Immunostimulatory Polymers as Adjuvants, Immunotherapies, and Delivery Systems

Synthetic and natural polymer hydrogels: A review of 3D spheroids and drug delivery

This review centers on the synthesis and characterization of both natural and synthetic hydrogels, highlighting their diverse applications across various fields. We will delve into the evolution of hydrogels, focusing on the importance of polysaccharide-based and synthetic variants, which have been particularly chosen for 3D spheroid development in cancer research and drug delivery. A detailed background on the research and specific methodologies, including the in-situ free radical polymerization used for synthesizing these hydrogels, will be extensively discussed. Additionally, the review will explore various applications of these hydrogels, such as their self-healing properties, swelling ratios, pH responsiveness, and cell viability. A comprehensive literature review will support this investigation. Ultimately, this review aims to clearly outline the objectives and significance of hydrogel synthesis and their applications.

mRNA vaccines contribute to innate and adaptive immunity to enhance immune response in vivo

Messenger RNA (mRNA) therapeutics have been widely employed as strategies for the treatment and prevention of diseases. Amid the global outbreak of COVID-19, mRNA vaccines have witnessed rapid development. Generally, in the case of mRNA vaccines, the initiation of the innate immune system serves as a prerequisite for triggering subsequent adaptive immune responses. Critical cells, cytokines, and chemokines within the innate immune system play crucial and beneficial roles in coordinating tailored immune reactions towards mRNA vaccines. Furthermore, immunostimulators and delivery systems play a significant role in augmenting the immune potency of mRNA vaccines. In this comprehensive review, we systematically delineate the latest advancements in mRNA vaccine research, present an in-depth exploration of strategies aimed at amplifying the immune effectiveness of mRNA vaccines, and offer some perspectives and recommendations regarding the future advancements in mRNA vaccine development.

Identification of CDK4/6 Inhibitors as Small Molecule NLRP3 Inflammasome Activators that Facilitate IL-1β Secretion and T Cell Adjuvanticity

Several FDA-approved adjuvants signal through the NLRP3 inflammasome and IL-1β release. Identifying small molecules that induce IL-1β release could allow targeted delivery and structure-function optimization, thereby improving safety and efficacy of next-generation adjuvants. In this work, we leverage our existing high throughput data set to identify small molecules that induce IL-1β release. We find that ribociclib induces IL-1β release when coadministered with a TLR4 agonist in an NLRP3- and caspase-dependent fashion. Ribociclib was formulated with a TLR4 agonist into liposomes, which were used as an adjuvant in an ovalbumin prophylactic vaccine model. The liposomes induced antigen-specific immunity in an IL-1 receptor-dependent fashion. Furthermore, the liposomes were coadministered with a tumor antigen and used in a therapeutic cancer vaccine, where they facilitated rejection of E.G7-OVA tumors. While further chemical optimization of the ribociclib scaffold is needed, this study provides proof-of-concept for its use as an IL-1 producing adjuvant in various immunotherapeutic contexts.

Advances in Nanomaterials for Immunotherapeutic Improvement of Cancer Chemotherapy

Immuno-stimulative effect of chemotherapy (ISECT) is recognized as a potential alternative to conventional immunotherapies, however, the clinical application is constrained by its inefficiency. Metronomic chemotherapy, though designed to overcome these limitations, offers inconsistent results, with effectiveness varying based on cancer types, stages, and patient-specific factors. In parallel, a wealth of preclinical nanomaterials holds considerable promise for ISECT improvement by modulating the cancer-immunity cycle. In the area of biomedical nanomaterials, current literature reviews mainly concentrate on a specific category of nanomaterials and nanotechnological perspectives, while two essential issues are still lacking, i.e., a comprehensive analysis addressing the causes for ISECT inefficiency and a thorough summary elaborating the nanomaterials for ISECT improvement. This review thus aims to fill these gaps and catalyze further development in this field. For the first time, this review comprehensively discusses the causes of ISECT inefficiency. It then meticulously categorizes six types of nanomaterials for improving ISECT. Subsequently, practical strategies are further proposed for addressing inefficient ISECT, along with a detailed discussion on exemplary nanomedicines. Finally, this review provides insights into the challenges and perspectives for improving chemo-immunotherapy by innovations in nanomaterials.

