Multifunctional polymeric micelle-based chemo-immunotherapy with immune checkpoint blockade for efficient treatment of orthotopic and metastatic breast cancer

Promotion of ICD via Nanotechnology

Immunotherapy represents the most promising treatment strategy for cancer, but suffers from compromised therapeutic efficiency due to low immune activity of tumor cells and an immunosuppressive microenvironment, which significantly hampers the clinical translations of this treatment strategy. To promote immunotherapy with desired therapeutic efficiency, immunogenic cell death (ICD), a particular type of death capable of reshaping body's antitumor immune activity, has drawn considerable attention due to the potential to stimulate a potent immune response. Still, the potential of ICD effect remains unsatisfactory because of the intricate tumor microenvironment and multiple drawbacks of the used inducing agents. ICD has been thoroughly reviewed so far with a general classification of ICD as a kind of immunotherapy strategy and repeated discussion of the related mechanism. However, there are no published reviews, to the authors' knowledge, providing a systematic summarization on the enhancement of ICD via nanotechnology. For this purpose, this review first discusses the four stages of ICD according to the development mechanisms, followed by a comprehensive description on the use of nanotechnology to enhance ICD in the corresponding four stages. The challenges of ICD inducers and possible solutions are finally summarized for future ICD-based enhanced immunotherapy.

Plasma D-dimer and interleukin-6 are associated with treatment response and progression-free survival in advanced NSCLC patients on anti-PD-1 therapy

BACKGROUND/AIMS

Response to therapy after using immune checkpoint inhibitors (ICIs) is unpredictable due to significant interindividual variation in efficacy among advanced non-small cell lung cancer (NSCLC) patients. The current study centered on the identification of perivascular blood biomarkers for predicting the effectiveness of anti-programmed cell death protein 1 (anti-PD-1) treatment and progression-free survival (PFS) in advanced NSCLC patients, that could be applied to help determine how to change treatment plans therapeutic regimens for optimizing clinical benefits.

METHODS

A comprehensive review of 100 advanced or recurrent NSCLC patients receiving anti-PD-1 therapy (Camrelizumab, pembrolizumab, sintilimab, or nivolumab) was conducted between January 2018 and April 2021 in Tianjin Medical University Cancer Hospital. The cutoff values of D-dimer were selected from rom our previous study, and interleukin-6 (IL-6) was divided according to the median. Using computed tomography, tumor response was evaluated in accordance with the Response Assessment Criteria in Solid Tumors, version 1.1.

RESULTS

High IL-6 level in advanced NSCLC patients was predictive of low efficacy and a short PFS duration after anti-PD-1 therapy. An increased D-dimer value of 981 ng/mL was significantly predictive of disease progression in NSCLC patients treated with anti-PD-1 and high D-dimer expression predictive of short duration of PFS. Further studies on the correlation between IL-6, D-dimer, and anti-PD-1 efficacy in NSCLC patients stratified by gender revealed that D-dimer and IL-6 levels were significantly associated with the risk of PFS in male patients.

CONCLUSIONS

High IL-6 content in peripheral blood in patients with advanced non-small cell lung cancer may contribute to poor anti-PD-1 efficacy and short duration of PFS through inducing alterations in the tumor microenvironment. D-dimer in peripheral blood is predictive of hyperfibrinolysis and contributes to the release of tumor-driven specific factors, leading to poor effects of anti-PD-1 therapy.

Polysaccharide-Based Stimulus-Responsive Nanomedicines for Combination Cancer Immunotherapy

Cancer immunotherapy is a promising antitumor approach, whereas nontherapeutic side effects, tumor microenvironment (TME) intricacy, and low tumor immunogenicity limit its therapeutic efficacy. In recent years, combination immunotherapy with other therapies has been proven to considerably increase antitumor efficacy. However, achieving codelivery of the drugs to the tumor site remains a major challenge. Stimulus-responsive nanodelivery systems show controlled drug delivery and precise drug release. Polysaccharides, a family of potential biomaterials, are widely used in the development of stimulus-responsive nanomedicines due to their unique physicochemical properties, biocompatibility, and modifiability. Here, the antitumor activity of polysaccharides and several combined immunotherapy strategies (e.g., immunotherapy combined with chemotherapy, photodynamic therapy, or photothermal therapy) are summarized. More importantly, the recent progress of polysaccharide-based stimulus-responsive nanomedicines for combination cancer immunotherapy is discussed, with the focus on construction of nanomedicine, targeted delivery, drug release, and enhanced antitumor effects. Finally, the limitations and application prospects of this new field are discussed.

Liposome-Based Co-Immunotherapy with TLR Agonist and CD47-SIRPα Checkpoint Blockade for Efficient Treatment of Colon Cancer

Antitumor immunity is an essential component of cancer therapy and is primarily mediated by the innate immune response, which plays a critical role in initiating and shaping the adaptive immune response. Emerging evidence has identified innate immune checkpoints and pattern recognition receptors, such as CD47 and Toll-like receptor 7 (TLR7), as promising therapeutic targets for cancer treatment. Based on the fusion protein Fc-CV1, which comprises a high-affinity SIRPα variant (CV1), and the Fc fragment of the human IgG1 antibody, we exploited a preparation which coupled Fc-CV1 to imiquimod (TLR7 agonist)-loaded liposomes (CILPs) to actively target CT26. WT syngeneic colon tumor models. In vitro studies revealed that CILPs exhibited superior sustained release properties and cell uptake efficiency compared to free imiquimod. In vivo assays proved that CILPs exhibited more efficient accumulation in tumors, and a more significant tumor suppression effect than the control groups. This immunotherapy preparation possessed the advantages of low doses and low toxicity. These results demonstrated that a combination of immune checkpoint blockade (ICB) therapy and innate immunity agonists, such as the Fc-CV1 and imiquimod-loaded liposome preparation utilized in this study, could represent a highly effective strategy for tumor therapy.

