Biomaterial-assisted targeted modulation of immune cells in cancer treatment

Advances in Engineered Polymer Nanoparticle Tracking Platforms towards Cancer Immunotherapy-Current Status and Future Perspectives

Engineering polymeric nanoparticles for their shape, size, surface chemistry, and functionalization using various targeting molecules has shown improved biomedical applications for nanoparticles. Polymeric nanoparticles have created tremendous therapeutic platforms, particularly applications related to chemo- and immunotherapies in cancer. Recently advancements in immunotherapies have broadened this field in immunology and biomedical engineering, where "immunoengineering" creates solutions to target translational science. In this regard, the nanoengineering field has offered the various techniques necessary to manufacture and assemble multifunctional polymeric nanomaterial systems. These include nanoparticles functionalized using antibodies, small molecule ligands, targeted peptides, proteins, and other novel agents that trigger and encourage biological systems to accept the engineered materials as immune enhancers or as vaccines to elevate therapeutic functions. Strategies to engineer polymeric nanoparticles with therapeutic and targeting molecules can provide solutions for developing immune vaccines via maintaining the receptor storage in T- and B cells. Furthermore, cancer immunotherapy using polymeric nanomaterials can serve as a gold standard approach for treating primary and metastasized tumors. The current status of the limited availability of immuno-therapeutic drugs highlights the importance of polymeric nanomaterial platforms to improve the outcomes via delivering anticancer agents at localized sites, thereby enhancing the host immune response in cancer therapy. This review mainly focuses on the potential scientific enhancements and recent developments in cancer immunotherapies by explicitly discussing the role of polymeric nanocarriers as nano-vaccines. We also briefly discuss the role of multifunctional nanomaterials for their therapeutic impacts on translational clinical applications.

Engineering Nanorobots for Tumor-Targeting Drug Delivery: From Dynamic Control to Stimuli-Responsive Strategy

Nanotechnology has been widely applied to the fabrication of drug delivery systems in the past decades. Recently, with the progress made in microfabrication approaches, nanorobots are steadily becoming a promising means for tumor-targeting drug delivery. In general, nanorobots can be divided into two categories: nanomotors and stimuli-responsive nanorobots. Nanomotors are nanoscale systems with the ability to convert surrounding energies into mechanical motion, whereas stimuli-responsive nanorobots are featured with activatable capacity in response to various endogenous and exogenous stimulations. In this minireview, the dynamic control of nanomotors and the rational design of stimuli-responsive nanorobots are overviewed, with particular emphasis on their contribution to tumor-targeting therapy. Moreover, challenges and perspectives associated with the future development of nanorobots are presented.

Nanoparticles for generating antigen-specific T cells for immunotherapy

T cell therapy shows promise as an immunotherapy in both immunostimulatory and immunosuppressive applications. However, the forms of T cell-based therapy that are currently in the clinic, such as adoptive cell transfer and vaccines, are limited by cost, time-to-treatment, and patient variability. Nanoparticles offer a modular, universal platform to improve the efficacy of various T cell therapies as nanoparticle properties can be easily modified for enhanced cell targeting, organ targeting, and cell internalization. Nanoparticles can enhance or even replace endogenous cells during each step of generating an antigen-specific T cell response - from antigen presentation and T cell activation to T cell maintenance. In this review, we discuss the unique applications of nanoparticles for antigen-specific T cell therapy, focusing on nanoparticles as vaccines (to activate endogenous antigen presenting cells (APCs)), as artificial Antigen Presenting Cells (aAPCs, to directly activate T cells), and as drug delivery vehicles (to support activated T cells).

Recent Advances in Engineered Materials for Immunotherapy-Involved Combination Cancer Therapy

Immunotherapy that can activate immunity or enhance the immunogenicity of tumors has emerged as one of the most effective methods for cancer therapy. Nevertheless, single-mode immunotherapy is still confronted with several critical challenges, such as the low immune response, the low tumor infiltration, and the complex immunosuppression tumor microenvironment. Recently, the combination of immunotherapy with other therapeutic modalities has emerged as a powerful strategy to augment the therapeutic outcome in fighting against cancer. In this review, recent research advances of the combination of immunotherapy with chemotherapy, phototherapy, radiotherapy, sonodynamic therapy, metabolic therapy, and microwave thermotherapy are summarized. Critical challenges and future research direction of immunotherapy-based cancer therapeutic strategy are also discussed.

Biodegradable and Peroxidase-Mimetic Boron Oxynitride Nanozyme for Breast Cancer Therapy

Nanomaterials having enzyme-like activities are recognized as potentially important self-therapeutic nanomedicines. Herein, a peroxidase-like artificial enzyme is developed based on novel biodegradable boron oxynitride (BON) nanostructures for highly efficient and multi-mode breast cancer therapies. The BON nanozyme catalytically generates cytotoxic hydroxyl radicals, which induce apoptosis of 4T1 cancer cells and significantly reduce the cell viability by 82% in 48 h. In vivo experiment reveals a high potency of the BON nanozyme for breast tumor growth inhibitions by 97% after 14-day treatment compared with the control, which are 10 times or 1.3 times more effective than the inert or B-releasing boron nitride (BN) nanospheres, respectively. This work highlights the BON nanozyme and its functional integrations within the BN nanomedicine platform for high-potency breast cancer therapies.

Injectable Supramolecular Hydrogel for Locoregional Immune Checkpoint Blockade and Enhanced Cancer Chemo-Immunotherapy

Immunotherapy has revolutionized the therapeutic modalities of cancer treatment but is severely limited by a low objective response rate and the risk of immune-related side effects. Herein, an injectable supramolecular hydrogel is developed for local delivery of the DPPA-1 peptide (a d-peptide antagonist with a high binding affinity to programmed cell death-ligand 1 (PD-L1)) and doxorubicin (DOX). On the one hand, DOX could kill tumor cells directly and also induce immunogenic cell death to provoke the antitumor immune response. On the other hand, the DPPA-1 peptide could locoregionally block the PD-1/PD-L1 pathway to potentiate T-cell-mediated immune responses and minimize side effects. Eventually, by local injection of this supramolecular hydrogel, the synergistic cancer therapeutic effect was evaluated, showing promise in improving the objective response rate of immunotherapy and minimizing its systemic side effects.

