Surface chemistry engineered selenium nanoparticles as bactericidal and immuno-modulating dual-functional agents for combating methicillin-resistant Staphylococcus aureus Infection.

Because of the extremely complexed microenvironment of drug-resistant bacterial infection, nanomaterials with both bactericidal and immuno-modulating activities are undoubtedly the ideal modality for overcoming drug resistance. Herein, we precisely engineered the surface chemistry of selenium nanoparticles (SeNPs) using neutral (polyvinylpyrrolidone-PVP), anionic (letinan-LET) and cationic (chitosan-CS) surfactants. It was found that surface chemistry greatly influenced the bioactivities of functionalized SeNPs, their interactions with methicillin-resistant Staphylococcus aureus (MRSA), immune cells and metabolisms. LET-functionalized SeNPs with distinct metabolisms exhibited the best inhibitory efficacy compared to other kinds of SeNPs against MRSA through inducing robust ROS generation and damaging bacterial cell wall. Meanwhile, only LET-SeNPs could effectively activate natural kill (NK) cells, and enhance the phagocytic capability of macrophages and its killing activity against bacteria. Furthermore, in vivo studies suggested that LET-SeNPs treatment highly effectively combated MRSA infection and promoted wound healing by triggering much more mouse NK cells, CD8+ and CD4+ T lymphocytes infiltrating into the infected area at the early stage to efficiently eliminate MRSA in the mouse model. This study demonstrates that the novel functionalized SeNP with dual functions could serve as an effective antibacterial agent and could guide the development of next generation antibacterial agents.

Locally Trapping the C-C Chemokine Receptor Type 7 by Gene Delivery Nanoparticle Inhibits Lymphatic Metastasis Prior to Tumor Resection.

Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype. Currently, no targeted treatment is available for TNBC, and the most common clinical therapy is tumor resection, which often promotes metastasis risks. Strong evidence suggests that the lymphatic metastasis is mediated by the C-C chemokine receptor type 7 (CCR7)/C-C motif chemokine ligand 21 crosstalk between tumor cells and the lymphatic system. It is hypothesized that CCR7 is a key immune modulator in the tumor microenvironment and the local blockade of CCR7 could effectively inhibit TNBC lymphatic metastasis. Accordingly, a plasmid encoding an antagonistic CCR7 affinity protein-CCR7 trap is delivered by tumor targeting nanoparticles in a highly metastatic 4T1 TNBC mouse model. Results show that CCR7 traps are transiently expressed, locally disrupt the signaling pathways in the tumor site, and efficiently inhibit TNBC lymphatic metastasis, without inducing immunosuppression as observed in systemic therapies using CCR7 monoclonal antibody. Significantly, upon applying CCR7 trap therapy prior to tumor resection, a 4T1 TNBC mouse model shows good prognosis without any further metastasis and relapse. In addition, CCR7 trap therapy efficiently inhibits the lymphatic metastasis in a B16F10 melanoma mouse model, indicating its great potential for various metastatic diseases treatment.

Cell-Penetrating Peptide Enhanced Antigen Presentation for Cancer Immunotherapy.

The development of effective cancer vaccines is an important direction in the area of cancer immunotherapy. Although certain types of preventive cancer vaccines have already been used in the clinic, therapeutic cancer vaccines for treatment of already established tumors are still in high demand. In this study, we develop a new type of cancer vaccine by mixing cell-penetrating peptide (CPP) conjugated antigen as the enhanced antigen, together with CpG as the immune adjuvant. A special CPP, cytosol-localizing internalization peptide 6 (CLIP6), which has the ability to enter cells exclusively via a nonendosomal mechanism, i.e., direct translocation across the cell membrane, is conjugated with model antigen ovalbumin (OVA). Compared to naked OVA, the obtained CLIP6-OVA conjugates show greatly increased uptake by dendritic cells (DCs) and, more importantly, remarkably enhanced antigen cross-presentation, eliciting stronger cytotoxic T lymphocyte (CTL) mediated immune responses with the help of CpG. This CLIP6-OVA/CpG formulation offers effective protection for mice against challenged B16-OVA tumors, and is able to further function as a therapeutic vaccine, which, in combination with immune checkpoint blockade therapy, can significantly suppress the already-established tumors. Such a CLIP6-based cancer vaccine developing strategy shows promising potential toward clinical practice owing to its features of easy preparation, low cost, and remarkable biocompatibility.

Smart Nanoreactors for pH-Responsive Tumor Homing, Mitochondria-Targeting, and Enhanced Photodynamic-Immunotherapy of Cancer.

