Systemic metastasis-targeted nanotherapeutic reinforces tumor surgical resection and chemotherapy

Improving hemocompatibility in tissue-engineered products employing heparin-loaded nanoplatforms

The enhancement of hemocompatibility through the use of nanoplatforms loaded with heparin represents a highly desirable characteristic in the context of emerging tissue engineering applications. The significance of employing heparin in biological processes is unquestionable, owing to its ability to interact with a diverse range of proteins. It plays a crucial role in numerous biological processes by engaging in interactions with diverse proteins and hydrogels. This review provides a summary of recent endeavors focused on augmenting the hemocompatibility of tissue engineering methods through the utilization of nanoplatforms loaded with heparin. This study also provides a comprehensive review of the various applications of heparin-loaded nanofibers and nanoparticles, as well as the techniques employed for encapsulating heparin within these nanoplatforms. The biological and physical effects resulting from the encapsulation of heparin in nanoplatforms are examined. The potential applications of heparin-based materials in tissue engineering are also discussed, along with future perspectives in this field.

A Virus-Inspired Inhalable Liponanogel Induces Potent Antitumor Immunity and Regression in Metastatic Lung Tumors

Pulmonary delivery of immunostimulatory agents such as poly(I:C) to activate double-stranded RNA sensors MDA5 and RIG-I within lung-resident antigen-presenting cells is a potential strategy to enhance antitumor immunity by promoting type I interferon secretion. Nevertheless, following pulmonary delivery, poly(I:C) suffers from rapid degradation and poor endosomal escape, thus limiting its potency. Inspired by the structure of a virus that utilizes internal viral proteins to tune the loading and cytosolic delivery of viral nucleic acids, we developed a liponanogel (LNG)-based platform to overcome the delivery challenges of poly(I:C). The LNG comprised an anionic polymer hyaluronic acid-based nanogel core coated by a lipid shell, which served as a protective layer to stabilize the nanogel core in the lungs. The nanogel core was protonated within acidic endosomes to enhance the endosomal membrane permeability and cytosolic delivery of poly(I:C). After pulmonary delivery, LNG-poly(I:C) induced 13.7-fold more IFNβ than poly(I:C) alone and two-fold more than poly(I:C) loaded in the state-of-art lipid nanoparticles [LNP-poly(I:C)]. Additionally, LNG-poly(I:C) induced more potent CD8+ T-cell immunity and stronger therapeutic effects than LNP-poly(I:C). The combination of LNG-poly(I:C) and PD-L1 targeting led to regression of established lung metastases. Due to the ease of manufacturing and the high biocompatibility of LNG, pulmonary delivery of LNG may be broadly applicable to the treatment of different lung tumors and may spur the development of innovative strategies for cancer immunotherapy. Significance: Pulmonary delivery of poly(I:C) with a virus-inspired inhalable liponanogel strongly activates cytosolic MDA5 and RIG-I and stimulates antitumor immunity, representing a promising strategy for safe and effective treatment of metastatic lung tumors.

Softening the tumor matrix through cholesterol depletion breaks the physical barrier for enhanced antitumor therapy

The tumor develops defense tactics, including conversing the mechanical characteristics of tumor cells and their surrounding environment. A recent study reported that cholesterol depletion stiffens tumor cells, which could enhance adaptive T-cell immunotherapy. However, it remains unclear whether reducing the cholesterol in tumor cells contributes to re-educating the stiff tumor matrix, which serves as a physical barrier against drug penetration. Herein, we found that depleting cholesterol from tumor cells can demolish the intratumor physical barrier by disrupting the mechanical signal transduction between tumor cells and the extracellular matrix through the destruction of lipid rafts. This disruption allows nanoparticles (H/S@hNP) to penetrate deeply, resulting in improved photodynamic treatment. Our research also indicates that cholesterol depletion can inhibit the epithelial-mesenchymal transition and repolarize tumor-associated macrophages from M2 to M1, demonstrating the essential role of cholesterol in tumor progression. Overall, this study reveals that a cholesterol-depleted, softened tumor matrix reduces the difficulty of drug penetration, leading to enhanced antitumor therapeutics.

Nanomaterial-Based Strategies for Preventing Tumor Metastasis by Interrupting the Metastatic Biological Processes

Tumor metastasis is the primary cause of cancer-related deaths. The prevention of tumor metastasis has garnered notable interest and interrupting metastatic biological processes is considered a potential strategy for preventing tumor metastasis. The tumor microenvironment (TME), circulating tumor cells (CTCs), and premetastatic niche (PMN) play crucial roles in metastatic biological processes. These processes can be interrupted using nanomaterials due to their excellent physicochemical properties. However, most studies have focused on only one aspect of tumor metastasis. Here, the hypothesis that nanomaterials can be used to target metastatic biological processes and explore strategies to prevent tumor metastasis is highlighted. First, the metastatic biological processes and strategies involving nanomaterials acting on the TME, CTCs, and PMN to prevent tumor metastasis are briefly summarized. Further, the current challenges and prospects of nanomaterials in preventing tumor metastasis by interrupting metastatic biological processes are discussed. Nanomaterial-and multifunctional nanomaterial-based strategies for preventing tumor metastasis are advantageous for the long-term fight against tumor metastasis and their continued exploration will facilitate rapid progress in the prevention, diagnosis, and treatment of tumor metastasis. Novel perspectives are outlined for developing more effective strategies to prevent tumor metastasis, thereby improving the outcomes of patients with cancer.