Engineering the Deformability of Albumin-Stabilized Emulsions for Lymph-Node Vaccine Delivery

A major challenge in vaccine delivery is to achieve robust lymph-node (LN) accumulation, which can capitalize on concentrated immunocytes and cytokines in LNs to stimulate the onset and persistence of adaptive immune responses. Previous attempts at developing vaccine delivery systems have focused on the sizes, charges, or surface ligands but not on their deformability. In fact, the LN homing of antigen-presenting cells depends on deformability to pass through the cellular gaps. Herein, the deformability of albumin-stabilized emulsions is engineered. Owing to self-adaptive deformability, the droplets (≈330 nm) can attach to and deform between cells and adjust their sizes to pass through the endothelial gaps (20-100 nm), favoring direct LN transfer (intercellular pathway). Additionally, owing to relatively large sizes, some emulsions can be retained at the administration sites for potent antigen uptake and activation of APCs as well as LN-targeted delivery of vaccines (intracellular pathway). Compared with solid particles, the dual LN transfer strategy evidently enhances antigen accumulation and activation of LN drainage, potently stimulates cellular immune responses, and increases the survival rate of tumor-bearing mice. Thus, the deformability of albumin-stabilized droplets may offer an efficient strategy for potent LN targeting and enhanced vaccinations.

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.

Platelet-rich plasma enhances mechanical strength of strattice in rat model of ventral hernia repair

Incisional hernia is a common complication of hernia repair despite the development of various synthetic and bio-synthetic repair materials. Poor long-term mechanical strength, leading to high recurrence rates, has limited the use of acellular dermal matrices (ADMs) in ventral hernia repair (VHR). Biologically derived meshes have been an area of increasing interest. Still these materials bring the risk of more aggressive immune response and fibrosis in addition to the mechanical failures suffered by the synthetic materials. Platelet-rich plasma (PRP), a growth-factor-rich autologous blood product, has been shown to improve early neovascularization, tissue deposition, and to decrease the rates of recurrence. Here, we demonstrate that PRP promotes the release of growth factors stromal derived factor (SDF)-1, transforming growth factor-beta, and platelet-derived growth factor in a dose-dependent manner. Additionally, we utilize an aortic ring angiogenesis assay to show that PRP promotes angiogenesis in vitro. A rat model of VHR using StratticeTM ADM demonstrates similar findings in vivo, corresponding with the increased expression of vascular endothelial growth factor and collagen type 1 alpha 1. Finally, we show that the molecular and cellular activity initiated by PRP results in an increased mechanical stiffness of the hernia repair mesh over time. Collectively, these data represent an essential step in demonstrating the utility and the mechanism of platelet-derived plasma in biomaterial-aided wound healing and provide promising preclinical data that suggest such materials may improve surgical outcomes.

Biodegradable Copper-Based Nanoparticles Augmented Chemodynamic Therapy through Deep Penetration and Suppressing Antioxidant Activity in Tumors

Chemodynamic therapy (CDT) efficacy has been limited by the poor penetration ability of large nanoparticles (NPs) and the antioxidant activity of tumors, especially high heme oxygenase (HO-1) and glutathione (GSH) levels. Herein, PEGylated CuMoO_x -coated and zinc protoporphyrin IX (ZP)-loaded Cu (CCMZ) NPs are designed to afford rapid degradation ability and augmented CDT efficacy through inhibiting HO-1 activity and depleting GSH. The deep penetration of tumor can be achieved under the high levels of GSH, which triggers the degradation of CuMoO_x shell. Meanwhile, GSH itself is depleted, which converts the reductive environment into constant oxidative environment, thus leading to the degradation of Cu core. Furthermore, the release of ZP from CCMZ NPs can inhibit HO-1 activity and provide a favorable microenvironment for CDT, and the release of Cu and Mo ions can convert hydrogen peroxide into hydroxyl radical to eliminate tumor cells more efficiently. In addition, CCMZ NPs also play an immune vaccine-like effect to recruit different immune cells for antitumor immunotherapy. In vitro and in vivo studies prove the augmented CDT property of CCMZ NPs, supplying a new strategy for improving CDT efficacy.

Multifaceted Design and Emerging Applications of Tissue Adhesives

Tissue adhesives can form appreciable adhesion with tissues and have found clinical use in a variety of medical settings such as wound closure, surgical sealants, regenerative medicine, and device attachment. The advantages of tissue adhesives include ease of implementation, rapid application, mitigation of tissue damage, and compatibility with minimally invasive procedures. The field of tissue adhesives is rapidly evolving, leading to tissue adhesives with superior mechanical properties and advanced functionality. Such adhesives enable new applications ranging from mobile health to cancer treatment. To provide guidelines for the rational design of tissue adhesives, here, existing strategies for tissue adhesives are synthesized into a multifaceted design, which comprises three design elements: the tissue, the adhesive surface, and the adhesive matrix. The mechanical, chemical, and biological considerations associated with each design element are reviewed. Throughout the report, the limitations of existing tissue adhesives and immediate opportunities for improvement are discussed. The recent progress of tissue adhesives in topical and implantable applications is highlighted, and then future directions toward next-generation tissue adhesives are outlined. The development of tissue adhesives will fuse disciplines and make broad impacts in engineering and medicine.

