Nano-delivery of fraxinellone remodels tumor microenvironment and facilitates therapeutic vaccination in desmoplastic melanoma

Tanshinone IIA Liposomes Treat Doxorubicin-Induced Glomerulonephritis by Modulating the Microenvironment of Fibrotic Kidneys

Renal fibrosis plays a key role in the pathogenesis of chronic kidney disease (CKD), in which the persistent high expression of transforming growth factor β1 (TGF-β1) and α-smooth muscle actin (α-SMA) contributes to the progression of CKD to renal failure. In order to improve the solubility, bioavailability, and targeting of tanshinone IIA (Tan IIA), a novel targeting material, aminoethyl anisamide-polyethylene glycol-1,2-distearoyl-sn-glycero-3-phosphate ethanolamine (AEAA-PEG-DSPE, APD) modified Tan IIA liposomes (APD-Tan IIA-L) was constructed. An animal model of glomerulonephritis induced by doxorubicin in BALB/c mice was established. APD-Tan IIA-L significantly decreased blood urea nitrogen and serum creatinine (SCr), and the consequences of renal tissue oxidative stress indicators showed that APD-Tan IIA-L downregulated malondialdehyde, upregulated superoxide dismutase, catalase, and glutathione peroxidase. Masson's trichrome staining showed that the deposition of collagen in the APD-Tan IIA-L group decreased significantly. The pro-fibrotic factors (fibronectin, collagen I, TGF-β1, and α-SMA) and epithelial-mesenchymal transition marker (N-cadherin) were significantly inhibited by APD-Tan IIA-L. By improving the microenvironment of fibrotic kidneys, APD-Tan IIA-L attenuated TGF-β1-induced excessive proliferation of fibroblasts and alleviated oxidative stress damage to the kidney, providing a new strategy for the clinical treatment of renal fibrosis.

Cell Membrane Hybrid Lipid Nanovesicles Enhance Innate Immunity for Synergistic Immunotherapy by Promoting Immunogenic Cell Death and cGAS Activation

Immunotherapy shows great therapeutic potential for long-term protection against tumor relapse and metastasis. Innate immune sensors, such as cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING), dissolve DNA and induce type I interferon. Through activation of the cGAS/STING pathway, chemotherapy drugs and reversine (REV) may provide synergetic anti-tumor effects. Here, we prepared drug-loaded cell membrane hybrid lipid nanovesicles (LEVs) (designated LEV@DOX@REV) by fusion of cell membranes, phospholipids, doxorubicin (DOX), and REV, to realize accurate delivery to tumors and chemo-immunotherapy. The cell membranes of LEVs confer "homing" abilities. DOX can induce immunogenic cell death as a result of its specific immunomodulatory effects, which promotes the maturation of immune cells and improves the microenvironment of the immune system. REV is proven to efficiently activate cGAS/STING signaling, thereby enhancing the immune system. The antitumor efficacy of LEV@DOX@REV was evaluated in a 4T1 subcutaneous tumor xenograft model, a distant metastatic tumor model, and a liver metastatic tumor model. LEV@DOX@REV facilitated the infiltration of cytotoxic T lymphocytes within tumors, increased the secretion of proinflammatory cytokines, and modified the tumor microenvironment. In conclusion, LEV@DOX@REV displayed favorable antitumor effects and extended the survival of tumor-bearing mice. We therefore successfully developed nanoparticles capable of enhancing immune activation that have potential therapeutic applications for cancer immunotherapy.

The Application of Nanoparticles Targeting Cancer-Associated Fibroblasts

Cancer-associated fibroblasts (CAF) are the most abundant stromal cells in the tumor microenvironment (TME), especially in solid tumors. It has been confirmed that it can not only interact with tumor cells to promote cancer progression and metastasis, but also affect the infiltration and function of immune cells to induce chemotherapy and immunotherapy resistance. So, targeting CAF has been considered an important method in cancer treatment. The rapid development of nanotechnology provides a good perspective to improve the efficiency of targeting CAF. At present, more and more researches have focused on the application of nanoparticles (NPs) in targeting CAF. These studies explored the effects of different types of NPs on CAF and the multifunctional nanomedicines that can eliminate CAF are able to enhance the EPR effect which facilitate the anti-tumor effect of themselves. There also exist amounts of studies focusing on using NPs to inhibit the activation and function of CAF to improve the therapeutic efficacy. The application of NPs targeting CAF needs to be based on an understanding of CAF biology. Therefore, in this review, we first summarized the latest progress of CAF biology, then discussed the types of CAF-targeting NPs and the main strategies in the current. The aim is to elucidate the application of NPs in targeting CAF and provide new insights for engineering nanomedicine to enhance immune response in cancer treatment.

Tumor microenvironment reprogramming combined with immunogenic enhancement by nanoemulsions potentiates immunotherapy

The combination of immune checkpoint inhibitors and immunogenic cell death (ICD) inducers has become a promising strategy for the treatment of various cancers. However, its efficacy remains unmet because of the dense stroma and defective vasculatures in the tumor microenvironment (TME) that restricts the intratumoral infiltration of cytotoxic T lymphocytes (CTLs). Herein, cancer-associated fibroblasts (CAFs)-targeted nanoemulsions are tailored to combine the ICD induction and the TME reprogramming to sensitize checkpoint blockade immunotherapy. Melittin, as an ICD inducer and an antifibrotic agent, is efficiently encapsulated into the nanoemulsion accompanied by a nitric oxide donor to improve its bioavailability and tumor targeting. The nanoemulsions exhibited dual functionality by directly inducing direct cancer cell death and enhancing the tumoral immunogenicity, while also synergistically reprogramming the TME through reversing the activated CAFs, decreasing collagen deposition and restoring tumor vessels. Consequently, these nanemulsions successfully facilitated the CTLs infiltration and suppressing the recruitment of immunosuppressive cells. A combination of AE-MGNPs and anti-CTLA-4 antibody greatly elicited a striking level of antitumor T-cell response to suppress tumor growth in CAFs-rich colorectal tumor models. Our work emphasized the integration of the ICD induction with simultaneous modulation of the TME to enhance the sensitivity of patients to checkpoint blockade immunotherapy.

Digital spatial proteomic profiling reveals immune checkpoints as biomarkers in lymphoid aggregates and tumor microenvironment of desmoplastic melanoma

BACKGROUND

Desmoplastic melanoma (DM) is a rare melanoma subtype characterized by dense fibrous stroma, a propensity for local recurrence, and a high response rate to programmed cell death protein 1 (PD-1) blockade. Occult sentinel lymph node positivity is significantly lower in both pure and mixed DM than in conventional melanoma, underscoring the need for better prognostic biomarkers to inform therapeutic strategies.