Rapid Glutathione Analysis with SERS Microneedles for Deep Glioblastoma Tissue Differentiation

Rapid tissue differentiation at the molecular level is a prerequisite for precise surgical resection, which is of special value for the treatment of malignant tumors, such as glioblastoma (GBM). Herein, a SERS-active microneedle is prepared by modifying glutathione (GSH)-responsive molecules, 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), on the surface of Au@Ag substrates for the distinction of different GBM tissues. Since the Raman signals on the surface of the DTNB@Au@Ag microneedle can be collected by both portable and benchtop Raman spectrometers, the distribution of GSH in different tissues at centimeter scale can be displayed through Raman spectroscopy and Raman imaging, and the entire analysis process can be accomplished within 12 min. Accordingly, in vivo brain tissues of orthotopic GBM xenograft mice and ex vivo tissues of GBM patients are accurately differentiated with the microneedle, and the results are well consistent with tissue staining and postoperative pathological reports. In addition, the outline of tumor, peritumoral, and normal tissues can be indicated by the DTNB@Au@Ag microneedle for at least 56 days. Considering that the tumor tissues are quickly discriminated at the molecular level without the restriction of depth, the DTNB@Au@Ag microneedle is promising to be a powerful intraoperative diagnostic tool for surgery navigation.

Revealing the Optimization Route of Piezoelectric Sonosensitizers: From Mechanism to Engineering Methods

Piezoelectric catalysis is a novel catalytic technology that has developed rapidly in recent years and has attracted extensive interest among researchers in the field of tumor therapy for its acoustic-sensitizing properties. Nevertheless, researchers are still controversial about the key technical difficulties in the modulation of piezoelectric sonosensitizers for tumor therapy applications, which is undoubtedly a major obstacle to the performance modulation of piezoelectric sonosensitizers. Clarification of this challenge will be beneficial to the design and optimization of piezoelectric sonosensitizers in the future. Here, the authors start from the mechanism of piezoelectric catalysis and elaborate the mechanism and methods of defect engineering and phase engineering for the performance modulation of piezoelectric sonosensitizers based on the energy band theory. The combined therapeutic strategy of piezoelectric sonosensitizers with enzyme catalysis and immunotherapy is introduced. Finally, the challenges and prospects of piezoelectric sonosensitizers are highlighted. Hopefully, the explorations can guide researchers toward the optimization of piezoelectric sonosensitizers and can be applied in their own research.

Lipid core-shell nanoparticles co-deliver FOLFOX regimen and siPD-L1 for synergistic targeted cancer treatment

FOLFOX regimen, composed of folinic acid, 5-fluorouracil (5-FU) and oxaliplatin (OXP), has been used as clinical standard therapeutic regimen in treatments of colorectal cancer (CRC) and esophageal squamous cell carcinoma (ESCC). To further improve its therapeutic outcomes, FOLFOX was combined with anti-PD-1 antibody to form an advanced chemo-immune combination strategy, which has been proven more efficient in controlling cancer progression and prolonging patients' survival in various clinical trials. However, bad tumor accumulation, relative high toxicity, numerous treatment cycles with high fees and low compliance as well as drug resistance seriously limit the prognosis of FOLFOX regimen. The "all-in-one" formulations, which could precisely delivery multidrug regimen into tumor sites and cells, showed a promising application prospect for targeted drug delivery as well as reducing side effects. However, the design and preparation of the "all-in-one" formulation with high drug encapsulation efficiencies for all drugs was still challenging. Herein, a lipid core-shell nanoparticle codelivery platform was designed for simultaneous encapsulation of variant FOLFOX composed of miriplatin (MiPt), 5-Fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP), calcium folinate (CF) and PD-L1 siRNA (siPD-L1) with high efficiencies, and their synergistic anti-tumor mechanisms were studied, respectively. MiPt, a precursor of OXP, was validated capable of inducing efficient immunogenic cell death (ICD) in this work. Additionally, ICD-mediated release of damage associated molecular patterns functionalized synergistically with PD-L1 silence by siPD-L1 to overcome chemoresistance, reverse suppressive tumor microenvironment and recruit more CD8+ T cells. FdUMP, as the intracellular active form of 5-FU, could induce large amounts of reactive oxygen species to enhance the ICD. CF worked as the sensitizer of FdUMP. The enhanced long-term anti-tumor effect of the prepared "all-in-one" formulation compared to free drug regimen and other controls, was verified in heterotopic CRC mice models and ESCC mice models, providing new thoughts for researchers and showing a promising prospect of translation into clinical applications.

