Low dose gemcitabine-loaded lipid nanocapsules target monocytic myeloid-derived suppressor cells and potentiate cancer immunotherapy

Immunological nanomaterials to combat cancer metastasis

Metastasis causes greater than 90% of cancer-associated deaths, presenting huge challenges for detection and efficient treatment of cancer due to its high heterogeneity and widespread dissemination to various organs. Therefore, it is imperative to combat cancer metastasis, which is the key to achieving complete cancer eradication. Immunotherapy as a systemic approach has shown promising potential to combat metastasis. However, current clinical immunotherapies are not effective for all patients or all types of cancer metastases owing to insufficient immune responses. In recent years, immunological nanomaterials with intrinsic immunogenicity or immunomodulatory agents with efficient loading have been shown to enhance immune responses to eliminate metastasis. In this review, we would like to summarize various types of immunological nanomaterials against metastasis. Moreover, this review will summarize a series of immunological nanomaterial-mediated immunotherapy strategies to combat metastasis, including immunogenic cell death, regulation of chemokines and cytokines, improving the immunosuppressive tumour microenvironment, activation of the STING pathway, enhancing cytotoxic natural killer cell activity, enhancing antigen presentation of dendritic cells, and enhancing chimeric antigen receptor T cell therapy. Furthermore, the synergistic anti-metastasis strategies based on the combinational use of immunotherapy and other therapeutic modalities will also be introduced. In addition, the nanomaterial-mediated imaging techniques (e.g., optical imaging, magnetic resonance imaging, computed tomography, photoacoustic imaging, surface-enhanced Raman scattering, radionuclide imaging, etc.) for detecting metastasis and monitoring anti-metastasis efficacy are also summarized. Finally, the current challenges and future prospects of immunological nanomaterial-based anti-metastasis are also elucidated with the intention to accelerate its clinical translation.

Engineering customized nanovaccines for enhanced cancer immunotherapy

Nanovaccines have gathered significant attention for their potential to elicit tumor-specific immunological responses. Despite notable progress in tumor immunotherapy, nanovaccines still encounter considerable challenges such as low delivery efficiency, limited targeting ability, and suboptimal efficacy. With an aim of addressing these issues, engineering customized nanovaccines through modification or functionalization has emerged as a promising approach. These tailored nanovaccines not only enhance antigen presentation, but also effectively modulate immunosuppression within the tumor microenvironment. Specifically, they are distinguished by their diverse sizes, shapes, charges, structures, and unique physicochemical properties, along with targeting ligands. These features of nanovaccines facilitate lymph node accumulation and activation/regulation of immune cells. This overview of bespoke nanovaccines underscores their potential in both prophylactic and therapeutic applications, offering insights into their future development and role in cancer immunotherapy.

Advances in nano-immunotherapy for hematological malignancies

Hematological malignancies (HMs) encompass a diverse group of blood neoplasms with significant morbidity and mortality. Immunotherapy has emerged as a validated and crucial treatment modality for patients with HMs. Despite notable advancements having been made in understanding and implementing immunotherapy for HMs over the past decade, several challenges persist. These challenges include immune-related adverse effects, the precise biodistribution and elimination of therapeutic antigens in vivo, immune tolerance of tumors, and immune evasion by tumor cells within the tumor microenvironment (TME). Nanotechnology, with its capacity to manipulate material properties at the nanometer scale, has the potential to tackle these obstacles and revolutionize treatment outcomes by improving various aspects such as drug targeting and stability. The convergence of nanotechnology and immunotherapy has given rise to nano-immunotherapy, a specialized branch of anti-tumor therapy. Nanotechnology has found applications in chimeric antigen receptor T cell (CAR-T) therapy, cancer vaccines, immune checkpoint inhibitors, and other immunotherapeutic strategies for HMs. In this review, we delineate recent developments and discuss current challenges in the field of nano-immunotherapy for HMs, offering novel insights into the potential of nanotechnology-based therapeutic approaches for these diseases.

Recent advances in nanotechnology for programmed death ligand 1-targeted cancer theranostics

Programmed cell death ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) checkpoint inhibitor-based immunotherapy has provided a unique and potent weapon against cancer in clinical practice. The likelihood of achieving beneficial effects from PD-L1/PD-1 immune checkpoint blockade (ICB) therapy is clinically assessed by detecting PD-L1 expression through invasive tissue biopsies. However, PD-L1 expression is susceptible to tumor heterogeneity and dynamic response to ICB therapy. Moreover, currently, anti-PD-L1 immunotherapy still faces challenges of the low targeting efficiency of antibody drugs and the risk of immune-associated adverse events. To overcome these issues, advanced nanotechnology has been developed for the purpose of quantitative, non-invasive, and dynamic analyses of PD-L1, and to enhance the efficiency of ICB therapy. In this review, we first introduce the nanoprobe-assisted in vitro/in vivo modalities for the selective and sensitive analysis of PD-L1 during the diagnostic and therapeutic process. On the other hand, the feasibility of fabricating diverse functional nanocarriers as smart delivery systems for precisely targeted delivery of PD-L1 immune checkpoint inhibitors and combined therapies is highlighted. Finally, the current challenges are discussed and future perspectives for PD-L1-targeted cancer theranostics in preclinical research and clinical settings are proposed.

An Adjuvant Micelle-Based Multifunctional Nanosystem for Tumor Immunotherapy by Remodeling Three Types of Immunosuppressive Cells

Immunotherapy is restricted by a complex tumor immunosuppressive microenvironment (TIM) and low drug delivery efficiency. Herein, a multifunctional adjuvant micelle nanosystem (PPD/MPC) integrated with broken barriers and re-education of three classes of immune-tolerant cells is constructed for cancer immunotherapy. The nanosystem significantly conquers the penetration barrier via the weakly acidic tumor microenvironment-responsive size reduction and charge reversal strategy. The detached core micelle MPC could effectively be internalized by tumor-associated macrophages (TAMs), tumor-infiltrating dendritic cells (TIDCs), and myeloid-derived suppressor cells (MDSCs) via mannose-mediated targeting endocytosis and electrostatic adsorption pathways, promoting the re-education of immunosuppressive cells for allowing them to reverse from pro-tumor to antitumor phenotypes by activating TLR4/9 pathways. This process in turn leads to the remodeling of TIM. In vitro and in vivo studies collectively indicate that the adjuvant micelle-based nanosystem not only relieves the intricate immune tolerance and remodels TIM via reprogramming the three types of immunosuppressive cells and regulating the secretion of relevant cytokines/immunity factors but also strengthens immune response and evokes immune memory, consequently suppressing the tumor growth and metastasis.

