Shape matters: Biodegradable anisotropic nanoparticle artificial antigen presenting cells for cancer immunotherapy

Metal Nanoparticles Produced Using Autotrophs and Their Bioproducts: A Comparative Overview between Photosynthesizing Taxonomic Groups

Metal nanoparticles (MNPs) exhibit unique properties influenced by their size, shape, and dispersion uniformity. They can be synthesized via chemical methods or green synthesis, commonly using plant or microorganism extracts as reducing and stabilizing agents. This eco-friendly approach is valued, but the literature is unclear about which taxonomic groups should be targeted to obtain certain types of MNPs. Given the ongoing growth of research in this area, this study offers a comparative overview that helps identify patterns and gaps in the current knowledge. This study reviewed 485 articles, describing 652 monometallic and 10 bimetallic nanoparticles synthesized using photosynthesizing organisms' extracts. Angiosperms and cyanobacteria were the most utilized groups. Silver and gold nanoparticles were the most studied MNPs. Gold nanoparticles' size varied with taxonomic groups, but they were smaller than the silver nanoparticles synthesized by the same group. Antimicrobial activity was the most common application, highlighting the potential of green-synthesized MNPs. This study provides valuable insights for optimizing sustainable nanoparticle production since knowledge about the specificities of different photosynthesizing taxa can be useful for directing efforts and enhancing the efficiency and precision of green-synthesized MNPs.

Sequential drug release nanocomposites for synergistic therapy in disease treatment

Time-sequenced drug release, or sequential drug release, represents a pivotal strategy in the synergistic treatment of diseases using nanocomposites. Achieving this requires the rational integration of multiple therapeutic agents within a single nanocomposite, coupled with precise time-controlled release mechanisms. These nanocomposites offer many advantages, including enhanced therapeutic synergy, reduced side effects, attenuated adverse interactions, improved stability and optimized drug utilization. Consequently, research in the field of drug delivery and synergistic therapy has become increasingly important. Currently, sequential drug release research is still in the data collection and basic research stages, and its potential has not yet been fully explored. Although prior studies have explored the sequential drug release strategy in various contexts, a comprehensive review of the underlying mechanisms and their applications in nanocomposites remains scarce. This review categorizes different types of sequential drug release strategies and summarizes diverse nanocomposites, focusing on both physical approaches driven by structural variations and chemical methods based on stimulus-responsive mechanisms. Furthermore, we highlight the major applications of sequential drug release strategies in the treatment of various diseases and detail their therapeutic efficacy. Finally, emerging trends and challenges in advancing sequential drug release strategies based on nanocomposites for disease treatment are also discussed.

Direct delivery of immune modulators to tumour-infiltrating lymphocytes using engineered extracellular vesicles

Extracellular vesicles (EVs) are important mediators of cell-cell communication, including immune regulation. Despite the recent development of several EV-based cancer immunotherapies, their clinical efficacy remains limited. Here, we created antigen-presenting EVs to express peptide-major histocompatibility complex (pMHC) class I, costimulatory molecule and IL-2. This enabled the selective delivery of multiple immune modulators to antigen-specific CD8+ T cells, promoting their expansion in vivo without severe adverse effects. Notably, antigen-presenting EVs accumulated in the tumour microenvironment, increasing IFN-γ+ CD8+ T cell and decreasing exhausted CD8+ T cell numbers, suggesting that antigen-presenting EVs transformed the 'cold' tumour microenvironment into a 'hot' one. Combination therapy with antigen-presenting EVs and anti-PD-1 demonstrated enhanced anticancer immunity against established tumours. We successfully engineered humanized antigen-presenting EVs, which selectively stimulated tumour antigen-specific CD8+ T cells. In conclusion, engineering EVs to co-express multiple immunomodulators represents a promising method for cancer immunotherapy.