METHODS

We assembled a tissue microarray comprising various cores of tumor, stroma, and lymphoid aggregates from 45 patients with histologically confirmed DM diagnosed between 1989 and 2018. Using a panel of 62 validated immune-oncology markers, we performed digital spatial profiling using the NanoString GeoMx platform and quantified expression in three tissue compartments defined by fluorescence colocalization (tumor (S100+/PMEL+/SYTO+), leukocytes (CD45+/SYTO+), and non-immune stroma (S100-/PMEL-/CD45-/SYTO+)).

RESULTS

We observed higher expression of immune checkpoints (lymphocyte-activation gene 3 [LAG-3] and cytotoxic T-lymphocyte associated protein-4 [CTLA-4]) and cancer-associated fibroblast (CAF) markers (smooth muscle actin (SMA)) in the tumor compartments of pure DMs than mixed DMs. When comparing lymphoid aggregates (LA) to non-LA tumor cores, LAs were more enriched with CD20+B cells, but non-LA intratumoral leukocytes were more enriched with macrophage/monocytic markers (CD163, CD68, CD14) and had higher LAG-3 and CTLA-4 expression levels. Higher intratumoral PD-1 and LA-based LAG-3 expression appear to be associated with worse survival.

CONCLUSIONS

Our proteomic analysis reveals an intra-tumoral population of SMA+CAFs enriched in pure DM. Additionally, increased expressions of immune checkpoints (LAG-3 and PD-1) in LA and within tumor were associated with poorer prognosis. These findings might have therapeutic implications and help guide treatment selection in addition to informing potential prognostic significance.

NK cell-based tumor immunotherapy

Natural killer (NK) cells display a unique inherent ability to identify and eliminate virus-infected cells and tumor cells. They are particularly powerful for elimination of hematological cancers, and have attracted considerable interests for therapy of solid tumors. However, the treatment of solid tumors with NK cells are less effective, which can be attributed to the very complicated immunosuppressive microenvironment that may lead to the inactivation, insufficient expansion, short life, and the poor tumor infiltration of NK cells. Fortunately, the development of advanced nanotechnology has provided potential solutions to these issues, and could improve the immunotherapy efficacy of NK cells. In this review, we summarize the activation and inhibition mechanisms of NK cells in solid tumors, and the recent advances in NK cell-based tumor immunotherapy boosted by diverse nanomaterials. We also propose the challenges and opportunities for the clinical application of NK cell-based tumor immunotherapy.

Tumor Environment Regression Therapy Implemented by Switchable Prune-to-Essence Nanoplatform Unleashed Systemic Immune Responses

Coevolution of tumor cells and surrounding stroma results in protective protumoral environment, in which abundant vessel, stiff structure and immunosuppression promote each other, cooperatively incurring deterioration and treatment compromise. Reversing suchenvironment may transform tumors from treatment-resistant to treatment-vulnerable. However, effective reversion requires synergistic comprehensive regression of such environment under precise control. Here, the first attempt to collaboratively retrograde coevolutionary tumor environment to pre-oncogenesis status, defined as tumor environment regression therapy, is made for vigorous immune response eruption by a switchable prune-to-essence nanoplatform (Pres) with simplified composition and fabrication process. Through magnetic targeting and multimodal imaging of Pres, tumor environment regression therapy is guided, optimized and accomplished in a trinity way: Antiangiogenesis is executed to rarefy vessels to impede tumor progression. By seizing the time, cancer associated fibroblasts are eliminated to diminish collagen and loosen the stiff structure for deep penetration of Pres, which alternately functioned in deeper tumors, forming a positive feedback loop. Through this loop, immune cell infiltration, immunosuppression mitigation and immunogenic cells death induction are all fulfilled and further escalated in the regressed environment. These transformations consequently unleashed systemic immune responses and generated immune memory against carcinoma. This study provides new insights intotreatment of solid tumors.

Preparation and anti-tumor effects of mesoporous silica nanoparticles loaded with trifluoperazine

We have developed a targeted nano-drug delivery system that effectively harnesses the anti-tumor properties of trifluoperazine (TFP), while concurrently mitigating its side effects on the central nervous system. The manufacturing process entailed the preparation of mesoporous silica nanoparticles (MSN-NH2), followed by the loading of trifluoperazine into the pores of MSN-NH2 and then surface modification with polyethylene glycol (PEG) and anisamide (AA), resulting in the formation of TFP@MSN@PEG-AA (abbreviated as TMPA) nanoparticles. In vitro and in vivo anti-tumor activity and hemolysis experiments showed that TMPA had an excellent safety profile and a good anti-tumor effect. Importantly, the drug content of the TMPA nanoparticle group was found to be significantly lower than that of the TFP group in the mouse brain tissue as determined by High Performance Liquid Chromatography (HPLC) detection. Therefore, the developed drug delivery system achieved the goal of maintaining TFP's anti-tumor action while avoiding its negative effects on the central nervous system.

A critical review of the novelties in the development of intravenous nanoemulsions

Nanoemulsions have gained increasing attention in recent years as a drug delivery system due to their ability to improve the solubility and bioavailability of poorly water-soluble drugs. This systematic review aimed to collect and critically analyze recent novelties in developing, designing, and optimizing intravenous nanoemulsions appearing in articles published between 2017 and 2022. The applied methodology involved searching two electronic databases PubMed and Scopus, using the keyword "nanoemulsion" in combination with "intravenous" or "parenteral". The resulting original articles were classified by the method of preparation into different categories. An overview of the current methods used for the preparation of such formulations, including high- and low-energy emulsification, was provided. The advantages and disadvantages of these methods were discussed, as well as their potential impact on the properties of the developed intravenous nanoemulsions. The problem of inconsistency in intravenous nanoemulsion terminology may lead to misunderstandings and misinterpretations of their properties and applications was also undertaken. Finally, the regulatory aspects of intravenous nanoemulsions, the state of the art in the field of intravenous emulsifiers, and the future perspectives were presented.

Remodeling tumor immunosuppression with molecularly imprinted nanoparticles to enhance immunogenic cell death for cancer immunotherapy

Insufficient tumor accumulation and distribution of immunogenic cell death (ICD) inducer as well as low antitumor immunity severely restrict the therapeutic efficacy of tumor immunotherapy. Tumor associated fibroblasts (TAFs) are important in tumor extracellular matrix (ECM) remodeling and immune evasion. Reprogramming tumor immunosuppressive microenvironment via TAFs regulation might present a promising way for enhanced ICD effect and complete tumor elimination. In this study, TAFs derived tryptase imprinted nanoparticles (DMSN@MIPs) are developed to modulate TAFs and improve tumor immunotherapy effect of doxorubicin liposomes (DOX/LIP). Tryptase (TPS), secreted by mast cells, are found to support tumor growth via transcriptionally activating TAFs to an activated state with increased expression of fibroblast activation marker α-smooth muscle actin (α-SMA). DMSN@MIPs canbe used as artificial antibodies, which effectively neutralize TPS, reduce TAFs activation, promote intra-tumor penetration of DOX/LIP and enhance ICD effect induced by DOX/LIP. In addition, the combined administration system remodels immunosuppressive microenvironment, which not only significantly up-regulates immune cells (DC cells, CD8+T cells, NK cells), but also significantly down-regulates immunosuppressive cells (Treg cells, MDSCs cells). Our results support the DMSN@MIPs canbe a promising approach to improve ICD efficacy in cancer immunotherapy.