Self-Assembled Nanobiomaterials for Combination Immunotherapy

Nanotechnological interventions for cancer immunotherapy are a rapidly evolving paradigm with immense potential. Self-assembled nanobiomaterials present safer alternatives to their nondegradable counterparts and pose better functionalities in terms of controlled drug delivery and phototherapy to activate immunogenic cell death. In this Review, we discuss several classes of self-assembled nanobiomaterials based on polymers, lipids, peptides, hydrogel, metal organic frameworks, and covalent-organic frameworks with the ability to activate systemic immune response and convert a "cold" immunosuppressive tumor mass to a "hot" antitumor immune cell rich microenvironment. The unique aspects of these materials are underpinned, and their mechanisms of combinatorial immunotherapeutic action are discussed. Future challenges associated with their clinical translation are also highlighted.

Cutting-edge research frontiers in oral cavity vaccines for respiratory diseases: a roadmap for scientific advancement

Intramuscular vaccines present limitations in eliciting robust mucosal immunity and preventing respiratory pathogens transmission. Sublingual vaccine administration offers promising advantages, including interconnected mucosal protection. Despite these advantages, only a few clinical trials have explored sublingual vaccines, underscoring the necessity of optimizing next-generation vaccine formulas. Critical research priorities include understanding vector behavior in the oral environment, understanding their interactions with mucosal immunity and developing formulations enabling sustained mucosal contact to facilitate efficient transduction. Consequently, tonsil organoids, as representative human mucosal models, could offer critical insights into sublingual immunization. Thus, a multi-disciplinary approach integrating pharmacological, immunological, and manufacturing considerations is pivotal for sublingual vaccines in targeting pathogen-aggravated prevalent respiratory diseases including asthma, COPD and lung cancer, as well as the antimicrobial resistance crisis.

Role of NLRP3 inflammasome in nanoparticle adjuvant-mediated immune response

The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome is pivotal in orchestrating the immune response induced by nanoparticle adjuvants. Understanding the intricate mechanisms underlying the activation of NLRP3 inflammasome by these adjuvants is crucial for deciphering their immunomodulatory properties. This review explores the involvement of the NLRP3 inflammasome in mediating immune responses triggered by nanoparticle adjuvants. It delves into the signaling pathways and cellular mechanisms involved in NLRP3 activation, highlighting its significance in modulating the efficacy and safety of nanoparticle-based adjuvants. A comprehensive grasp of the interplay between NLRP3 inflammasome and nanoparticle adjuvants holds promise for optimizing vaccine design and advancing immunotherapeutic strategies.

Vaccine adjuvants: current status, research and development, licensing, and future opportunities

Vaccines represent one of the most significant inventions in human history and have revolutionized global health. Generally, a vaccine functions by triggering the innate immune response and stimulating antigen-presenting cells, leading to a defensive adaptive immune response against a specific pathogen's antigen. As a key element, adjuvants are chemical materials often employed as additives to increase a vaccine's efficacy and immunogenicity. For over 90 years, adjuvants have been essential components in many human vaccines, improving their efficacy by enhancing, modulating, and prolonging the immune response. Here, we provide a timely and comprehensive review of the historical development and the current status of adjuvants, covering their classification, mechanisms of action, and roles in different vaccines. Additionally, we perform systematic analysis of the current licensing processes and highlights notable examples from clinical trials involving vaccine adjuvants. Looking ahead, we anticipate future trends in the field, including the development of new adjuvant formulations, the creation of innovative adjuvants, and their integration into the broader scope of systems vaccinology and vaccine delivery. The article posits that a deeper understanding of biochemistry, materials science, and vaccine immunology is crucial for advancing vaccine technology. Such advancements are expected to lead to the future development of more effective vaccines, capable of combating emerging infectious diseases and enhancing public health.