Potential of Nuclear Imaging Techniques to Study the Oral Delivery of Peptides

Peptides are small biomolecules known to stimulate or inhibit important functions in the human body. The clinical use of peptides by oral delivery, however, is very limited due to their sensitive structure and physiological barriers present in the gastrointestinal tract. These barriers can be overcome with chemical and mechanical approaches protease inhibitors, permeation enhancers, and polymeric encapsulation. Studying the success of these approaches pre-clinically with imaging techniques such as fluorescence imaging (IVIS) and optical microscopy is difficult due to the lack of in-depth penetration. In comparison, nuclear imaging provides a better platform to observe the gastrointestinal transit and quantitative distribution of radiolabeled peptides. This review provides a brief background on the oral delivery of peptides and states examples from the literature on how nuclear imaging can help to observe and analyze the gastrointestinal transit of oral peptides. The review connects the fields of peptide delivery and nuclear medicine in an interdisciplinary way to potentially overcome the challenges faced during the study of oral peptide formulations.

Toll-like receptor-targeted anti-tumor therapies: Advances and challenges

Toll-like receptors (TLRs) are pattern recognition receptors, originally discovered to stimulate innate immune reactions against microbial infection. TLRs also play essential roles in bridging the innate and adaptive immune system, playing multiple roles in inflammation, autoimmune diseases, and cancer. Thanks to the immune stimulatory potential of TLRs, TLR-targeted strategies in cancer treatment have proved to be able to regulate the tumor microenvironment towards tumoricidal phenotypes. Quantities of pre-clinical studies and clinical trials using TLR-targeted strategies in treating cancer have been initiated, with some drugs already becoming part of standard care. Here we review the structure, ligand, signaling pathways, and expression of TLRs; we then provide an overview of the pre-clinical studies and an updated clinical trial watch targeting each TLR in cancer treatment; and finally, we discuss the challenges and prospects of TLR-targeted therapy.

Targeted drug delivery system for ovarian cancer microenvironment: Improving the effects of immunotherapy

Immunotherapies have shown modest benefits in the current clinical trials for ovarian cancer. The tumor microenvironment (TME) in an immunosuppressive phenotype contributes to this “failure” of immunotherapy in ovarian cancer. Many stromal cell types in the TME (e.g., tumor-associated macrophages and fibroblasts) have been identified as having plasticity in pro- and antitumor activities and are responsible for suppressing the antitumor immune response. Thus, the TME is an extremely valuable target for adjuvant interventions to improve the effects of immunotherapy. The current strategies targeting the TME include: 1) eliminating immunosuppressive cells or transforming them into immunostimulatory phenotypes and 2) inhibiting their immunosuppressive or pro-tumor production. Most of the effective agents used in the above strategies are genetic materials (e.g., cDNA, mRNA, or miRNA), proteins, or other small molecules (e.g., peptides), which are limited in their target and instability. Various formulations of drug delivery system (DDS) have been designed to realize the controlled release and targeting delivery of these agents to the tumor sites. Nanoparticles and liposomes are the most frequently exploited materials. Based on current evidence from preclinical and clinical studies, the future of the DDS is promising in cancer immunotherapy since the combination of agents with a DDS has shown increased efficacy and decreased toxicities compared with free agents. In the future, more efforts are needed to further identify the hallmarks and biomarkers in the ovarian TME, which is crucial for the development of more effective, safe, and personalized DDSs.

Combining immune checkpoint blockade with ATP-based immunogenic cell death amplifier for cancer chemo-immunotherapy

Amplifying "eat me signal" during tumor immunogenic cell death (ICD) cascade is crucial for tumor immunotherapy. Inspired by the indispensable role of adenosine triphosphate (ATP, a necessary "eat me signal" for ICD), a versatile ICD amplifier was developed for chemotherapy-sensitized immunotherapy. Doxorubicin (DOX), ATP and ferrous ions (Fe²⁺) were co-assembled into nanosized amplifier (ADO-Fe) through π‒π stacking and coordination effect. Meanwhile, phenylboric acid-polyethylene glycol-phenylboric acid (PBA-PEG-PBA) was modified on the surface of ADO-Fe (denoted as PADO-Fe) by the virtue of d-ribose unit of ATP. PADO-Fe could display active targetability against tumor cells via sialic acid/PBA interaction. In acidic microenvironment, PBA-PEG-PBA would dissociate from amplifier. Moreover, high H₂O₂ concentration would induce hydroxyl radical (·OH) and oxygen (O₂) generation through Fenton reaction by Fe²⁺. DOX and ATP would be released from the amplifier, which could induce ICD effect and "ICD adjuvant" to amplify this process. Together with programmed death ligands 1 (PD-L1) checkpoint blockade immunotherapy, PADO-Fe could not only activate immune response against primary tumor, but also strong abscopal effect against distant tumor. Our simple and multifunctional ICD amplifier opens a new window for enhancing ICD effect and immune checkpoint blockade therapy.