Predicting nanocarriers' efficacy in 3D models with Brillouin microscopy

Thanks to their unique nanoscale properties, nanomedicines can overcome some of the shortcomings of conventional therapies. For better predictive screening, it is important to assess their performance in three-dimensional (3D) multicellular tumour spheroids (MCTS) that can recapitulate the physiological barriers found in real tumours. Today, the evaluation of drug delivery nanosystems in MCTS is mainly explored by means of microscopy techniques that are invasive and require fluorescent labels which modify the composition and fate of the carriers. In recent years, a new quantitative microscopy technique based on Brillouin light scattering (BLS) has been proposed that uses the interaction of laser light with picosecond timescale density fluctuations in the sample. Because it is label-free, all-optical and non-destructive, BLS has gained interest in the pharmaceutical and biomedical fields. In this work, we implemented a fast BLS spectrometer and used the Brillouin frequency shift at the center of the MCTS as a quantitative readout for drug efficacy. We first investigated the ability of this setup to quantify drug efficacy in MCTS grown in classical multiwell plates and concluded that the low number of samples available in the multiwells limits the statistical significance of the results. To improve the throughput, we then combined the microscope with agarose microwells designed to fabricate a large number of MCTS and test 50 MCTS in less than a minute. Using this platform, we assessed the efficacy of polymeric nanoparticles (NPs) loaded with a platinum derivative anticancer drug (dichloro(1,2-diaminocyclohexane)platinum(II)) in reducing the growth of colorectal cancer cells (HCT-116) in MCTS. We observe a time- and dose-dependent decrease in the frequency shift, revealing the progressive loss of mechanical integrity in the MCTS. These results demonstrate that BLS probing of MCTS grown in agarose microwells is a promising tool for high-throughput screening of nanocarriers in 3D models.

Tumor Vaccines: Unleashing the Power of the Immune System to Fight Cancer

This comprehensive review delves into the rapidly evolving arena of cancer vaccines. Initially, we examine the intricate constitution of the tumor microenvironment (TME), a dynamic factor that significantly influences tumor heterogeneity. Current research trends focusing on harnessing the TME for effective tumor vaccine treatments are also discussed. We then provide a detailed overview of the current state of research concerning tumor immunity and the mechanisms of tumor vaccines, describing the complex immunological processes involved. Furthermore, we conduct an exhaustive analysis of the contemporary research landscape of tumor vaccines, with a particular focus on peptide vaccines, DNA/RNA-based vaccines, viral-vector-based vaccines, dendritic-cell-based vaccines, and whole-cell-based vaccines. We analyze and summarize these categories of tumor vaccines, highlighting their individual advantages, limitations, and the factors influencing their effectiveness. In our survey of each category, we summarize commonly used tumor vaccines, aiming to provide readers with a more comprehensive understanding of the current state of tumor vaccine research. We then delve into an innovative strategy combining cancer vaccines with other therapies. By studying the effects of combining tumor vaccines with immune checkpoint inhibitors, radiotherapy, chemotherapy, targeted therapy, and oncolytic virotherapy, we establish that this approach can enhance overall treatment efficacy and offset the limitations of single-treatment approaches, offering patients more effective treatment options. Following this, we undertake a meticulous analysis of the entire process of personalized cancer vaccines, elucidating the intricate process from design, through research and production, to clinical application, thus helping readers gain a thorough understanding of its complexities. In conclusion, our exploration of tumor vaccines in this review aims to highlight their promising potential in cancer treatment. As research in this field continues to evolve, it undeniably holds immense promise for improving cancer patient outcomes.

The future of cancer immunotherapy: DNA vaccines leading the way

Immuno-oncology has revolutionized cancer treatment and has opened up new opportunities for developing vaccination methods. DNA-based cancer vaccines have emerged as a promising approach to activating the bodily immune system against cancer. Plasmid DNA immunizations have shown a favorable safety profile and there occurs induction of generalized as well as tailored immune responses in preclinical and early-phase clinical experiments. However, these vaccines have notable limitations in immunogenicity and heterogeneity and these require refinements. DNA vaccine technology has been focusing on improving vaccine efficacy and delivery, with parallel developments in nanoparticle-based delivery systems and gene-editing technologies such as CRISPR/Cas9. This approach has showcased great promise in enhancing and tailoring the immune response to vaccination. Strategies to enhance the efficacy of DNA vaccines include the selection of appropriate antigens, optimizing insertion in a plasmid, and studying combinations of vaccines with conventional strategies and targeted therapies. Combination therapies have attenuated immunosuppressive activities in the tumor microenvironment and enhanced the capability of immune cells. This review provides an overview of the current framework of DNA vaccines in oncology and focuses on novel strategies, including established combination therapies and those still under development.The challenges that oncologists, scientists, and researchers need to overcome to establish DNA vaccines as an avant-garde approach to defeating cancer, are also emphasized. The clinical implications of the immunotherapeutic approaches and the need for predictive biomarkers have also been reviewed upon. We have also tried to extend the role of Neutrophil extracellular traps (NETs) to the DNA vaccines. The clinical implications of the immunotherapeutic approaches have also been reviewed upon. Ultimately, refining and optimizing DNA vaccines will enable harnessing the immune system's natural ability to recognize and eliminate cancer cells, leading the world towards a revolution in cancer cure.

Recent advances in targeting myeloid-derived suppressor cells and their applications to radiotherapy

Myeloid-derived suppressor cells (MDSCs) are a group of heterogenous immature myeloid cells with potent immune suppressive properties that not only constrain anti-tumor immune activation and functions, promote tumor progression, but also contribute to treatment resistance and tumor relapse. Targeting MDSCs may be a promising new cancer treatment method, but there is still a problem of low treatment efficiency. Combined application with radiotherapy may be a potential method to solve this problem. Drug delivery systems (DDSs) provide more efficient targeted drug delivery capability and can reduce the toxicity and side effects of drugs. Recent advance in DDSs targeting development, recruitment, differentiation, and elimination of MDSCs have shown promising effect in reversing immune inhibition and in overcoming radiotherapy resistance. In this review, we systematically summarized DDSs applied to target MDSCs for the first time, and classified and discussed it according to its different mechanisms of action. In addition, this paper also reviewed the biological characteristics of MDSCs and their role in the initiation, progression, and metastasis of cancer. Moreover, this review also summarizes the role of DDSs targeting MDSCs in radiosensitization. Finally, the future development of DDSs targeting MDSCs is also prospected.

Myeloid-derived suppressor cells: key immunosuppressive regulators and therapeutic targets in hematological malignancies

The immunosuppressive tumor microenvironment (TME) supports the development of tumors and limits tumor immunotherapy, including hematological malignancies. Hematological malignancies remain a major public health issue with high morbidity and mortality worldwide. As an important component of immunosuppressive regulators, the phenotypic characteristics and prognostic value of myeloid-derived suppressor cells (MDSCs) have received much attention. A variety of MDSC-targeting therapeutic approaches have produced encouraging outcomes. However, the use of various MDSC-targeted treatment strategies in hematologic malignancies is still difficult due to the heterogeneity of hematologic malignancies and the complexity of the immune system. In this review, we summarize the biological functions of MDSCs and further provide a summary of the phenotypes and suppressive mechanisms of MDSC populations expanded in various types of hematological malignancy contexts. Moreover, we discussed the clinical correlation between MDSCs and the diagnosis of malignant hematological disease, as well as the drugs targeting MDSCs, and focused on summarizing the therapeutic strategies in combination with other immunotherapies, such as various immune checkpoint inhibitors (ICIs), that are under active investigation. We highlight the new direction of targeting MDSCs to improve the therapeutic efficacy of tumors.