Biocompatibility of intraperitoneally implanted TEMPO-oxidized cellulose nanofiber hydrogels for antigen delivery in Atlantic salmon (Salmo salar L.) vaccines

Disease outbreaks are a major impediment to aquaculture production, and vaccines are integral for disease management. Vaccines can be expensive, vary in effectiveness, and come with adjuvant-induced adverse effects, causing fish welfare issues and negative economic impacts. Three-dimensional biopolymer hydrogels are an appealing new technology for vaccine delivery in aquaculture, with the potential for controlled release of multiple immunomodulators and antigens simultaneously, action as local depots, and tunable surface properties. This research examined the intraperitoneal implantation of a cross-linked TEMPO cellulose nanofiber (TOCNF) hydrogel formulated with a Vibrio anguillarum bacterin in Atlantic salmon with macroscopic and microscopic monitoring to 600-degree days post-implantation. Results demonstrated a modified passive integrated transponder tagging (PITT) device allowed for implantation of the hydrogel. However, the Atlantic salmon implanted with TOCNF hydrogels exhibited a significant foreign body response (FBR) compared to sham-injected negative controls. The FBR was characterized by gross and microscopic external and visceral proliferative lesions, granulomas, adhesions, and fibrosis surrounding the hydrogel using Speilberg scoring of the peritoneum and histopathology of the body wall and coelom. Acutely, gross monitoring displayed rapid coagulation of blood in response to the implantation wound with development of fibrinous adhesions surrounding the hydrogel by 72 h post-implantation consistent with early stage FBR. While these results were undesirable for aquaculture vaccines, this work informs on the innate immune response to an implanted biopolymer hydrogel in Atlantic salmon and directs future research using cellulose nanomaterial formulations in Atlantic salmon for a new generation of aquaculture vaccine technology.

Therapeutic synthetic and natural materials for immunoengineering

Immunoengineering is a rapidly evolving field that has been driving innovations in manipulating immune system for new treatment tools and methods. The need for materials for immunoengineering applications has gained significant attention in recent years due to the growing demand for effective therapies that can target and regulate the immune system. Biologics and biomaterials are emerging as promising tools for controlling immune responses, and a wide variety of materials, including proteins, polymers, nanoparticles, and hydrogels, are being developed for this purpose. In this review article, we explore the different types of materials used in immunoengineering applications, their properties and design principles, and highlight the latest therapeutic materials advancements. Recent works in adjuvants, vaccines, immune tolerance, immunotherapy, and tissue models for immunoengineering studies are discussed.

Mannose Ligands for Mannose Receptor Targeting

The mannose receptor (MR, CD 206) is an endocytic receptor primarily expressed by macrophages and dendritic cells, which plays a critical role in both endocytosis and antigen processing and presentation. MR carbohydrate recognition domains (CRDs) exhibit a high binding affinity for branched and linear oligosaccharides. Furthermore, multivalent mannose presentation on the various templates like peptides, proteins, polymers, micelles, and dendrimers was proven to be a valuable approach for the selective and efficient delivery of various therapeutically active agents to MR. This review provides a detailed account of the most relevant and recent aspects of the synthesis and application of mannosylated bioactive formulations for MR-mediated delivery in treatments of cancer and other infectious diseases. It further highlights recent findings related to the necessary structural features of the mannose-containing ligands for successful binding to the MR.

Nucleic acid degradation as barrier to gene delivery: a guide to understand and overcome nuclease activity

Gene therapy is on its way to revolutionize the treatment of both inherited and acquired diseases, by transferring nucleic acids to correct a disease-causing gene in the target cells of patients. In the fight against infectious diseases, mRNA-based therapeutics have proven to be a viable strategy in the recent Covid-19 pandemic. Although a growing number of gene therapies have been approved, the success rate is limited when compared to the large number of preclinical and clinical trials that have been/are being performed. In this review, we highlight some of the hurdles which gene therapies encounter after administration into the human body, with a focus on nucleic acid degradation by nucleases that are extremely abundant in mammalian organs, biological fluids as well as in subcellular compartments. We overview the available strategies to reduce the biodegradation of gene therapeutics after administration, including chemical modifications of the nucleic acids, encapsulation into vectors and co-administration with nuclease inhibitors and discuss which strategies are applied for clinically approved nucleic acid therapeutics. In the final part, we discuss the currently available methods and techniques to qualify and quantify the integrity of nucleic acids, with their own strengths and limitations.