Emerging advances in nanomedicine for breast cancer immunotherapy: opportunities and challenges

Breast cancer is one of the most common causes of cancer-related morbidity and mortality in women worldwide. Early diagnosis and an appropriate therapeutic approach for all cancers are climacterics for a favorable prognosis. Targeting the immune system in breast cancer is already a clinical reality with notable successes, specifically with checkpoint blockade antibodies and chimeric antigen receptor T-cell therapy. However, there have been inevitable setbacks in the clinical application of cancer immunotherapy, including inadequate immune responses due to insufficient delivery of immunostimulants to immune cells and uncontrolled immune system modulation. Rapid advancements and new evidence have suggested that nanomedicine-based immunotherapy may be a viable option for treating breast cancer.

Nanomedicine as a Promising Tool to Overcome Immune Escape in Breast Cancer

Breast cancer is the most common type of malignancy and leading cause of cancer death among women worldwide. Despite the current revolutionary advances in the field of cancer immunotherapy, clinical response in breast cancer is frequently below expectations, in part due to various mechanisms of cancer immune escape that produce tumor variants that are resistant to treatment. Thus, a further understanding of the molecular events underlying immune evasion in breast cancer may guarantee a significant improvement in the clinical success of immunotherapy. Furthermore, nanomedicine provides a promising opportunity to enhance the efficacy of cancer immunotherapy by improving the delivery, retention and release of immunostimulatory agents in targeted cells and tumor tissues. Hence, it can be used to overcome tumor immune escape and increase tumor rejection in numerous malignancies, including breast cancer. In this review, we summarize the current status and emerging trends in nanomedicine-based strategies targeting cancer immune evasion and modulating the immunosuppressive tumor microenvironment, including the inhibition of immunosuppressive cells in the tumor area, the activation of dendritic cells and the stimulation of the specific antitumor T-cell response.

Nano-immunotherapeutics: targeting approach as strategic regulation at tumor microenvironment for cancer treatment

Cancer is the leading cause of mortality worldwide, which necessitates our consideration related to novel treatment approach. Tumor cells at the tumor microenvironment (TME), regulate a plethora of key mechanistic signaling pathways that obstruct antitumor immune responses by immune suppression, immune resistance or acquired immune tolerance. The present therapeutic regimes are provided independently or in combination, or as immunotherapies for cancer immune targeting. Immunotherapy has altered the arena of oncology and patient care. By using the host immune system, the immunostimulatory molecules can exert a robust, personalized response against the patient’s own tumors. Alternatively, tumors may exploit these strategies to escape immune recognition, and accordingly, such mechanisms represent chances for immunotherapy intervention. Nonetheless, despite promising outcomes from immunotherapies in recurrent and metastatic cancers, immune-therapeutics in clinics has been limited owing to unpredictability in the produced immune response and reported instances of immune-related adverse effects. The unrealized potential of immunotherapies in cancer management maybe due to the obstacles such as heterogeneous nature, multiple targets, patients’ immune response, specificity for cancer or variability in response generation in toxicity levels, delivery and cost related to therapeutics etc. Further revolutionary trends related to immunotherapies are noticeable with slower progress for cancer management. Recent advances in nanomedicine strategize to ameliorate the lacuna of immunotherapy as it relies on the inherent biophysical characteristics of nanocarriers: size, shape, surface charge and multifunctionality and exploiting them as first line therapy for delivery of biomolecules, single checkpoint inhibitors and for imaging of TME. Therefore, nano-assisted immunotherapies can boost the immunotherapeutic approach, overcoming factors that are with imminent potential risks related to it, thereby significantly improving the survival rate associated with it in cancer patients. Nanotechnology is anticipated to overcome the confines of existing cancer immunotherapy and to successfully combine various cancer treatment modes.

Hyperthermia based individual in situ recombinant vaccine enhances lymph nodes drainage for de novo antitumor immunity

The continuing challenges that limit effectiveness of tumor therapeutic vaccines were high heterogeneity of tumor immunogenicity, low bioactivity of antigens, as well as insufficient lymph nodes (LNs) drainage of antigens and adjuvants. Transportation of in situ neoantigens and adjuvants to LNs may be an effective approach to solve the abovementioned problems. Therefore, an FA-TSL/AuNCs/SV nanoplatform was constructed by integrating simvastatin (SV) adjuvant loaded Au nanocages (AuNCs) as cores (AuNCs/SV) and folic acid modified thermal-sensitive liposomes (FA-TSL) as shells to enhance de novo antitumor immunity. After accumulation in tumor guided by FA, AuNCs mediated photothermal therapy (PTT) induced the release of tumor-derived protein antigens (TDPAs) and the shedding of FA-TSL. Exposed AuNCs/SV soon captured TDPAs to form in situ recombinant vaccine (AuNCs/SV/TDPAs). Subsequently, AuNCs/SV/TDPAs could efficiently transport to draining LNs owing to the hyperthermia induced vasodilation effect and small particle size, achieving co-delivery of antigens and adjuvant for initiation of specific T cell response. In melanoma bearing mice, FA-TSL/AuNCs/SV and laser irradiation effectively ablated primary tumor, against metastatic tumors and induced immunological memory. This approach served a hyperthermia enhanced platform drainage to enable robust personalized cancer vaccination.