Fanarraga M. Carbon nanotubes targeted to the tumor microenvironment inhibit metastasis in a preclinical model of melanoma

Despite notable progress in cancer therapy, metastatic diseases continue to be the primary cause of cancer-related mortality. Multi-walled carbon nanotubes (MWCNTs) can enter tissues and cells and interfere with the dynamics of the cytoskeletal nanofilaments biomimetically. This endows them with intrinsic anti-tumoral effects comparable to those of microtubule-binding chemotherapies such as Taxol®. In this study, our focus was on exploring the potential of oxidized MWCNTs in selectively targeting the vascular endothelial growth factor receptor (VEGFR). Our objective was to evaluate their effectiveness in inhibiting metastatic growth by inducing anti-proliferative, anti-migratory, and cytotoxic effects on both cancer and tumor microenvironment cells. Our findings demonstrated a significant reduction of over 80 % in malignant melanoma lung metastases and a substantial enhancement in overall animal welfare following intravenous administration of the targeted biodegradable MWCNTs. Furthermore, the combination of these nanomaterials with the conventional chemotherapy agent Taxol® yielded a remarkable 90 % increase in the antimetastatic effect. These results highlight the promising potential of this combined therapeutic approach against metastatic disease and are of paramount importance as metastasis is responsible for nearly 60,000 deaths each year.

Durable Attenuation of Tumor pH-Platelet Linkage Reinstates Bioorthogonal Targeting of Residual Tumors Post-Debulking

There are circumstances where tumors can only be partially resected. Therefore, multimodality therapy targeting post-operative residuals is important. Here, we show that bioorthogonal click chemistry enables targeted delivery to heterogeneous tumors, but its utility against tumor post-debulking is ineffective due to platelet cloaks that shield tumor cells from bioorthogonal pairing. We further discover tumor-infiltrating platelet levels respond to local pH changes. Elucidating this pH-platelet linkage, we design an injectable hydrogel for resection cavity implantation that simultaneously azido-tags tumor cells and inhibit their catalysis to acidify surrounding milieu. Unlike transient buffering, tumor acidification blockade sustains pH normalization, leading to durable platelet reduction. This reinstates bioorthogonal targeting of dibenzyl cyclooctyne-modified nanoparticles, thereby enhancing photodynamic ablation of residuals while amplifying systemic antitumor immunity. Concurrently, platelet/pH normalization interrupts metastasis cascade from invasion to circulation to colonization. Overall, attenuating tumor pH-platelet linkage unlocks bioorthogonal chemistry as a potential option for adjuvant therapy after tumor debulking.

Photothermal hyaluronic acid composite hydrogel targeting cancer stem cells for inhibiting recurrence and metastasis of breast cancer

Recurrence and metastasis have been recognized as a great challenge in cancer treatment. Cancer stem cells (CSCs), as a small subset of cancer cells, are closely associated with tumor metastasis and recurrence due to their resistance and multi-differentiation characteristics. Herein, we developed a local injectable hyaluronic acid (HA) composite hydrogel (HAAG) that targets CSCs, which can continuously release all-trans retinoic acid (ATRA) and gold nanoparticles (AuNPs) at tumor sites. The composite hydrogel was endowed with the ability to target CSCs through the specific binding of HA to CD44. ATRA was loaded into HA micelles to induce CSCs to differentiate into normal cancer cells, while AuNPs was incorporated into the hydrogel for photothermal therapy (PTT). HAAG exhibited good injectability, photothermal properties and CSCs targeting ability. HAAG not only significantly inhibited the growth of 4T1 mouse breast cancer cells and 4T1-CSCs in vitro, but also effectively inhibited tumor recurrence and metastasis in a 4T1-CSC mouse model in vivo. Our study provides a novel strategy of local differentiation combined with PTT for inhibiting the recurrence and metastasis of breast cancer.

Nano-Plumber Reshapes Glymphatic-Lymphatic System to Sustain Microenvironment Homeostasis and Improve Long-Term Prognosis after Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Long-term changes in the microenvironment of the brain contribute to the degeneration of neurological function following TBI. However, current research focuses primarily on short-term modulation during the early phases of TBI, not on the critical significance of long-term homeostasis in the brain microenvironment. Notably, dysfunction of the glymphatic-lymphatic system results in the accumulation of danger/damage-associated molecular patterns (DAMPs) in the brain, which is regarded as the leading cause of long-term microenvironmental disturbances following TBI. Here, a nanostructure, Nano-plumber, that co-encapsulates the microenvironment regulator pro-DHA and the lymphatic-specific growth factor VEGF-C is developed, allowing for a sustainable and orderly regulation of the microenvironment to promote long-term neurological recovery. Nano-plumber reverses the injury microenvironment by suppressing microglia and astrocytes activation and maintaining reduced activation via enhanced glymphatic-lymphatic drainage, and significantly improves the neurological function of rodents with TBI. This study demonstrates that glymphatic-lymphatic system reconstruction is essential for enhancing long-term prognosis following TBI, and that the Nano-plumber developed here may serve as a clinically translatable treatment option for TBI.