Biomaterial-based platforms for modulating immune components against cancer and cancer stem cells

Immunotherapy involves the therapeutic alteration of the patient's immune system to identify, target, and eliminate cancer cells. Dendritic cells, macrophages, myeloid-derived suppressor cells, and regulatory T cells make up the tumor microenvironment. In cancer, these immune components (in association with some non-immune cell populations like cancer-associated fibroblasts) are directly altered at a cellular level. By dominating immune cells with molecular cross-talk, cancer cells can proliferate unchecked. Current clinical immunotherapy strategies are limited to conventional adoptive cell therapy or immune checkpoint blockade. Targeting and modulating key immune components presents an effective opportunity. Immunostimulatory drugs are a research hotspot, but their poor pharmacokinetics, low tumor accumulation, and non-specific systemic toxicity limit their use. This review describes the cutting-edge research undertaken in the field of nanotechnology and material science to develop biomaterials-based platforms as effective immunotherapeutics. Various biomaterial types (polymer-based, lipid-based, carbon-based, cell-derived, etc.) and functionalization methodologies for modulating tumor-associated immune/non-immune cells are explored. Additionally, emphasis has been laid on discussing how these platforms can be used against cancer stem cells, a fundamental contributor to chemoresistance, tumor relapse/metastasis, and failure of immunotherapy. Overall, this comprehensive review strives to provide up-to-date information to an audience working at the juncture of biomaterials and cancer immunotherapy. STATEMENT OF SIGNIFICANCE: Cancer immunotherapy possesses incredible potential and has successfully transitioned into a clinically lucrative alternative to conventional anti-cancer therapies. With new immunotherapeutics getting rapid clinical approval, fundamental problems associated with the dynamic nature of the immune system (like limited clinical response rates and autoimmunity-related adverse effects) have remained unanswered. In this context, treatment approaches that focus on modulating the compromised immune components within the tumor microenvironment have garnered significant attention amongst the scientific community. This review aims to provide a critical discussion on how various biomaterials (polymer-based, lipid-based, carbon-based, cell-derived, etc.) can be employed along with immunostimulatory agents to design innovative platforms for selective immunotherapy directed against cancer and cancer stem cells.

Tumor Microenvironment Regulation and Cancer Targeting Therapy Based on Nanoparticles

Although we have made remarkable achievements in cancer awareness and medical technology, there are still tremendous increases in cancer incidence and mortality. However, most anti-tumor strategies, including immunotherapy, show low efficiency in clinical application. More and more evidence suggest that this low efficacy may be closely related to the immunosuppression of the tumor microenvironment (TME). The TME plays a significant role in tumorigenesis, development, and metastasis. Therefore, it is necessary to regulate the TME during antitumor therapy. Several strategies are developing to regulate the TME as inhibiting tumor angiogenesis, reversing tumor associated macrophage (TAM) phenotype, removing T cell immunosuppression, and so on. Among them, nanotechnology shows great potential for delivering regulators into TME, which further enhance the antitumor therapy efficacy. Properly designed nanomaterials can carry regulators and/or therapeutic agents to eligible locations or cells to trigger specific immune response and further kill tumor cells. Specifically, the designed nanoparticles could not only directly reverse the primary TME immunosuppression, but also induce effective systemic immune response, which would prevent niche formation before metastasis and inhibit tumor recurrence. In this review, we summarized the development of nanoparticles (NPs) for anti-cancer therapy, TME regulation, and tumor metastasis inhibition. We also discussed the prospect and potential of nanocarriers for cancer therapy.

Osmani R, Hani U, Yoonus Thajudeen K, Kiran Raj G, Gowda DV. Recent advances in the liposomal nanovesicles based immunotherapy in the treatment of cancer: A review

Immunotherapy, along with chemotherapy, targeted delivery, radiation and surgery has become one of the most common cancer treatments. The aim of cancer immunology is to use the bodys immune system to combat tumors and develop a robust antitumor immune response. In the last few years, immune checkpoint inhibitors and chimeric antigen receptor-modified T cells have made substantial advancements in cancer immunotherapy. By boosting cell type-specific delivery and immunological responses, nanocarriers like liposomes have the ability to enhance greater immune responses. The efficacy of anti-tumor therapeutics is being significantly improved as liposomes can assist in resolving a number of issues that can arise from a variety of cancer immunotherapies. Since, liposomes can be loaded with both hydrophilic and hydrophobic drugs and protect the immunotherapeutic agents loaded inside the core, they offer significant advantages over other nano delivery systems. The use of liposomes for accurate and timely delivery of immunotherapies to particular targeted neoplasms, with little or no injury to healthy cells, maximizes immunotherapy efficacy. Liposomes are also suitable vehicles for delivering medications simultaneously with other therapies such as chemotherapy, radiation, and phototherapy. Liposomal nanoparticles will be introduced and used as an objective immunotherapy delivery system for great precision, making them a viable cancer treatment approach.With an emphasis on dendritic cells, T cells, tumor and natural killer cells, and macrophages; outline of many forms of immune-therapies in oncology and cutting-edge advances in liposomal nanovesicles for cancer immunotherapy are covered in this review.

Acute inflammatory reaction during anti-angiogenesis therapy combined with immunotherapy as a possible indicator of the therapeutic effect: Three case reports and literature review

The posterior line treatment of unresectable advanced or metastatic gastrointestinal (GI) tumors has always been a challenging point. In particular, for patients with microsatellite stable (MSS)/mismatch repair proficient (pMMR) 0GI tumors, the difficulty of treatment is exacerbated due to their insensitivity to immune drugs. Accordingly, finding a new comprehensive therapy to improve the treatment effect is urgent. In this study, we report the treatment histories of three patients with MSS/pMMR GI tumors who achieved satisfactory effects by using a comprehensive treatment regimen of apatinib combined with camrelizumab and TAS-102 after the failure of first- or second-line regimens. The specific contents of the treatment plan were as follows: apatinib (500 mg/d) was administered orally for 10 days, followed by camrelizumab (200 mg, ivgtt, day 1, 14 days/cycle) and TAS-102 (20 mg, oral, days 1-21, 28 days/cycle). Apatinib (500 mg/d) was maintained during treatment. Subsequently, we discuss the possible mechanism of this combination and review the relevant literature, and introduce clinical trials on anti-angiogenesis therapy combined with immunotherapy.

Alcian Blue Staining to Visualize Intracellular Hyaluronic Acid-Based Nanoparticles

Investigating at transmission electron microscopy the intracellular trafficking of hyaluronic acid-based nanoparticles remains a challenge due to their intrinsic weak electron density. Here we describe a simple protocol to stain hyaluronic acid that allows visualization of hyaluronic acid-based nanoparticles inside cells at both light and electron microscopy. By applying the critical-electrolyte-concentration Alcian blue method, these nanoparticles were observed as blue dots at bright-field microscopy or filled with fine electron dense precipitates at transmission electron microscopy.

