factors. The effectiveness of available treatment regimens (small molecules, cytotoxic agents, and inhibitors) decreased due to their poor penetration across biological barriers, limited targeting, and rapid body clearance along with their effect on normal resident cells of bone marrow, gastrointestinal tract, and hair follicles. This significantly reduced their clinical outcomes, which led to an unprecedented increase in the number of cases worldwide. Nanomedicine, a nano-formulation of therapeutics, emerged as a versatile delivering module for employment in achieving the effective and target specific delivery of pharmaceutical payloads. Adoption of nanotechnological approaches in delivering therapeutic molecules to target cells ensures not only reduced immune response and toxicity, but increases the stability of therapeutic entities in the systemic circulation that averts their degradation and as such increased extravasations and accumulation via enhanced permeation and the retention (EPR) effect in target tissues. Additionally, nanoparticle (NP)-induced ER stress, which enhances apoptosis and autophagy, has been utilized as a combative strategy in the treatment of cancerous cells. As nanoparticles-based avenues have been capitalized to achieve better efficacy of the new genera of therapeutics with enhanced specificity and safety, the present study is aimed at providing the fundamentals of BC, nanotechnological modules (organic, inorganic, and hybrid) employed in delivering different therapeutic molecules, and mechanistic insights of nano-ER stress induced apoptosis and autophagy with a perspective of exploring this avenue for use in the nano-toxicological studies. Furthermore, the current scenario of USA FDA approved nano-formulations and the future perspective of nanotechnological based interventions to overcome the existing challenges are also discussed.

Recent Advances in Cell Membrane-Derived Biomimetic Nanotechnology for Cancer Immunotherapy

Immunotherapy will significantly impact the standard of care in cancer treatment. Recent advances in nanotechnology can improve the efficacy of cancer immunotherapy. However, concerns regarding efficiency of cancer nanomedicine, complex tumor microenvironment, patient heterogeneity, and systemic immunotoxicity drive interest in more novel approaches to be developed. For this purpose, biomimetic nanoparticles are developed to make innovative changes in the delivery and biodistribution of immunotherapeutics. Biomimetic nanoparticles have several advantages that can advance the clinical efficacy of cancer immunotherapy. Thus there is a greater push toward the utilization of biomimetic nanotechnology for developing effective cancer immunotherapeutics that demonstrate increased specificity and potency. The recent works and state-of-the-art strategies for anti-tumor immunotherapeutics are highlighted here, and particular emphasis has been given to the applications of cell-derived biomimetic nanotechnology for cancer immunotherapy.

Recent Advances in Nanotechnology for the Treatment of Melanoma

Melanoma is one of the most aggressive forms of skin cancer, with few possibilities for therapeutic approaches, due to its multi-drug resistance and, consequently, low survival rate for patients. Conventional therapies for treatment melanoma include radiotherapy, chemotherapy, targeted therapy, and immunotherapy, which have various side effects. For this reason, in recent years, pharmaceutical and biomedical research has focused on new sito-specific alternative therapeutic strategies. In this regard, nanotechnology offers numerous benefits which could improve the life expectancy of melanoma patients with very low adverse effects. This review aims to examine the latest advances in nanotechnology as an innovative strategy for treating melanoma. In particular, the use of different types of nanoparticles, such as vesicles, polymers, metal-based, carbon nanotubes, dendrimers, solid lipid, microneedles, and their combination with immunotherapies and vaccines will be discussed.

Point-source burst of coordination polymer nanoparticles for tri-modality cancer therapy

Cancer immunotherapy, particularly the inhibition of immune checkpoints with neutralizing antibodies, has revolutionized the treatment of some cancer patients. However, immune checkpoint blockade has not provided survival benefits to most patients with colorectal and ovarian cancers. This work reports the design of acid-sensitive core-shell nanoscale coordination polymer particles (NCP) comprising a carboplatin prodrug and an siRNA against PD-L1 (siPD-L1) in the core and digitoxin on the shell for tri-modality cancer therapy. Upon cellular uptake, NCP particles rapidly burst in acidic organelles to release carboplatin for apoptosis, digitoxin for inducing immunogenicity, and siPD-L1 for PD-L1 knockdown. With long blood circulation and high tumor accumulation, NCP particles efficiently suppress the growth and metastasis of syngeneic cancers through reactivating innate and adaptive immune responses. NCP particles thus provide a promising platform to synergistically combine chemotherapy and immunotherapy for the treatment of advanced and aggressive cancers.

