Immunoengineering through cancer vaccines – A personalized and multi-step vaccine approach towards precise cancer immunity

Targeting of Low-Immunogenic Poly(ethylene glycol) Nanoparticles for Photothermal-Enhanced Immunotherapy

The assembly of low-immunogenic poly(ethylene glycol) nanoparticles (PEG NPs) for targeted delivery of therapeutics (i.e., mitoxantrone and imidazoquinoline) and improved photothermal-immunotherapy is reported. The targeted PEG NPs incorporating targeting molecules of hyaluronic acid are engineered via the templating of metal-organic frameworks, which can circumvent accelerated blood clearance and exhibit prolonged circulation time as well as improved accumulation of therapeutics at tumor sites. The targeted delivery of mitoxantrone under laser radiation induces immunogenic cell death of tumor cells, which is combined with toll-like receptor 7/8 agonists of imidazoquinoline to trigger immune responses of cytotoxic T lymphocytes for the eradication of tumor cells. Furthermore, the treatment can induce tumor-specific immune responses that inhibit metastatic lung tumor growth. This reported targeted PEG NPs provide a rational design for cancer immunotherapy.

Nanoplasmonic Single-Tumoroid Microarray for Real-Time Secretion Analysis

Organoid tumor models have emerged as a powerful tool in the fields of biology and medicine as such 3D structures grown from tumor cells recapitulate better tumor characteristics, making these tumoroids unique for personalized cancer research. Assessment of their functional behavior, particularly protein secretion, is of significant importance to provide comprehensive insights. Here, a label-free spectroscopic imaging platform is presented with advanced integrated optofluidic nanoplasmonic biosensor that enables real-time secretion analysis from single tumoroids. A novel two-layer microwell design isolates tumoroids, preventing signal interference, and the microarray configuration allows concurrent analysis of multiple tumoroids. The dual imaging capability combining time-lapse plasmonic spectroscopy and bright-field microscopy facilitates simultaneous observation of secretion dynamics, motility, and morphology. The integrated biosensor is demonstrated with colorectal tumoroids derived from both cell lines and patient samples to investigate their vascular endothelial growth factor A (VEGF-A) secretion, growth, and movement under various conditions, including normoxia, hypoxia, and drug treatment. This platform, by offering a label-free approach with nanophotonics to monitor tumoroids, can pave the way for new applications in fundamental biological studies, drug screening, and the development of therapies.

Concepts and Approaches to Reduce or Avoid Protein Corona Formation on Nanoparticles: Challenges and Opportunities

This review describes the formation of a protein corona (or its absence) on different classes of nanoparticles, its basic principles, and its consequences for nanomedicine. For this purpose, it describes general concepts to control (guide/minimize) the interaction between artificial nanoparticles and plasma proteins to reduce protein corona formation. Thereafter, methods for the qualitative or quantitative determination of protein corona formation are presented, as well as the properties of nanoparticle surfaces, which are relevant for protein corona prevention (or formation). Thereby especially the role of grafting density of hydrophilic polymers on the surface of the nanoparticle is discussed to prevent the formation of a protein corona. In this context also the potential of detergents (surfactants) for a temporary modification as well as grafting-to and grafting-from approaches for a permanent modification of the surface are discussed. The review concludes by highlighting several promising avenues. This includes (i) the use of nanoparticles without protein corona for active targeting, (ii) the use of synthetic nanoparticles without protein corona formation to address the immune system, (iii) the recollection of nanoparticles with a defined protein corona after in vivo application to sample the blood proteome and (iv) further concepts to reduce protein corona formation.