Ethyl lauroyl arginate-based hydrophobic ion pair complex in lipid nanocapsules: A novel oral delivery approach of rosmarinic acid for enhanced permeability and bioavailability

Limited oral bioavailability due to high hydrophilicity restricts the beneficial use of Rosmaranic acid (RM) that is characterized by many biological and pharmacological effects. The present work was addressed to extract RM from Rosmarinus officinalis L. leaves and then increase its lipophilicity and permeability through the application of hydrophobic ion pair (HIP) approach using ethyl lauroyl arginate (ELA) as a novel counter-ion. Different RM:ELA ratios were screened to optimize HIP formation process. The encapsulation of the optimized HIP into lipid nanocapsules (LNCs) was then achieved to facilitate oral administration. The results of % transmittance, % complexation efficiency (87.32 ± 0.19%) and partition coefficient revealed the successful formation of the HIP complex occurred at RM:ELA molar ratio of 1:2. The formed HIP was successfully loaded into spherical small sized (39.32 ± 0.18 nm) LNCs. The ex vivo permeability studies across porcine intestine showed that the cumulative RM amount permeated/area after 6 h from HIP and LNCs were 3.79 ± 0.57 and 5.71 ± 0.32 µg/cm², respectively. Pharmacokinetic study results showed that the maximum RM concentrations in plasma (C_max) can be arranged in a descending manner as follows; 61.33 ± 8.89 < 42.13 ± 11.22 < 20.96 ± 3.12 ng/ml attained after 4.80, 8.00 and 10.40 h in case of LNC, HIP and solution, respectively. Moreover, the HIP and LNC formulae showed higher total drug amounts in plasma reaching 1.46 and 1.88-fold relative to RM solution, respectively. In conclusion, the HIP complex and HIP loaded LNCs prosper in enhancing the permeability and absorption of the low permeable drugs.

The prognostic value and therapeutic targeting of myeloid-derived suppressor cells in hematological cancers

The success of immunotherapeutic approaches in hematological cancers is partially hampered by the presence of an immunosuppressive microenvironment. Myeloid-derived suppressor cells (MDSC) are key components of this suppressive environment and are frequently associated with tumor cell survival and drug resistance. Based on their morphology and phenotype, MDSC are commonly subdivided into polymorphonuclear MDSC (PMN-MDSC or G-MDSC) and monocytic MDSC (M-MDSC), both characterized by their immunosuppressive function. The phenotype, function and prognostic value of MDSC in hematological cancers has been intensively studied; however, the therapeutic targeting of this cell population remains challenging and needs further investigation. In this review, we will summarize the prognostic value of MDSC and the different attempts to target MDSC (or subtypes of MDSC) in hematological cancers. We will discuss the benefits, challenges and opportunities of using MDSC-targeting approaches, aiming to enhance anti-tumor immune responses of currently used cellular and non-cellular immunotherapies.

A novel immunochemotherapy based on immunogenicity-activated and immunosuppression-reversed biomimetic nanoparticles

Studies show that infiltrated myeloid-derived suppressor cells (MDSCs) are vital in the immunosuppressive tumor microenvironment and account for lymphoma refractoriness and recurrence. Here, we developed a biomimetic nanoplatform (PM-PLGA-DOX/GEM) in which platelet membranes (PM) wrap PLGA nanoparticles co-loaded with doxorubicin (DOX) and gemcitabine (GEM). PM-PLGA-DOX/GEM would accumulate in tumor tissues because of the enhanced permeation and retention (EPR) effect and the tumor cell-induced platelet aggregation (TCIPA) effect. GEM could eliminate the MDSCs in tumor tissues, thereby reversing the immunosuppressive tumor microenvironment. Furthermore, DOX could invoke the immunogenic cell death (ICD) of lymphoma cells. Consequently, numerous T cells were recruited and activated to improve the therapeutic effects. This study will offer a potential platform for clinical treatment of lymphoma and other solid tumors.

Inflammation-targeted nanomedicine against brain cancer: From design strategies to future developments

Brain cancer is an aggressive type of cancer with poor prognosis. While the immune system protects against cancer in the early stages, the tumor exploits the healing arm of inflammatory reactions to accelerate its growth and spread. Various immune cells penetrate the developing tumor region, establishing a pro-inflammatory tumor milieu. Additionally, tumor cells may release chemokines and cytokines to attract immune cells and promote cancer growth. Inflammation and its associated mechanisms in the progression of cancer have been extensively studied in the majority of solid tumors, especially brain tumors. However, treatment of the malignant brain cancer is hindered by several obstacles, such as the blood-brain barrier, transportation inside the brain interstitium, inflammatory mediators that promote tumor growth and invasiveness, complications in administering therapies to tumor cells specifically, the highly invasive nature of gliomas, and the resistance to drugs. To resolve these obstacles, nanomedicine could be a potential strategy that has facilitated advancements in diagnosing and treating brain cancer. Due to the numerous benefits provided by their small size and other features, nanoparticles have been a prominent focus of research in the drug-delivery field. The purpose of this article is to discuss the role of inflammatory mediators and signaling pathways in brain cancer as well as the recent advances in understanding the nano-carrier approaches for enhancing drug delivery to the brain in the treatment of brain cancer.

Pharmacological modulation of myeloid-derived suppressor cells to dampen inflammation

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous cell population with potent suppressive and regulative properties. MDSCs’ strong immunosuppressive potential creates new possibilities to treat chronic inflammation and autoimmune diseases or induce tolerance towards transplantation. Here, we summarize and critically discuss different pharmacological approaches which modulate the generation, activation, and recruitment of MDSCs in vitro and in vivo, and their potential role in future immunosuppressive therapy.

Rosmarinus officinalis L. hexane extract: phytochemical analysis, nanoencapsulation, and in silico, in vitro, and in vivo anti-photoaging potential evaluation

A shift towards natural anti-aging ingredients has spurred the research to valorize traditionally used plants. In this context, Rosmarinus officinalis L. was evaluated for its photoprotective, antioxidant, anti-inflammatory, and anti-wrinkling properties. GC/MS and LC-ESI-HRMS based phytochemical profiling of rosemary leaves hexane extract resulted in the identification of 47 and 31 compounds, respectively and revealed rich content in triterpenoids, monoterpenoids and phenolic diterpenes. In vitro assays confirmed the antioxidant, anti-aging, and wound healing potential of rosemary extract along with a good safety profile, encouraging further development. A systematic molecular modelling study was conducted to elucidate the mechanistic background of rosemary anti-aging properties through the inhibitory effects of its major constituents against key anti-aging targets viz. elastase, collagenase, and hyaluronidase. Development of rosemary extract lipid nanocapsules-based mucoadhesive gels was performed to improve skin contact, permeation, and bioavailability prior to in vivo testing. The developed formulae demonstrated small particle size (56.55–66.13 nm), homogenous distribution (PDI of 0.207–0.249), and negatively charged Zeta potential (− 13.4 to − 15.6). In UVB-irradiated rat model, topical rosemary hexane extract-loaded lipid nanocapsules-based gel provided photoprotection, restored the antioxidant biochemical state, improved epidermal and dermal histological features, and decreased the level of inflammatory and wrinkling markers. The use of rosemary hexane extract in anti-aging and photoprotective cosmeceuticals represents a safe, efficient, and cost-effective approach.