Dual Enzyme Cascade-Activated Popcorn-Like Nanoparticles Efficiently Remodeled Stellate Cells to Alleviate Pancreatic Desmoplasia

In pancreatic cancer, excessive desmoplastic stroma severely impedes drug access to tumor cells. By reverting activated pancreatic stellate cells (PSCs) to quiescence, all-trans retinoic acid (ATRA) can attenuate their stromal synthesis and remodel the tumor-promoting microenvironment. However, its modulatory effects have been greatly weakened due to its limited delivery to PSCs. Therefore, we constructed a tripeptide RFC-modified gelatin/oleic acid nanoparticle (RNP@ATRA), which delivered ATRA in an enzyme-triggered popcorn-like manner and effectively resolved the delivery challenges. Specifically, surface RFC was cleaved by aminopeptidase N (APN) on the tumor endothelium to liberate l-arginine, generating nitric oxide (NO) for tumor-specific vasodilation. Then, massive nanoparticles were pushed from the vessels into tumors, showing 5.1- and 4.0-fold higher intratumoral accumulation than free ATRA and APN-inert nanoparticles, respectively. Subsequently, in the interstitium, matrix metalloproteinase-2-induced gelatin degradation caused RNP@ATRA to rapidly release ATRA, promoting its interstitial penetration and PSC delivery. Thus, activated PSCs were efficiently reverted to quiescence, and stroma secretion and vascular compression were reduced, thereby enhancing intratumoral delivery of small-molecule or nanosized chemotherapeutics. Ultimately, RNP@ATRA combined with chemotherapeutics markedly suppressed tumor growth and metastasis without causing additional toxicities. Overall, this work provides a potential nanoplatform for the efficient delivery of PSC-modifying agents in pancreatic cancer and other stroma-rich tumors.

Advancement in precision diagnosis and therapeutic for triple-negative breast cancer: Harnessing diagnostic potential of CRISPR-cas & engineered CAR T-cells mediated therapeutics

Cancer is characterized by uncontrolled cell growth, disrupted regulatory pathways, and the accumulation of genetic mutations. These mutations across different types of cancer lead to disruptions in signaling pathways and alterations in protein expression related to cellular growth and proliferation. This review highlights the AKT signaling cascade and the retinoblastoma protein (pRb) regulating cascade as promising for novel nanotheranostic interventions. Through synergizing state-of-the-art gene editing tools like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system with nanomaterials and targeting AKT, there is potential to enhance cancer diagnostics significantly. Furthermore, the integration of modified CAR-T cells into multifunctional nanodelivery systems offers a promising approach for targeted cancer inhibition, including the eradication of cancer stem cells (CSCs). Within the context of highly aggressive and metastatic Triple-negative Breast Cancer (TNBC), this review specifically focuses on devising innovative nanotheranostics. For both pre-clinical and post-clinical TNBC detection, the utilization of the CRISPR-Cas system, guided by RNA (gRNA) and coupled with a fluorescent reporter specifically designed to detect TNBC's mutated sequence, could be promising. Additionally, a cutting-edge approach involving the engineering of TNBC-specific iCAR and syn-Notch CAR T-cells, combined with the co-delivery of a hybrid polymeric nano-liposome encapsulating a conditionally replicative adenoviral vector (CRAdV) against CSCs, could present an intriguing intervention strategy. This review thus paves the way for exciting advancements in the field of nanotheranostics for the treatment of TNBC and beyond.

Surgical Treatment of Osteosarcoma Induced Distant Pre-Metastatic Niche in Lung to Facilitate the Colonization of Circulating Tumor Cells

Recently, the major challenge in treating osteosarcoma patients is the metastatic disease, most commonly in the lungs. However, the underlying mechanism of recurrence and metastasis of osteosarcoma after surgical resection of primary tumor remains unclear. This study aims to investigate whether the pulmonary metastases characteristic of osteosarcoma is associated with surgical treatment and whether surgery contributes to the formation of pre-metastatic niche in the distant lung tissue. In the current study, the authors observe the presence of circulating tumor cells in patients undergoing surgical resection of osteosarcoma which is correlated to tumor recurrence. The pulmonary infiltrations of neutrophils and Gr-1+ myeloid cells are characterized to form a pre-metastatic niche upon the exposure of circulating tumor cells after surgical resection. It is found that mitochondrial damage-associated molecular patterns released from surgical resection contribute to the formation of pre-metastatic niche in lung through IL-1β secretion. This study reveals that surgical management for osteosarcoma, irrespective of the primary tumor, might promote the formation of postoperative pre-metastatic niche in lung which is with important implications for developing rational therapies during peri-operative period.

Nanotechnology-Aided Advancement in Combating the Cancer Metastasis

Modern medicine has been working to find a cure for cancer for almost a century, but thus far, they have not been very successful. Although cancer treatment has come a long way, more work has to be carried out to boost specificity and reduce systemic toxicity. The diagnostic industry is on the cusp of a technological revolution, and early diagnosis is essential for improving prognostic outlook and patient quality of life. In recent years, nanotechnology's use has expanded, demonstrating its efficacy in enhancing fields such as cancer treatment, radiation therapy, diagnostics, and imaging. Applications for nanomaterials are diverse, ranging from enhanced radiation adjuvants to more sensitive early detection instruments. Cancer, particularly when it has spread beyond the original site of cancer, is notoriously tough to combat. Many people die from metastatic cancer, which is why it remains a huge issue. Cancer cells go through a sequence of events known as the "metastatic cascade" throughout metastasis, which may be used to build anti-metastatic therapeutic techniques. Conventional treatments and diagnostics for metastasis have their drawbacks and hurdles that must be overcome. In this contribution, we explore in-depth the potential benefits that nanotechnology-aided methods might offer to the detection and treatment of metastatic illness, either alone or in conjunction with currently available conventional procedures. Anti-metastatic drugs, which can prevent or slow the spread of cancer throughout the body, can be more precisely targeted and developed with the help of nanotechnology. Furthermore, we talk about how nanotechnology is being applied to the treatment of patients with cancer metastases.