Supramolecular Tadalafil Nanovaccine for Cancer Immunotherapy by Alleviating Myeloid-Derived Suppressor Cells and Heightening Immunogenicity

Tumor-induced immune suppression mediated by myeloid-derived suppressor cells (MDSCs) and insufficient immunogenicity are two major factors for the poor overall response rate to the immune checkpoint blockade (ICB). Here, a tumor microenvironment responsive nanoprodrug (FIT nanoparticles) is presented for co-delivering tadalafil (TAD) and indocyanine green (ICG) photosensitizer to simultaneously targeting intratumor MDSCs and amplifying tumor immunogenicity. The resulting nanoprodrug shows high drug loading (nearly 100%), tumor-specific release, and robust therapeutic efficacy by virtue of promoting immunogenic cell death (ICD) induction and alleviation of MDSCs for augmenting the photothermal immunotherapy. In an in vivo colon tumor model, the released TAD in the tumor can effectively ameliorate MDSCs immunosuppressive activity, while the photosensitizer ICG is capable of inducing ICD to promote sufficient dendritic cells maturation and T cell infiltration. The results reported here may provide a superior candidate of adjuvants for strengthening immune response and ICB efficacy.

An MRI-trackable therapeutic nanovaccine preventing cancer liver metastasis

Cancer vaccines consisting of tumor-associated antigens (TAAs) can initiate a powerful antitumor immune response through antigen-presenting cells, such as dendritic cells (DCs) and macrophages, and have shown great potential in cancer prevention and therapy. However, poor anticancer efficacy and an uncertain immunization process have hitherto limited the application of cancer vaccines. Herein, a multifunctional nanovaccine comprising ovalbumin (OVA), MnO₂, and polydopamine (OMPN) was prepared by a facile one-pot method. OMPN displayed excellent anticancer efficacy against an orthotopic melanoma and could also prevent liver metastasis in a tumor re-challenge mice model. Additionally, the migration behavior of DCs in the inguinal lymph node after vaccination was tracked by MRI contrasted with OMPN, indicating successful DC activation and immune response. The superior anticancer efficacy, especially the high efficiency against tumor metastasis, and the capability of tracking the immunization process make OMPN a very promising multifunctional nanovaccine for cancer therapy.

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.

Immunomodulatory nanosystems for treating inflammatory diseases

Inflammatory disease (ID) is an umbrella term encompassing all illnesses involving chronic inflammation as the central manifestation of pathogenesis. These include, inflammatory bowel diseases, hepatitis, pulmonary disorders, atherosclerosis, myocardial infarction, pancreatitis, arthritis, periodontitis, psoriasis. The IDs create a severe burden on healthcare and significantly impact the global socio-economic balance. Unfortunately, the standard therapies that rely on a combination of anti-inflammatory and immunosuppressive agents are palliative and provide only short-term relief. In contrast, the emerging concept of immunomodulatory nanosystems (IMNs) has the potential to address the underlying causes and prevent reoccurrence, thereby, creating new opportunities for treating IDs. The IMNs offer exquisite ability to precisely modulate the immune system for a therapeutic advantage. The nano-sized dimension of IMNs allows them to efficiently infiltrate lymphatic drainage, interact with immune cells, and subsequently to undergo rapid endocytosis by hyperactive immune cells (HICs) at inflamed sites. Thus, IMNs serve to restore dysfunctional or HICs and alleviate the inflammation. We identified that different IMNs exert their immunomodulatory action via either of the seven mechanisms to modulate; cytokine production, cytokine neutralization, cellular infiltration, macrophage polarization, HICs growth inhibition, stimulating T-reg mediated tolerance and modulating oxidative-stress. In this article, we discussed representative examples of IMNs by highlighting their rationalization, design principle, and mechanism of action in context of treating various IDs. Lastly, we highlighted technical challenges in the application of IMNs and explored the future direction of research, which could potentially help to overcome those challenges.

Immunomodulation of Tumor Microenvironment by Arginine-Loaded Iron Oxide Nanoparticles for Gaseous Immunotherapy

Tumor-associated macrophages (TAMs) of M2 phenotype have mediated the immunosuppression in a tumor microenvironment, facilitating the escape of tumor cells from immunosurveillance. Reprograming the immunosuppressive M2 TAMs to immunostimulatory M1 phenotype can activate the antitumor immune responses for cancer immunotherapy. Herein, hollow iron oxide (Fe₃O₄) nanoparticles (NPs) were employed to reprogram M2 TAMs toward M1 TAMs, aiming to release proinflammatory cytokines and recruit T cells to kill tumor cells. After loaded with l-arginine (l-Arg) and sealed with poly(acrylic acid) (PAA), hollow Fe₃O₄ NPs were fabricated into _LPFe₃O₄ NPs, which could release l-Arg based on pH-responsive PAA and produce nitric oxide (NO) with the help of nitric oxide synthase (iNOS) overexpressed by M1 TAMs, as a result of additional tumor elimination for gas therapy. In vitro and in vivo studies demonstrate that _LPFe₃O₄ NPs could effectively reprogram M2 to M1 macrophages, activating T cells, releasing TNF-α, and producing high levels of NO, leading to synergistic tumor therapy.

Engineering Nano-Therapeutics to Boost Adoptive Cell Therapy for Cancer Treatment

Although adoptive transfer of therapeutic cells to cancer patients is demonstrated with great success and fortunately approved for the treatment of leukemia and B-cell lymphoma, potential issues, including the unclear mechanism, complicated procedures, unfavorable therapeutic efficacy for solid tumors, and side effects, still hinder its extensive applications. The explosion of nanotechnology recently has led to advanced development of novel strategies to address these challenges, facilitating the design of nano-therapeutics to improve adoptive cell therapy (ACT) for cancer treatment. In this review, the emerging nano-enabled approaches, that design multiscale artificial antigen-presenting cells for cell proliferation and stimulation in vitro, promote the transducing efficiency of tumor-targeting domains, engineer therapeutic cells for in vivo imaging, tumor infiltration, and in vivo functional sustainability, as well as generate tumoricidal T cells in vivo, are summarized. Meanwhile, the current challenges and future perspectives of the nanostrategy-based ACT for cancer treatment are also discussed in the end.