Immunosuppressive cells in cancer: mechanisms and potential therapeutic targets

Immunotherapies like the adoptive transfer of gene-engineered T cells and immune checkpoint inhibitors are novel therapeutic modalities for advanced cancers. However, some patients are refractory or resistant to these therapies, and the mechanisms underlying tumor immune resistance have not been fully elucidated. Immunosuppressive cells such as myeloid-derived suppressive cells, tumor-associated macrophages, tumor-associated neutrophils, regulatory T cells (Tregs), and tumor-associated dendritic cells are critical factors correlated with immune resistance. In addition, cytokines and factors secreted by tumor cells or these immunosuppressive cells also mediate the tumor progression and immune escape of cancers. Thus, targeting these immunosuppressive cells and the related signals is the promising therapy to improve the efficacy of immunotherapies and reverse the immune resistance. However, even with certain success in preclinical studies or in some specific types of cancer, large perspectives are unknown for these immunosuppressive cells, and the related therapies have undesirable outcomes for clinical patients. In this review, we comprehensively summarized the phenotype, function, and potential therapeutic targets of these immunosuppressive cells in the tumor microenvironment.

Advances in Nanotechnology-Based Immunotherapy for Glioblastoma

Glioblastoma (GBM) is the most aggressive type of brain tumor. Despite the multimodal therapies, the effectiveness of traditional treatments is not much satisfying. In recent years, immunotherapy has become the focus of tumor treatment. Unlike traditional treatments that directly target tumor cells, immunotherapy uses the body’s immune system to kill tumors. However, due to the severe immunosuppressive microenvironment of GBM, it generally has a poor response to immunotherapy. In addition, the existence of the blood-brain barrier (BBB) also compromises the immunotherapeutic efficacy. Therefore, effective immunotherapy of GBM requires the therapeutic agents to not only efficiently cross the BBB but also relieve the strong immunosuppression of the tumor microenvironment of GBM. In this review, we will first introduce the CNS immune system, immunosuppressive mechanism of GBM, and current GBM immunotherapy strategies. Then, we will discuss the development of nanomaterials for GBM immunotherapy based on different strategies, roughly divided into four parts: immune checkpoint therapy, targeting tumor-associated immune cells, activating immune cells through immunogenic cell death, and combination therapy, to provide new insights for future GBM immunotherapy.

Anticancer Vaccination with Immunogenic Micelles That Capture and Release Pristine CD8+ T-Cell Epitopes and Adjuvants

The development of nanocarriers capable of codelivering antigens and immune-activating adjuvants is an emerging area of research and is relevant for cancer vaccines that target induction of antigen-specific CD8⁺ T-cell responses. Here, we report a system for delivery of short peptide antigens to dendritic cells for strong cellular immune responses, based on block copolymers chemically modified with a hydrophobic and self-immolative linker. After modification, micelles effectively and reversibly capture antigens and adjuvants via a covalent bond within several minutes in an aqueous solution. After uptake in antigen presenting cells, the polymer disulfide bond is cleaved by intracellular glutathione, leading to release of pristine antigens, along with the upregulated expression of costimulatory molecules. The induced antigen-specific CD8⁺ T cells have strong tumor cell killing efficacy in the murine B16OVA and human papilloma virus-E6/E7 subcutaneous and lung metastasis tumor models. In addition, delivery to lymph nodes can be imaged to visualize vaccine trafficking. Taken together, multifunctional self-immolative micelles represent a versatile class of a vaccine delivery system for the generation of a cellular immune response that warrants further exploration as a component of cancer immunotherapy.

Targeting innate immune system by nanoparticles for cancer immunotherapy

Various cancer therapies have advanced remarkably over the past decade. Unlike the direct therapeutic targeting of tumor cells, cancer immunotherapy is a new strategy that boosts the host's immune system...

Stability, pharmacokinetics, and biodistribution in mice of the EPAC1 inhibitor (R)-CE3F4 entrapped in liposomes and lipid nanocapsules

(R)-CE3F4, a specific inhibitor of EPAC1 (exchange protein directly activated by cAMP type 1), has been demonstrated in vitro and in vivo to reduce hypertrophic signaling contributing to heart failure or to control arrhythmia and has shown promise as a drug candidate. However, (R)-CE3F4 exhibits poor solubility in aqueous media and has shown sensitivity to enzyme hydrolysis in plasma. To overcome these issues, the drug was entrapped in liposomes and lipid nanocapsules. Both systems considerably increased the drug apparent solubility in aqueous media. Among these nanocarriers, lipid nanocapsules offered significant protection in vitro against enzymatic degradation by increasing the (R)-CE3F4 apparent half-life from around 40 min to 6 h. Pharmacokinetics and biodistribution of (R)-CE3F4 radiolabeled or not were studied in healthy C57BL/6 mice. The non-encapsulated ³H-CE3F4 showed a very rapid distribution outside the blood compartment. Similar results were observed when using nanocarriers together with a fast dissociation of ³H-CE3F4 from nanocapsules simultaneously labeled with ¹⁴C. Thus, essential preclinical information on CE3F4 fate has been obtained, as well as the impact of its formulation using lipid-based nanocarriers.

Tumor microenvironment and nanotherapeutics: intruding the tumor fort

Over recent years, advancements in nanomedicine have allowed new approaches to diagnose and treat tumors. Nano drug delivery systems exploit the enhanced permeability and retention (EPR) effect and enter the tumor tissue's interstitial space. However, tumor barriers play a crucial role, and cause inefficient EPR or the homing effect. Mounting evidence supports the hypothesis that the components of the tumor microenvironment, such as the extracellular matrix, and cellular and physiological components collectively or cooperatively hinder entry and distribution of drugs, and therefore, limit the theragnostic applications of cancer nanomedicine. This abnormal tumor microenvironment plays a pivotal role in cancer nanomedicine and was recently recognized as a promising target for improving nano-drug delivery and their therapeutic outcomes. Strategies like passive or active targeting, stimuli-triggered nanocarriers, and the modulation of immune components have shown promising results in achieving anticancer efficacy. The present review focuses on the tumor microenvironment and nanoparticle-based strategies (polymeric, inorganic and organic nanoparticles) for intruding the tumor barrier and improving therapeutic effects.

Nanotechnology-based products for cancer immunotherapy

Abstract

Currently, nanoscale materials and scaffolds carrying antitumor agents to the tumor target site are practical approaches for cancer treatment. Immunotherapy is a modern approach to cancer treatment in which the body’s immune system adjusts to deal with cancer cells. Immuno-engineering is a new branch of regenerative medicine-based therapies that uses engineering principles by using biological tools to stimulate the immune system. Therefore, this branch’s final aim is to regulate distribution, release, and simultaneous placement of several immune factors at the tumor site, so then upgrade the current treatment methods and subsequently improve the immune system’s handling. In this paper, recent research and prospects of nanotechnology-based cancer immunotherapy have been presented and discussed. Furthermore, different encouraging nanotechnology-based plans for targeting various innate and adaptive immune systems will also be discussed. Due to novel views in nanotechnology strategies, this field can address some biological obstacles, although studies are ongoing.