Alginate-based artificial antigen presenting cells expand functional CD8+ T cells with memory characteristics for adoptive cell therapy

The development of artificial Antigen Presenting Cells (aAPCs) has led to improvements in adoptive T cell therapy (ACT), an immunotherapy, for cancer treatment. aAPCs help to streamline the consistent production and expansion of T cells, thus reducing the time and costs associated with ACT. However, several issues still exist with ACT, such as insufficient T cell potency, which diminishes the translational potential for ACT. While aAPCs have been used primarily to increase production efficiency of T cells for ACT, the intrinsic properties of a biomaterial-based aAPC may affect T cell phenotype and function. In CD8+ T cells, reactive oxygen species (ROS) and oxidative stress accumulation can activate Forkhead box protein O1 (FOXO1) to transcribe antioxidants which reduce ROS and improve memory formation. Alginate, a biocompatible and antioxidant rich biomaterial, is promising for incorporation into an aAPC formulation to modulate T cell phenotype. To investigate its utility, a novel alginate-based aAPC platform was developed that preferentially expanded CD8+ T cells with memory related features. Alginate-based aAPCs allowed for greater control of CD8+ T cell qualities, including, significantly improved in vivo persistence and augmented in vivo anti-tumor T cell responses.

A review of innovative design strategies: Artificial antigen presenting cells in cancer immunotherapy

Developing nanocarriers that can carry medications directly to tumors is an exciting development in cancer nanomedicine. The efficacy of this intriguing therapeutic approach is, however, compromised by intricate and immunosuppressive circumstances that arise concurrently with the onset of cancer. The artificial antigen presenting cell (aAPC), a micro or nanoparticle based device that mimics an antigen presenting cell by providing crucial signal proteins to T lymphocytes to activate them against cancer, is one cutting-edge method for cancer immunotherapy. This review delves into the critical design considerations for aAPCs, particularly focusing on particle size, shape, and the non-uniform distribution of T cell activating proteins on their surfaces. Adequate surface contact between T cells and aAPCs is essential for activation, prompting engineers to develop nano-aAPCs with microscale contact areas through techniques such as shape modification and nanoparticle clustering. Additionally, we explore recommendations for future advancements in this field.

Biomimetic Anisotropic-Functionalized Platelet-Membrane-Coated Polymeric Particles for Targeted Drug Delivery to Human Breast Cancer Cells

Biomimetic particles that can replicate aspects of natural biological cell function are useful for advanced biological engineering applications. Engineering such particles requires mimicking the chemical complexity of the surface of biological cells, and this can be achieved by coating synthetic particles with naturally derived cell membranes. Past research has demonstrated the feasibility of utilizing cell membrane coatings from a variety of cell types to achieve extended blood circulation half-life. A particle's shape can also be designed to mimic a biological cell or virus, and this physical attribute can cause particular transport and biodistribution properties. However, the potential synergy between engineering a biomimetic particle's core shape in combination with functionalizing its surface with cell membranes to achieve targeted drug delivery has not been well-investigated. Here, anisotropic poly(lactic-co-glycolic acid) (PLGA) particles are coated with platelet membranes to engineer particles with enhanced stealth properties that are biomimetic in size, shape, and surface composition to natural platelets. The natural ability of platelets to target tumor cells was harnessed to develop a particulate system for targeted dual delivery of a small molecule and protein to cancer cells. The particles had targeted binding to metastatic human breast cancer cells, leading to enhanced killing of these cells in a mouse model through codelivery of TRAIL and doxorubicin. This system can be used for cancer cell killing and could potentially be utilized in preventing breast cancer metastasis. By engineering both the physical and chemical properties of the particles, biomimicry and therapeutic promise can be best achieved.

Targeting the tumor microenvironment with biomaterials for enhanced immunotherapeutic efficacy

The tumor microenvironment (TME) is a complex system characterized by low oxygen, low pH, high pressure, and numerous growth factors and protein hydrolases that regulate a wide range of biological behaviors in the tumor and have a profound impact on cancer progression. Immunotherapy is an innovative approach to cancer treatment that activates the immune system, resulting in the spontaneous killing of tumor cells. However, the therapeutic efficacy of these clinically approved cancer immunotherapies (e.g., immune checkpoint blocker (ICB) therapies and chimeric antigen receptor (CAR) T-cell therapies) is far from satisfactory due to the presence of immunosuppressive TMEs created in part by tumor hypoxia, acidity, high levels of reactive oxygen species (ROS), and a dense extracellular matrix (ECM). With continuous advances in materials science and drug-delivery technologies, biomaterials hold considerable potential for targeting the TME. This article reviews the advances in biomaterial-based targeting of the TME to advance our current understanding on the role of biomaterials in enhancing tumor immunity. In addition, the strategies for remodeling the TME offer enticing advantages; however, the represent a double-edged sword. In the process of reshaping the TME, the risk of tumor growth, infiltration, and distant metastasis may increase.