Sequential Treatment of Bioresponsive Nanoparticles Elicits Antiangiogenesis and Apoptosis and Synergizes with a CD40 Agonist for Antitumor Immunity

The combination of antiangiogenesis and chemotherapy regimens with cancer immunotherapy has the potential to synergistically boost antitumor immunity. Herein, we report the construction of two bioresponsive nanoparticles, namely, Podo-NP and CbP-NP, comprising prodrugs of podophyllotoxin (Podo) and carboplatin, respectively. Sequential treatment with esterase-responsive Podo-NP, redox-sensitive CbP-NP, and a CD40 agonist promotes antitumor T cell response. Podo-NP suppresses angiogenesis by preventing proliferation and migration of endothelial cells, sprouting of neovessels, formation of tubules, and stabilization of newly formed vessels. Vascular endothelial growth factor blockade and endostatin stimulation normalize tortuous tumor vasculatures to allow efficient infiltration of effector immune cells. Subsequent treatment with CbP-NP arrests the cell-division cycle and elicits the apoptosis of tumor cells. CD40 agonist activates antigen-presenting cells to process the released tumor-associated antigens from dying tumor cells, thus reversing immunosuppressive tumor microenvironments. Sequential delivery of antiangiogenic and chemotherapeutic agents with bioresponsive NPs activates tumor microenvironments and synergizes with CD40 agonist to regress transplanted tumors and inhibit disseminated tumors in a lung cancer mouse model.

Activatable Polymer Nanoenzymes for Photodynamic Immunometabolic Cancer Therapy

Tumor immunometabolism contributes substantially to tumor proliferation and immune cell activity, and thus plays a crucial role in the efficacy of cancer immunotherapy. Modulation of immunometabolism to boost cancer immunotherapy is mostly based on small-molecule inhibitors, which often encounter the issues of off-target adverse effects, drug resistance, and unsustainable response. In contrast, enzymatic therapeutics can potentially bypass these limitations but has been less exploited. Herein, an organic polymer nanoenzyme (SPNK) with near-infrared (NIR) photoactivatable immunotherapeutic effects is reported for photodynamic immunometabolic therapy. SPNK is composed of a semiconducting polymer core conjugated with kynureninase (KYNase) via PEGylated singlet oxygen (¹ O₂ ) cleavable linker. Upon NIR photoirradiation, SPNK generates ¹ O₂ not only to exert photodynamic effect to induce the immunogenic cell death of cancer, but also to unleash KYNase and trigger its activity to degrade the immunosuppressive kynurenine (Kyn). Such a combinational effect mediated by SPNK promotes the proliferation and infiltration of effector T cells, enhances systemic antitumor T cell immunity, and ultimately permits inhibition of both primary and distant tumors in living mice. Therefore, this study provides a promising photodynamic approach toward remotely controlled enzymatic immunomodulation for improved anticancer therapy.

Nanoscale metal-organic frameworks for x-ray activated in situ cancer vaccination

Cancer vaccines have been actively pursued to bolster antitumor immunity. Here, we designed nanoscale metal-organic frameworks (nMOFs) as locally activable immunotherapeutics to release danger-associated molecular patterns (DAMPs) and tumor antigens and deliver pathogen-associated molecular patterns (PAMPs) for in situ personalized cancer vaccination. When activated by x-rays, nMOFs effectively generate reactive oxygen species to release DAMPs and tumor antigens while delivering CpG oligodeoxynucleotides as PAMPs to facilitate the maturation of antigen-presenting cells. Together, DAMPs, tumor antigens, and PAMPs expand cytotoxic T cells in tumor-draining lymph nodes to reinvigorate the adaptive immune system for local tumor regression. When treated in combination with an immune checkpoint inhibitor, the local therapeutic effects of nMOF-based vaccines were extended to distant tumors via attenuating T cell exhaustion. Our work demonstrates the potential of nMOFs as x-ray-activable in situ cancer vaccines to awaken the host's innate and adaptive immune systems for systemic antitumor immunity.