Nanoparticle-based immunoengineering strategies for enhancing cancer immunotherapy

Cancer immunotherapy is a groundbreaking strategy that has revolutionized the field of oncology compared to other therapeutic strategies, such as surgery, chemotherapy, or radiotherapy. However, cancer complexity, tumor heterogeneity, and immune escape have become the main hurdles to the clinical application of immunotherapy. Moreover, conventional immunotherapies cause many harmful side effects owing to hyperreactivity in patients, long treatment durations and expensive cost. Nanotechnology is considered a transformative approach that enhances the potency of immunotherapy by capitalizing on the superior physicochemical properties of nanocarriers, creating highly targeted tissue delivery systems. These advantageous features include a substantial specific surface area, which enhances the interaction with the immune system. In addition, the capability to finely modify surface chemistry enables the achievement of controlled and sustained release properties. These advances have significantly increased the potential of immunotherapy, making it more powerful than ever before. In this review, we introduce recent nanocarriers for application in cancer immunotherapy based on strategies that target different main immune cells, including T cells, dendritic cells, natural killer cells, and tumor-associated macrophages. We also provide an overview of the role and significance of nanotechnology in cancer immunotherapy.

Polymerizable 2-Propionic-3-methylmaleic Anhydrides as a Macromolecular Carrier Platform for pH-Responsive Immunodrug Delivery

The design of functional polymers coupled with stimuli-triggered drug release mechanisms is a promising achievement to overcome various biological barriers. pH trigger methods yield significant potential for controlled targeting and release of therapeutics due to their simplicity and relevance, especially upon cell internalization. Here, we introduce reactive polymers that conjugate primary or secondary amines and release potential drugs under acidic conditions. For that purpose, we introduced methacrylamide-based monomers with pendant 2-propionic-3-methylmaleic anhydride groups. Such groups allow the conjugation of primary and secondary amines but are resistant to radical polymerization conditions. We, therefore, polymerized 2-propionic-3-methylmaleic anhydride amide-based methacrylates via reversible addition-fragmentation chain transfer (RAFT) polymerization. Their amine-reactive anhydrides could sequentially be derivatized by primary or secondary amines into hydrophilic polymers. Acidic pH-triggered drug release from the polymeric systems was fine-tuned by comparing different amines. Thereby, the conjugation of primary amines led to the formation of irreversible imide bonds in dimethyl sulfoxide, while secondary amines could quantitatively be released upon acidification. In vitro, this installed pH-responsiveness can contribute to an effective release of conjugated immune stimulatory drugs under endosomal pH conditions. Interestingly, the amine-modified polymers generally showed no toxicity and a high cellular uptake. Furthermore, secondary amine-modified immune stimulatory drugs conjugated to the polymers yielded better receptor activity and immune cell maturation than their primary amine derivatives due to their pH-sensitive drug release mechanism. Consequently, 2-propionic-3-methylmaleic anhydride-based polymers can be considered as a versatile platform for pH-triggered delivery of various (immuno)drugs, thus enabling new strategies in macromolecule-assisted immunotherapy.

Neoantigen-directed therapeutics in the clinic: where are we?

In the past decade, immune checkpoint inhibitors (ICIs) and chimeric antigen receptor (CAR) T cell therapy have brought immunotherapy to the forefront of cancer treatment; however, only subsets of patients benefit from current approaches. Neoantigen-driven therapeutics specifically redirect the immune system of the patient to enable or reinduce its ability to recognize and eliminate cancer cells. The tumor specificity of this strategy spares healthy and normal cells from being attacked. Consistent with this concept, initial clinical trials have demonstrated the feasibility, safety, and immunogenicity of neoantigen-directed personalized vaccines. We review neoantigen-driven therapy strategies as well as their promise and clinical successes to date.

Therapeutic Potential of Melatonin Counteracting Chemotherapy-Induced Toxicity in Breast Cancer Patients: A Systematic Review

The purpose of this systematic review is to provide an overview of the existing knowledge on the therapeutic potential of melatonin to counteract the undesirable effects of chemotherapy in breast cancer patients. To this aim, we summarized and critically reviewed preclinical- and clinical-related evidence according to the PRISMA guidelines. Additionally, we developed an extrapolation of melatonin doses in animal studies to the human equivalent doses (HEDs) for randomized clinical trials (RCTs) with breast cancer patients. For the revision, 341 primary records were screened, which were reduced to 8 selected RCTs that met the inclusion criteria. We assembled the evidence drawn from these studies by analyzing the remaining gaps and treatment efficacy and suggested future translational research and clinical trials. Overall, the selected RCTs allow us to conclude that melatonin combined with standard chemotherapy lines would derive, at least, a better quality of life for breast cancer patients. Moreover, regular doses of 20 mg/day seemed to increase partial response and 1-year survival rates. Accordingly, this systematic review leads us to draw attention to the need for more RCTs to provide a comprehensive view of the promising actions of melatonin in breast cancer and, given the safety profile of this molecule, adequate translational doses should be established in further RCTs.