Nanomedicine Strategies for Targeting Tumor Stroma

The tumor stroma, or the microenvironment surrounding solid tumors, can significantly impact the effectiveness of cancer therapies. The tumor microenvironment is characterized by high interstitial pressure, a consequence of leaky vasculature, and dense stroma created by excessive deposition of various macromolecules such as collagen, fibronectin, and hyaluronic acid (HA). In addition, non-cancerous cells such as cancer-associated fibroblasts (CAFs) and the extracellular matrix (ECM) itself can promote tumor growth. In recent years, there has been increased interest in combining standard cancer treatments with stromal-targeting strategies or stromal modulators to improve therapeutic outcomes. Furthermore, the use of nanomedicine, which can improve the delivery and retention of drugs in the tumor, has been proposed to target the stroma. This review focuses on how different stromal components contribute to tumor progression and impede chemotherapeutic delivery. Additionally, this review highlights recent advancements in nanomedicine-based stromal modulation and discusses potential future directions for developing more effective stroma-targeted cancer therapies.

A new approach to overcoming resistance to immunotherapy: nanotechnology

Immunotherapy for immune response has ushered in a new era of cancer treatment. In recent years, new immunotherapeutic agents have been introduced into clinical trials and even approved for marketing. However, the widespread use of immunotherapeutic agents faces an unavoidable challenge: immunotherapy does not work at all for some patients, or has good efficacy in the initial phase, but immunotherapy resistance develops within a short period of time, and immunotherapy can also cause serious adverse effects such as autoimmune inflammation and non-specific inflammation. How to enable patients to overcome drug resistance, reduce the toxic side effects of drugs, enhance patient compliance and improve patient survival has become a problem that clinicians have to face. The advent of nanotechnology provides an encouraging platform for immunotherapy. It can not only improve the bioavailability and stability of drugs and reduce toxic side effects, but also reduce resistance to immunotherapy. Here, we discuss these research advances and discuss potential challenges and future directions.

Comparison of tumor-derived total RNA and cell lysate on antitumor immune activity

Tumor-derived total RNA (TdRNA) and cell lysate (TCL), with almost all the relevant tumor antigens, represent attractive alternative sources of antigens in antitumor immunotherapy. However, the comparison of their capacity to elicit immune responses against breast cancer is still lacking. In this study, the antitumor immune effects of TdRNA and TCL were systematically compared. We isolated TdRNA and TCL from 4T1 mouse breast cancer cells, and found that both sources of antigens could stimulate the maturation of dendritic cells (DCs) at the cellular and in vivo levels, and induce robust cellular immune responses, as evidenced by the increased percentages of both CD4⁺ and CD8⁺ T cells in the inguinal lymph nodes and spleen. But TdRNA performed stronger immunoactivities than TCL on the increase of T cell population through DCs activation. Additionally, the synergistic antitumor efficacy of paclitaxel (PTX) with TdRNA and TCL respectively was further evaluated in the murine 4T1 tumor model. Compared with TCL, TdRNA could inhibit tumor growth more effectively with low systemic toxicity when combined with PTX, which was, at least in part, attributable to the improvement of systemic immune function and tumor immune infiltration. Overall, TdRNA outperforms TCL in antitumor immunity, and is expected to be a promising candidate for application as the source of tumor antigens.

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.

Vibratome sectioning of tumors to evaluate the interactions between nanoparticles and the tumor microenvironment ex-vivo

Nanoparticles have been investigated as drug carriers and promising agents for cancer therapy. However, the tumor microenvironment (TME), which is formed by the tumor, is considered a barrier for nanocarriers to enter the internal tumor tissue. Therefore, the evaluation of the biological distribution of nanocarriers in TME can provide useful information on their role in tumor-targeted drug delivery. Although the tumor-bearing mouse model is commonly used to investigate the distribution of nanocarriers in the TME, there is currently a lack of a testing system to predict the distribution of nanocarriers in tumor tissues, especially in patients. This study revealed that the macrophages and dendritic cells (DCs) were more distributed in the peripheral part than the central part of the tumor, which might be an obstacle to the uniform distribution of nanoparticles in the tumor. In addition, the cellular uptake of gold nanoparticles (AuNR and AuNS) in macrophages and DCs cell lines (RAW264.7 and DC1.2) was markedly different from that in the TME. Hence, the study model of the interaction between nanoparticles and macrophages and DCs has an important impact on the accuracy of the results. The vibratome sections of tumor tissues preserved the spatial distribution of immune cells and tumor cells, and had very little effects on their morphologies and activities. More importantly, we found that the distribution of nanocarriers in vibratome sections was similar to that in tumors in vivo. In all, ex vivo analysis using vibratome sections of tumor tissues provides a more convenient and stable method for elucidating the influences of TME on the distribution of nanocarriers.

Nucleic acid strategies for infectious disease treatments: The nanoparticle-based oral delivery route

Therapies based on orally administrated nucleic acids have significant potential for the treatment of infectious diseases, including chronic inflammatory diseases such as inflammatory bowel disease (IBD)-associated with the gastrointestinal (GI) tract, and infectious and acute contagious diseases like coronavirus disease 2019 (COVID-19). This is because nucleic acids could precisely regulate susceptibility genes in regulating the pro- and anti-inflammatory cytokines expression related to the infections. Unfortunately, gene delivery remains a major hurdle due to multiple intracellular and extracellular barriers. This review thoroughly discusses the challenges of nanoparticle-based nucleic acid gene deliveries and strategies for overcoming delivery barriers to the inflammatory sites. Oral nucleic acid delivery case studies were also present as vital examples of applications in infectious diseases such as IBD and COVID-19.