When liposomes met antibodies: Drug delivery and beyond

Drug encapsulated liposomes and monoclonal antibodies (Mabs) are two distinctively different classes of therapeutics, but both aim to become the ultimate "magic bullet". While PEGylated liposomes rely on the enhanced permeability and retention (EPR) effect for accumulation in solid tumor tissues, Mabs are designed to bind tightly to specific surface antigens on target cells to exert effector functions. Immunoliposome (IL) refers to the structural combination of liposomes and antibodies, whereas the antibodies are usually decorated on the liposome surface. ILs can therefore take advantage of interactions between antibodies and cancer cells for more efficient endocytosis and intracellular drug delivery. The antibody structure, affinity, density, as well as the liposome surface properties and drug to lipid ratios all contribute to the IL pharmacokinetic(PK) and pharmacodynamic(PD) behaviors. The optimal formulation parameters may vary for different target cells and tissues. Furthermore, besides the delivery of cytotoxic drugs to cancer cells, new ILs are being developed to interact with multiple target receptors, multiple target cells and trigger multiple therapeutic effects. We envision that the IL format can be a great platform for the molecular engineering of multi-valent, multi-specific interactions to achieve complex biological functions for therapeutic benefits, especially in the area of cancer immunotherapy.

Nanoscale Metal-Organic Framework Co-delivers TLR-7 Agonists and Anti-CD47 Antibodies to Modulate Macrophages and Orchestrate Cancer Immunotherapy

Nanoscale metal-organic frameworks (nMOFs) are excellent radiosensitizers for radiotherapy-radiodynamic therapy (RT-RDT). Herein, we report surface modification of a Hf-DBP nMOF for the co-delivery of a hydrophobic small-molecule toll-like receptor 7 agonist, imiquimod (IMD), and a hydrophilic macromolecule, anti-CD47 antibody (αCD47), for macrophage modulation and reversal of immunosuppression in tumors. IMD repolarizes immunosuppressive M2 macrophages to immunostimulatory M1 macrophages, while αCD47 blocks CD47 tumor cell surface marker to promote phagocytosis. Upon X-ray irradiation, IMD@Hf-DBP/αCD47 effectively modulates the immunosuppressive tumor microenvironment and activates innate immunity to orchestrate adaptive immunity when synergized with an anti-PD-L1 immune checkpoint inhibitor, leading to complete eradication of both primary and distant tumors on a bilateral colorectal tumor model. nMOFs thus provide a unique platform to co-deliver multiple immunoadjuvants for macrophage therapy to induce systematic immune responses and superb antitumor efficacy.

Harnessing nanomedicine to overcome the immunosuppressive tumor microenvironment

Cancer immunotherapy has received extensive attention due to its ability to activate the innate or adaptive immune systems of patients to combat tumors. Despite a few clinical successes, further endeavors are still needed to tackle unresolved issues, including limited response rates, development of resistance, and immune-related toxicities. Accumulating evidence has pinpointed the tumor microenvironment (TME) as one of the major obstacles in cancer immunotherapy due to its detrimental impacts on tumor-infiltrating immune cells. Nanomedicine has been battling with the TME in the past several decades, and the experience obtained could be exploited to improve current paradigms of immunotherapy. Here, we discuss the metabolic features of the TME and its influence on different types of immune cells. The recent progress in nanoenabled cancer immunotherapy has been summarized with a highlight on the modulation of immune cells, tumor stroma, cytokines and enzymes to reverse the immunosuppressive TME.