Emerging Strategies for Local Delivery of Immune Checkpoint Inhibitors to Potentiate Cancer Immunotherapy: Current Status and Future Prospects

Cancer constitutes a significant threat to patients' lives worldwide. Immunotherapy, particularly immune checkpoint inhibitors (ICIs) that boost antitumor immunity by targeting immune checkpoint components, has emerged as a promising strategy for its treatment in recent years. However, the objective response rates of the ICIs are unsatisfactory. As the primary route, systemic administration of ICIs is often accompanied by immune-related adverse events. Local delivery of ICIs serves as a potential therapeutic strategy that can improve the efficacy while simultaneously reducing side effects through precise drug release at the tumor site. Initial validation of direct local application of ICIs for tumors in clinical trials has indicated reduced side effects and improved efficacy, while low bioavailability remains a challenge. Furthermore, research on various carriers, including nanoparticles, microneedles, hydrogels, combined platforms, and implantable devices for local release of ICIs has exhibited applying potential in treating murine tumors, among which combined platforms such as combined hydrogel system hold the highest promise due to their encompassment of the advantages of multiple carriers. These carriers, by incorporating ICIs and other therapeutics, could manage cancers more potently, which needs to be confirmed in clinical trials after the refinement of their biocompatibility. This review summarizes the latest research advancements regarding local administration of ICIs, with a particular focus on the carriers for local delivery as well as the combination therapies, thus providing novel insights and research guidance for scholars to enhance the efficacy of locally delivered ICIs on managing multiple cancers in the future.

Adaptive immunity of materials: Implications for tissue healing and regeneration

Recent cumulative findings signify the adaptive immunity of materials as a key agenda in tissue healing that can improve regenerative events and outcomes. Modulating immune responses, mainly the recruitment and functions of T and B cells and their further interplay with innate immune cells (e.g., dendritic cells, macrophages) can be orchestrated by materials. For instance, decellularized matrices have been shown to promote muscle healing by inducing T helper 2 (Th2) cell immunity, while synthetic biopolymers exhibit differential effects on B cell responses and fibrosis compared decellularized matrices. We discuss the recent findings on how implantable materials instruct the adaptive immune events and the subsequent tissue healing process. In particular, we dissect the materials' physicochemical properties (shape, size, topology, degradation, rigidity, and matrix dynamic mechanics) to demonstrate the relations of these parameters with the adaptive immune responses in vitro and the underlying biological mechanisms. Furthermore, we present evidence of recent in vivo phenomena, including tissue healing, cancer progression, and fibrosis, wherein biomaterials potentially shape adaptive immune cell functions and in vivo outcomes. Our discussion will help understand the materials-regulated immunology events more deeply, and offer the design rationale of materials with tunable matrix properties for accelerated tissue repair and regeneration.

Immunomodulatory nanoparticles activate cytotoxic T cells for enhancement of the effect of cancer immunotherapy