Metformin reprograms tumor microenvironment and boosts chemoimmunotherapy in colorectal cancer

Tumor stroma plays an important role in the occurrence, development, and metastasis of colorectal cancer (CRC). The dense collagenous stroma forms a physical barrier for antitumor drugs and sustains a highly tumor immunosuppressive microenvironment. To address this issue, a spatiotemporal combination of antitumor stroma and nanoscale functional materials was used as an antitumor strategy for reprogramming the tumor immune microenvironment. In this combination, metformin hydrochloride (MET) was intraperitoneally injected to disrupt the dense tumor stroma for promoting drug delivery and remodeling the tumor immune microenvironment. Subsequently, intravenously injected multifunctional drug-delivery materials (MIL-100/mitoxantrone/hyaluronic acid nanoparticles, MMH NPs) were visualized by double imaging (photoacoustic (PA) and fluorescence imaging) and generated a robust immune response via immunogenic cell death (ICD). More importantly, the combination treatment also acted synergistically with the anti-OX40 agonist antibody (αOX40), which enhanced the treatment of orthotopic CRC. In summary, the combination strategy of MET/MMH NPs/αOX40 provides a novel and effective clinical option for CRC therapy.

Bioinspired soft nanovesicles for site-selective cancer imaging and targeted therapies

Cell-to-cell communication within the heterogeneous solid tumor environment plays a significant role in the uncontrolled metastasis of cancer. To inhibit the metastasis and growth of cancer cells, various chemically designed and biologically derived nanosized biomaterials have been applied for targeted cancer therapeutics applications. Over the years, bioinspired soft nanovesicles have gained tremendous attention for targeted cancer therapeutics due to their easy binding with tumor microenvironment, natural targeting ability, bio-responsive nature, better biocompatibility, high cargo capacity for multiple therapeutics agents, and long circulation time. These cell-derived nanovesicles guard their loaded cargo molecules from immune clearance and make them site-selective to cancer cells due to their natural binding and delivery abilities. Furthermore, bioinspired soft nanovesicles prevent cell-to-cell communication and secretion of cancer cell markers by delivering the therapeutics agents predominantly. Cell-derived vesicles, namely, exosomes, extracellular vesicles, and so forth have been recognized as versatile carriers for therapeutic biomolecules. However, low product yield, poor reproducibility, and uncontrolled particle size distribution have remained as major challenges of these soft nanovesicles. Furthermore, the surface biomarkers and molecular contents of these vesicles change with respect to the stage of disease and types. Here in this review, we have discussed numerous examples of bioinspired soft vesicles for targeted imaging and cancer therapeutic applications with their advantages and limitations. Importance of bioengineered soft nanovesicles for localized therapies with their clinical relevance has also been addressed in this article. Overall, cell-derived nanovesicles could be considered as clinically relevant platforms for cancer therapeutics. This article is categorized under: Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Nano-delivery of salvianolic acid B induces the quiescence of tumor-associated fibroblasts via interfering with TGF-β1/Smad signaling to facilitate chemo- and immunotherapy in desmoplastic tumor

As the key stromal cells that mediate the desmoplastic reaction, tumor-associated fibroblasts (TAFs) play a critical role in the limited nanoparticle penetration and suppressive immune tumor microenvironment. Herein, we found that salvianolic acid B-loaded PEGylated liposomes (PEG-SAB-Lip) can interfere with the activation of TAFs by inhibiting the secretion of TGF-β1. After inhibiting the activation of TAFs, collagen deposition in tumors was reduced, and the penetration of nanoparticles in tumors was enhanced. The results of RT-qPCR and immunofluorescence staining showed the high expression of Th1 cytokines and chemokines (CXCL9 and CXCL10) and the recruitment of CD4⁺, CD8⁺ T cells, and M1 macrophages in the tumor area. At the same time, the low expression of Th2 cytokine and chemokine CXCL13, as well as the decrease of MDSCs, Tregs, and M2 macrophages were also observed in the tumor area. These results were related to the inactivation of TAFs. The combined treatment of PEG-SAB-Lip and docetaxel-loaded PEG-modified liposomes (PEG-DTX-Lip) can significantly inhibit tumor growth. Moreover, PEG-SAB-Lip further inhibited tumor metastasis to the lung. Therefore, our results showed that PEG-SAB-Lip can remodel the tumor microenvironment and improve the efficacy of nanoparticles.

Hydrogen-Bonds Mediated Nanomedicine: Design, Synthesis and Applications

Among the various challenges in medicine, diagnosis, complete cure and healing of cancers remain difficult given the heterogeneity and complexity of such disease. Differing from conventional platforms with often unsatisfactory theranostic capabilities, the contribution of supramolecular interactions, such as hydrogen-bonds (H-bonds), to cancer nanotheranostics opens new perspectives for the design of biomedical materials, exhibiting remarkable properties and easier processability. Thanks to their dynamic characteristics, a feature generally observed for non-covalent interactions, H-bonding (macro)molecules can be used as supramolecular motifs for yielding drug- and diagnostic carriers that possess attractive features, arising from the combination of assembled nanoplatforms and the responsiveness of H-bonds. Thus H-bonded nanomedicine provides a rich toolbox that is useful to fulfill biomedical needs with unique advantages in early-stage diagnosis and therapy, demonstrating the promising potential in clinical translations and applications. We here summarize the design and synthetic routes towards H-bonded nanomedicines, focus on the growing understanding of the structure-function relationship for efficient cancer treatment. We propose a guidance for designing new H-bonded intelligent theranostic agents, to inspire more successful explorations of cancer nanotheranostics and finally to promote potential clinical translations. This article is protected by copyright. All rights reserved.

A pH-responsive mesoporous silica nanoparticle-based drug delivery system for targeted breast cancer therapy

In order to make the drug specifically aggregate at the tumor site, we had developed a targeted drug delivery system based on pH responsive mesoporous silica nanoparticles. Mesoporous silica nanoparticles (MSN-COOH) were prepared and doxorubicin (DOX) was loaded into the pores of MSN-COOH, and then polyethyleneimine (PEI) and anisamide (AA) were modified on the surface of mesoporous silica, named DOX@MSN-PEI-AA(DMPA). DMPA specifically entered tumor cells through AA-mediated receptor endocytosis; PEI dissociated from the surface of the MSN in the acidic environment of cellular lysosomes/endosomes due to protonation of PEI, resulting in steady release of the encapsulated DOX from the pores of MSN in the cytoplasm of the target cells. In vitro and in vivo anti-tumor experiments and hemolytic experiments indicated that DMPA can accurately target breast cancer cells and show excellent safety at the same time, showing great potential for tumor therapy.

Strategies targeting tumor immune and stromal microenvironment and their clinical relevance

The critical role of tumor microenvironment (TME) in tumor initiation and development has been well-recognized after more than a century of studies. Numerous therapeutic approaches targeting TME are rapidly developed including those leveraging nanotechnology, which have been further accelerated since the emergence of immune checkpoint blockade therapies in the past decade. While there are many reviews focusing on TME remodeling therapies via drug delivery and engineering strategies in animal models, state-of-the-art evaluation of clinical development states of TME-targeted therapeutics is rarely found. Here, we illustrate opportunities for integrating nano-delivery system for the development of TME-specific therapeutic regimen, followed by a comprehensive summary of the most up to date approved or clinically evaluated therapeutics targeting cellular and extracellular components within tumor immune and stromal microenvironment, including small molecule and monoclonal antibody drugs as well as nanomedicines. In the end, we also discuss challenges and possible solutions for clinical translation of TME-targeted nanomedicines.