Nanovaccines: A game changing approach in the fight against infectious diseases

The field of nanotechnology has revolutionised global attempts to prevent, treat, and eradicate infectious diseases in the foreseen future. Nanovaccines have proven to be a valuable pawn in this novel technology. Nanovaccines are made up of nanoparticles that are associated with or prepared with components that can stimulate the host's immune system. In addition to their delivery capabilities, the nanocarriers have been demonstrated to possess intrinsic adjuvant properties, working as immune cell stimulators. Thus, nanovaccines have the potential to promote rapid as well as long-lasting humoral and cellular immunity. The nanovaccines have several possible benefits, including site-specific antigen delivery, increased antigen bioavailability, and a diminished adverse effect profile. To avail these benefits, several nanoparticle-based vaccines are being developed, including virus-like particles, liposomes, polymeric nanoparticles, nanogels, lipid nanoparticles, emulsion vaccines, exomes, and inorganic nanoparticles. Inspired by their distinctive properties, researchers are working on the development of nanovaccines for a variety of applications, such as cancer immunotherapy and infectious diseases. Although a few challenges still need to be overcome, such as modulation of the nanoparticle pharmacokinetics to avoid rapid elimination from the bloodstream by the reticuloendothelial system, The future prospects of this technology are also assuring, with multiple options such as personalised vaccines, needle-free formulations, and combination nanovaccines with several promising candidates.

Understanding How Cationic Polymers' Properties Inform Toxic or Immunogenic Responses via Parametric Analysis

Cationic polymers are widely used materials in diverse biotechnologies. Subtle variations in these polymers' properties can change them from exceptional delivery agents to toxic inflammatory hazards. Conventional screening strategies optimize for function in a specific application rather than observing how underlying polymer-cell interactions emerge from polymers' properties. An alternative approach is to map basic underlying responses, such as immunogenicity or toxicity, as a function of basic physicochemical parameters to inform the design of materials for a breadth of applications. To demonstrate the potential of this approach, we synthesized 107 polymers varied in charge, hydrophobicity, and molecular weight. We then screened this library for cytotoxic behavior and immunogenic responses to map how these physicochemical properties inform polymer-cell interactions. We identify three compositional regions of interest and use confocal microscopy to uncover the mechanisms behind the observed responses. Finally, immunogenic activity is confirmed in vivo. Highly cationic polymers disrupted the cellular plasma membrane to induce a toxic phenotype, while high molecular weight, hydrophobic polymers were uptaken by active transport to induce NLRP3 inflammasome activation, an immunogenic phenotype. Tertiary amine- and triethylene glycol-containing polymers did not invoke immunogenic or toxic responses. The framework described herein allows for the systematic characterization of new cationic materials with different physicochemical properties for applications ranging from drug and gene delivery to antimicrobial coatings and tissue scaffolds.

"AMP plus": Immunostimulant-Inspired Design Based on Chemotactic Motif-(PhHAhPH)n