Systemic tumour suppression via the preferential accumulation of erythrocyte-anchored chemokine-encapsulating nanoparticles in lung metastases

Eliciting immune responses against primary tumours is hampered by their immunosuppressive microenvironment and by the greater inaccessibility of deeper intratumoural cells. However, metastatic tumour cells are exposed to highly perfused and immunoactive organs, such as the lungs. Here, by taking advantage of the preferential colocalization of intravenously administered erythrocytes with metastases in the lungs, we show that treatment with chemokine-encapsulating nanoparticles that are non-covalently anchored onto the surface of injected erythrocytes results in local and systemic tumour suppression in mouse models of lung metastasis. Such erythrocyte-anchored systemic immunotherapy led to the infiltration of effector immune cells into the lungs, in situ immunization without the need for exogenous antigens, inhibition of the progression of lung metastasis, and significantly extended animal survival and systemic immunity that suppressed the growth of distant tumours after rechallenge. Erythrocyte-mediated systemic immunotherapy may represent a general and potent strategy for cancer vaccination.

Aliphatic Polyester-Based Materials for Enhanced Cancer Immunotherapy

Poly(lactic acid) (PLA) and its copolymer, poly(lactic-co-glycolic acid) (PLGA), based aliphatic polyesters have been extensively used for biomedical applications, such as drug delivery system and tissue engineering, thanks to their biodegradability, benign toxicity, renewability, and adjustable mechanical properties. A rapidly growing field of cancer research, the development of therapeutic cancer vaccines or treatment modalities is aimed to deliver immunomodulatory signals that control the quality of immune responses against tumors. Herein, the progress and applications of PLA and PLGA are reviewed in delivering immunotherapeutics to treat cancers.

Reprogramming Immune Cells for Enhanced Cancer Immunotherapy: Targets and Strategies

Cancer is one of the leading causes of death and a major public health problem all over the world. Immunotherapy is becoming a revolutionary clinical management for various cancer types. Restoration of aberrant immune surveillance on cancers has achieved markable progress in the past years by either in vivo or ex vivo engineering of the immune cells. Here, we summarized the central roles of immune cells in tumor progression and regression, and the existing and emerging strategies for different immune cell-based immunotherapies. In addition, the current challenges and the potential solutions in translating the immunotherapies into the clinic are also discussed.

Injectable Hydrogels as Local Depots at Tumor Sites for Antitumor Immunotherapy and Immune-Based Combination Therapy

Despite the encouraging clinical responses of several human cancers to immunotherapy, the efficacy of this treatment remains limited by variable objective response rates and severe systemic immune-related adverse events. To overcome these issues, injectable hydrogels have been developed as local depots that permit the sustained release of single or multiple immunotherapy agents, including traditional immunomodulatory factors, immune checkpoint blocking antibodies, and exogenous immune cells. The antitumor efficacy of immunotherapy can also be enhanced by its combination with other therapeutic approaches, including chemotherapy, radiotherapy, and phototherapy. Despite local treatment strategies, potent systemic antitumor immune responses with low systemic toxicity can be obtained, leading to significant local and abscopal tumor-killing, reduced tumor metastasis, and the prevention of tumor recurrence. This review highlights recent progress in injectable hydrogel-based local depots for tumor immunotherapy and immune-based combination therapy. Moreover, the proposed mechanisms responsible for these antitumor effects are discussed.

Effect of physicochemical properties on in vivo fate of nanoparticle-based cancer immunotherapies

Current advances of immunotherapy have greatly changed the way of cancer treatment. At the same time, a great number of nanoparticle-based cancer immunotherapies (NBCIs) have also been explored to elicit potent immune responses against tumors. However, few NBCIs are nearly in the clinical trial which is mainly ascribed to a lack understanding of in vivo fate of nanoparticles (NPs) for cancer immunotherapy. NPs for cancer immunotherapy mainly target the immune organs or immune cells to enable efficient antitumor immune responses. The physicochemical properties of NPs including size, shape, elasticity and surface properties directly affect their interaction with immune systems as well as their in vivo fate and therapeutic effect. Hence, systematic analysis of the physicochemical properties and their effect on in vivo fate is urgently needed. In this review, we first recapitulate the fundamentals for the in vivo fate of NBCIs including physio-anatomical features of lymphatic system and strategies to modulate immune responses. Moreover, we highlight the effect of physicochemical properties on their in vivo fate including lymph nodes (LNs) drainage, cellular uptake and intracellular transfer. Challenges and opportunities for rational design of NPs for cancer immunotherapy are also discussed in detail.

Target Reprogramming Lysosomes of CD8+ T Cells by a Mineralized Metal-Organic Framework for Cancer Immunotherapy

T cell immunotherapy holds significant challenges in solid tumors, mainly due to the T cells' low activation and the decreased synthesis-release of therapeutic proteins, including perforin and granzyme B, which are present in lysosomes. In this study, a lysosome-targeting nanoparticle (LYS-NP) is developed by way of a mineralized metal-organic framework (MOF) coupled with a lysosome-targeting aptamer (CD63-aptamer) to enhance the antitumor effect of T cells. The MOF synthesized from Zn²⁺ and dimethylimidazole has good protein encapsulation and acid sensitivity, and is thus an ideal lysosomal delivery vector. Calcium carbonate (CaCO₃ ) is used to induce MOF mineralization, improve the composite material's stability in encapsulating therapeutic protein, and provide calcium ions with synergistic effects. Before mineralization, perforin and granzyme B-T cell-needed therapeutic proteins for tumors-are preloaded with the MOF. Moreover, T cells are pretreated with processed tumor-specific antigens to activate or produce memory before reprogramming the lysosomes, facilitating the T cell receptor (TCR) for release of the therapeutic proteins. Using T cells recombined by LYS-NPs, a significant enhancement of breast cancer control is confirmed.

Novel approaches for vaccine development

Vaccines are critical tools for maintaining global health. Traditional vaccine technologies have been used across a wide range of bacterial and viral pathogens, yet there are a number of examples where they have not been successful, such as for persistent infections, rapidly evolving pathogens with high sequence variability, complex viral antigens, and emerging pathogens. Novel technologies such as nucleic acid and viral vector vaccines offer the potential to revolutionize vaccine development as they are well-suited to address existing technology limitations. In this review, we discuss the current state of RNA vaccines, recombinant adenovirus vector-based vaccines, and advances from biomaterials and engineering that address these important public health challenges.