Insights into Melanoma Fibroblast Populations and Therapeutic Strategy Perspectives: Friends or Foes?

Cutaneous melanoma (CM) is an aggressive and highly metastatic solid tumor associated with drug resistance. Before 2011, despite therapies based on cytokines or molecules inhibiting DNA synthesis, metastatic melanoma led to patient death within 18 months from diagnosis. However, recent studies on bidirectional interactions between melanoma cells and tumor microenvironment (TME) have had a significant impact on the development of new therapeutic strategies represented by targeted therapy and immunotherapy. In particular, the heterogeneous stromal fibroblast populations, including fibroblasts, fibroblast aggregates, myofibroblasts, and melanoma associated fibroblasts (MAFs), represent the most abundant cell population of TME and regulate cancer growth differently. Therefore, in this perspective article, we have highlighted the different impacts of fibroblast populations on cancer development and growth. In particular, we focused on the role of MAFs in sustaining melanoma cell survival, proliferation, migration and invasion, drug resistance, and immunoregulation. The important role of constitutively activated MAFs in promoting CM growth and immunoediting makes this cell type a promising target for cancer therapy.

Systematic Review of Cancer Targeting by Nanoparticles Revealed a Global Association between Accumulation in Tumors and Spleen

Active targeting of nanoparticles toward tumors is one of the most rapidly developing topics in nanomedicine. Typically, this strategy involves the addition of cancer-targeting biomolecules to nanoparticles, and studies on this topic have mainly focused on the localization of such formulations in tumors. Here, the analysis of the factors determining efficient nanoparticle targeting and therapy, various parameters such as types of targeting molecules, nanoparticle type, size, zeta potential, dose, and the circulation time are given. In addition, the important aspects such as how active targeting of nanoparticles alters biodistribution and how non-specific organ uptake influences tumor accumulation of the targeted nanoformulations are discussed. The analysis reveals that an increase in tumor accumulation of targeted nanoparticles is accompanied by a decrease in their uptake by the spleen. There is no association between targeting-induced changes of nanoparticle concentrations in tumors and other organs. The correlation between uptake in tumors and depletion in the spleen is significant for mice with intact immune systems in contrast to nude mice. Noticeably, modulation of splenic and tumor accumulation depends on the targeting molecules and nanoparticle type. The median survival increases with the targeting-induced nanoparticle accumulation in tumors; moreover, combinatorial targeting of nanoparticle drugs demonstrates higher treatment efficiencies. Results of the comprehensive analysis show optimal strategies to enhance the efficiency of actively targeted nanoparticle-based medicines.

Traditional herbal medicine and nanomedicine: Converging disciplines to improve therapeutic efficacy and human health

Traditional herbal medicine (THM), an ancient science, is a gift from nature. For thousands of years, it has helped humans fight diseases and protect life, health, and reproduction. Nanomedicine, a newer discipline has evolved from exploitation of the unique nanoscale morphology and is widely used in diagnosis, imaging, drug delivery, and other biomedical fields. Although THM and nanomedicine differ greatly in time span and discipline dimensions, they are closely related and are even evolving toward integration and convergence. This review begins with the history and latest research progress of THM and nanomedicine, expounding their respective developmental trajectory. It then discusses the overlapping connectivity and relevance of the two fields, including nanoaggregates generated in herbal medicine decoctions, the application of nanotechnology in the delivery and treatment of natural active ingredients, and the influence of physiological regulatory capability of THM on the in vivo fate of nanoparticles. Finally, future development trends, challenges, and research directions are discussed.

Targeting MDSC for Immune-Checkpoint Blockade in Cancer Immunotherapy: Current Progress and New Prospects

Immune-checkpoint blockade (ICB) demonstrated inspiring effect and great promise in anti-cancer therapy. However, many obstacles, such as drug resistance and difficulty in patient selection, limited the efficacy of ICB therapy and awaited to be overcome. By timely identification and intervention of the key immune-suppressive promotors in the tumor microenvironment (TME), we may better understand the mechanisms of cancer immune-escape and use novel strategies to enhance the therapeutic effect of ICB. Myeloid-derived suppressor cell (MDSC) is recognized as a major immune suppressor in the TME. In this review, we summarized the roles MDSC played in the cancer context, focusing on its negative biologic functions in ICB therapy, discussed the strategies targeted on MDSC to optimize the diagnosis and therapy process of ICB and improve the efficacy of ICB therapy against malignancies.

Influencing factors and strategies of enhancing nanoparticles into tumors in vivo

The administration of nanoparticles (NPs) first faces the challenges of evading renal filtration and clearance of reticuloendothelial system (RES). After that, NPs infiltrate through the expanded endothelial space and penetrated the dense stroma of tumor microenvironment to tumor cells. As long as possible to prolong the time of NPs remaining in tumor tissue, NPs release active agent and induce pharmacological action. This review provides a comprehensive summary of the physical and chemical properties of NPs and the influence of various biological factors in tumor microenvironment, and discusses how to improve the final efficacy through adjusting the characteristics and structure of NPs. Perspectives and future directions are also provided.

Colloidal Assemblies Composed of Polymeric Micellar/Emulsified Systems Integrate Cancer Therapy Combining a Tumor-Associated Antigen Vaccine and Chemotherapeutic Regimens

Integrative medicine comprising a tumor-associated antigen vaccine and chemotherapeutic regimens has provided new insights into cancer therapy. In this study, the AB-type diblock copolymers poly(ethylene glycol)–polylactide (PEG–PLA) were subjected to the dispersion of poorly water-soluble molecules in aqueous solutions. The physicochemical behavior of the chemotherapeutic agent DBPR114 in the PEG–PLA-polymeric aqueous solution was investigated by dynamic light scattering (DLS) technology. In vitro cell culture indicated that replacing the organic solvent DMSO with PEG–PLA polymeric micelles could maintain the anti-proliferative effect of DBPR114 on leukemia cell lines. A murine tumor-associated antigen vaccine model was established in tumor-bearing mice to determine the effectiveness of these formulas in inducing tumor regression. The results demonstrated that the therapeutic treatments effectively reinforced each other via co-delivery of antitumor drug/antigen agents to synergistically integrate the efficacy of cancer therapy. Our findings support the potential use of polymeric micellar systems for aqueous solubilization and expansion of antitumor activity intrinsic to DBPR114 and tumor-associated antigen therapy.