Graphic abstract

A Complex Metabolic Network Confers Immunosuppressive Functions to Myeloid-Derived Suppressor Cells (MDSCs) within the Tumour Microenvironment

Myeloid-derived suppressor cells (MDSCs) constitute a plastic and heterogeneous cell population among immune cells within the tumour microenvironment (TME) that support cancer progression and resistance to therapy. During tumour progression, cancer cells modify their metabolism to sustain an increased energy demand to cope with uncontrolled cell proliferation and differentiation. This metabolic reprogramming of cancer establishes competition for nutrients between tumour cells and leukocytes and most importantly, among tumour-infiltrating immune cells. Thus, MDSCs that have emerged as one of the most decisive immune regulators of TME exhibit an increase in glycolysis and fatty acid metabolism and also an upregulation of enzymes that catabolise essential metabolites. This complex metabolic network is not only crucial for MDSC survival and accumulation in the TME but also for enhancing immunosuppressive functions toward immune effectors. In this review, we discuss recent progress in the field of MDSC-associated metabolic pathways that could facilitate therapeutic targeting of these cells during cancer progression.

Localized Chemotherapy Based on Injectable Hydrogel Boosts the Antitumor Activity of Adoptively Transferred T Lymphocytes In Vivo

The adoptive transfer of antigen-specific T cells has been successfully applied in the treatment of hematological malignancies. However, its application in the treatment of solid tumors has been overshadowed by the immunosuppressive tumor microenvironment. In this context, a preprocessing strategy is developed to reprogram the immunosuppressive tumor microenvironment using a thermoresponsive hydrogel loaded with doxorubicin (DOX@Gel). Compared with hydrogel-based chemotherapy alone or adoptive T cell therapy alone, this combination exhibits enhanced anti-tumor efficacy. In addition to the direct killing of tumor cells, the local chemotherapy releases tumor-associated antigens which enhance the proliferation and effector function of endogenous and adoptively transferred T cells. Moreover, DOX@Gel significantly reduces the numbers of both myeloid derived suppressor cells and Tregs in tumor microenvironment. It is suggested that DOX@Gel promotes the efficacy of adoptively transferred T cells against solid tumors, overcoming the key limitations of adoptive T cell therapy.

DTX@VTX NPs synergy PD-L1 immune checkpoint nanoinhibitor to reshape immunosuppressive tumor microenvironment for enhancing chemo-immunotherapy

Immunosuppressed tumor microenvironment (TME) is a major cause of the low response rate in solid tumor patients during PD-1/PD-L1 checkpoint blockade therapy. In this study, a series of small molecule nanomedicines with a 100% drug loading rate were prepared via the nanoprecipitation method. They were used in synergistic chemo-immunotherapy for 4T1 tumors. Among four PD-L1 small-molecule nanoinhibitors, BMS-1 NP with the best anti-tumor performance was selected to replace the therapeutic PD-L1 antibody. The core-shell small-molecule nanomedicine DTX@VTX NP (DTX: Docetaxel and VTX: VTX-2337 or Motolimod) was used to reverse immunosuppressed TME through the depletion of myeloid-derived suppressor cells (MDSCs) and the polarization of macrophages from an M2-like phenotype to M1-like phenotype. Thus, the frequency of cytotoxic CD8⁺ T cells was significantly increased, resulting in an effective attack on cancer cells. Combining BMS-1 NPs with DTX@VTX NPs, synergistic chemo-immunotherapy of 4T1 tumors was performed, and the results indicate that the inhibition rates of primary and rechallenge tumors achieved 90.5% and 94.3%, respectively. These results indicate that DTX@VTX NPs can synergize PD-L1 nanoinhibitor BMS-1 NPs to reshape the immunosuppressive tumor microenvironment for enhancing the anti-tumor effect of chemo-immunotherapy for breast.

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

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

MDSC in Mice and Men: Mechanisms of Immunosuppression in Cancer

Myeloid-derived suppressor cells (MDSCs) expand during pathological conditions in both humans and mice and their presence is linked to poor clinical outcomes for cancer patients. Studying MDSC immunosuppression is restricted by MDSCs’ rarity, short lifespan, heterogeneity, poor viability after freezing and the lack of MDSC-specific markers. In this review, we will compare identification and isolation strategies for human and murine MDSCs. We will also assess what direct and indirect immunosuppressive mechanisms have been attributed to MDSCs. While some immunosuppressive mechanisms are well-documented in mice, e.g., generation of ROS, direct evidence is still lacking in humans. In future, bulk or single-cell genomics could elucidate which phenotypic and functional phenotypes MDSCs adopt in particular microenvironments and help to identify potential targets for therapy.

Polymer-free hydrogel made of lipid nanocapsules, as a local drug delivery platform

Nanoparticle-loaded hydrogels are attractive pharmaceutical drug delivery systems that combine the advantages of both hydrogel (local administration and/or sustained drug release) and nanoparticle (stealthiness, targeting and decreased toxicity). The design of nanoparticle-loaded hydrogels is largely conventional, consisting of the dispersion of nanoparticles in a natural or synthetic polymer matrix to form a gel network. Novel nanoparticle-loaded hydrogels architecture could provide advantages in terms of innovation and application. We focused on the development of lipid nanocapsule (LNC)-based hydrogels without the use of a polymer matrix as a platform for drug delivery. Cytidine was modified by grafting palmitoyl chains (CytC16) and the new entity was added during the LNC phase-inversion formulation process allowing spontaneous gelation. Positioned at the oil/water interface, CytC16 acts as a crosslinking agent between LNCs. Association of the LNCs in a three-dimensional network led to the formation of polymer-free hydrogels. The viscoelastic properties of the LNC-based hydrogels depended on the LNC concentration and CytC16 loading but were not affected by the LNC size distribution. The LNC and drug-release profiles were controlled by the mechanical properties of the LNC-based hydrogels (slower release profiles correlated with higher viscoelasticity). Finally, the subcutaneous administration of LNC-based hydrogels led to classic inflammatory reactions of the foreign body-reaction type due to the endogenous character of CytC16, shown by cellular viability assays. New-generation nanoparticle-loaded hydrogels (LNC-based polymer-free hydrogels) show promise as implants for pharmaceutical applications. Once LNC release is completed, no gel matrix remains at the injection site, minimizing the additional toxicity due to the persistence of polymeric implants. Sustained drug-release profiles can be controlled by the mechanical properties of the hydrogels and could be tailor-made, depending on the therapeutic strategy chosen.

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.

Recent Advancements in Nanomedicine for 'Cold' Tumor Immunotherapy

Although current anticancer immunotherapies using immune checkpoint inhibitors (ICIs) have been reported with a high clinical success rate, numerous patients still bear 'cold' tumors with insufficient T cell infiltration and low immunogenicity, responding poorly to ICI therapy. Considering the advancements in precision medicine, in-depth mechanism studies on the tumor immune microenvironment (TIME) among cold tumors are required to improve the treatment for these patients. Nanomedicine has emerged as a promising drug delivery system in anticancer immunotherapy, activates immune function, modulates the TIME, and has been applied in combination with other anticancer therapeutic strategies. This review initially summarizes the mechanisms underlying immunosuppressive TIME in cold tumors and addresses the recent advancements in nanotechnology for cold TIME reversal-based therapies, as well as a brief talk about the feasibility of clinical translation.