The role of irreversible electroporation in promoting M1 macrophage polarization via regulating the HMGB1-RAGE-MAPK axis in pancreatic cancer

Irreversible electroporation (IRE) is an effective method for treating pancreatic ductal adenocarcinoma (PDAC). It remains unclear whether IRE can induce a specific immune response by stimulating macrophages. Here, the associated markers of macrophages were analyzed after exposure to tumor culture supernatant (TSN) of tumor cells treated with electroporation. Subcutaneous and orthotopic PDAC models were also used to evaluate the effect of macrophage polarization induced by IRE. Aside from its direct killing effect, IRE could induce the immunogenic cell death of tumor cells by increasing the synthesis and secretion of damage associated molecular patterns. Moreover, IRE could increase the release of HMGB1, which activates the MAPK-p38 pathway and leads to the increased expression of M1 markers in macrophages, through binding to the receptor of the advanced glycation end-product (RAGE) receptor. M1 polarization was inhibited by the inhibitors of HMGB1 release, the RAGE receptor, and the MAPK-p38 signaling pathway, but it was activated by rHMGB1 or the stimulator of MAPK-p38. In addition, the promotion of M1 macrophage polarization was enhanced by the positive-feedback release or expression of HMGB1 and RAGE through the MAPK-ERK pathway in macrophages. The promotion of M1 macrophage polarization induced by IRE provided a specific rationale for the combination of IRE and immune therapy in treating PDAC.

Therapeutic strategies of iron-based nanomaterials for cancer therapy

Iron-based nanomaterials have appeared in various cancer treatments owing to their promising functions and safety. Various sophisticated iron-based nanomaterials have been designed to exhibit great therapeutic effects through different strategies. Given the rapid progression, there is a great need to integrate the recent advances to learn about the latest innovation in this field. In this review, we classified the strategies of iron-based nanomaterials for cancer treatment into the following categories: immunotherapy, ferroptosis, magnetic hyperthermia and magneto-mechanical destruction. On the one hand, we discussed the underlining mechanism of iron-based nanomaterials in these therapies and applications; on the other hand, we analyzed the feasible combination of these applications and other therapies. Finally, the current challenges and expectation of iron-based nanomaterials in this field were highlighted.

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

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

Tailoring Materials for Modulation of Macrophage Fate

Human immune system acts as a pivotal role in the tissue homeostasis and disease progression. Immunomodulatory biomaterials that can manipulate innate immunity and adaptive immunity hold great promise for a broad range of prophylactic and therapeutic purposes. This review is focused on the design strategies and principles of immunomodulatory biomaterials from the standpoint of materials science to regulate macrophage fate, such as activation, polarization, adhesion, migration, proliferation, and secretion. It offers a comprehensive survey and discussion on the tunability of material designs regarding physical, chemical, biological, and dynamic cues for modulating macrophage immune response. The range of such tailorable cues encompasses surface properties, surface topography, materials mechanics, materials composition, and materials dynamics. The representative immunoengineering applications selected herein demonstrate how macrophage-immunomodulating biomaterials are being exploited for cancer immunotherapy, infection immunotherapy, tissue regeneration, inflammation resolution, and vaccination. A perspective on the future research directions of immunoregulatory biomaterials is also provided.

The construction of a lymphoma cell-based, DC-targeted vaccine, and its application in lymphoma prevention and cure

In recent years, Non-Hodgkin lymphoma (NHL) has been one of the most fast-growing malignant tumor diseases. NHL poses severe damages to physical health and a heavy burden to patients. Traditional therapies (chemotherapy or radiotherapy) bring some benefit to patients, but have severe adverse effects and do not prevent relapse. The relevance of emerging immunotherapy options (immune-checkpoint blockers or adoptive cellular methods) for NHL remains uncertain, and more intensive evaluations are needed. In this work, inspired by the idea of vaccination to promote an immune response to destroy tumors, we used a biomaterial-based strategy to improve a tumor cell-based vaccine and constructed a novel vaccine named Man-EG7/CH@CpG with antitumor properties. In this vaccine, natural tumor cells are used as a vector to load CpG-ODN, and following lethal irradiation, the formulations were decorated with mannose. The study of the characterization of the double-improved vaccine evidenced the enhanced ability of DCs targeting and improved immunocompetence, which displayed an antitumor function. In the lymphoma prevention model, the Man-EG7/CH@CpG vaccine restrained tumor formation with high efficiency. Furthermore, unlike the non-improved vaccine, the double-improved vaccine elicited an enhanced antitumor effect in the lymphoma treatment model. Next, to improve the moderate therapeutic effect of the mono-treatment method, we incorporated a chemotherapeutic drug (doxorubicin, DOX) into the process of vaccination and devised a combination regimen. Fortunately, a tumor inhibition rate of ~85% was achieved via the combination therapy, which could not be achieved by mono-chemotherapy or mono-immunotherapy. In summary, the strategy presented here may provide a novel direction in the establishment of a tumor vaccine and is the basis for a prioritization scheme of immuno-chemotherapy in enhancing the therapeutic effect on NHL.

Cell-derived vesicles for delivery of cancer immunotherapy

In recent years, cancer immunotherapy has received unprecedented attention due to the clinical achievements. The applications of biomedical engineering and materials science to cancer immunotherapy have solved the challenges caused by immunotherapy to a certain extent. Among them, cell-derived vesicles are natural biomaterials chosen as carriers or immune-engineering in view of their many unique advantages. This review will briefly introduce the recent applications of cell-derived vesicles for cancer immunotherapy.