Nanomedicine-based immunotherapy for central nervous system disorders

Central nervous system (CNS) disorders represent a broad spectrum of brain ailments with short- and long-term disabilities, and nanomedicine-based approaches provide a new therapeutic approach to treating CNS disorders. A variety of potential drugs have been discovered to treat several neuronal disorders; however, their therapeutic success can be limited by the presence of the blood-brain barrier (BBB). Furthermore, unique immune functions within the CNS provide novel target mechanisms for the amelioration of CNS diseases. Recently, various therapeutic approaches have been applied to fight brain-related disorders, with moderate outcomes. Among the various therapeutic strategies, nanomedicine-based immunotherapeutic systems represent a new era that can deliver useful cargo with promising pharmacokinetics. These approaches exploit the molecular and cellular targeting of CNS disorders for enhanced safety, efficacy, and specificity. In this review, we focus on the efficacy of nanomedicines that utilize immunotherapy to combat CNS disorders. Furthermore, we detailed summarize nanomedicine-based pathways for CNS ailments that aim to deliver drugs across the BBB by mimicking innate immune actions.

Nanotechnology and immunoengineering: How nanotechnology can boost CAR-T therapy

Chimeric antigen receptor (CAR) therapy has achieved remarkable clinical efficacy against hematological cancers and has been approved by FDA for treatment of B-cell tumors. However, the complex manufacturing process and limited success in solid tumors hamper its widespread applications, thus prompting the development of new strategies for overcoming the abovementioned hurdles. In the last decade, nanotechnology has provided sustainable strategies for improving cancer immunotherapy through vaccine development and delivery of immunomodulatory drugs. Nanotechnology can boost CAR-T therapy and may overcome the existing challenges by emerging as a carrier for CAR-T therapy or in combination with CAR-T, it may inhibit solid tumors more effectively than conventional approaches. The revealing of cellular mechanisms, barriers and potential strategies that could be used to manipulate and/or modify cells would enable unprecedented advances in nanotechnology for biologics delivery. This review outlines the journey and barriers of nanoparticles (NPs) across the cell. Subsequently, the approaches to tackle the barriers and strategies to modulate NPs as a carrier for CAR-T therapy are discussed. Finally, the role of NPs in CAR-T therapy and the potential challenges are summarized. This review aims to provide the readers with a detailed overview of NP-based CAR-T therapy research and distil this information into an accessible form conducive to design desired CAR-T therapy using NP approach. STATEMENT OF SIGNIFICANCE: Chimeric antigen receptor (CAR) T-cell therapy is the most vibrant field in immuno-oncology today, with enormous benefits to patients with B-cell malignancies. However, a rapid and straightforward procedure for CAR-T generation is an exigent need to broaden its therapeutic avenue. Nanotechnology has emerged as a novel alternative approach for CAR-T generation. To the best of our knowledge, this is the first in-depth review that briefly highlights the various aspects of nanotechnology in CAR-T therapy, including the strategies to brand NPs as an effective carrier for CAR cargo, its potential advantages, challenges, and future roadmap. It provides readers with a detailed overview of NP-based CAR-T therapy research, and researchers would be able to distill this information into an accessible form conducive to design the desired CAR therapy using the nanotechnology approach.

Designing immunogenic nanotherapeutics for photothermal-triggered immunotherapy involving reprogramming immunosuppression and activating systemic antitumor responses

Low tumor mutational burden and absence of T cells within the tumor sites are typical characteristics of "cold immune tumors" that paralyzes the immune system. The strategy of reversing "cold tumors" to "hot tumors" infiltrated high degree of T cells in order to activate anti-tumor immunity has attracted lots of attentions. Herein, immunogenic core-shell Au@Se NPs is fabricated by gold-selenium coordination bond to realize nanoparticles-mediated local photothermal-triggered immunotherapy. As expected, incorporation of gold nanostars (AuNSs) with improved photothermal stability and conversion efficiency promotes the disintegration and transformation of selenium nanoparticles (SeNPs), thus leading to enhanced cancer cells apoptosis by producing higher hyperthermia. Moreover, the results of in vivo experiments demonstrate that the synergy between SeNPs-mediated chemotherapy and AuNSs-induced photothermal therapy not only generated a localized antitumor-immune response with excellent cancer killing effect under the presence of tumor-associated antigens, but also effectively reprogrammed the tumor associated macrophages (TAMs) from M2 to M1 phenotype with tumoricidal activity to devour distant tumors. Without a doubt, this study not only provides a potent strategy to reverse the immunosuppressive tumor microenvironment, but also offers a new insight for potential clinical application in tumor immunotherapy.