Fraxinellone alleviates kidney fibrosis by inhibiting CUG-binding protein 1-mediated fibroblast activation

Chronic Kidney Disease (CKD) is a serious threat to human health. In addition, kidney fibrosis is a key pathogenic intermediate for the progression of CDK. Moreover, excessive activation of fibroblasts is key to the development of kidney fibrosis and this process is difficult to control. Notably, fraxinellone is a natural compound isolated from Dictamnus dasycarpus and has a variety of pharmacological activities, including hepatoprotective, anti-inflammatory and anti-cancer effects. However, the effect of fraxinellone on kidney fibrosis is largely unknown. The present study showed that fraxinellone could alleviate folic acid-induced kidney fibrosis in mice in a dose dependent manner. Additionally, the results revealed that fraxinellone could effectively down-regulate the expression of CUGBP1, which was highly up-regulated in human and murine fibrotic renal tissues. Furthermore, expression of CUGBP1 was selectively induced by the Transforming Growth Factor-beta (TGF-β) through p38 and JNK signaling in kidney fibroblasts. On the other hand, downregulating the expression of CUGBP1 significantly inhibited the activation of kidney fibroblasts. In conclusion, these findings demonstrated that fraxinellone might be a new drug candidate and CUGBP1 could be a promising target for the treatment of kidney fibrosis.

Exploiting a New Approach to Destroy the Barrier of Tumor Microenvironment: Nano-Architecture Delivery Systems

Recent findings suggest that tumor microenvironment (TME) plays an important regulatory role in the occurrence, proliferation, and metastasis of tumors. Different from normal tissue, the condition around tumor significantly altered, including immune infiltration, compact extracellular matrix, new vasculatures, abundant enzyme, acidic pH value, and hypoxia. Increasingly, researchers focused on targeting TME to prevent tumor development and metastasis. With the development of nanotechnology and the deep research on the tumor environment, stimulation-responsive intelligent nanostructures designed based on TME have attracted much attention in the anti-tumor drug delivery system. TME-targeted nano therapeutics can regulate the distribution of drugs in the body, specifically increase the concentration of drugs in the tumor site, so as to enhance the efficacy and reduce adverse reactions, can utilize particular conditions of TME to improve the effect of tumor therapy. This paper summarizes the major components and characteristics of TME, discusses the principles and strategies of relevant nano-architectures targeting TME for the treatment and diagnosis systematically.

Tumor microenvironment remodeling-based penetration strategies to amplify nanodrug accessibility to tumor parenchyma

Remarkable advances in nano delivery systems have provided new hope for tumor prevention, diagnosis and treatment. However, only limited clinical therapeutic effects against solid tumors were achieved. One of the main reasons is the presence of abundant physiological and pathological barriers in vivo that impair tumoral penetration and distribution of the nanodrugs. These barriers are related to the components of tumor microenvironment (TME) including abnormal tumor vasculature, rich composition of the extracellular matrix (ECM), and abundant stroma cells. Herein, we review the advanced strategies of TME remodeling to overcome these biological obstacles against nanodrug delivery. This review aims to offer a perspective guideline for the implementation of promising approaches to facilitate intratumoral permeation of nanodrugs through alleviation of biological barriers. At the same time, we analyze the advantages and disadvantages of the corresponding methods and put forward possible directions for the future researches.

Fraxinellone Has Anticancer Activity by Inducing Osteosarcoma Cell Apoptosis via Promoting Excessive Autophagy Flux

Osteosarcoma is a malignant bone tumor that is easy to metastasize in the early stage and has a very poor prognosis. Fraxinellone (FRA) is one of the main components isolated from the D. dasycarpus plant. Its anti-inflammatory and neuroprotective effects have been confirmed, but the research on the anti-cancer effect of FRA and its potential mechanism is relatively scarce. In this study, we found that FRA inhibited the proliferation and migration of osteosarcoma cells HOS and MG63 in a dose-dependent manner. Immunofluorescence, fluorescence staining and western blotting analysis showed that FRA could simultaneously induce osteosarcoma cell apoptosis and increase autophagy flux. Subsequent turnaround experiments suggested that the pro-apoptotic effect of FRA was achieved through excessive autophagy flux. The results of the xenograft orthotopic model further supported the anti-cancer effects of FRA, indicating that FRA treatment inhibited the growth of osteosarcoma, and the pro-apoptotic and autophagy effects of FRA were also proved in vivo. These studies provide new ideas for the future treatment of osteosarcoma and offer theoretical support for the anti-cancer mechanism of FRA.

Celastrol nanoemulsion induces immunogenicity and downregulates PD-L1 to boost abscopal effect in melanoma therapy

Programmed cell death-ligand 1 (PD-L1)-based immune checkpoint blockade therapy using the anti-PD-L1 antibody is effective for a subset of patients with advanced metastatic melanoma but about half of the patients do not respond to the therapy because of the tumor immunosuppressive microenvironment. Immunogenic cell death (ICD) induced by cytotoxins such as doxorubicin (DOX) allows damaged dying tumor cells to release immunostimulatory danger signals to activate dendritic cells (DCs) and T-cells; however, DOX also makes tumor cells upregulate PD-L1 expression and thus deactivate T-cells via the PD-1/PD-L1 pathway. Herein, we show that celastrol (CEL) induced not only strong ICD but also downregulation of PD-L1 expression of tumor cells. Thus, CEL was able to simultaneously activate DCs and T-cells and interrupt the PD-1/PD-L1 pathway between T-cells and tumor cells. In a bilateral tumor model, intratumorally (i.t.) injected celastrol nanoemulsion retaining a high tumor CEL concentration activated the immune system efficiently, which inhibited both the treated tumor and the distant untreated tumor in the mice (i.e., abscopal effect). Thus, this work demonstrates a new and much cost-effective immunotherapy strategy - chemotherapy-induced immunotherapy against melanoma without the need for expensive immune-checkpoint inhibitors.

Enhancing TNBC Chemo-immunotherapy via combination reprogramming tumor immune microenvironment with Immunogenic Cell Death

Tumor-associated fibroblasts (TAFs) play an important role in tumor progression and therapeutic response, especially in the immunosuppressive tumor microenvironment (TME). To remodel immunosuppressive TME of 4T1 tumor, we developed a nano liposome to deliver silybin (SLN, an anti-liver fibrosis Chinese Traditional Medicine). Liposomal silybin (SLN/LIP) possessed a spherical shape with particle sizes of 75.2 nm, high stability, and good accumulation in the tumor site. After treated with SLN/LIP, α-SMA positive TAFs and the deposition of stroma were decreased significantly. SLN/LIP also changed the tumor immune microenvironment through the increase of IFN-γ and IL-12, as well as reduced of TGF-β, SDF-1, IL6 and TNF-α. Importantly, SLN/LIP enhanced the infiltration of cytotoxic T cells (CTLs) and transformed a "cold" tumor into a "hot" tumor. To achieve the higher antitumor efficacy, an immunogenic cell death (ICD) inducer, liposomal doxorubicin (DOX/LIP) was combined with SLN/LIP. The combination treatment led to trigger immunogenic tumor apoptosis, and enhance antitumor immunity, therefore, improved anti-tumor efficiency, and further prolonged survival duration. The combination of liposomal silybin and liposomal doxorubicin might be a new chemo-immunotherapy approach for triple negative breast cancer (TNBC) tumor treatment.