Lenvatinib- and vadimezan-loaded synthetic high-density lipoprotein for combinational immunochemotherapy of metastatic triple-negative breast cancer

Metastatic triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer. Combination of systemic chemotherapy and immune checkpoint blockade is effective but of limited benefit due to insufficient intratumoral infiltration of cytotoxic T lymphocytes (CTLs) and the accumulation of immunosuppressive cells. Herein, we designed a lenvatinib- and vadimezan-loaded synthetic high-density lipoprotein (LV-sHDL) for combinational immunochemotherapy of metastatic TNBC. The LV-sHDL targeted scavenger receptor class B type 1-overexpressing 4T1 cells in the tumor after intravenous injection. The multitargeted tyrosine kinase inhibitor (TKI) lenvatinib induced immunogenic cell death of the cancer cells, and the stimulator of interferon genes (STING) agonist vadimezan triggered local inflammation to facilitate dendritic cell maturation and antitumor macrophage differentiation, which synergistically improved the intratumoral infiltration of total and active CTLs by 33- and 13-fold, respectively. LV-sHDL inhibited the growth of orthotopic 4T1 tumors, reduced pulmonary metastasis, and prolonged the survival of animals. The efficacy could be further improved when LV-sHDL was used in combination with antibody against programmed cell death ligand 1. This study highlights the combination use of multitargeted TKI and STING agonist a promising treatment for metastatic TNBC.

Lipid-Based Nanoparticles for Targeted Delivery of the Anti-Cancer Drugs: A Review

Abstract:

Cancer is one of the main reasons for mortality worldwide. Chemotherapeutic agents have been effectively designed to increase certain patients' survival rates, but ordinarily designed chemotherapeutic agents necessarily deliver toxic chemotherapeutic drugs to healthy tissues, resulting in serious side effects. Cancer cells can often acquire drug resistance after repeated dosing of current chemotherapeutic agents, restricting their efficacy. Given such obstacles, investigators have attempted to distribute chemotherapeutic agents using targeted drug delivery systems (DDSs), especially nanotechnology-based DDSs. Lipid-Based Nanoparticles (LBNPs) are a large and complex class of substances that have been utilized to manage a variety of diseases, mostly cancer. Liposomes seem to be the most frequently employed LBNPs, owing to their high biocompatibility, bioactivity, stability, and flexibility; howbeit Solid Lipid Nanoparticles (SLNs) and Non-structured Lipid Carriers (NLCs) have lately received a lot of interest. Besides that, there are several reports that concentrate on novel therapies via LBNPs to manage various forms of cancer. In the present research, the latest improvements in the application of LBNPs have been shown to deliver different therapeutic agents to cancerous cells and have been demonstrated LBNPs also can be a quite successful candidate in cancer therapy for subsequent use.

Polysaccharide-based nanomedicines for cancer immunotherapy: A review

Cancer immunotherapy is an effective antitumor approach through activating immune systems to eradicate tumors by immunotherapeutics. However, direct administration of "naked" immunotherapeutic agents (such as nucleic acids, cytokines, adjuvants or antigens without delivery vehicles) often results in: (1) an unsatisfactory efficacy due to suboptimal pharmacokinetics; (2) strong toxic and side effects due to low targeting (or off-target) efficiency. To overcome these shortcomings, a series of polysaccharide-based nanoparticles have been developed to carry immunotherapeutics to enhance antitumor immune responses with reduced toxicity and side effects. Polysaccharides are a family of natural polymers that hold unique physicochemical and biological properties, as they could interact with immune system to stimulate an enhanced immune response. Their structures offer versatility in synthesizing multifunctional nanocomposites, which could be chemically modified to achieve high stability and bioavailability for delivering therapeutics into tumor tissues. This review aims to highlight recent advances in polysaccharide-based nanomedicines for cancer immunotherapy and propose new perspectives on the use of polysaccharide-based immunotherapeutics.

Anti-PD-L1 mediating tumor-targeted codelivery of liposomal irinotecan/JQ1 for chemo-immunotherapy

Immune checkpoint blockade therapy has become a first-line treatment in various cancers. But there are only a small percent of colorectal patients responding to PD-1/PD-L1 blockage immunotherapy. How to increase their treatment efficacy is an urgent and clinically unmet need. It is acknowledged that immunogenic cell death (ICD) induced by some specific chemotherapy can enhance antitumor immunity. Chemo-based combination therapy can yield improved outcomes by activating the immune system to eliminate the tumor, compared with monotherapy. Here, we develop a PD-L1-targeting immune liposome (P-Lipo) for co-delivering irinotecan (IRI) and JQ1, and this system can successfully elicit antitumor immunity in colorectal cancer through inducing ICD by IRI and interfering in the immunosuppressive PD-1/PD-L1 pathway by JQ1. P-Lipo increases intratumoral drug accumulation and promotes DC maturation, and thereby facilitates adaptive immune responses against tumor growth. The remodeling tumor immune microenvironment was reflected by the increased amount of CD8⁺ T cells and the release of IFN-γ, and the reduced CD4⁺Foxp3⁺ regulatory T cells (Tregs). Collectively, the P-Lipo codelivery system provides a chemo-immunotherapy strategy that can effectively remodel the tumor immune microenvironment and activate the host immune system and arrest tumor growth.

Chemotherapeutic potency stimulated by SNAI1-knockdown based on multifaceted nanomedicine

Molecular insights into tumorigenesis have uncovered intimate correlation of SNAI1 with tumor malignancy. Herein, to explore merits of SNAI1-knockdown in tumor therapy, we harnessed RNA interference tool (shSNAI1), together with chemotherapeutic doxorubicin. Owing to abundant hydroxyl groups, pullulan was attempted to be covalently conjugated with a multiple of functional moieties, including positively-charged oligoethylenimine components for electrostatic entrapment of polyanionic shSNAI1 and hydrophobic components for entrapment of lipophilic doxorubicin. Notably, the aforementioned covalent conjugations were tailored to be detachable in response to intracellular reducing microenvironment owing to redox disulfide linkage, thereby accounting for selective intracellular liberation of the therapeutic payloads. Moreover, the surface of nanomedicine was modified with hyaluronic acid, endowing not only excellent biocompatibilities but active tumor-targeting function due to its receptors (CD44) overexpressed on tumor cells. Subsequent investigations approved appreciably targeted co-delivery of shSNAI1 and doxorubicin into solid lung tumors via systemic administration and demonstrated critical contribution of SNAI1-knockdown in amplifying chemotherapeutic potencies.