Cancer immunotherapy represents a promising targeted treatment by leveraging the patient's immune system or adoptive transfer of active immune cells to selectively eliminate cancer cells. Despite notable clinical successes, conventional immunotherapies face significant challenges stemming from the poor infiltration of endogenous or adoptively transferred cytotoxic T cells in tumors, immunosuppressive tumor microenvironment and the immune evasion capability of cancer cells, leading to limited efficacy in many types of solid tumors. Overcoming these hurdles is essential to broaden the applicability of immunotherapies. Recent advances in nanotherapeutics have emerged as an innovative tool to overcome these challenges and enhance the therapeutic potential of tumor immunotherapy. The unique biochemical and biophysical properties of nanomaterials offer advantages in activation of immune cells in vitro for cell therapy, targeted delivery, and controlled release of immunomodulatory agents in vivo. Nanoparticles are excellent carriers for tumor associated antigens or neoantigen peptides for tumor vaccine, empowering activation of tumor specific T cell responses. By precisely delivering immunomodulatory agents to the tumor site, immunoactivating nanoparticles can promote tumor infiltration of endogenous T cells or adoptively transferred T cells into tumors, to overcoming delivery and biological barriers in the tumor microenvironment, augmenting the immune system's ability to recognize and eliminate cancer cells. This review provides an overview of the current advances in immunotherapeutic approaches utilizing nanotechnology. With a focus on discussions concerning strategies to enhance activity and efficacy of cytotoxic T cells and explore the intersection of engineering nanoparticles and immunomodulation aimed at bolstering T cell-mediated immune responses, we introduce various nanoparticle formulations designed to deliver therapeutic payloads, tumor antigens and immunomodulatory agents for T cell activation. Diverse mechanisms through which nanoparticle-based approaches influence T cell responses by improving antigen presentation, promoting immune cell trafficking, and reprogramming immunosuppressive tumor microenvironments to potentiate anti-tumor immunity are examined. Additionally, the synergistic potential of combining nanotherapeutics with existing immunotherapies, such as immune checkpoint inhibitors and adoptive T cell therapies is explored. In conclusion, this review highlights emerging research advances on activation of cytotoxic T cells using nanoparticle agents to support the promises and potential applications of nanoparticle-based immunomodulatory agents for cancer immunotherapy.

Nanoparticle Targeting Strategies for Lipid and Polymer-Based Gene Delivery to Immune Cells In Vivo

Lipid nanoparticles and polymeric nanoparticles are promising biomaterial platforms for robust intracellular DNA and mRNA delivery, highlighted by the widespread use of nanoparticle- (NP) based mRNA vaccines to help end the COVID-19 pandemic. Recent research has sought to adapt this nanotechnology to transfect and engineer immune cells in vivo. The immune system is an especially appealing target due to its involvement in many different diseases, and ex vivo-engineered immune cell therapies like chimeric antigen receptor (CAR) T therapy have already demonstrated remarkable clinical success in certain blood cancers. Although gene delivery can potentially address some of the cost and manufacturing concerns associated with current autologous immune cell therapies, transfecting immune cells in vivo is challenging. Not only is extrahepatic NP delivery to lymphoid organs difficult, but immune cells like T cells have demonstrated particular resistance to transfection. Despite these challenges, the modular nature of NPs allows researchers to examine critical structure-function relationships between a particle's properties and its ability to specifically engineer immune cells in vivo. Herein, several nanomaterial components are outlined, including targeting ligands, nucleic acid cargo, chemical properties, physical properties, and the route of administration to specifically target NPs to immune cells for optimal in vivo transfection.

Tailoring biomaterials for vaccine delivery

Biomaterials are substances that can be injected, implanted, or applied to the surface of tissues in biomedical applications and have the ability to interact with biological systems to initiate therapeutic responses. Biomaterial-based vaccine delivery systems possess robust packaging capabilities, enabling sustained and localized drug release at the target site. Throughout the vaccine delivery process, they can contribute to protecting, stabilizing, and guiding the immunogen while also serving as adjuvants to enhance vaccine efficacy. In this article, we provide a comprehensive review of the contributions of biomaterials to the advancement of vaccine development. We begin by categorizing biomaterial types and properties, detailing their reprocessing strategies, and exploring several common delivery systems, such as polymeric nanoparticles, lipid nanoparticles, hydrogels, and microneedles. Additionally, we investigated how the physicochemical properties and delivery routes of biomaterials influence immune responses. Notably, we delve into the design considerations of biomaterials as vaccine adjuvants, showcasing their application in vaccine development for cancer, acquired immunodeficiency syndrome, influenza, corona virus disease 2019 (COVID-19), tuberculosis, malaria, and hepatitis B. Throughout this review, we highlight successful instances where biomaterials have enhanced vaccine efficacy and discuss the limitations and future directions of biomaterials in vaccine delivery and immunotherapy. This review aims to offer researchers a comprehensive understanding of the application of biomaterials in vaccine development and stimulate further progress in related fields.