Synthesis and Characterization of Rapidly Degrading Polyanhydrides as Vaccine Adjuvants

There is a currently a need to develop adjuvants that are best suited to simultaneously enhance immune responses, induce immunologic memory, improve patient compliance (i.e., reduce doses and inflammation), and provide vaccine shelf stability for stockpiling and global deployment to challenging environments. Biodegradable polyanhydrides have been investigated extensively to overcome such challenges. It has been shown that controlling copolymer composition can result in chemistry-dependent immunomodulatory capabilities. These studies have revealed that copolymers rich in sebacic acid (SA) are highly internalized by antigen presenting cells and confer improved shelf stability of encapsulated proteins, while copolymers rich in 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane (CPTEG) also exhibit enhanced internalization by and activation of antigen presenting cells (APCs), in addition to providing superior retention of protein stability following encapsulation and release. However, to date, CPTEG:SA copolymers have not been synthesized and described. In this work, we hypothesized that new copolymers composed of CPTEG and SA would combine the advantages of both monomers in terms of enhanced thermal properties, maintaining antigenicity of encapsulated proteins following nanoparticle synthesis, and superior cellular internalization and activation by APCs, demonstrated by the upregulation of costimulatory markers CD80, CD86, and CD40, as well as the secretion of proinflammatory cytokines IL-6, IL-1β, and TNF-α. Herein, we describe the synthesis and design of novel CPTEG:SA nanoparticles with improved thermal properties, payload stability, and internalization by antigen presenting cells for applications in vaccine delivery. The performance of these new CPTEG:SA formulations was compared to that of traditional polyanhydride copolymers.

Recent progress in supramolecular peptide assemblies as virus mimics for cancer immunotherapy

Supramolecular peptide assemblies can mimic natural viruses and serve as well-defined, dynamic and multifunctional nanoplatforms for cancer immunotherapy, where the peptide segments act as antigens, adjuvants and carriers.

Stimuli-responsive nanoparticle-assisted immunotherapy: a new weapon against solid tumours

The interplay between photo-thermal therapy and immunotherapy allows the realization of new nanotechnology-based cancer treatments for solid tumors.

Nanomaterials for cancer medication: from individual nanoparticles toward nanomachines and nanorobots

The nanomaterials for cancer medication are already reality providing a wide range of new tools and possibilities, from earlier diagnostics and improved imaging to better, more efficient, and more targeted anticancer therapies. The purpose of this critical review is to focus on the current use of clinically approved nanoparticles for cancer theranostic, nanovaccines and delivery platforms for gene therapy. These include inorganic, metal and polymer nanoparticles, nanocrystals and varieties of drug delivery nanosystems (micelles, liposomes, microcapsules and etc.). The recent progress in cancer nanomedicine enables to combine the benefits of individual nanoparticles with biomolecules into a multifunction nanomachines and even highly advanced nanorobots for targeted therapies. Nowadays clinical trials with advanced anticancer nanomachines provide potential for more accurately and effective identification and destruction of the cancer cells present in the human body.

A fast-dissolving microneedle array loaded with chitosan nanoparticles to evoke systemic immune responses in mice

Microneedle (MN) arrays offer an alternative approach to hypodermic injection via syringe needles. In this work, polyvinylpyrrolidone (PVP)-based fast dissolving MN arrays were developed in which the needle tips were loaded with chitosan nanoparticles (NPs) for coencapsulation of a model antigen, ovalbumin (OVA), and an adjuvant, CpG oligodeoxynucleotides (CpG). After insertion into the skin, these MN arrays fully dissolved within 3 min to release antigen and adjuvant co-loaded NPs rapidly in the epidermal layer. Positively charged chitosan was proven to be an excellent carrier for negatively charged OVA and CpG, which formed nanocomplexes via simple electrostatic interactions and greatly enhanced the uptake efficiency of OVA in DC2.4 dendritic cells. Vaccination studies in mice further demonstrated that chitosan NPs effectively accumulated in peripheral lymph nodes, thus inducing greatly enhanced immune responses compared to those of free OVA. The antibody dose-response curve further demonstrated that MN immunization achieved comparable levels of immune responses as compared to conventional subcutaneous injections in a more convenient and less invasive way. Overall, a PVP-based fast dissolving MN array with chitosan NPs represents a promising and robust platform system for efficient transcutaneous vaccine delivery.