In situ injection of dual-delivery PEG based MMP-2 sensitive hydrogels for enhanced tumor penetration and chemo-immune combination therapy

Improving the deep penetration of nanoparticles and realizing the combination of chemotherapy and immunotherapy have become a promising strategy for cancer treatment. Herein, a nuclear-targeted tetrahedral DNA nanostructure (NLS-TDNs, NT) was synthesized to construct matrix metalloproteinase (MMP-2) sensitive hydrogels as delivery vehicles with co-loaded disulfide cross-linked polyethyleneimine (PSP)/nuclear-targeted tetrahedral DNA (NLS-TDNs, NT)/doxorubicin (DOX) nanoparticles (NPs) (PSP/NT/DOX NPs and PNT/DOX NPs) and an immune adjuvant imiquimod (R837) to realize a combination of chemotherapy and immunization for metastatic breast cancer. Due to the membrane-breaking ability of the PNT/DOX NPs, the nanoparticles could effectively achieve deep penetration into tumor tissues, and the in situ generation of tumor-associated antigens by PNT/DOX elicited a strong immune response in the presence of R837, achieving a chemo-immune combination therapy of breast cancer, inducing the maturation of dendritic cells (DCs) and secretion of related cytokines, such as interleukin-6 (IL-6), interleukin-12 (IL-12p70) and tumor necrosis factor (TNF-α) in vitro. The combination significantly promoted the proportions of cytotoxic T cells (CD8+ CTL) and cytotoxic T cells/regulatory T cells (CD8+ CTL/Treg) (5.52% and 11.46%, respectively) and the secretion of cytokines, which cooperatively eradicated primary tumor growth (the tumor growth inhibition (TGI) value was 78.3%) and inhibited the tumor from metastasizing effectively in vivo. Our study provided the basis for activating the antitumor immune system to realize chemo-immunotherapy and tumor metastasis therapy.

Novel decorated nanostructured lipid carrier for simultaneous active targeting of three anti-cancer agents

Cancer-targeted co-delivery of therapeutic agents has been recognized as an effective strategy for increasing efficacy and reducing side effects of therapeutic agents. In this study, we used methotrexate (MTX) alone as a targeting moiety and chemotherapeutic agent and in combination with docetaxel (DTX) and doxorubicin (DOX) as chemotherapeutic agents to stop cancer cell proliferation with the aid of newly designed nanostructured lipid carriers (NLCs). The physicochemical properties of our designed nanocomplexes were evaluated by DLS, FT-IR spectroscopy, SEM, and TEM. Moreover, the targeting efficiency of the designed and synthesized nanoplatforms was evaluated on the folate receptor (FR) positive human breast cancer cell line (MCF-7) and FR negative human alveolar basal epithelial cells (A549). The NLCs/DTX/DOX/CS and NLCs/DTX/DOX/CS-MTX complexes significantly increased the cell cytotoxicity and the cell apoptosis rate. However, the complexes significantly reduced the capability of colony formation and cell migration. Our results revealed that NLCs/DTX/DOX/CS-MTX had synergistic cytotoxicity, reactive oxygen spaces, autophagy, and the apoptosis induction ability with an enhanced cellular internalization rate in FR-positive cancer cells, thorough MTX recognition capability. We conclude that the NLCs/DTX/DOX/CS-MTX complex is a new promising paradigm for breast cancer-targeted co-delivery.

PD1 blockade potentiates the therapeutic efficacy of photothermally-activated and MRI-guided low temperature-sensitive magnetoliposomes

This study investigates the effect of PD1 blockade on the therapeutic efficacy of novel doxorubicin-loaded temperature-sensitive liposomes. Herein, we report photothermally-activated, low temperature-sensitive magnetoliposomes (mLTSL) for efficient drug delivery and magnetic resonance imaging (MRI). The mLTSL were prepared by embedding small nitrodopamine palmitate (NDPM)-coated iron oxide nanoparticles (IO NPs) in the lipid bilayer of low temperature-sensitive liposomes (LTSL), using lipid film hydration and extrusion. Doxorubicin (DOX)-loaded mLTSL were characterized using dynamic light scattering, differential scanning calorimetry, electron microscopy, spectrofluorimetry, and atomic absorption spectroscopy. Photothermal experiments using 808 nm laser irradiation were conducted. In vitro photothermal DOX release studies and cytotoxicity was assessed using flow cytometry and resazurin viability assay, respectively. In vivo DOX release and tumor accumulation of mLTSL(DOX) were assessed using fluorescence and MR imaging, respectively. Finally, the therapeutic efficacy of PD1 blockade in combination with photothermally-activated mLTSL(DOX) in CT26-tumor model was evaluated by monitoring tumor growth, cytokine release and immune cell infiltration in the tumor tissue. Interestingly, efficient photothermal heating was obtained by varying the IO NPs content and the laser power, where on-demand burst DOX release was achievable in vitro and in vivo. Moreover, our mLTSL exhibited promising MR imaging properties with high transverse r₂ relaxivity (333 mM^-1 s^-1), resulting in superior MR imaging in vivo. Furthermore, mLTSL(DOX) therapeutic efficacy was potentiated in combination with anti-PD1 mAb, resulting in a significant reduction in CT26 tumor growth via immune cell activation. Our study highlights the potential of combining PD1 blockade with mLTSL(DOX), where the latter could facilitate chemo/photothermal therapy and MRI-guided drug delivery.