Recent Advances in Lipid-Based Nanosystems for Gemcitabine and Gemcitabine-Combination Therapy

The anti-metabolite drug gemcitabine is widely used for the treatment of a variety of cancers. At present, gemcitabine is administered as a hydrochloride salt that is delivered by slow intravenous injection in cycles of three or four weeks. Although regarded as a 'front-line' chemotherapeutic agent, its efficacy is hampered by poor target cell specificity, sub-optimal cellular uptake, rapid clearance from circulation, the development of chemoresistance, and undesirable side-effects. The use of organic, inorganic, and metal-based nanoparticles as delivery agents presents an opportunity to overcome these limitations and safely harness optimal drug efficacy and enhance their therapeutic indices. Among the many and varied nano delivery agents explored, the greatest body of knowledge has been generated in the field of lipid-mediated delivery. We review here the liposomes, niosomes, solid lipid nanoparticles, nanostructured lipid carriers, exosomes, lipid-polymer hybrids, and other novel lipid-based agents that have been developed within the past six years for the delivery of gemcitabine and its co-drugs.

Nanomedicine for Gene Delivery and Drug Repurposing in the Treatment of Muscular Dystrophies

Muscular Dystrophies (MDs) are a group of rare inherited genetic muscular pathologies encompassing a variety of clinical phenotypes, gene mutations and mechanisms of disease. MDs undergo progressive skeletal muscle degeneration causing severe health problems that lead to poor life quality, disability and premature death. There are no available therapies to counteract the causes of these diseases and conventional treatments are administered only to mitigate symptoms. Recent understanding on the pathogenetic mechanisms allowed the development of novel therapeutic strategies based on gene therapy, genome editing CRISPR/Cas9 and drug repurposing approaches. Despite the therapeutic potential of these treatments, once the actives are administered, their instability, susceptibility to degradation and toxicity limit their applications. In this frame, the design of delivery strategies based on nanomedicines holds great promise for MD treatments. This review focuses on nanomedicine approaches able to encapsulate therapeutic agents such as small chemical molecules and oligonucleotides to target the most common MDs such as Duchenne Muscular Dystrophy and the Myotonic Dystrophies. The challenge related to in vitro and in vivo testing of nanosystems in appropriate animal models is also addressed. Finally, the most promising nanomedicine-based strategies are highlighted and a critical view in future developments of nanomedicine for neuromuscular diseases is provided.

Emerging nanotechnological strategies to reshape tumor microenvironment for enhanced therapeutic outcomes of cancer immunotherapy

Immunotherapy was emerged as a novel cancer treatment in the last decade, however, efficacious responses to mono-immunotherapy have only been achieved in a relatively small portion of patients whereas combinational immunotherapies often lead to concurrent side effects. It has been proved that the tumor microenvironment (TME) is responsible for tumor immune escape and the ultimate treatment failure. Recently, both the understanding of the TME and the applications of nanotechnological strategies have achieved remarkable progresses, and reviewing the emerging immune-regulatory nanosystems may provide valuable information for specifically modulating the TME at different immune stages. In this review, we focus on comprehending the recently proposed T-cell-based tumor classification and identifying the most promising targets for different tumor phenotypes, and then summarizing the nanotechnological strategies to best target corresponding immune-related factors. For future precise personalized immunotherapy, the tailor-made TME modulation strategies conducted by well-designed nanosystems to alleviate the suppressive TME and then promote anti-tumor immune responses will significantly benefit the clinical outcomes of cancer patients.

The Use of Alternative Strategies for Enhanced Nanoparticle Delivery to Solid Tumors

Nanomaterial (NM) delivery to solid tumors has been the focus of intense research for over a decade. Classically, scientists have tried to improve NM delivery by employing passive or active targeting strategies, making use of the so-called enhanced permeability and retention (EPR) effect. This phenomenon is made possible due to the leaky tumor vasculature through which NMs can leave the bloodstream, traverse through the gaps in the endothelial lining of the vessels, and enter the tumor. Recent studies have shown that despite many efforts to employ the EPR effect, this process remains very poor. Furthermore, the role of the EPR effect has been called into question, where it has been suggested that NMs enter the tumor via active mechanisms and not through the endothelial gaps. In this review, we provide a short overview of the EPR and mechanisms to enhance it, after which we focus on alternative delivery strategies that do not solely rely on EPR in itself but can offer interesting pharmacological, physical, and biological solutions for enhanced delivery. We discuss the strengths and shortcomings of these different strategies and suggest combinatorial approaches as the ideal path forward.

Monocytic Myeloid-Derived Suppressor Cells Underpin Resistance to Adoptive T Cell Therapy in Nasopharyngeal Carcinoma

Advanced, late-stage Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) is incurable, and its treatment remains a clinical and therapeutic challenge. Results from a phase II clinical trial in advanced NPC patients employing a combined chemotherapy and EBV-specific T cell (EBVST) immunotherapy regimen showed a response rate of 71.4%. Longitudinal analysis of patient samples showed that an increase in EBV DNA plasma concentrations and the peripheral monocyte-to-lymphocyte ratio negatively correlated with overall survival. These parameters were combined into a multivariate analysis to stratify patients according to risk of death. Immunophenotyping at serial time points showed that low-risk individuals displayed significantly decreased amounts of monocytic myeloid-derived suppressor cells postchemotherapy, which subsequently influenced successful cytotoxic T-lymphocyte (CTL) immunotherapy. Examination of the low-risk group, 2 weeks post-EBVST infusion, showed that individuals with a greater overall survival possessed an increased frequency of CD8 central and effector memory T cells, together with higher levels of plasma interferon (IFN)-γ, and cytotoxic lymphocyte-associated transcripts. These results highlight the importance of the rational selection of chemotherapeutic agents and consideration of their impact on both systemic immune responses and downstream cellular immunotherapy outcomes.

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.

Cargo-free immunomodulatory nanoparticles combined with anti-PD-1 antibody for treating metastatic breast cancer

The presence of immunosuppressive innate immune cells such as myeloid derived suppressor cells (MDSCs), Ly6C-high monocytes, and tumor-associated macrophages (TAMs) at a tumor can inhibit effector T cell and NK cell function. Immune checkpoint blockade using anti-PD-1 antibody aims to overcome the immune suppressive environment, yet only a fraction of patients responds. Herein, we test the hypothesis that cargo-free PLG nanoparticles administered intravenously can divert circulating immune cells from the tumor microenvironment to enhance the efficacy of anti-PD-1 immunotherapy in the 4T1 mouse model of metastatic triple-negative breast cancer. In vitro studies demonstrate that these nanoparticles decrease the expression of MCP-1 by 5-fold and increase the expression of TNF-α by more than 2-fold upon uptake by innate immune cells. Intravenous administration of particles results in internalization by MDSCs and monocytes, with particles detected in the liver, lung, spleen, and primary tumor. Nanoparticle delivery decreased the abundance of MDSCs in circulation and in the lung, the latter being the primary metastatic site. Combined with anti-PD-1 antibody, nanoparticles significantly slowed tumor growth and resulted in a survival benefit. Gene expression analysis by GSEA indicated inflammatory myeloid cell pathways were downregulated in the lung and upregulated in the spleen and tumor. Upregulation of extrinsic apoptotic pathways was also observed in the primary tumor. Collectively, these results demonstrate that cargo-free PLG nanoparticles can reprogram immune cell responses and alter the tumor microenvironment in vivo to overcome the local immune suppression attributed to myeloid cells and enhance the efficacy of anti-PD-1 therapy.