Stimuli-Responsive Polymeric Nanovaccines Toward Next-Generation Immunotherapy

The development of nanovaccines that employ polymeric delivery carriers has garnered substantial interest in therapeutic treatment of cancer and a variety of infectious diseases due to their superior biocompatibility, lower toxicity and reduced immunogenicity. Particularly, stimuli-responsive polymeric nanocarriers show great promise for delivering antigens and adjuvants to targeted immune cells, preventing antigen degradation and clearance, and increasing the uptake of specific antigen-presenting cells, thereby sustaining adaptive immune responses and improving immunotherapy for certain diseases. In this review, the most recent advances in the utilization of stimulus-responsive polymer-based nanovaccines for immunotherapeutic applications are presented. These sophisticated polymeric nanovaccines with diverse functions, aimed at therapeutic administration for disease prevention and immunotherapy, are further classified into several active domains, including pH, temperature, redox, light and ultrasound-sensitive intelligent nanodelivery systems. Finally, the potential strategies for the future design of multifunctional next-generation polymeric nanovaccines by integrating materials science with biological interface are proposed.

Managing the immune microenvironment of osteosarcoma: the outlook for osteosarcoma treatment

Osteosarcoma, with poor survival after metastasis, is considered the most common primary bone cancer in adolescents. Notwithstanding the efforts of researchers, its five-year survival rate has only shown limited improvement, suggesting that existing therapeutic strategies are insufficient to meet clinical needs. Notably, immunotherapy has shown certain advantages over traditional tumor treatments in inhibiting metastasis. Therefore, managing the immune microenvironment in osteosarcoma can provide novel and valuable insight into the multifaceted mechanisms underlying the heterogeneity and progression of the disease. Additionally, given the advances in nanomedicine, there exist many advanced nanoplatforms for enhanced osteosarcoma immunotherapy with satisfactory physiochemical characteristics. Here, we review the classification, characteristics, and functions of the key components of the immune microenvironment in osteosarcoma. This review also emphasizes the application, progress, and prospects of osteosarcoma immunotherapy and discusses several nanomedicine-based options to enhance the efficiency of osteosarcoma treatment. Furthermore, we examine the disadvantages of standard treatments and present future perspectives for osteosarcoma immunotherapy.

A signature of six-hypoxia-related genes to evaluate the tumor immune microenvironment and predict prognosis in gastric cancer

BACKGROUND

Hypoxia will trigger a series of immunosuppressive process in tumor microenvironment, leading to the progression in gastric cancer (GC). This research aims to establish a prognostic model made up of hypoxia-risk-related genes in GC.

METHODS

Hypoxic genes were outlined via the protein-protein interaction network. And a prognostic model was developed using univariate cox analysis and lasso regression from data in TCGA. Two independent queues of GEO were used for validation.

RESULTS

We set up a hypoxic model presented as an independent prognostic factor for GC. And a nomogram combined this model with clinical features can predict OS with great performance. Furthermore, DNA methylation, IHC and cell line analyses validated the expression of hypoxic genes in GC.

CONCLUSIONS

In summary, we proposed and verified a hypoxia-risk-related model, which could reflect the immune microenvironment and predict prognosis in GC.