Self-assembled nanomedicine combining a berberine derivative and doxorubicin for enhanced antitumor and antimetastatic efficacy via mitochondrial pathways

Mitochondria play a central role in cancer progression and tumor metastasis, and nanomedicines targeting mitochondria have emerged as a promising strategy for tumor therapy. However, mitochondria targeting strategies have not been widely explored in the inhibition of tumor metastasis, and they have disadvantages of complicated preparation, low drug loading, systemic toxicity of the carriers and poor accumulation at tumor sites. Here we firstly developed self-assembled nanodrugs with a high drug loading (∼68%) comprised of a berberine derivative (Ber) and doxorubicin (Dox) by a simple nano-precipitation method, which successfully altered the target location of Dox from the nucleus to mitochondria and therefore inhibited the proliferation, invasion and migration of MDA-MB-231 cells by triggering cell apoptosis. The surface of nanodrugs was modified with DSPE-PEG-folic acid (DSPE-PEG-FA) and hyaluronic acid (HA) for precise tumor recognition and enhanced accumulation (HA-FA-BD NDs). Upon arrival at the tumor site with the help of the enhanced permeability and retention (EPR) effect, the partial degradation of HA by hyaluronidase (HAase) at the tumor site allowed the partial exposure of the positively charged FA-BD NDs to the cells, then nanodrugs would accumulate and enter tumor cells by dual binding to both folic acid (FA) and CD-44 receptors. Once internalized into lysosomes, both the HA outer shell and DSPE-PEG-FA of nanodrugs were degraded or decomposed completely to expose positively charged BD NDs. Driven by delocalized lipophilic cations, nanodrugs could escape from lysosomes and reach mitochondria to induce a cascade reaction and finally cell apoptosis, as well as suppressing matrix metalloprotease (MMP)-2 and -9 activities and finally cell migration and invasion. In a xenograft mice model of MDA-MB-231 breast cancer cells, the nanodrugs repaired the defects in Mfn 1/Drp 1 mitochondrial proteins, suppressed the activity of MMP-2 and -9, and significantly inhibited tumor cell proliferation and pulmonary metastasis. Our study showed a promising strategy for the treatment of metastatic breast cancer by targeting mitochondria followed by enhanced apoptosis.

Abrogation of USP7 is an alternative strategy to downregulate PD-L1 and sensitize gastric cancer cells to T cells killing

Targeting immune checkpoints such as programmed cell death protein 1 (PD-1) and programmed death ligand-1 (PD-L1) have been approved for treating melanoma, gastric cancer (GC) and bladder cancer with clinical benefit. Nevertheless, many patients failed to respond to anti-PD-1/PD-L1 treatment, so it is necessary to seek an alternative strategy for traditional PD-1/PD-L1 targeting immunotherapy. Here with the data from The Cancer Genome Atlas (TCGA) and our in-house tissue library, PD-L1 expression was found to be positively correlated with the expression of ubiquitin-specific processing protease 7 (USP7) in GC. Furthermore, USP7 directly interacted with PD-L1 in order to stabilize it, while abrogation of USP7 attenuated PD-L1/PD-1 interaction and sensitized cancer cells to T cell killing in vitro and in vivo. Besides, USP7 inhibitor suppressed GC cells proliferation by stabilizing P53 in vitro and in vivo. Collectively, our findings indicate that in addition to inhibiting cancer cells proliferation, USP7 inhibitor can also downregulate PD-L1 expression to enhance anti-tumor immune response simultaneously. Hence, these data posit USP7 inhibitor as an anti-proliferation agent as well as a novel therapeutic agent in PD-L1/PD-1 blockade strategy that can promote the immune response of the tumor.

Engineered Multifunctional Nano- and Biological Materials for Cancer Immunotherapy

Cancer immunotherapy is set to emerge as the future of cancer therapy. However, recent immunotherapy trials in different cancers have yielded sub-optimal results, with durable responses seen in only a small fraction of patients. Engineered multifunctional nanomaterials and biological materials are versatile platforms that can elicit strong immune responses and improve anti-cancer efficacy when applied to cancer immunotherapy. While there are traditional systems such as polymer- and lipid-based nanoparticles, there is a wide variety of other materials with inherent and additive properties that can allow for more potent activation of the immune system. By synthesizing and applying multifunctional strategies, it allows for a more extensive and more effective repertoire of tools to use in the wide variety of situations that cancer presents itself. Here, several types of nanoscale and biological material strategies and platforms that provide their inherent benefits for targeting and activating multiple aspects of the immune system are discussed. Overall, this review aims to provide a comprehensive understanding of recent advances in the field of multifunctional cancer immunotherapy and trends that pave the way for more diverse and tactical regression of tumors through soliciting responses by either the adaptive or innate immune system, and even both simultaneously.