Nanoparticles as Smart Carriers for Enhanced Cancer Immunotherapy

Cancer immunotherapy has emerged as a promising strategy for the treatment of many forms of cancer by stimulating body's own immune system. This therapy not only eradicates tumor cells by inducing strong anti-tumor immune response but also prevent their recurrence. The clinical cancer immunotherapy faces some insurmountable challenges including high immune-mediated toxicity, lack of effective and targeted delivery of cancer antigens to immune cells and off-target side effects. However, nanotechnology offers some solutions to overcome those limitations, and thus can potentiate the efficacy of immunotherapy. This review focuses on the advancement of nanoparticle-mediated delivery of immunostimulating agents for efficient cancer immunotherapy. Here we have outlined the use of the immunostimulatory nanoparticles as a smart carrier for effective delivery of cancer antigens and adjuvants, type of interactions between nanoparticles and the antigen/adjuvant as well as the factors controlling the interaction between nanoparticles and the receptors on antigen presenting cells. Besides, the role of nanoparticles in targeting/activating immune cells and modulating the immunosuppressive tumor microenvironment has also been discussed extensively. Finally, we have summarized some theranostic applications of the immunomodulatory nanomaterials in treating cancers based on the earlier published reports.

Tumor-permeated bioinspired theranostic nanovehicle remodels tumor immunosuppression for cancer therapy

The robust immunosuppressive microenvironment in tumor represents a key challenge of cancer treatment, and their modulations by versatile therapeutic agents are critically hampered by the limited intratumoral delivery. Herein, we report a bioinspired tumor-responsive theranostic nanovehicle (BTN) with striking tumor-penetrating capability to relieve the profound immunosuppression in tumor for effective cancer therapy. BTN is designed by loading tumor-activated melittin pro-peptide, theranostic photochlor and reactive oxygen species (ROS)-responsive prodrug of chemo-immunomodulator gemcitabine into a bioinspired lipoprotein-based nanovehicle, which display prominent tumor accumulation and flexible intratumoral permeation. Notably, the BTN-mediated combinational treatment caused drastic elimination of multiple immunosuppressive cells and remarkable infiltration of cytotoxic lymphocytes in tumor, thereby essentially relieving the tumor immunosuppression and strikingly depressing the tumor growth. Therefore, this design provides an encouraging delivery nanoplatform with distinguished immunosuppression-relieving capacity for effective cancer therapy.

The double-edged sword effect of macrophage targeting delivery system in different macrophage subsets related diseases

Background

Monocyte/macrophage-targeting delivery systems (MTDSs) have been focused upon as an emerging routine for delivering drugs to treat various macrophage-related diseases. However, the ability of MTDSs to distinguish different macrophage-related diseases and their impact on macrophage function and disease progression have not been systematically revealed, which is important for actively targeted therapeutic or diagnostic strategies.

Results

Herein, we used dextran-modified polystyrene nanoparticles (DEX-PS) to demonstrate that modification of nanoparticles by dextran can specifically enhance their recognition by M2 macrophages in vitro, but it is obstructed by monocytes in peripheral blood according to in vivo assays. DEX-PS not only targeted and became distributed in tumors, an M2 macrophage-related disease, but was also highly distributed in an M1 macrophage-related disease, namely acute peritonitis. Thus, DEX-PS acts as a double-edged sword in these two different diseases by reeducating macrophages to a pro-inflammatory phenotype.

Conclusions

Our results suggest that MTDSs, even those designed based on differential expression of receptors on specific macrophage subtypes, lack the ability to distinguish different macrophage subtype-related diseases in vivo. In addition to the potential impact of these carrier materials on macrophage function, studies of MTDSs should pay greater attention to the distribution of nanoparticles in non-target macrophage-infiltrated disease sites and their impact on disease processes.

Lipid-based Nanoplatforms in Cancer Therapy: Recent Advances and Applications

Though modern available cancer therapies are effective, they possess major adverse effects, causing non-compliance to patients. Furthermore, the majority of the polymeric-based medication platforms are certainly not universally acceptable, due to their several restrictions. With this juxtaposition, lipid-based medication delivery systems have appeared as promising drug nanocarriers to replace the majority of the polymer-based products because they are in a position to reverse polymer as well as, drug-associated restrictions. Furthermore, the amalgamation of the basic principle of nanotechnology in designing lipid nanocarriers, which are the latest form of lipid carriers, has tremendous chemotherapeutic possibilities as tumor-targeted drug-delivery pertaining to tumor therapy. Apart from this, it is reported that nearly 40% of the modern medication entities are lipophilic. Moreover, research continues to be efficient in attaining a significant understanding of the absorption and bioavailability of the developed lipids systems.

Novel T7-Modified pH-Responsive Targeted Nanosystem for Co-Delivery of Docetaxel and Curcumin in the Treatment of Esophageal Cancer

Background

Although single-drug chemotherapy is still an effective treatment for esophageal cancer, its long-term application is limited by severe side-effects, poor bioavailability, and drug-resistance. Increasing attention has been paid to nanomedicines because of their good biological safety, targeting capabilities, and high-efficiency loading of multiple drugs. Herein, we have developed a novel T7 peptide-modified pH-responsive targeting nanosystem co-loaded with docetaxel and curcumin for the treatment of esophageal cancer.

Methods

Firstly, CM-β-CD-PEI-PEG-T7/DTX/CUR (T7-NP-DC) was synthesized by the double emulsion (W/O/W) method. The targeting capacity of the nanocarrier was then investigated by in vitro and in vivo assays using targeted (T7-NP) and non-targeted nanoparticles (NP). Furthermore, the anti-tumor efficacy of T7-NP-DC was studied using esophageal cancer cells (KYSE150 and KYSE510) and a KYSE150 xenograft tumor model.

Results

T7-NP-DC was synthesized successfully and its diameter was determined to be about 100 nm by transmission electron microscopy and dynamic light scattering. T7-NP-DC with docetaxel and curcumin loading of 10% and 6.1%, respectively, had good colloidal stability and exhibited pH-responsive drug release. Good biosafety was observed, even when the concentration was as high as 800 μg/mL. Significant enhancement of T7-NP uptake was observed 6 hours after intravenous injection compared with NP. In addition, the therapeutic efficacy of T7-NP-DC was better than NP-DC and docetaxel in terms of growth suppression in the KYSE150 esophageal cancer model.

Conclusion

The findings demonstrated that T7-NP-DC is a promising, non-toxic, and controllable nanoparticle that is capable of simultaneous delivery of the chemotherapy drug, docetaxel, and the Chinese Medicine, curcumin, for treatment of esophageal cancer. This novel T7-modified targeting nanosystem releases loaded drugs when exposed to the acidic microenvironment of the tumor and exerts a synergistic anti-tumor effect. The data indicate that the nanomaterials can safely exert synergistic anti-tumor effects and provide an excellent therapeutic platform for combination therapy of esophageal cancer.