Weaving the nest: extracellular matrix roles in pre-metastatic niche formation

The discovery that primary tumors condition distant organ sites of future metastasis for seeding by disseminating tumor cells through a process described as the pre-metastatic niche (PMN) formation revolutionized our understanding of cancer progression and opened new avenues for therapeutic interventions. Given the inherent inefficiency of metastasis, PMN generation is crucial to ensure the survival of rare tumor cells in the otherwise hostile environments of metastatic organs. Early on, it was recognized that preparing the "soil" of the distal organ to support the outgrowth of metastatic cells is the initiating event in PMN development, achieved through the remodeling of the organ's extracellular matrix (ECM). Remote restructuring of ECM at future sites of metastasis under the influence of primary tumor-secreted factors is an iterative process orchestrated through the crosstalk between resident stromal cells, such as fibroblasts, epithelial and endothelial cells, and recruited innate immune cells. In this review, we will explore the ECM changes, cellular effectors, and the mechanisms of ECM remodeling throughout PMN progression, as well as its impact on shaping the PMN and ultimately promoting metastasis. Moreover, we highlight the clinical and translational implications of PMN ECM changes and opportunities for therapeutically targeting the ECM to hinder PMN formation.

cRGD-modified nanoparticles of multi-bioactive agent conjugate with pH-sensitive linkers and PD-L1 antagonist for integrative collaborative treatment of breast cancer

Targeted co-delivery and co-release of multi-drugs is essential to have an integrative collaborative effect on treating cancer. It is valuable to use few drug carriers for multi-drug delivery. Herein, we develop cRGD-modified nanoparticles (cRGD-TDA) of a conjugate of doxorubicin as cytotoxic agent, adjudin as an anti-metastasis agent and D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) as a reactive oxygen species inducer linked with pH-sensitive bonds, and then combine the nanoparticles with PD-L1 antagonist to treat 4T1 triple-negative breast cancer. cRGD-TDA NPs present tumor-targeted co-delivery and pH-sensitive co-release of triple agents. cRGD-TDA NPs combined with PD-L1 antagonist much more significantly inhibit tumor growth and metastasis than single-drug treatment, which is due to their integrative collaborative effect. It is found that TPGS elicits a powerful immunogenic cell death effect. Meanwhile, PD-L1 antagonist mitigates the immunosuppressive environment and has a synergistic effect with the cRGD-TDA NPs. The study provides a new strategy to treat refractory cancer integratively and collaboratively.

Immune determinants of the pre-metastatic niche

Primary tumors actively and specifically prime pre-metastatic niches (PMNs), the future sites of organotropic metastasis, preparing these distant microenvironments for disseminated tumor cell arrival. While initial studies of the PMN focused on extracellular matrix alterations and stromal reprogramming, it is increasingly clear that the far-reaching effects of tumors are in great part achieved through systemic and local PMN immunosuppression. Here, we discuss recent advances in our understanding of the tumor immune microenvironment and provide a comprehensive overview of the immune determinants of the PMN's spatiotemporal evolution. Moreover, we depict the PMN immune landscape, based on functional pre-clinical studies as well as mounting clinical evidence, and the dynamic, reciprocal crosstalk with systemic changes imposed by cancer progression. Finally, we outline emerging therapeutic approaches that alter the dynamics of the interactions driving PMN formation and reverse immunosuppression programs in the PMN ensuring early anti-tumor immune responses.

Cell migration induces apoptosis in osteosarcoma cell via inhibition of Wnt-β-catenin signaling pathway

The current design scheme on anti-cancer materials is mainly through tuning the mechanical properties of the materials to induce apoptosis in cancer cells, with the involvement of Rho/ROCK signaling pathway. We hypothesize that tuning the motility is another potential important approach to modifying the tumor microenvironment and inducing tumor apoptosis. To this aim, we have prepared RGD-modified substrates to regulate cell motility through modification of RGD with different concentrations, and systematically examined the effect of motility on the apoptosis of tumor cells, and the potential involvement of Wnt signaling pathway. Our studies indicated that RGD modification could be readily used to tune the motility of cancer cells. High RGD concentration significantly suppressed the migration of cancer cells, leading to significantly increased apoptosis rate, about three times of that of the unmodified samples. Western-blot analysis also showed that cell with low motility expressed more caspase-3 and PARP proteins. Further RNA sequence study strongly suggested that low motility inhibited the canonical Wnt signaling pathway, which in turn led to the activation of the mitochondria-associated caspase signaling pathway, and ultimately to the apoptosis of osteosarcoma cells. Activation of the Wnt-β-catenin pathway through HLY78 significantly suppressed the apoptosis of MG-63 cells, further suggesting the critical role of Wnt pathway in motility-regulated-apoptosis of tumor cells. Our findings shed insights to understand the underlying mechanisms that induced the tumor cell apoptosis, and might provide new strategy for designing the novel anti-tumor materials.