Application of biomimetic nanovaccines in cancer immunotherapy: A useful strategy to help combat immunotherapy resistance

Breakthroughs in actual clinical applications have begun through vaccine-based cancer immunotherapy, which uses the body's immune system, both humoral and cellular, to attack malignant cells and fight diseases. However, conventional vaccine approaches still face multiple challenges eliciting effective antigen-specific immune responses, resulting in immunotherapy resistance. In recent years, biomimetic nanovaccines have emerged as a promising alternative to conventional vaccine approaches by incorporating the natural structure of various biological entities, such as cells, viruses, and bacteria. Biomimetic nanovaccines offer the benefit of targeted antigen-presenting cell (APC) delivery, improved antigen/adjuvant loading, and biocompatibility, thereby improving the sensitivity of immunotherapy. This review presents a comprehensive overview of several kinds of biomimetic nanovaccines in anticancer immune response, including cell membrane-coated nanovaccines, self-assembling protein-based nanovaccines, extracellular vesicle-based nanovaccines, natural ligand-modified nanovaccines, artificial antigen-presenting cells-based nanovaccines and liposome-based nanovaccines. We also discuss the perspectives and challenges associated with the clinical translation of emerging biomimetic nanovaccine platforms for sensitizing cancer cells to immunotherapy.

Antigen Presenting Cell Mimetic Lipid Nanoparticles for Rapid mRNA CAR T Cell Cancer Immunotherapy

Chimeric antigen receptor (CAR) T cell therapy has achieved remarkable clinical success in the treatment of hematological malignancies. However, producing these bespoke cancer-killing cells is a complicated ex vivo process involving leukapheresis, artificial T cell activation, and CAR construct introduction. The activation step requires the engagement of CD3/TCR and CD28 and is vital for T cell transfection and differentiation. Though antigen-presenting cells (APCs) facilitate activation in vivo, ex vivo activation relies on antibodies against CD3 and CD28 conjugated to magnetic beads. While effective, this artificial activation adds to the complexity of CAR T cell production as the beads must be removed prior to clinical implementation. To overcome this challenge, this work develops activating lipid nanoparticles (aLNPs) that mimic APCs to combine the activation of magnetic beads and the transfection capabilities of LNPs. It is shown that aLNPs enable one-step activation and transfection of primary human T cells with the resulting mRNA CAR T cells reducing tumor burden in a murine xenograft model, validating aLNPs as a promising platform for the rapid production of mRNA CAR T cells.

Enhancing cancer immunotherapy with photodynamic therapy and nanoparticle: making tumor microenvironment hotter to make immunotherapeutic work better

Cancer immunotherapy has made tremendous advancements in treating various malignancies. The biggest hurdle to successful immunotherapy would be the immunosuppressive tumor microenvironment (TME) and low immunogenicity of cancer cells. To make immunotherapy successful, the 'cold' TME must be converted to 'hot' immunostimulatory status to activate residual host immune responses. To this end, the immunosuppressive equilibrium in TME should be broken, and immunogenic cancer cell death ought to be induced to stimulate tumor-killing immune cells appropriately. Photodynamic therapy (PDT) is an efficient way of inducing immunogenic cell death (ICD) of cancer cells and disrupting immune-restrictive tumor tissues. PDT would trigger a chain reaction that would make the TME 'hot' and have ICD-induced tumor antigens presented to immune cells. In principle, the strategic combination of PDT and immunotherapy would synergize to enhance therapeutic outcomes in many intractable tumors. Novel technologies employing nanocarriers were developed to deliver photosensitizers and immunotherapeutic to TME efficiently. New-generation nanomedicines have been developed for PDT immunotherapy in recent years, which will accelerate clinical applications.