Cell-derived vesicles for delivery of cancer immunotherapy

In recent years, cancer immunotherapy has received unprecedented attention due to the clinical achievements. The applications of biomedical engineering and materials science to cancer immunotherapy have solved the challenges caused by immunotherapy to a certain extent. Among them, cell-derived vesicles are natural biomaterials chosen as carriers or immune-engineering in view of their many unique advantages. This review will briefly introduce the recent applications of cell-derived vesicles for cancer immunotherapy.

Albumin-stabilized layered double hydroxide nanoparticles synergized combination chemotherapy for colorectal cancer treatment

Combination chemotherapy with two or more complimentary drugs has been widely used for clinical cancer treatment. However, the efficacy and side effects of combination chemotherapy still remain a challenge. Here, we constructed an albumin-stabilized layered double hydroxide nanoparticle (BLDH) system to simultaneously load and deliver two widely used anti-tumor drugs, i.e. 5-fluorouracil (5FU) and albumin-bound PTX (Abraxane, ABX) for colorectal cancer treatment. The cellular uptake test has revealed that 5FU-ABX encapsulated BLDH (BLDH/5FU-ABX) nanoparticles were efficiently internalized by the colorectal cancer cell (HCT-116), synergistically inducing apoptosis of colon cancer cells. The in vivo test has demonstrated that BLDH/5FU-ABX nanomedicine significantly inhibited the tumor growth after three intravenous injections, without any detectable side effects. The enhanced therapeutic effectiveness is attributed to efficient accumulation of BLDH/5FU-ABX at tumor sites and acid-sensitive release of co-loaded drugs. Thus, combination chemotherapy based on BLDH/5FU-ABX nanomedicine would be a new strategy for colorectal cancer treatment.

In Situ Self-Assembly Nanomicelle Microneedles for Enhanced Photoimmunotherapy via Autophagy Regulation Strategy

Although certain therapeutic agents with immunogenic properties may enhance antitumor immunity, cancer cells can eliminate harmful cytoplasmic entities and escape immunosurveillance by orchestrating autophagy. Here, an ingenious in situ self-assembled nanomicelle dissolving microneedle (DMN) patch was designed for intralesional delivery of immunogenic cell death-inducer (IR780) and autophagy inhibitor (chloroquine, CQ) coencapsulated micelles (C/I-Mil) for efficient antitumor therapy. Upon insertion into skin, the self-assembled C/I-Mil was generated, followed by electrostatic binding of hyaluronic acid, the matrix material of DMNs, accompanied by the dissolution of DMNs. Subsequently, photothermal-mediated size-tunable C/I-Mil could effectively penetrate into deep tumor tissue and be massively internalized via CD44 receptor-mediated endocytosis, precisely ablate tumors with the help of autophagy inhibition, and promote the release of damage-associated molecular patterns. Moreover, CQ could also act as an immune modulator to remodel tumor-associated macrophages toward the M1 phenotype via activating NF-κB. In vivo results showed that the localized photoimmunotherapy in synergy with autophagy inhibition could effectively eliminate primary and distant tumors, followed by a relapse-free survival of more than 40 days via remodeling the tumor immunosuppressive microenvironment. Our work provides a versatile, generalizable framework for employing self-assembled DMN-mediated autophagy inhibition integrated with photoimmunotherapy to sensitize superficial tumors and initiate optimal antitumor immunity.

Application of Bionanomaterials in Tumor Immune Microenvironment Therapy

Targeted therapy for the cancer immune system has become a clinical reality with remarkable success. Immune checkpoint blockade therapy and chimeric antigen receptor T-cell (CAR-T) immunotherapy are clinically effective in a variety of cancers. However, the clinical utility of immunotherapy in cancer is limited by severe off-target toxicity, long processing time, limited efficacy, and extremely high cost. Bionanomaterials combined with these therapies address these issues by enhancing immune regulation, integrating the synergistic effects of different molecules, and, most importantly, targeting and manipulating immune cells within the tumor. In this review, we will summarize the most current researches on bionanomaterials for targeted regulation of tumor-associated macrophages, myeloid-derived suppressor cells, dendritic cells, T lymphocyte cells, and cancer-associated fibroblasts and summarize the prospects and challenges of cell-targeted therapy and clinical translational potential in a tumor immune microenvironment in cancer treatment.

Polymer-based hydrogels with local drug release for cancer immunotherapy

Immunotherapy that boosts the body's immune system to treat local and distant metastatic tumors has offered a new treatment option for cancer. However, cancer immunotherapy via systemic administration of immunotherapeutic agents often has two major issues of limited immune responses and potential immune-related adverse events in the clinic. Hydrogels, a class of three-dimensional network biomaterials with unique porous structures can achieve local delivery of drugs into tumors to trigger the antitumor immunity, resulting in amplified immunotherapy at lower dosages. In this review, we summarize the recent development of polymer-based hydrogels as drug release systems for local delivery of various immunotherapeutic agents for cancer immunotherapy. The constructions of polymer-based hydrogels and their local delivery of various drugs in tumors to achieve sole immunotherapy, and chemotherapy-, and phototherapy-combinational immunotherapy are introduced. Furthermore, a brief conclusion is given and existing challenges and further perspectives of polymer-based hydrogels for cancer immunotherapy are discussed.

Designing and Immunomodulating Multiresponsive Nanomaterial for Cancer Theranostics

Cancer has been widely investigated yet limited in its manifestation. Cancer treatment holds innovative and futuristic strategies considering high disease heterogeneity. Chemotherapy, radiotherapy and surgery are the most explored pillars; however optimal therapeutic window and patient compliance recruit constraints. Recently evolved immunotherapy demonstrates a vital role of the host immune system to prevent metastasis recurrence, still undesirable clinical response and autoimmune adverse effects remain unresolved. Overcoming these challenges, tunable biomaterials could effectively control the co-delivery of anticancer drugs and immunomodulators. Current status demands a potentially new approach for minimally invasive, synergistic, and combinatorial nano-biomaterial assisted targeted immune-based treatment including therapeutics, diagnosis and imaging. This review discusses the latest findings of engineering biomaterial with immunomodulating properties and implementing novel developments in designing versatile nanosystems for cancer theranostics. We explore the functionalization of nanoparticle for delivering antitumor therapeutic and diagnostic agents promoting immune response. Through understanding the efficacy of delivery system, we have enlightened the applicability of nanomaterials as immunomodulatory nanomedicine further advancing to preclinical and clinical trials. Future and present ongoing improvements in engineering biomaterial could result in generating better insight to deal with cancer through easily accessible immunological interventions.