Systemically Administered TLR7/8 Agonist and Antigen-Conjugated Nanogels Govern Immune Responses against Tumors

The generation of specific humoral and cellular immune responses plays a pivotal role in the development of effective vaccines against tumors. Especially the presence of antigen-specific, cytotoxic T cells influences the outcome of therapeutic cancer vaccinations. Different strategies, ranging from delivering antigen-encoding mRNAs to peptides or full antigens, are accessible but often suffer from insufficient immunogenicity and require immune-boosting adjuvants as well as carrier platforms to ensure stability and adequate retention. Here, we introduce a pH-responsive nanogel platform as a two-component antitumor vaccine that is safe for intravenous application and elicits robust immune responses in vitro and in vivo. The underlying chemical design allows for straightforward covalent attachment of a model antigen (ovalbumin) and an immune adjuvant (imidazoquinoline-type TLR7/8 agonist) onto the same nanocarrier system. In addition to eliciting antigen-specific T and B cell responses that outperform mixtures of individual components, our two-component nanovaccine leads in prophylactic and therapeutic studies to an antigen-specific growth reduction of different tumors expressing ovalbumin intracellularly or on their surface. Regarding the versatile opportunities for functionalization, our nanogels are promising for the development of highly customized and potent nanovaccines.

Polymer Nanoparticle-Mediated Delivery of Oxidized Tumor Lysate-Based Cancer Vaccines

Cancer vaccination is a powerful strategy to combat cancer. A very attractive approach to prime the immune system against cancer cells involves the use of tumor lysate as antigen source. The immunogenicity of tumor lysate can be further enhanced by treatment with hypochlorous acid. This study explores poly(lactic-co-glycolic acid) (PLGA) nanoparticles to enhance the delivery of oxidized tumor lysate to dendritic cells. Using human donor-derived dendritic cells, it is found that the use of PLGA nanoparticles enhances antigen uptake and dendritic cell maturation, as compared to the use of the free tumor lysate. The ability of the activated dendritic cells to stimulate autologous peripheral blood mononuclear cells (PBMCs) is assessed in vitro by coculturing PBMCs with A375 melanoma cells. Live cell imaging analysis of this experiment highlights the potential of nanoparticle-mediated dendritic-cell-based vaccination approaches. Finally, the efficacy of the PLGA nanoparticle formulation is evaluated in vivo in a therapeutic vaccination study using B16F10 tumor-bearing C57BL/6J mice. Animals that are challenged with the polymer nanoparticle-based oxidized tumor lysate formulation survive for up to 50 days, in contrast to a maximum of 41 days for the group that receives the corresponding free oxidized tumor lysate-based vaccine.

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

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

Squaric Ester-Based, pH-Degradable Nanogels: Modular Nanocarriers for Safe, Systemic Administration of Toll-like Receptor 7/8 Agonistic Immune Modulators

Small-molecular Toll-like receptor 7/8 (TLR7/8) agonists hold promise as immune modulators for a variety of immune therapeutic purposes including cancer therapy or vaccination. However, due to their rapid systemic distribution causing difficult-to-control inflammatory off-target effects, their application is still problematic, in particular systemically. To address this problem, we designed and robustly fabricated pH-responsive nanogels serving as versatile immunodrug nanocarriers for safe delivery of TLR7/8-stimulating imidazoquinolines after intravenous administration. To this aim, a primary amine-reactive methacrylamide monomer bearing a pendant squaric ester amide is introduced, which is polymerized under controlled RAFT polymerization conditions. Corresponding PEG-derived squaric ester amide block copolymers self-assemble into precursor micelles in polar protic solvents. Their cores are amine-reactive and can sequentially be transformed by acid-sensitive cross-linkers, dyes, and imidazoquinolines. Remaining squaric ester amides are hydrophilized affording fully hydrophilic nanogels with profound stability in human plasma but stimuli-responsive degradation upon exposure to endolysosomal pH conditions. The immunomodulatory behavior of the imidazoquinolines alone or conjugated to the nanogels was demonstrated by macrophages in vitro. In vivo, however, we observed a remarkable impact of the nanogel: After intravenous injection, a spatially controlled immunostimulatory activity was evident in the spleen, whereas systemic off-target inflammatory responses triggered by the small-molecular imidazoquinoline analogue were absent. These findings underline the potential of squaric ester-based, pH-degradable nanogels as a promising platform to permit intravenous administration routes of small-molecular TLR7/8 agonists and, thus, the opportunity to explore their adjuvant potency for systemic vaccination or cancer immunotherapy purposes.