Manipulation of Inflammasome: A Promising Approach Towards Immunotherapy of Lung Cancer

Chronic inflammation has emerged as a key player at different stages of cancer development. A prominent signaling pathway for acute and chronic inflammation is the activation of the caspase-1 inflammasomes. These are complexes that assemble on activation of certain nucleotide-binding domain, leucine-rich repeat containing proteins (NLRs), AIM2-like receptors (ALRs), or pyrin due to activation via PAMPs or DAMPs. Of these, five complexes-NLRP1, NLRP3, NLRC4, Pyrin, and AIM2 are of importance in the context of cancer for their activities in modulating immune responses, cell proliferation, and apoptosis. Inflammasomes have emerged as clinically relevant in multiple forms of cancer making them highly promising targets for cancer therapy. As lungs are a tissue niche that is prone to inflammation owing to its exposure to external substances, inflammasomes play a vital role in the development and pathogenesis of lung cancer. Therefore, manipulation of inflammasome by various immunomodulatory means could prove a full-proof strategy for the treatment of lung cancer. Here, in this review, we tried to explore the various strategies to target the inflammasomes for the treatment of lung cancer.

The potential of nanomedicine to alter cancer stem cell dynamics: the impact of extracellular vesicles

The presence of highly resistant cancer stem cells (CSCs) within tumors as drivers of metastatic spread has been commonly accepted. Nonetheless, the likelihood of its dynamic phenotype has been strongly discussed. Importantly, intratumoral cell-to-cell communication seems to act as the main regulatory mechanism of CSC reversion. Today, new strategies for cancer treatment focusing into modulating tumor cell intercommunication and the possibility to modulate the composition of the tumor microenvironment are being explored. In this review, we summarize the literature describing the phenomenon of CSC reversion and the factors known to influence this phenotypic switch. Furthermore, we will discuss the possible role of nanomedicine toward altering this reversion, and to influence the tumor microenvironment composition and the metastatic spread of the disease.

Natural products remodel cancer-associated fibroblasts in desmoplastic tumors

Desmoplastic tumors have an abundance of stromal cells and the extracellular matrix which usually result in therapeutic resistance. Current treatment prescriptions for desmoplastic tumors are usually not sufficient to eliminate the malignancy. Recently, through modulating cancer-associated fibroblasts (CAFs) which are the most abundant cell type among all stromal cells, natural products have improved chemotherapies and the delivery of nanomedicines to the tumor cells, showing promising ability to improve treatment effects on desmoplastic tumors. In this review, we discussed the latest advances in inhibiting desmoplastic tumors by modeling CAFs using natural products, highlighting the potential therapeutic abilities of natural products in targeting CAFs for cancer treatment.

Nanomedicines modulating tumor immunosuppressive cells to enhance cancer immunotherapy

Cancer immunotherapy has veered the paradigm of cancer treatment. Despite recent advances in immunotherapy for improved antitumor efficacy, the complicated tumor microenvironment (TME) is highly immunosuppressive, yielding both astounding and unsatisfactory clinical successes. In this regard, clinical outcomes of currently available immunotherapy are confined to the varied immune systems owing in large part to the lack of understanding of the complexity and diversity of the immune context of the TME. Various advanced designs of nanomedicines could still not fully surmount the delivery barriers of the TME. The immunosuppressive TME may even dampen the efficacy of antitumor immunity. Recently, some nanotechnology-related strategies have been inaugurated to modulate the immunosuppressive cells within the tumor immune microenvironment (TIME) for robust immunotherapeutic responses. In this review, we will highlight the current understanding of the immunosuppressive TIME and identify disparate subclasses of TIME that possess an impact on immunotherapy, especially those unique classes associated with the immunosuppressive effect. The immunoregulatory cell types inside the immunosuppressive TIME will be delineated along with the existing and potential approaches for immunosuppressive cell modulation. After introducing the various strategies, we will ultimately outline both the novel therapeutic targets and the potential issues that affect the efficacy of TIME-based nanomedicines.

Nano-Enhanced Cancer Immunotherapy: Immunology Encounters Nanotechnology

Cancer immunotherapy utilizes the immune system to fight cancer and has already moved from the laboratory to clinical application. However, and despite excellent therapeutic outcomes in some hematological and solid cancers, the regular clinical use of cancer immunotherapies reveals major limitations. These include the lack of effective immune therapy options for some cancer types, unresponsiveness to treatment by many patients, evolving therapy resistance, the inaccessible and immunosuppressive nature of the tumor microenvironment (TME), and the risk of potentially life-threatening immune toxicities. Given the potential of nanotechnology to deliver, enhance, and fine-tune cancer immunotherapeutic agents, the combination of cancer immunotherapy with nanotechnology can overcome some of these limitations. In this review, we summarize innovative reports and novel strategies that successfully combine nanotechnology and cancer immunotherapy. We also provide insight into how nanoparticular combination therapies can be used to improve therapy responsiveness, to reduce unwanted toxicity, and to overcome adverse effects of the TME.

Fraxinellone: From pesticidal control to cancer treatment

Fraxinellone (FRA) is a degraded limonoid isolated from the root bark of Dictamnus plants. The potent insecticidal activity of FRA has led to the synthesis of numerous derivatives (presented here with the structure-activity relationships) active against the oriental armyworm Mythimna separata Walker. In addition to its pesticidal activity, the natural product displays potent anti-inflammatory and immuno-modulatory effects at the origin of hepatoprotective and anticancer properties. This mini-review provides an update of the mechanism of action of FRA to highlight the recently discovered capacity of the compound to deactivate cancer-associated fibroblasts and thus to limit the immunosuppressive tumor microenvironment. The anticancer mode of action of FRA raises new ideas to better understand its primary insecticidal activity. The relationship between drug-induced cancer cell death and insect cell death is discussed. A drug interaction with the insect cytokine growth-blocking peptide (GBP), a member of the large EGF family, is proposed, supported by preliminary molecular modeling data. Altogether, the review shed light on the pharmacological properties of fraxinellone as an antitumor agent and a natural insecticide.