Localized NIR-II photo-immunotherapy through the combination of photothermal ablation and in situ generated interleukin-12 cytokine for efficiently eliminating primary and abscopal tumors

Recently, photothermal therapy (PTT) in the second near-infrared (NIR-II) biowindow has emerged as a promising treatment modality; however, its therapeutic outcomes are still limited by heterogeneous heat distribution and insufficient control of metastatic lesions. Tremendous efforts have been made to overcome the PTT's shortcomings by combining PTT with immunotherapy, but unfortunately current strategies still suffer from low response rates, primary/acquired resistance or severe immune-related adverse events. Herein, a novel photothermal agent and gene co-delivery nanoparticle (CSP), with CuS inside the SiO2 pore channels and PDMAEMA polycation on the outside of SiO2 surface, is explored for tumor localized NIR-II PTT and in situ immunotherapy through local generation of IL-12 cytokine. The resulting CSP integrated with the plasmid encoding IL-12 gene (CSP@IL-12) exhibited good gene transfection efficiency, outstanding NIR-II PTT effect and excellent therapeutic outcomes both in vitro and in vivo. Meanwhile, such an in situ joint therapy modality could significantly induce systemic immune responses including promoting DC maturation, CD8+ T cell proliferation and infiltration to efficiently eliminate possible metastatic lesions through abscopal effects. Hence, this creative combinational strategy of NIR-II PTT and IL-12 cytokine therapy might provide a more efficient, controllable and safer alternative strategy for future photo-immunotherapy.

Tumor-associated macrophages promote pancreatic ductal adenocarcinoma progression by inducing epithelial-to-mesenchymal transition

In this study, we investigated the role of tumor-associated macrophages (TAMs) in the progression of pancreatic ductal adenocarcinoma (PDAC). PDAC patients with higher levels of CD68⁺ TAMs exhibited shorter overall survival. In Transwell assays, PDAC cells incubated with TAMs or conditioned media from TAM cells (TAM-CM) showed higher migration and invasion rates than controls. PET/CT scan analysis of orthotopic PDAC model mice revealed greater primary tumor growth and liver metastasis in the TAM-CM treatment group than the controls. H&E staining of liver tissues showed significantly higher numbers of metastatic nodules in the TAM-CM treatment group. Heat inactivation of TAM-CM significantly reduced Transwell migration by PDAC cells, suggesting the involvement of one or more secreted proteins in PDAC progression. Transcriptome sequencing analysis of PDAC cells treated with TAM-CM revealed significant enrichment of transforming growth factor-β (TGF-β) signaling pathway genes. Western blot and qRT-PCR analysis showed that TAM-CM enhanced PDAC migration cells by inducing epithelial-to-mesenchymal transition through the TGF-β-Smad2/3/4-Snail signaling axis. The pro-tumorigenic effects of TAMs or TAM-CM were abolished by TGF-β signaling pathway inhibitors and neutralizing TGF-β antibody. These results demonstrate that TAMs promote PDAC progression through the TGF-β signaling pathway.

Controlled release of immunotherapeutics for enhanced cancer immunotherapy after local delivery

Cancer immunotherapy has been demonstrated as a promising therapeutic strategy in clinic owing to its unique advantages. However, although more and more immunotherapeutic agents have been approved for clinical use to activate the immune system, they also could interfere with the homeostatic role of immune system at non-target sites after systemic administration, which may be associated with fatal side effects such as lifelong autoimmune diseases. Thus, it is desirable to develop local delivery systems that could be applied at the targeted sides and engineered to locally control the pharmacokinetics of various immunotherapeutics, including small molecules, macromolecules or even cells. Advancements in biomaterials, biotechnology, nanomedicine and engineering have facilitated the development of local delivery systems for enhanced cancer immunotherapy. This review will summarize the recent advances in developing different local delivery systems and discuss how these delivery systems could be designed to regulate the release behavior of different immunotherapeutics to sustainably stimulate the systemic immune system, effectively and safely inhibiting the cancer recurrence and metastasis. Furthermore, we will discuss how biomaterials-assisted local delivery systems would contribute to the development of cancer immunotherapy, together with their challenges and potential of clinical translation.

Oncological Ligand-Target Binding Systems and Developmental Approaches for Cancer Theranostics

Targeted treatment of cancer hinges on the identification of specific intracellular molecular receptors on cancer cells to stimulate apoptosis for eventually inhibiting growth; the development of novel ligands to target biomarkers expressed by the cancer cells; and the creation of novel multifunctional carrier systems for targeted delivery of anticancer drugs to specific malignant sites. There are numerous receptors, antigens, and biomarkers that have been discovered as oncological targets (oncotargets) for cancer diagnosis and treatment applications. Oncotargets are critically important to navigate active anticancer drug ingredients to specific disease sites with no/minimal effect on surrounding normal cells. In silico techniques relating to genomics, proteomics, and bioinformatics have catalyzed the discovery of oncotargets for various cancer types. Effective oncotargeting requires high-affinity probes engineered for specific binding of receptors associated with the malignancy. Computational methods such as structural modeling and molecular dynamic (MD) simulations offer opportunities to structurally design novel ligands and optimize binding affinity for specific oncotargets. This article proposes a streamlined approach for the development of ligand-oncotarget bioaffinity systems via integrated structural modeling and MD simulations, making use of proteomics, genomic, and X-ray crystallographic resources, to support targeted diagnosis and treatment of cancers and tumors.