Polymeric Micelles in Cancer Immunotherapy

Cancer immunotherapies have generated some miracles in the clinic by orchestrating our immune system to combat cancer cells. However, the safety and efficacy concerns of the systemic delivery of these immunostimulatory agents has limited their application. Nanomedicine-based delivery strategies (e.g., liposomes, polymeric nanoparticles, silico, etc.) play an essential role in improving cancer immunotherapies, either by enhancing the anti-tumor immune response, or reducing their systemic adverse effects. The versatility of working with biocompatible polymers helps these polymeric nanoparticles stand out as a key carrier to improve bioavailability and achieve specific delivery at the site of action. This review provides a summary of the latest advancements in the use of polymeric micelles for cancer immunotherapy, including their application in delivering immunological checkpoint inhibitors, immunostimulatory molecules, engineered T cells, and cancer vaccines.

Cancer-associated-platelet-inspired nanomedicines for cancer therapy

Platelets, with hemostasis and thrombosis activities, are one of the key components in the blood circulation. As a guard, they rapidly respond to any abnormal blood vessel injury signal and release their granules' contents, which induce their adhesion and aggregation on wound site for hemostasis. Recently, increasing evidence has indicated that platelets are critically involved in the growth and metastasis of cancer cells by releasing a variety of cytokines and chemokines to stimulate cancer cell proliferation and various angiogenic regulators to accelerate tumor angiogenesis. Platelets also secrete active transforming growth factor beta (TGF-β) to promote the epithelial-mesenchymal transition of cancer cells and their extravasation from primary site, and form microthrombus on the surface of cancer cells to protect them from immune attack and high-speed shear force in the circulation. Therefore, blocking platelet-cancer cell interaction may be an attractive strategy to treat primary tumor and/or prevent cancer metastasis. However, systemic inhibition or depletion of platelets brings risk of severe bleeding complication. Cancer-associated-platelets-targeted nanomedicines and biomimetic nanomedicines coated with platelet membrane can be used for targeted anticancer drug delivery, due to their natural targeting ability to tumor cells and platelets. In the current review, we first summarized the platelet mechanisms of action in physiological condition and their multiple roles in cancer progression and conventional antiplatelet therapeutics. We then highlighted the recent progress on the design and fabrication of cancer-associated-platelet-targeted nanomedicines and platelet membrane coating nanomedicines for cancer therapy. Finally, we discussed opportunities and challenges and offered our thoughts for the future development. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures.

Emerging nanomedicines for effective breast cancer immunotherapy

Breast cancer continues to be the most frequently diagnosed malignancy among women, putting their life in jeopardy. Cancer immunotherapy is a novel approach with the ability to boost the host immune system to recognize and eradicate cancer cells with high selectivity. As a promising treatment, immunotherapy can not only eliminate the primary tumors, but also be proven to be effective in impeding metastasis and recurrence. However, the clinical application of cancer immunotherapy has faced some limitations including generating weak immune responses due to inadequate delivery of immunostimulants to the immune cells as well as uncontrolled modulation of immune system, which can give rise to autoimmunity and nonspecific inflammation. Growing evidence has suggested that nanotechnology may meet the needs of current cancer immunotherapy. Advanced biomaterials such as nanoparticles afford a unique opportunity to maximize the efficiency of immunotherapy and significantly diminish their toxic side-effects. Here we discuss recent advancements that have been made in nanoparticle-involving breast cancer immunotherapy, varying from direct activation of immune systems through the delivery of tumor antigens and adjuvants to immune cells to altering immunosuppression of tumor environment and combination with other conventional therapies.

Clinical implication of cellular vaccine in glioma: current advances and future prospects

Gliomas, especially glioblastomas, represent one of the most aggressive and difficult-to-treat human brain tumors. In the last few decades, clinical immunotherapy has been developed and has provided exceptional achievements in checkpoint inhibitors and vaccines for cancer treatment. Immunization with cellular vaccines has the advantage of containing specific antigens and acceptable safety to potentially improve cancer therapy. Based on T cells, dendritic cells (DC), tumor cells and natural killer cells, the safety and feasibility of cellular vaccines have been validated in clinical trials for glioma treatment. For TAA engineered T cells, therapy mainly uses chimeric antigen receptors (IL13Rα2, EGFRvIII and HER2) and DNA methylation-induced technology (CT antigen) to activate the immune response. Autologous dendritic cells/tumor antigen vaccine (ADCTA) pulsed with tumor lysate and peptides elicit antigen-specific and cytotoxic T cell responses in patients with malignant gliomas, while its pro-survival effect is biased. Vaccinations using autologous tumor cells modified with TAAs or fusion with fibroblast cells are characterized by both effective humoral and cell-mediated immunity. Even though few therapeutic effects have been observed, most of this therapy showed safety and feasibility, asking for larger cohort studies and better guidelines to optimize cellular vaccine efficiency in anti-glioma therapy.

Adverse Effects of Anti-PD-1/PD-L1 Therapy in Non-small Cell Lung Cancer

Currently, immunotherapy has shown great efficacy in clinical trials, and monoclonal antibodies directed against immune checkpoint PD-1/PD-L1 have shown encouraging results in first-line or second-line treatment of non-small cell lung cancer patients. Meanwhile, anti-PD-1/PD-L1 immune checkpoint drugs combined with other treatments, such as chemotherapy, targeted therapy as well as anti-CTLA-4 checkpoint therapy, are considered an attractive treatment with higher efficacy. However, toxicity associated with PD-1/PD-L1 blockade is worth attention. Understanding the adverse effects caused by anti-PD-1/PD-L1 immunosuppressive agents is vital to guide the clinical rational use of drug. In this review, we summarized the adverse effects that occurred during the clinical use of anti-PD-1/PD-L1 inhibitors in the treatment of non-small cell lung cancer and discussed how to effectively manage and respond to these adverse reactions.