Ability to stimulate antimicrobial immunity has proven to be a useful therapeutic strategy in treating infections, especially in the face of increasing antibiotic resistance. Natural antimicrobial peptides (AMPs) exhibiting immunomodulatory functions normally encompass complex activities, which make it difficult to optimize their therapeutic benefits. Here, a chemotactic motif was harnessed as a template to design a series of AMPs with immunostimulatory activities plus bacteria-killing activities ("AMP plus"). An amphipathic peptide ((PhHAhPH)n) was employed to improve the antimicrobial impact and expand the therapeutic potential of the chemotactic motif that lacked obvious bacteria-killing properties. A total of 18 peptides were designed and evaluated for their structure-activity relationships. Among the designed, KWH2 (1) potently killed bacteria and exhibited a narrow antimicrobial spectrum against Gram-negative bacteria and (2) activated macrophages (i.e., inducing Ca2+ influx, cell migration, and reactive oxygen species production) as a macrophage chemoattractant. Membrane permeabilization is the major antimicrobial mechanism of KWH2. Furthermore, the mouse subcutaneous abscess model supported the dual immunomodulatory and antimicrobial potential of KWH2 in vivo. The above results confirmed the efficiency of KWH2 in treating bacterial infection and provided a viable approach to develop immunomodulatory antimicrobial materials with desired properties.

Polymer Chemistry Defines Adjuvant Properties and Determines the Immune Response against the Antigen or Vaccine

Activation of the immune system is a needed for designing new antigen/drug delivery systems to develop new therapeutics and for developing animal disease models to study the disease pathogenesis. A weak antigen alone is insufficient to activate the immune system. Sometimes, assistance in the form of polymers is needed to control the release of antigens under in vivo conditions or in the form of an adjuvant to activate the immune system efficiently. Many kinds of polymers from different functional groups are suitable as microbial antigens for inducing therapeutic immune responses against infectious diseases at the preclinical level. The choice of the functionality of polymer varies as per the application type. Polymers from the acid and ester groups are the most common types investigated for protein-based antigens. However, electrostatic interaction-displaying polymers like cationic polymers are the most common type for nucleic acid-based antigens. Metal coordination chemistry is commonly used in polymers designed for cancer immunotherapeutic applications to suppress inflammation and induce a protective immune response. Amide chemistry is widely deployed in polymers used to develop antigen-specific disease models like the experimental autoimmune arthritis murine model.

Cell-targeted vaccines: implications for adaptive immunity

Recent advancements in immunology and chemistry have facilitated advancements in targeted vaccine technology. Targeting specific cell types, tissue locations, or receptors can allow for modulation of the adaptive immune response to vaccines. This review provides an overview of cellular targets of vaccines, suggests methods of targeting and downstream effects on immune responses, and summarizes general trends in the literature. Understanding the relationships between vaccine targets and subsequent adaptive immune responses is critical for effective vaccine design. This knowledge could facilitate design of more effective, disease-specialized vaccines.

Polymer-Based Hydrogels Applied in Drug Delivery: An Overview

Polymer-based hydrogels are hydrophilic polymer networks with crosslinks widely applied for drug delivery applications because of their ability to hold large amounts of water and biological fluids and control drug release based on their unique physicochemical properties and biocompatibility. Current trends in the development of hydrogel drug delivery systems involve the release of drugs in response to specific triggers such as pH, temperature, or enzymes for targeted drug delivery and to reduce the potential for systemic toxicity. In addition, developing injectable hydrogel formulations that are easily used and sustain drug release during this extended time is a growing interest. Another emerging trend in hydrogel drug delivery is the synthesis of nano hydrogels and other functional substances for improving targeted drug loading and release efficacy. Following these development trends, advanced hydrogels possessing mechanically improved properties, controlled release rates, and biocompatibility is developing as a focus of the field. More complex drug delivery systems such as multi-drug delivery and combination therapies will be developed based on these advancements. In addition, polymer-based hydrogels are gaining increasing attention in personalized medicine because of their ability to be tailored to a specific patient, for example, drug release rates, drug combinations, target-specific drug delivery, improvement of disease treatment effectiveness, and healthcare cost reduction. Overall, hydrogel application is advancing rapidly, towards more efficient and effective drug delivery systems in the future.