Hybrid Membrane-Coated Biomimetic Nanoparticles (HM@BNPs): A Multifunctional Nanomaterial for Biomedical Applications

The application of nanoparticles in the diagnosis and treatment of diseases has undergone different developmental stages, but phagocytosis and nonspecific distribution have been the main factors restricting the transformation of nanobased drugs into clinical practice. In the past decade, the design of membrane-coated nanoparticles has gained increasing attention. It is hoped that the combination of the cell membrane's natural biological properties and the functional integration of synthetic nanoparticle systems can compensate for the shortage of traditional nanoparticles. The membrane coating gives the nanoparticles unique biological functions such as immune evasion and targeting capability. However, when the encapsulation of monotypic membranes does not meet the diverse demands of biomedicine, the combination of different cell membranes may offer more possibilities. In this review, the composition, preparation, and advantages of biomimetic nanoparticles coated with hybrid cell membranes are summarized, and the applications of hybrid membrane-coated biomimetic nanoparticles (HM@BNPs) in drug delivery, phototherapy, liquid biopsy, tumor vaccines, immune therapy, and detoxification are reviewed. Finally, the current challenges and opportunities with regard to HM@BNPs are discussed.

Development of Effective Tumor Vaccine Strategies Based on Immune Response Cascade Reactions

To solve the problems of high toxicity and poor efficacy of existing tumor treatment methods, researchers have developed a variety of tumor immunotherapies. Among them, tumor vaccines activate antigen-presenting cells and T lymphocytes upstream of the cancer-immunity cycle are considered the most promising therapy to activate the immune system. Nanocarriers are considered the most promising tumor vaccine delivery vehicles, including polymer nanocarriers, lipid nanocarriers, inorganic nanocarriers, and biomimetic nanocarriers that have been developed for vaccine delivery. Based on the cascade reaction for tumor vaccines to exert their effects, this review summarizes the four key factors for the design and construction of nano-tumor vaccines. The composition and functional characteristics of the corresponding preferred nanocarriers are illustrated to provide a reference for the development of effective tumor vaccines. Finally, potential challenges and perspectives are illustrated in the hope of improving the efficacy of tumor vaccine immunotherapy and accelerating the clinical transformation of next-generation tumor vaccines.

Hitchhiking on Controlled-Release Drug Delivery Systems: Opportunities and Challenges for Cancer Vaccines

Cancer vaccines represent among the most promising strategies in the battle against cancers. However, the clinical efficacy of current cancer vaccines is largely limited by the lack of optimized delivery systems to generate strong and persistent antitumor immune responses. Moreover, most cancer vaccines require multiple injections to boost the immune responses, leading to poor patient compliance. Controlled-release drug delivery systems are able to address these issues by presenting drugs in a controlled spatiotemporal manner, which allows co-delivery of multiple drugs, reduction of dosing frequency and avoidance of significant systemic toxicities. In this review, we outline the recent progress in cancer vaccines including subunit vaccines, genetic vaccines, dendritic cell-based vaccines, tumor cell-based vaccines and in situ vaccines. Furthermore, we highlight the efforts and challenges of controlled or sustained release drug delivery systems (e.g., microparticles, scaffolds, injectable gels, and microneedles) in ameliorating the safety, effectiveness and operability of cancer vaccines. Finally, we briefly discuss the correlations of vaccine release kinetics and the immune responses to enlighten the rational design of the next-generation platforms for cancer therapy.

Dendritic Cell-Based Immunotherapy in Lung Cancer

Lung cancer remains the leading cause of cancer-related death worldwide. The advent of immune checkpoint inhibitors has led to a paradigm shift in the treatment of metastatic non-small cell and small cell lung cancer. However, despite prolonged overall survival, only a minority of the patients derive clinical benefit from these treatments suggesting that the full anti-tumoral potential of the immune system is not being harnessed yet. One way to overcome this problem is to combine immune checkpoint blockade with different strategies aimed at inducing or restoring cellular immunity in a tumor-specific, robust, and durable way. Owing to their unique capacity to initiate and regulate T cell responses, dendritic cells have been extensively explored as tools for immunotherapy in many tumors, including lung cancer. In this review, we provide an update on the nearly twenty years of experience with dendritic cell-based immunotherapy in lung cancer. We summarize the main results from the early phase trials and give an overview of the future perspectives within this field.