Recent Advances in Nanovaccines Using Biomimetic Immunomodulatory Materials

The development of vaccines plays a vital role in the effective control of several fatal diseases. However, effective prophylactic and therapeutic vaccines have yet to be developed for completely curing deadly diseases, such as cancer, malaria, HIV, and serious microbial infections. Thus, suitable vaccine candidates need to be designed to elicit appropriate immune responses. Nanotechnology has been found to play a unique role in the design of vaccines, providing them with enhanced specificity and potency. Nano-scaled materials, such as virus-like particles, liposomes, polymeric nanoparticles (NPs), and protein NPs, have received considerable attention over the past decade as potential carriers for the delivery of vaccine antigens and adjuvants, due to their beneficial advantages, like improved antigen stability, targeted delivery, and long-time release, for which antigens/adjuvants are either encapsulated within, or decorated on, the NP surface. Flexibility in the design of nanomedicine allows for the programming of immune responses, thereby addressing the many challenges encountered in vaccine development. Biomimetic NPs have emerged as innovative natural mimicking biosystems that can be used for a wide range of biomedical applications. In this review, we discuss the recent advances in biomimetic nanovaccines, and their use in anti-bacterial therapy, anti-HIV therapy, anti-malarial therapy, anti-melittin therapy, and anti-tumor immunity.

Nanoenabled Reversal of IDO1-Mediated Immunosuppression Synergizes with Immunogenic Chemotherapy for Improved Cancer Therapy

Certain chemotherapeutics (e.g., oxaliplatin, OXA) can evoke effective antitumor immunity responses by inducing immunogenic cell death (ICD). Unfortunately, tumors always develop multiple immunosuppressive mechanisms, such as the upregulation of immunosuppressive factors, to counteract the effects of immunogenic chemotherapy. Indoleamine 2,3-dioxygenase-1 (IDO1), a tryptophan catabolic enzyme overexpressed in tumor-draining lymph nodes (TDLNs) and tumor tissues, plays a pivotal role in the generation of the immunosuppressive microenvironment. Reversing IDO1-mediated immunosuppression may strengthen the ICD-induced immune response. Herein, we developed a nanoenabled approach for IDO1 pathway interference, which is accomplished by delivering IDO1 siRNA to both TDLNs and tumor tissues with the help of cationic lipid-assisted nanoparticles (CLANs). We demonstrated that the contemporaneous administration of OXA and CLAN_siIDO1 could achieve synergetic antitumor effects via promoting dendritic cell maturation, increasing tumor-infiltrating T lymphocytes and decreasing the number of regulatory T cells in a subcutaneous colorectal tumor model. We further proved that this therapeutic strategy is applicable for the treatment of orthotopic pancreatic tumors and offers a strong immunological memory effect, which can provide protection against tumor rechallenge.

Optimizing Advances in Nanoparticle Delivery for Cancer Immunotherapy

Cancer immunotherapy is one of the fastest growing and most promising fields in clinical oncology. T-cell checkpoint inhibitors are revolutionizing the management of advanced cancers including non-small cell lung cancer and melanoma. Unfortunately, many common cancers are not responsive to these drugs and resistance remains problematic. A growing number of novel cancer immunotherapies have been discovered but their clinical translation has been limited by shortcomings of conventional drug delivery. Immune signaling is tightly-regulated and often requires simultaneous or near-simultaneous activation of multiple signals in specific subpopulations of immune cells. Nucleic acid therapies, which require intact intracellular delivery, are among the most promising approaches to modulate the tumor microenvironment to a pro-immunogenic phenotype. Advanced nanomedicines can be precisely engineered to overcome many of these limitations and appear well-poised to enable the clinical translation of promising cancer immunotherapies.