Tumor-Infiltrating Immune Cell Landscapes in the Lymph Node Metastasis of Papillary Thyroid Cancer

Regional lymph node metastasis (LNM) increases the risk of distant metastasis in papillary thyroid cancer (PTC) patients. However, it remains unclear how tumor cells in PTC patients with LNM evade immune system surveillance and proceed to colonize distant organs. Here, we comprehensively characterize the tumor-infiltrating immune cell landscape in PTC with LNM. LNM-related genes include multiple important soluble mediators such as CXCL6, IL37, MMP10, and COL11A1, along with genes involved in areas such as extracellular matrix organization and TLR regulation by endogenous ligands. In PTC without LNM, the tumor infiltration of activated dendritic cells and M0 macrophages showed increases from normal cells, but with yet greater increases and correspondingly worse prognosis in PTC with LNM. Conversely, the tumor infiltration of activated NK cells and eosinophils was decreased in PTC without LNM, as compared to normal cells, and yet further decreased in PTC with LNM, with such decreases associated with poor prognosis. We further demonstrate that mutations of driver genes in tumor cells influence the infiltration of surrounding immune cells in the tumor microenvironment (TME). Particularly, patients carrying TG mutations tend to show increased filtration of M2 macrophages and activated NK cells in the TME, whereas patients carrying HRAS mutations tend to show reduced filtration of M0 macrophages and show enhanced filtration of activated dendritic cells in the TME. These findings increase our understanding of the mechanisms of regional lymph node metastasis in PTC and its associated tumor microenvironment, potentially facilitating the development of personalized treatment regimens to combat immunotherapy failure.

A hierarchical tumor-targeting strategy for eliciting potent antitumor immunity against triple negative breast cancer

Triple negative breast cancer (TNBC) as a highly aggressive and metastatic malignancy lacks targeting therapies nowadays. Moreover, although immune checkpoint blockade (ICB) is known to trigger anti-tumor immune response, most TNBC falls into the immunologically "cold" category unsuitable for ICB therapy due to insufficient lymphocyte infiltration. Herein, we develop a hierarchical targeting strategy for preparing a core-shell-structural nanodrug to concurrently block the programmed death ligand 1 (PD-L1) and deliver a stimulator of interferon gene (STING) agonist into tumor-infiltrating antigen-presenting cells (APCs). The nanodrug complexed the interferon stimulatory DNA (ISD) for STING activation in its core, conjugated PD-L1 antibody (aPD-L1) on its shell through a matrix metalloproteinase-2 (MMP-2) substrate peptide, and incorporated "hidden" mannose in its sublayer. Through aPD-L1-mediated active targeting of tumor cells and tumor-infiltrating APCs, the nanodrug efficiently accumulated in tumor sites. Then, the PD-L1-conjugating peptide was cleaved by tumor-enriched MMP-2, leaving aPD-L1 on target cells for ICB while exposing mannose to mediate targeted delivery of ISD into tumor-infiltrating dendritic cells (DCs) and tumor-associated macrophages (TAMs). Activating the STING signaling in DCs and TAMs not only stimulated the APCs maturation to prime anti-tumor immunity but also induced their chemokine secretion to promote tumor infiltration of anti-tumor effector T cells, thus sensitizing TNBC to the ICB therapy. Consequently, a potent antitumor immunity was evoked to effectively inhibit the tumor growth and metastasis in mice bearing orthotopic 4T1 breast cancer, showing the great potential in treating immunologically "cold" tumors.

Recent progress in molecular mechanisms of postoperative recurrence and metastasis of hepatocellular carcinoma

Hepatectomy is currently considered the most effective option for treating patients with early and intermediate hepatocellular carcinoma (HCC). Unfortunately, the postoperative prognosis of patients with HCC remains unsatisfactory, predominantly because of high postoperative metastasis and recurrence rates. Therefore, research on the molecular mechanisms of postoperative HCC metastasis and recurrence will help develop effective intervention measures to prevent or delay HCC metastasis and recurrence and to improve the long-term survival of HCC patients. Herein, we review the latest research progress on the molecular mechanisms underlying postoperative HCC metastasis and recurrence to lay a foundation for improving the understanding of HCC metastasis and recurrence and for developing more precise prevention and intervention strategies.

Metformin and histone deacetylase inhibitor based anti-inflammatory nanoplatform for epithelial-mesenchymal transition suppression and metastatic tumor treatment

Epithelial-mesenchymal transition (EMT), a differentiation process with aberrant changes of tumor cells, is identified as an initial and vital procedure for metastatic processes. Inflammation is a significant inducer of EMT and provides an indispensable target for blocking EMT, however, an anti-inflammatory therapeutic with highlighted safety and efficacy is deficient. Metformin is a promising anti-inflammatory agent with low side effects, but tumor monotherapy with an anti-inflammation drug could generate therapy resistance, cell adaptation or even promote tumor development. Combination therapies with various anti-inflammatory mechanisms can be favorable options improving therapeutic effects of metformin, here we develop a tumor targeting hybrid micelle based on metformin and a histone deacetylase inhibitor propofol-docosahexaenoic acid for efficient therapeutic efficacies of anti-inflammatory drugs. Triptolide is further encapsulated in hybrid micelles for orthotopic tumor therapies. The final multifunctional nanoplatforms (HAOPTs) with hyaluronic acid (HA) modification can target tumor efficiently, inhibit tumor cell EMT processes, repress metastasis establishment and suppress metastatic tumor development in a synergistic manner. Collectively, the results afford proof of concept that the tumor targeting anti-inflammatory nanoplatform can provide a potent, safe and clinical translational approach for EMT inhibition and metastatic tumor therapy.