Tumor-Associated Macrophages in Pancreatic Ductal Adenocarcinoma: Origin, Polarization, Function, and Reprogramming

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy. PDAC is only cured by surgical resection in its early stage, but there remains a relatively high possibility of recurrence. The development of PDAC is closely associated with the tumor microenvironment. Tumor-associated macrophages (TAMs) are one of the most abundant immune cell populations in the pancreatic tumor stroma. TAMs are inclined to M2 deviation in the tumor microenvironment, which promotes and supports tumor behaviors, including tumorigenesis, immune escape, metastasis, and chemotherapeutic resistance. Herein, we comprehensively reviewed the latest researches on the origin, polarization, functions, and reprogramming of TAMs in PDAC.

Biohybrid Nanosystems for Cancer Treatment: Merging the Best of Two Worlds

During the last 20+ years, research into the biomedical application of nanotechnology has helped in reshaping cancer treatment. The clinical use of several passively targeted nanosystems resulted in improved quality of care for patients. However, the therapeutic efficacy of these systems is not superior to the original drugs. Moreover, despite extensive investigations into actively targeted nanocarriers, numerous barriers still remain before their successful clinical translation, including sufficient bloodstream circulation time and efficient tumor targeting. The combination of synthetic nanomaterials with biological elements (e.g., cells, cell membranes, and macromolecules) is presently the cutting-edge research in cancer nanotechnology. The features provided by the biological moieties render the particles with prolonged bloodstream circulation time and homotopic targeting to the tumor site. Moreover, cancer cell membranes serve as sources of neoantigens, useful in the formulation of nanovaccines. In this chapter, we will discuss the advantages of biohybrid nanosystems in cancer chemotherapy, immunotherapy, and combined therapy, as well as highlight their preparation methods and clinical translatability.

Novel Opportunities for Cathepsin S Inhibitors in Cancer Immunotherapy by Nanocarrier-Mediated Delivery

Cathepsin S (CatS) is a secreted cysteine protease that cleaves certain extracellular matrix proteins, regulates antigen presentation in antigen-presenting cells (APC), and promotes M2-type macrophage and dendritic cell polarization. CatS is overexpressed in many solid cancers, and overall, it appears to promote an immune-suppressive and tumor-promoting microenvironment. While most data suggest that CatS inhibition or knockdown promotes anti-cancer immunity, cell-specific inhibition, especially in myeloid cells, appears to be important for therapeutic efficacy. This makes the design of CatS selective inhibitors and their targeting to tumor-associated M2-type macrophages (TAM) and DC an attractive therapeutic strategy compared to the use of non-selective immunosuppressive compounds or untargeted approaches. The selective inhibition of CatS can be achieved through optimized small molecule inhibitors that show good pharmacokinetic profiles and are orally bioavailable. The targeting of these inhibitors to TAM is now more feasible using nanocarriers that are functionalized for a directed delivery. This review discusses the role of CatS in the immunological tumor microenvironment and upcoming possibilities for a nanocarrier-mediated delivery of potent and selective CatS inhibitors to TAM and related APC to promote anti-tumor immunity.

Control over Imidazoquinoline Immune Stimulation by pH-Degradable Poly(norbornene) Nanogels

The reactivation of the innate immune system by toll-like receptor (TLR) agonists holds promise for anticancer immunotherapy. Severe side effects caused by unspecific and systemic activation of the immune system upon intravenous injection prevent the use of small-molecule TLR agonists for such purposes. However, a covalent attachment of small-molecule imidazoquinoline (IMDQ) TLR7/8 agonists to pH-degradable polymeric nanogels could be shown to drastically reduce the systemic inflammation but retain the activity to tumoral tissues and their draining lymph nodes. Here, we introduce the synthesis of poly(norbornene)-based, acid-degradable nanogels for the covalent ligation of IMDQs. While the intact nanogels trigger sufficient TLR7/8 receptor stimulation, their degraded version of soluble, IMDQ-conjugated poly(norbornene) chains hardly activates TLR7/8. This renders their clinical safety profile, as degradation products are obtained, which would not only circumvent nanoparticle accumulation in the body but also provide nonactive, polymer-bound IMDQ species. Their immunologically silent behavior guarantees both spatial and temporal control over immune activity and, thus, holds promise for improved clinical applications.