Developing neobavaisoflavone nanoemulsion suppresses lung cancer progression by regulating tumor microenvironment

It is necessary to create novel, efficacious and harmless therapeutic strategy for lung cancer treatment. The application of nanoemulsion to specifically suppress cancer progression in the tumor microenvironment would be an effective therapy. Neobavaisoflavone (Neo) is an isoflavone isolated from Psoralea corylifolia L, possesses striking anti-inflammatory and anti-cancer effects. In our stduy, Neo significantly reduced reactive oxygen species (ROS) generation in the activated myofibroblast. Furthermore, a novel Neo nanoemulsion (nano-Neo) was prepared to improve Neo solubility and bioavailability. Nano-Neo showed more effectively anti-proliferative role in lung cancer cells. In addition, in vivo analysis further demonstrated that nano-Neo could effectively suppress tumor growth compared to the free Neo-treated mice without noticeable damage to major organs. Furthermore, nano-Neo treatment markedly reduced extracellular matrix (ECM) deposition in tumor samples by repressing transforming growth factor-β (TGF-β)/SMADs signaling pathway. Meanwhile, the activated immune microenvironment in tumor tissues was dramatically improved by nano-Neo through reducing regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) infiltration, as well as improving the count of natural killer (NK) cells and M2 macrophage phenotype switch to pro-inflammatory M1. In addition, we found that the prepared nano-Neo exerted promising tumor targeting efficiency with improved pharmacokinetic properties. Therefore, the novel approach to prepare nano-Neo introduced here might provide an effective strategy for lung cancer treatment with few adverse effects.

Manganese-Based Nanoactivator Optimizes Cancer Immunotherapy via Enhancing Innate Immunity

Cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) are essential components of the innate immune sensors to cytosolic DNA and elicit type I interferon (IFN). Recent studies have revealed that manganese (Mn) can enhance cGAS and STING activation to viral infection. However, the role of Mn in antitumor immunity has not been explored. Here, we designed a nanoactivator, which can induce the presence of DNA in cytoplasm and simultaneously elevate Mn²⁺ accumulation within tumor cells. In detail, amorphous porous manganese phosphate (APMP) NPs that are highly responsive to tumor microenvironment were employed to construct doxorubicin (DOX)-loaded and phospholipid (PL)-coated hybrid nanoparticles (PL/APMP-DOX NPs). PL/APMP-DOX NPs were stably maintained during systemic circulation, but triggered to release DOX for inducing DNA damage and Mn²⁺ to augment cGAS/STING activity. We found that PL/APMP-DOX NPs with superior tumor-targeting capacity boosted dendritic cell maturation and increased cytotoxic T lymphocyte infiltration as well as natural killer cell recruitment into the tumor site. Furthermore, the NPs increased production of type I IFN and secretion of pro-inflammatory cytokines (for example, TNF-α and IL-6). Consequently, PL/APMP-DOX NPs exhibited excellent antitumor efficacy and prolonged the lifespan of the tumor-bearing mice. Collectively, we developed a PL-decorated Mn-based hybrid nanoactivator to intensify immune activation and that might provide therapeutic potential for caner immunotherapy.

Induction of CML-specific immune response through cross-presentation triggered by CTP-mediated BCR-ABL-derived peptides

Although targeted therapy using tyrosine kinase inhibitors (TKIs) has made remarkable progress in treating chronic myeloid leukemia (CML), this disease remains largely incurable, warranting further investigation of new therapeutic strategies. BCR-ABL is a highly specific tumor antigen in CML and provides an attractive opportunity for vaccination therapy. Exogenous antigens must be presented on MHC class I molecules-via a process termed cross-presentation-to activate specific cytotoxic T lymphocyte response. The relative efficiency of cross-presentation is determined in part by the ability of dendritic cells (DCs) to internalize and present antigens. Here, we present a novel tool that uses cytoplasmic transduction peptide (CTP) to facilitate the internalization of antigens by DCs in an endocytosis-independent manner, which greatly enhances the efficiency of antigen presentation, thereby inducing stronger cytotoxic activity to ensure the elimination of CML cells. The data suggest that CTP-fused CML-specific peptides can be applied in vaccination therapies for CML patients.

Tumor-targeted delivery of silibinin and IPI-549 synergistically inhibit breast cancer by remodeling the microenvironment

We induced changes in the tumor microenvironment (TME) through the synergistic actions of two drugs used in breast cancer therapy. The anti-fibrotic drug silibinin (SLB) targets tumor-associated fibroblasts and exerts immune-mediated anti-cancer effects. IPI-549, an efficient and highly selective phosphoinositide-3-kinase-gamma (PI3Kγ) inhibitor, was applied to alter the balance of immunosuppressive cells by inhibiting PI3Kγ molecules; it also promotes anti-tumor immunity. We developed nanoparticle formulations to encapsulate both drugs into the targeting carrier aminoethyl anisamide-polyethylene glycol-polycaprolactone (AEAA-PEG-PCL) respectively. The drugs were intravenously delivered in mice and resulted in an increase in anti-tumor efficacy and apoptotic tumor tissue compared with either IPI-549 or SLB alone in 4T1 breast cancer cell-derived tumors. Furthermore, a significant reduction in regulatory T (Treg) cells and myeloid suppressor cells (MDSCs) was observed. A normalized TME structure was also observed, including angiogenesis suppression, antifibrotic effects and the inhibition of collagen formation in the tumor tissue, significantly enhancing the anti-tumor effects. In summary, this combination strategy may offer an alternative treatment for breast cancer.

Remodeling the fibrotic tumor microenvironment of desmoplastic melanoma to facilitate vaccine immunotherapy

Highly fibrotic and collagen-rich properties in desmoplastic melanoma (DM) result in an immune-suppressive fibrotic tumor microenvironment (TME) that resists clinical therapies. The different clinical and pathological properties, as compared to conventional melanoma, lead to delayed diagnosis and it is difficult to deliver drugs effectively due to fibrosis. Herein, we designed a chemo-immuno strategy focused on combining vaccination immunotherapy with multi-targeting sunitinib (SUN) nano-therapy to remodel TME and generate a robust immune response and a stronger synergistic anti-cancer effect. This strategy was evaluated side-by-side with non-desmoplastic melanoma and achieved significant improvement in therapeutic efficacy. The combination treatment was also synergistically assessed with the desmoplastic melanoma model. This strategy can remodel the fibrotic immunosuppressive TME and result in a robust cytotoxic T-cell response by reducing the collagen content, normalizing blood vessels, inhibiting tumor-associated fibroblasts and reducing high levels of suppressor immune cells. The modification of fibrotic immunosuppressive TME may serve as a good approach to further enhance immunotherapy for desmoplastic tumors.