Programmed prodrug breaking the feedback regulation of P-selectin in plaque inflammation for atherosclerotic therapy

Inflammation is the main driver of the aggravation of arteriosclerosis, and the complex inflammatory response in plaque is usually the result of the interaction of various cells and cytokines. Therefore, it is difficult to comprehensively regulate the inflammatory process of arteriosclerosis by intervening a single target, resulting in the poor effect of existing treatment method. Based on our clinical findings that P-selectin stably and highly expressed in patients' plaque endothelial cells, the programmed prodrug, low molecular weight heparin-indomethacin nanoparticles (LI NPs), were established as anti-inflammatory agent to multiphase inhibit arteriosclerosis by cascade interference of P-selectin. Structurally, LI NPs was obtained by simple esterification of low molecular weight heparin and indomethacin without any additives, guaranteeing the biocompatibility and applicability of LI NPs. Functionally, LI NPs could interfere with P-selectin in the inflammatory process, such as inhibiting macrophage adhesion, reducing the secretion of inflammatory factors, and inducing macrophage apoptosis. In the arteriosclerosis mice model, LI NPs significantly reduced the plaque area and showed satisfactory curative effect, which is related to the intervention of the multiphase inflammation between endothelial cells and macrophages. In conclusion, the programmed prodrug LI NPs offered a promising approach for the clinical therapy of arteriosclerosis.

Metabolic Intervention Nanoparticles for Triple-Negative Breast Cancer Therapy via Overcoming FSP1-Mediated Ferroptosis Resistance

Triple-negative breast cancer (TNBC) patients have a predisposition to poor prognosis due to the strong malignancy. Ferroptosis, a new form of cell death, is a candidate treatment for TNBC owing to its effectiveness in killing cancer cells. However, some TNBC cells exhibit an abnormal tumor metabolism, especially the ferroptosis suppressor protein 1 (FSP1)-mediated ubiquinone redox metabolism, which can promote ferroptosis resistance. Here, rosuvastatin (RSV) is encapsulated in silk fibroin (SF) nanoparticle (designated as Cu-SF(RSV) NPs) for TNBC inhibition by overcoming FSP1-mediated ferroptosis resistance. RSV intervenes in metabolic mevalonate pathway to disturb the redox homeostasis regulated by CoQ/FSP1 axis, thereby overcoming ferroptosis resistance. Besides, Cu-SF(RSV) NPs can generate reactive oxygen species and deplete glutathione to facilitate redox stress, thereby amplifying ferroptosis effect. Thus, it is anticipated that the metabolic intervention nanoparticles, Cu-SF(RSV) NPs, can be exploited as a promising therapeutic platform for clinical TNBC treatment.

Combining Fruquintinib and Doxorubicin in Size-Converted Nano-Drug Carriers for Tumor Therapy

Single-modality tumor therapy confronts many challenges, such as incomplete tumor ablation, tumor metastasis, and limited tumor tissue penetration. Combination therapy simultaneously achieves deep drug delivery to fully exert synergistic effects and has received increasing attention. Herein, based on the excellent efficacy of anti-angiogenesis therapy combined with chemotherapy and the specific size of the poly-amidoamine dendrimer (PAMAM), we developed a pH-triggered size-converted nano-drug delivery system to co-deliver fruquintinib (FRU) and doxorubicin (DOX). This study used cyclic Arg-Gly-Asp (cRGD) as the target, pH-responsive liposomes (PRLs), and PAMAM as the drug carrier. The FRU and DOX-loaded small-particle-size complex polyamide-amine-doxorubicin (PD) was encapsulated into PRLs with the target to construct a size-converted nano-drug delivery system, PRL-PD/FRU-cRGD. This nanoparticle (∼120 nm) actively targeted tumor tissues and used the acidic microenvironment outside tumor cells to release FRU and small-particle-size complex PD (∼15 nm), enabling the conversion of large-size nanoparticles to small-size nanoparticles and resulting in efficient tumor accumulation. In addition, the released PD could realize the deep delivery of DOX, showing efficient deep tumor penetration and further enhancing the tumor-suppressing effect. The results of in vivo and in vitro experiments showed that PRL-PD/FRU-cRGD exhibited the excellent synergistic effects of anti-angiogenesis therapy combined with chemotherapy and effectively inhibited tumor cell proliferation and metastasis, thereby achieving efficient tumor therapy. Thus, PRL-PD/FRU-cRGD shows great potential for combined tumor therapy.