Potent Lymphatic Translocation and Spatial Control Over Innate Immune Activation by Polymer-Lipid Amphiphile Conjugates of Small-Molecule TLR7/8 Agonists

Uncontrolled systemic inflammatory immune triggering has hampered the clinical translation of several classes of small-molecule immunomodulators, such as imidazoquinoline TLR7/8 agonists for vaccine design and cancer immunotherapy. By taking advantage of the inherent serum-protein-binding property of lipid motifs and their tendency to accumulate in lymphoid tissue, we designed amphiphilic lipid-polymer conjugates that suppress systemic inflammation but provoke potent lymph-node immune activation. This work provides a rational basis for the design of lipid-polymer amphiphiles for optimized lymphoid targeting.

Multi-antigen Vaccination With Simultaneous Engagement of the OX40 Receptor Delays Malignant Mesothelioma Growth and Increases Survival in Animal Models

Malignant Mesothelioma (MM) is a rare and highly aggressive cancer that develops from mesothelial cells lining the pleura and other internal cavities, and is often associated with asbestos exposure. To date, no effective treatments have been made available for this pathology. Herein, we propose a novel immunotherapeutic approach based on a unique vaccine targeting a series of antigens that we found expressed in different MM tumors, but largely undetectable in normal tissues. This vaccine, that we term p-Tvax, is comprised of a series of immunogenic peptides presented by both MHC-I and -II to generate robust immune responses. The peptides were designed using in silico algorithms that discriminate between highly immunogenic T cell epitopes and other harmful epitopes, such as suppressive regulatory T cell epitopes and autoimmune epitopes. Vaccination of mice with p-Tvax led to antigen-specific immune responses that involved both CD8⁺ and CD4⁺ T cells, which exhibited cytolytic activity against MM cells in vitro. In mice carrying MM tumors, p-Tvax increased tumor infiltration of CD4⁺ T cells. Moreover, combining p-Tvax with an OX40 agonist led to decreased tumor growth and increased survival. Mice treated with this combination immunotherapy displayed higher numbers of tumor-infiltrating CD8⁺ and CD4⁺ T cells and reduced T regulatory cells in tumors. Collectively, these data suggest that the combination of p-Tvax with an OX40 agonist could be an effective strategy for MM treatment.

Bioinspired and Biomimetic Nanotherapies for the Treatment of Infectious Diseases

There are still great challenges for the effective treatment of infectious diseases, although considerable achievement has been made by using antiviral and antimicrobial agents varying from small-molecule drugs, peptides/proteins, to nucleic acids. The nanomedicine approach is emerging as a new strategy capable of overcoming disadvantages of molecular therapeutics and amplifying their anti-infective activities, by localized delivery to infection sites, reducing off-target effects, and/or attenuating resistance development. Nanotechnology, in combination with bioinspired and biomimetic approaches, affords additional functions to nanoparticles derived from synthetic materials. Herein, we aim to provide a state-of-the-art review on recent progress in biomimetic and bioengineered nanotherapies for the treatment of infectious disease. Different biomimetic nanoparticles, derived from viruses, bacteria, and mammalian cells, are first described, with respect to their construction and biophysicochemical properties. Then, the applications of diverse biomimetic nanoparticles in anti-infective therapy are introduced, either by their intrinsic activity or by loading and site-specifically delivering various molecular drugs. Bioinspired and biomimetic nanovaccines for prevention and/or therapy of infectious diseases are also highlighted. At the end, major translation issues and future directions of this field are discussed.