Role of nano-sensitizers in radiation therapy of metastatic tumors

Cancer metastasis remains the major cause of global cancer deaths. Radiation therapy remains one of the golden standards for cancer treatment. Nanomedicine based strategies have been designed and developed in order to improve the clinical outcomes of cancer therapy and diagnosis at molecular levels. Over the years, several researchers have shown their interest in using radiosensitizers made of high Z elements. Metal-based nanosystems also play a dual role by enhancing the synergistic effect of cell killing via various biological immune responses. This review summarizes the role of Nano-sensitizers in boosting radiation (ionizing/non-ionizing radiations) induced biological responses in treatment of metastatic cancer models.

Sustained and targeted delivery of checkpoint inhibitors by metal-organic frameworks for cancer immunotherapy

The major impediments to the implementation of cancer immunotherapies are the sustained immune effect and the targeted delivery of these therapeutics, as they have life-threatening adverse effects. In this work, biomimetic metal-organic frameworks [zeolitic imidazolate frameworks (ZIFs)] are used for the controlled delivery of nivolumab (NV), a monoclonal antibody checkpoint inhibitor that was U.S. Food and Drug Administration-approved back in 2014. The sustained release behavior of NV-ZIF has shown a higher efficacy than the naked NV to activate T cells in hematological malignancies. The system was further modified by coating NV-ZIF with cancer cell membrane to enable tumor-specific targeted delivery while treating solid tumors. We envisage that such a biocompatible and biodegradable immunotherapeutic delivery system may promote the development and the translation of hybrid superstructures into smart and personalized delivery platforms.

Biomaterials to enhance antigen-specific T cell expansion for cancer immunotherapy

T cells are often referred to as the 'guided missiles' of our immune system because of their capacity to traffic to and accumulate at sites of infection or disease, destroy infected or mutated cells with high specificity and sensitivity, initiate systemic immune responses, sterilize infections, and produce long-lasting memory. As a result, they are a common target for a range of cancer immunotherapies. However, the myriad of challenges of expanding large numbers of T cells specific to each patient's unique tumor antigens has led researchers to develop alternative, more scalable approaches. Biomaterial platforms for expansion of antigen-specific T cells offer a path forward towards broadscale translation of personalized immunotherapies by providing "off-the-shelf", yet modular approaches to customize the phenotype, function, and specificity of T cell responses. In this review, we discuss design considerations and progress made in the development of ex vivo and in vivo technologies for activating antigen-specific T cells, including artificial antigen presenting cells, T cell stimulating scaffolds, biomaterials-based vaccines, and artificial lymphoid organs. Ultimate translation of these platforms as a part of cancer immunotherapy regimens hinges on an in-depth understanding of T cell biology and cell-material interactions.

Recent Advances in Hyperthermia Therapy-Based Synergistic Immunotherapy

The past decades have witnessed hyperthermia therapy (HTT) as an emerging strategy against malignant tumors. Nanomaterial-based photothermal therapy (PTT) and magnetic hyperthermia (MHT), as highly effective and noninvasive treatment models, offer advantages over other strategies in the treatment of different types of tumors. However, both PTT and MHT cannot completely cure cancer due to recurrence and distal metastasis. In recent years, cancer immunotherapy has attracted widespread attention owing to its capability to activate the body's own natural defense to identify, attack, and eradicate cancer cells. Significant efforts have been devoted to studying the activated immune responses caused by hyperthermia-ablated tumors. In this article, the synergistic mechanism of HTT in immunotherapy, including immunogenic cell death and reversal of the immunosuppressive tumor microenvironment is discussed. The reports of the combination of HTT or HTT-based multimodal therapy with immunotherapy, including immunoadjuvant exploitation, immune checkpoint blockade therapy, and adoptive cellular immunotherapy are summarized. As highlighted, these strategies could achieve synergistically enhanced therapeutic outcomes against both primary tumors and metastatic lesions, prevent cancer recurrence, and prolong the survival period. Finally, current challenges and prospective developments in HTT-synergized immunotherapy are also reviewed.

Second Near-Infrared Photothermal Semiconducting Polymer Nanoadjuvant for Enhanced Cancer Immunotherapy

Immunotherapy has offered new treatment options for cancer; however, the therapeutic benefits are often modest and desired to be improved. A semiconducting polymer nanoadjuvant (SPN_II R) with a photothermally triggered cargo release for second near-infrared (NIR-II) photothermal immunotherapy is reported here. SPN_II R consists of a semiconducting polymer nanoparticle core as an NIR-II photothermal converter, which is doped with a toll-like receptor (TLR) agonist as an immunotherapy adjuvant and coated with a thermally responsive lipid shell. Upon NIR-II photoirradiation, SPN_II R effectively generates heat not only to ablate tumors and induce immunogenic cell death (ICD), but also to melt the lipid layers for on-demand release of the TLR agonist. The combination of ICD and activation of TLR7/TLR8 enhances the maturation of dendritic cells, which amplifies anti-tumor immune responses. Thus, a single treatment of SPN_II R-mediated NIR-II photothermal immunotherapy effectively inhibits growth of both primary and distant tumors and eliminates lung metastasis in a murine mouse model. This study thus provides a remote-controlled smart delivery system to synergize photomedicine with immunotherapy for enhanced cancer treatment.

Nanomaterials for T-cell cancer immunotherapy

T-cell-based immunotherapies hold promise for the treatment of many types of cancer, with three approved products for B-cell malignancies and a large pipeline of treatments in clinical trials. However, there are several challenges to their broad implementation. These include insufficient expansion of adoptively transferred T cells, inefficient trafficking of T cells into solid tumours, decreased T-cell activity due to a hostile tumour microenvironment and the loss of target antigen expression. Together, these factors restrict the number of therapeutically active T cells engaging with tumours. Nanomaterials are uniquely suited to overcome these challenges, as they can be rationally designed to enhance T-cell expansion, navigate complex physical barriers and modulate tumour microenvironments. Here, we present an overview of nanomaterials that have been used to overcome clinical barriers to T-cell-based immunotherapies and provide our outlook of this emerging field at the interface of cancer immunotherapy and nanomaterial design.