Particle-Based Artificial Antigen-Presenting Cell Systems for T Cell Activation in Adoptive T Cell Therapy

T cell-based adoptive cell therapy (ACT) has emerged as a promising treatment for various diseases, particularly cancers. Unlike other immunotherapy modalities, ACT involves directly transferring engineered T cells into patients to eradicate diseased cells; hence, it necessitates methods for effectively activating and expanding T cells in vitro. Artificial antigen-presenting cells (aAPCs) have been widely developed based on biomaterials, particularly micro- and nanoparticles, and functionalized with T cell stimulatory antibodies to closely mimic the natural T cell-APC interactions. Due to their vast clinical utility, aAPCs have been employed as an off-the-shelf technology for T cell activation in FDA-approved ACTs, and the development of aAPCs is constantly advancing with the emergence of aAPCs with more sophisticated designs and additional functionalities. Here, we review the recent advancements in particle-based aAPCs for T cell activation in ACTs. Following a brief introduction, we first describe the manufacturing processes of ACT products. Next, the design and synthetic strategies for micro- and nanoparticle-based aAPCs are discussed separately to emphasize their features, advantages, and limitations. Then, the impact of design parameters of aAPCs, such as size, shape, ligand density/mobility, and stiffness, on their functionality and biomedical performance is explored to provide deeper insights into the design concepts and principles for more efficient and safer aAPCs. The review concludes by discussing current challenges and proposing future perspectives for the development of more advanced aAPCs.

Artificial Antigen-Presenting Cell Fabrication for Murine T Cell Expansion

Antigen-presenting cells (APCs), such as dendritic cells and macrophages, have a unique ability to survey the body and present information to T cells via peptide-loaded major histocompatibility complexes (signal 1). This presentation, along with a co-stimulatory signal (signal 2), leads to activation and subsequent expansion of T cells. This process can be harnessed and utilized for therapeutic applications, but the use of patient-derived APCs can be complex and inefficient. Alternatively, artificial APCs (aAPCs) provide a simplified method to achieve T cell activation by presenting the two necessary stimulatory signals. This protocol describes the utilization of magnetic nanoparticles and stimulatory proteins to create aAPCs that can be employed for activating and expanding antigen-specific T cells for both basic and translational immunology and immunotherapy studies. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Protein and particle modification for aAPC fabrication Basic Protocol 2: aAPC validation by immunolabeling of conjugated protein Support Protocol 1: Quantification of aAPC stock concentration Basic Protocol 3: Determination of aAPC usage for murine CD8+ T cell activation Support Protocol 2: Isolation of murine CD8+ T cells.

Intracellular Trafficking of Size-Tuned Nanoparticles for Drug Delivery

Polymeric nanoparticles (NPs) are widely used as drug delivery systems in nanomedicine. Despite their widespread application, a comprehensive understanding of their intracellular trafficking remains elusive. In the present study, we focused on exploring the impact of a 20 nm difference in size on NP performance, including drug delivery capabilities and intracellular trafficking. For that, poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PLGA-PEG) NPs with sizes of 50 and 70 nm were precisely tailored. To assess their prowess in encapsulating and releasing therapeutic agents, we have employed doxorubicin (Dox), a well-established anticancer drug widely utilized in clinical settings, as a model drug. Then, the beneficial effect of the developed nanoformulations was evaluated in breast cancer cells. Finally, we performed a semiquantitative analysis of both NPs' uptake and intracellular localization by immunostaining lysosomes, early endosomes, and recycling endosomes. The results show that the smaller NPs (50 nm) were able to reduce the metabolic activity of cancer cells more efficiently than NPs of 70 nm, in a time and concentration-dependent manner. These findings are corroborated by intracellular trafficking studies that reveal an earlier and higher uptake of NPs, with 50 nm compared to the 70 nm ones, by the breast cancer cells. Consequently, this study demonstrates that NP size, even in small increments, has an important impact on their therapeutic effect.

The DC-T cell axis is an effective target for the treatment of non-small cell lung cancer

The dendritic cell (DC)-T cell axis is a bridge that connects innate and adaptive immunities. The initial immune response against tumors is mainly induced by mature antigen-presenting DCs. Enhancing the crosstalk between DCs and T cells may be an effective approach to improve the immune response to non-small cell lung cancer (NSCLC). In this article, a review was made of the interaction between DCs and T cells in the treatment of NSCLC and how this interaction affects the treatment outcome.