Nanotechnology-aided advancement in the combating of cancer metastasis

Cancer, especially when it has metastasized to different locations in the body, is notoriously difficult to treat. Metastatic cancer accounts for most cancer deaths and thus remains an enormous challenge. During the metastasis process, cancer cells negotiate a series of steps termed the “metastatic cascadeˮ that offer potential for developing anti-metastatic therapy strategies. Currently available conventional treatment and diagnostic methods addressing metastasis come with their own pitfalls and roadblocks. In this contribution, we comprehensively discuss the potential improvements that nanotechnology-aided approaches are able to bring, either alone or in combination with the existing conventional techniques, to the identification and treatment of metastatic disease. We tie specific nanotechnology-aided strategies to the complex biology of the different steps of the metastatic cascade in order to open up new avenues for fine-tuned targeting and development of anti-metastatic agents designed specifically to prevent or mitigate the metastatic outgrowth of cancer. We also present a viewpoint on the progress of translation of nanotechnology into cancer metastasis patient care.

In vivo self-assembled drug nanocrystals for metastatic breast cancer all-stage targeted therapy

Chemotherapy is still the mainstay treatment for metastatic triple-negative breast cancers (TNBC) currently in clinical practice. The unmet needs of chemotherapy for metastatic TNBC are mainly from the insufficient drug delivery and unavailable targeting strategy that thwart the whole progression of metastatic TNBC. The in vivo ligands-mediated active targeting efficiency is usually affected by protein corona. While, the protein corona-bridged natural targeting, in turn, provides a new way for specific drug delivery. Herein, we develop a novel metastatic progression-oriented in vivo self-assembled Cabazitaxel nanocrystals (CNC) delivery system (PC/CNC) through the CNC automatically absorbing functional plasma proteins (transferrin, apolipoprotein A-IV and apolipoprotein E) in vivo, aiming to achieve the simultaneously targeted delivery to primary tumors, circulating tumor cells and metastatic lesions. With the unique advantages of superhigh drug-loading and protein corona empowered active targeting properties to tumor cells, HUVECs, active-platelets and blood-brain barrier/blood-tumor barrier, the PC/CNC exhibits a significantly improved therapeutic effect in metastatic TNBC therapy compared with free drug and CNC-loaded liposomes.

Engineering a multi-target therapy nanoplatform against tumor growth and metastasis via a novel NSAID-Pt(IV) prodrug

Tumor growth and metastasis are caused by many factors. The complexity means that a multi-target combination therapy strategy should be selected against tumor growth and metastasis. Here, cisplatin (CDDP) and bendazac (Ben) were designed as a novel NSAID-Pt(IV) nanoplatform, which is an effective weapon for combating tumor growth and metastasis.

Neutrophil Cyto-Pharmaceuticals Suppressing Tumor Metastasis via Inhibiting Hypoxia-Inducible Factor-1α in Circulating Breast Cancer Cells

Circulating tumor cells (CTCs) are reported as the precursor of tumor metastases, implying that stifling CTCs would be beneficial for metastasis prevention. However, challenges remain for the application of therapies that aim at CTCs due to lack of effective CTC-targeting strategy and sensitive therapeutic agents. Herein, a general CTC-intervention strategy based on neutrophil cyto-pharmaceuticals is proposed for suppressing CTC colonization and metastasis formation. Breast cancer 4T1 cells are infused as the mimic CTCs, and 4T1 cells trapped are first elucidated in neutrophil extracellular traps (NETs) expressing high levels of hypoxia-inducible factor-1α (HIF-1α) due to NET formation and thus promoting tumor cell colonization through enhanced migration, invasion and stemness. After verifying HIF-1α as a potential target for metastasis prevention, living neutrophil cyto-pharmaceuticals (CytPNEs) loaded with HIF-1α inhibitor are fabricated to therapeutically inhibit HIF-1α. It is demonstrated that CytPNEs can specially convey the HIF-1α inhibitor to 4T1 cells according to the inflammatory chemotaxis of neutrophils and down-regulate HIF-1α, thereby inhibiting metastasis and prolonging the median survival of mice bearing breast cancer lung metastasis. The research offers a new perspective for understanding the mechanism of CTC colonization, and puts forward the strategy of targeted intervention of CTCs as a meaningful treatment for tumor metastasis.

Combination of mitochondria impairment and inflammation blockade to combat metastasis

Targeted induction of mitochondria impairment has emerged as a promising strategy for anti-metastasis therapy. However, problems such as limited mitochondria targeting efficiency, undesired drug leakage and insufficient drug release inside mitochondria remain crucial challenges for mitochondria-targeting therapy. Here, we constructed an N-(2-hydroxypropyl) methacrylamide (HPMA) polymer based cationic system that could target to mitochondria and facilitate on demand drug release in response to excessive mitochondrial reactive oxygen species. Whereas, this drug delivery system is still challenged by limitations of (1) in vivo application, and (2) inflammatory tumor microenvironment (TME). On one aspect, to prolong blood circulation and increase tumor targeting, we designed a nanocomposite (PDT-NCs) that assembled from the cationic HPMA polymer and anionic hyaluronic acid via electrostatic interaction. On another aspect, a celecoxib loaded liposome (Lip-Cel) was further fabricated to alleviate inflammation in TME by downregulating various metastasis-associated factors. Ultimately, PDT-NCs and Lip-Cel led to a drastic improvement in the suppression of primary tumor growth and distant lung metastasis. Our work provided a generalizable approach of mitochondria dysfunction and inflammation blockade to combat metastatic tumors.