Nanovaccine that activates the NLRP3 inflammasome enhances tumor specific activation of anti-cancer immunity

Neoantigen cancer vaccines that target tumor specific mutations are emerging as a promising modality for cancer immunotherapy. To date, various approaches have been adopted to enhance efficacy of these therapies, but the low immunogenicity of neoantigens has hindered clinical application. To address this challenge, we developed a polymeric nanovaccine platform that activates the NLRP3 inflammasome, a key immunological signaling pathway in pathogen recognition and clearance. The nanovaccine is comprised of a poly (orthoester) scaffold engrafted with a small-molecule TLR7/8 agonist and an endosomal escape peptide that facilitates lysosomal rupture and NLRP3 inflammasome activation. Upon solvent transfer, the polymer self-assembles with neoantigens to form ∼50 nm nanoparticles that facilitate co-delivery to antigen-presenting cells. This polymeric activator of the inflammasome (PAI) was found to induce potent antigen-specific CD8+ T cell responses characterized by IFN-γ and GranzymeB secretion. Moreover, in combination with immune checkpoint blockade therapy, the nanovaccine stimulated robust anti-tumor immune responses against established tumors in EG.7-OVA, B16·F10, and CT-26 models. Results from our studies indicate that NLRP3 inflammasome activating nanovaccines demonstrate promise for development as a robust platform to enhance immunogenicity of neoantigen therapies.

In vivo tracing of immunostimulatory raw starch microparticles after mucosal administration

Raw starch microparticles (SMPs) proved efficient antigen carriers with adjuvant properties when administered via the mucosal route; however, the underlying mechanisms associated with this bioactivity are unknown. In the present study, we explored the mucoadhesion properties, fate, and toxicity of starch microparticles after mucosal administration. Nasally administered microparticles were mainly retained in nasal turbinates, reaching the nasal-associated lymphoid tissue; this step is facilitated by the ability of the microparticles to penetrate through the mucous epithelium. Likewise, we found intraduodenally administered SMPs on the small intestinal villi, follicle-associated epithelium, and Peyer's patches. Furthermore, under simulated gastric and intestinal pH conditions, we detected mucoadhesion between the SMPs and mucins, regardless of microparticle swelling. SMPs' mucoadhesion and translocation to mucosal immune responses induction sites explain the previously reported role of these microparticles as vaccine adjuvants and immunostimulants.

Modification with Conventional Surfactants to Improve a Lipid-Based Ionic-Liquid-Associated Transcutaneous Anticancer Vaccine

Transcutaneous vaccination is one of the successful, affordable, and patient-friendly advanced immunization approaches because of the presence of multiple immune-responsive cell types in the skin. However, in the absence of a preferable facilitator, the skin’s outer layer is a strong impediment to delivering biologically active foreign particles. Lipid-based biocompatible ionic-liquid-mediated nanodrug carriers represent an expedient and distinct strategy to permit transdermal drug delivery; with acceptable surfactants, the performance of drug formulations might be further enhanced. For this purpose, we formulated a lipid-based nanovaccine using a conventional (cationic/anionic/nonionic) surfactant loaded with an antigenic protein and immunomodulator in its core to promote drug delivery by penetrating the skin and boosting drug delivery and immunogenic cell activity. In a follow-up investigation, a freeze–dry emulsification process was used to prepare the nanovaccine, and its transdermal delivery, pharmacokinetic parameters, and ability to activate autoimmune cells in the tumor microenvironment were studied in a tumor-budding C57BL/6N mouse model. These analyses were performed using ELISA, nuclei and HE staining, flow cytometry, and other biological techniques. The immunomodulator-containing nanovaccine significantly (p < 0.001) increased transdermal drug delivery and anticancer immune responses (IgG, IgG1, IgG2, CD8+, CD207+, and CD103+ expression) without causing cellular or biological toxicity. Using a nanovaccination approach, it is possible to create a more targeted and efficient delivery system for cancer antigens, thereby stimulating a stronger immune response compared with conventional aqueous formulations. This might lead to more effective therapeutic and preventative outcomes for patients with cancer.