Recent progress of hypoxia-modulated multifunctional nanomedicines to enhance photodynamic therapy: opportunities, challenges, and future development

Hypoxia, a salient feature of most solid tumors, confers invasiveness and resistance to the tumor cells. Oxygen-consumption photodynamic therapy (PDT) suffers from the undesirable impediment of local hypoxia in tumors. Moreover, PDT could further worsen hypoxia. Therefore, developing effective strategies for manipulating hypoxia and improving the effectiveness of PDT has been a focus on antitumor treatment. In this review, the mechanism and relationship of tumor hypoxia and PDT are discussed. Moreover, we highlight recent trends in the field of nanomedicines to modulate hypoxia for enhancing PDT, such as oxygen supply systems, down-regulation of oxygen consumption and hypoxia utilization. Finally, the opportunities and challenges are put forward to facilitate the development and clinical transformation of PDT.

A Review on Nano-Based Drug Delivery System for Cancer Chemoimmunotherapy

Although notable progress has been made on novel cancer treatments, the overall survival rate and therapeutic effects are still unsatisfactory for cancer patients. Chemoimmunotherapy, combining chemotherapeutics and immunotherapeutic drugs, has emerged as a promising approach for cancer treatment, with the advantages of cooperating two kinds of treatment mechanism, reducing the dosage of the drug and enhancing therapeutic effect. Moreover, nano-based drug delivery system (NDDS) was applied to encapsulate chemotherapeutic agents and exhibited outstanding properties such as targeted delivery, tumor microenvironment response and site-specific release. Several nanocarriers have been approved in clinical cancer chemotherapy and showed significant improvement in therapeutic efficiency compared with traditional formulations, such as liposomes (Doxil®, Lipusu®), nanoparticles (Abraxane®) and micelles (Genexol-PM®). The applications of NDDS to chemoimmunotherapy would be a powerful strategy for future cancer treatment, which could greatly enhance the therapeutic efficacy, reduce the side effects and optimize the clinical outcomes of cancer patients. Herein, the current approaches of cancer immunotherapy and chemoimmunotherapy were discussed, and recent advances of NDDS applied for chemoimmunotherapy were further reviewed.

Enhanced anti-tumor and anti-metastasis therapy for triple negative breast cancer by CD44 receptor-targeted hybrid self-delivery micelles

Tumor growth and metastasis are multistep processes regulated by multiple signaling pathways. The successful treatment of cancer largely depends on the ability to inhibit metastatic process. Multiphase inhibition of metastasis is a promising approach. Here, we described a targeting delivery system which was constructed by mixing hyaluronic acid-d-α-tocopheryl succinate (HA-TOS, HT) and low molecular weight heparin-TOS (LMWH-TOS, LT) to form a stable hybrid micelle (HT-LT), encapsulating chemotherapeutic drug doxorubicin (DOX). The prepared HT-LT NPs was about 125 nm in diameter with high drug encapsulation rate and continuous drug release behavior. We confirmed that HT-LT NPs exhibited an effective targeting ability both in vitro and in vivo using a 4T1 model that was attributed to HA binding to CD44 receptors. In addition, HT-LT NPs acted on different phases of the invasion-metastasis cascade and inhibited tumor cell migration and invasion, thus inhibiting tumor metastasis. This combinatorial strategy provided an alternative approach for triple negative breast cancer therapy.

Cancer Metastasis: The Role of the Extracellular Matrix and the Heparan Sulfate Proteoglycan Perlecan

Cancer metastasis is the dissemination of tumor cells to new sites, resulting in the formation of secondary tumors. This process is complex and is spatially and temporally regulated by intrinsic and extrinsic factors. One important extrinsic factor is the extracellular matrix, the non-cellular component of tissues. Heparan sulfate proteoglycans (HSPGs) are constituents of the extracellular matrix, and through their heparan sulfate chains and protein core, modulate multiple events that occur during the metastatic cascade. This review will provide an overview of the role of the extracellular matrix in the events that occur during cancer metastasis, primarily focusing on perlecan. Perlecan, a basement membrane HSPG is a key component of the vascular extracellular matrix and is commonly associated with events that occur during the metastatic cascade. Its contradictory role in these events will be discussed and we will highlight the recent advances in cancer therapies that target HSPGs and their modifying enzymes.

Autophagy Modulators: Mechanistic Aspects and Drug Delivery Systems

Autophagy modulation is considered to be a promising programmed cell death mechanism to prevent and cure a great number of disorders and diseases. The crucial step in designing an effective therapeutic approach is to understand the correct and accurate causes of diseases and to understand whether autophagy plays a cytoprotective or cytotoxic/cytostatic role in the progression and prevention of disease. This knowledge will help scientists find approaches to manipulate tumor and pathologic cells in order to enhance cellular sensitivity to therapeutics and treat them. Although some conventional therapeutics suffer from poor solubility, bioavailability and controlled release mechanisms, it appears that novel nanoplatforms overcome these obstacles and have led to the design of a theranostic-controlled drug release system with high solubility and active targeting and stimuli-responsive potentials. In this review, we discuss autophagy modulators-related signaling pathways and some of the drug delivery strategies that have been applied to the field of therapeutic application of autophagy modulators. Moreover, we describe how therapeutics will target various steps of the autophagic machinery. Furthermore, nano drug delivery platforms for autophagy targeting and co-delivery of autophagy modulators with chemotherapeutics/siRNA, are also discussed.