Progress on innate immune evasion and live attenuated vaccine of pseudorabies virus

Pseudorabies virus (PRV) is a highly infectious disease that can infect most mammals, with pigs as the only natural host, has caused considerable economic losses to the pig husbandry of the world. Innate immunity is the first defense line of the host against the attack of pathogens and is essential for the proper establishment of adaptive immunity. The host uses the innate immune response to against the invasion of PRV; however PRV makes use of various strategies to inhibit the innate immunity to promote the virus replication. Currently, live attenuated vaccine is used to prevent pig from infection with the PRV worldwide, such as Bartha K61. However, a growing number of data indicates that these vaccines do not provide complete protection against new PRV variants that have emerged since late 2011. Here we summarized the interactions between PRV and host innate immunity and the current status of live attenuated PRV vaccines to promote the development of novel and more effective PRV vaccines.

Recent Trends and Opportunities for the Targeted Immuno-Nanomaterials for Cancer Theranostics Applications

The targeted delivery of cancer immunotherapies has increased noticeably in recent years. Recent advancements in immunotherapy, particularly in blocking the immune checkpoints (ICs) axis, have shown favorable treatment outcomes for multiple types of cancer including melanoma and non-small-cell lung cancer (NSLC). Engineered micromachines, including microparticles, and nanoplatforms (organic and inorganic), functionalized with immune agonists can effectively deliver immune-targeting molecules to solid tumors. This review focuses on the nanomaterial-based strategies that have shown promise in identifying and targeting various immunological markers in the tumor microenvironment (TME) for cancer diagnosis and therapy. Nanomaterials-based cancer immunotherapy has improved treatment outcomes by triggering an immune response in the TME. Evaluating the expression levels of ICs in the TME also could potentially aid in diagnosing patients who would respond to IC blockade therapy. Detecting immunological checkpoints in the TME using noninvasive imaging systems via tailored nanosensors improves the identification of patient outcomes in immuno-oncology (IO). To enhance patient-specific analysis, lab-on-chip (LOC) technology is a rapid, cost-effective, and accurate way of recapitulating the TME. Such novel nanomaterial-based technologies have been of great interest for testing immunotherapies and assessing biomarkers. Finally, we provide a perspective on the developments in artificial intelligence tools to facilitate ICs-based nano theranostics toward cancer immunotherapy.

Nanovaccines against Viral Infectious Diseases

Infectious diseases have always been regarded as one of the greatest global threats for the last century. The current ongoing COVID-19 pandemic caused by SARS-CoV-2 is living proof that the world is still threatened by emerging infectious diseases. Morbidity and mortality rates of diseases caused by Coronavirus have inflicted devastating social and economic outcomes. Undoubtedly, vaccination is the most effective method of eradicating infections and infectious diseases that have been eradicated by vaccinations, including Smallpox and Polio. To date, next-generation vaccine candidates with novel platforms are being approved for emergency use, such as the mRNA and viral vectored vaccines against SARS-CoV-2. Nanoparticle based vaccines are the perfect candidates as they demonstrated targeted antigen delivery, improved antigen presentation, and sustained antigen release while providing self-adjuvanting functions to stimulate potent immune responses. In this review, we discussed most of the recent nanovaccines that have found success in immunization and challenge studies in animal models in comparison with their naked vaccine counterparts. Nanovaccines that are currently in clinical trials are also reviewed.

Mannose in vaccine delivery

Adjuvants and vaccine delivery systems are used widely to improve the efficacy of vaccines. Their primary roles are to protect antigen from degradation and allow its delivery and uptake by antigen presenting cells (APCs). Carbohydrates, including various structures/forms of mannose, have been broadly utilized to target carbohydrate binding receptors on APCs. This review summarizes basic functions of the immune system, focusing on the role of mannose receptors in antigen recognition by APCs. The most popular strategies to produce mannosylated vaccines via conjugation and formulation are presented. The efficacy of mannosylated vaccines is discussed in detail, taking into consideration factors, such as valency and number of mannose in mannose ligands, mannose density, length of spacers, special arrangement of mannose ligands, and routes of administration of mannosylated vaccines. The advantages and disadvantages of mannosylation strategy and future directions in the development of mannosylated vaccines are also debated.