Photodynamic therapy (PDT) is an oxygen-dependent light-triggered noninvasive therapeutic method showing many promising aspects in cancer treatment. For effective PDT, nanoscale carriers are often needed to realize tumor-targeted delivery of photosensitizers, which ideally should further target specific cell organelles that are most vulnerable to reactive oxygen species (ROS). Second, as oxygen is critical for PDT-induced cancer destruction, overcoming hypoxia existing in the majority of solid tumors is important for optimizing PDT efficacy. Furthermore, as PDT is a localized treatment method, achieving systemic antitumor therapeutic outcomes with PDT would have tremendous clinical values. Aiming at addressing the above challenges, we design a unique type of enzyme-encapsulated, photosensitizer-loaded hollow silica nanoparticles with rationally designed surface engineering as smart nanoreactors. Such nanoparticles with pH responsive surface coating show enhanced retention responding to the acidic tumor microenvironment and are able to further target mitochondria, the cellular organelle most sensitive to ROS. Meanwhile, decomposition of tumor endogenous H2O2 triggered by those nanoreactors would lead to greatly relieved tumor hypoxia, further favoring in vivo PDT. Moreover, by combining our nanoparticle-based PDT with check-point-blockade therapy, systemic antitumor immune responses could be achieved to kill nonirradiated tumors 1-2 cm away, promising for metastasis inhibition.

Surface-Engineering of Red Blood Cells as Artificial Antigen Presenting Cells Promising for Cancer Immunotherapy.

The development of artificial antigen presenting cells (aAPCs) to mimic the functions of APCs such as dendritic cells (DCs) to stimulate T cells and induce antitumor immune responses has attracted substantial interests in cancer immunotherapy. In this work, a unique red blood cell (RBC)-based aAPC system is designed by engineering antigen peptide-loaded major histocompatibility complex-I and CD28 activation antibody on RBC surface, which are further tethered with interleukin-2 (IL2) as a proliferation and differentiation signal. Such RBC-based aAPC-IL2 (R-aAPC-IL2) can not only provide a flexible cell surface with appropriate biophysical parameters, but also mimic the cytokine paracrine delivery. Similar to the functions of matured DCs, the R-aAPC-IL2 cells can facilitate the proliferation of antigen-specific CD8+ T cells and increase the secretion of inflammatory cytokines. As a proof-of-concept, we treated splenocytes from C57 mice with R-aAPC-IL2 and discovered those splenocytes induced significant cancer-cell-specific lysis, implying that the R-aAPC-IL2 were able to re-educate T cells and induce adoptive immune response. This work thus presents a novel RBC-based aAPC system which can mimic the functions of antigen presenting DCs to activate T cells, promising for applications in adoptive T cell transfer or even in direct activation of circulating T cells for cancer immunotherapy.

Emerging nanomedicine approaches fighting tumor metastasis: animal models, metastasis-targeted drug delivery, phototherapy, and immunotherapy.

Metastasis is directly or indirectly responsible for the majority of cancer deaths. Anti-metastasis treatment is thus the key to cure cancer. Recent development in nanomedicine has shown great promise for tackling cancer metastasis. In recent years, nanoparticle-based drug delivery systems have been extensively explored for improving cancer treatment, showing the ability to reduce the risk of tumor metastasis compared with conventional chemotherapy. Photothermal therapy, by employing nano-theranostic agents, has also been found to be able to inhibit lymphatic tumor metastasis. Moreover, the post-immunological effects of certain types of nano-therapies may also be utilized to treat tumor metastasis, presenting an exciting new avenue towards successful cancer treatment. In this review article, we would like to summarize the latest research advances in the development of various emerging nanomedicine approaches for cancer metastasis treatment, and discuss future prospects in this emerging field as well as the clinical translation potential of these techniques.

Functionalized graphene oxide in microbial engineering: An effective stimulator for bacterial growth.

Whether graphene and graphene oxide (GO) would affect the activities of bacteria has been under debate. Nevertheless, how graphene derivatives with biocompatible coatings interact with microorganisms and the underlying mechanisms are important issues for nanobiotechnology, and remain to be further explored. Herein, three new types of nano-GOs functionalized with polyethylene glycol (nGO-PEGs) were synthesized by varying the PEGylation degree, and their effects on Escherichia coli (E. coli) were carefully investigated. Interestingly, nGO-PEG (1:1), the one with relatively lower PEGylation degree, could significantly stimulate bacterial growth, whereas as-made GO and the other two nGO-PEGs showed no effect. Further analysis revealed that nGO-PEG (1:1) treatment significantly accelerated FtsZ-ring assembly, shortening Phase 1 in the bacterial cell cycle. Both DNA synthesis and extracellular polymeric substance (EPS) secretion were also dramatically increased. This unique phenomenon suggests promising potentials in microbial engineering as well as in clinical detection of bacterial pathogens. As a proof-of-concept, nGO-PEG (1:1) treatment could remarkably enhance (up to 6-fold) recombinant protein production in engineered bacteria cells. To our best knowledge, this is the first demonstration of functionalized GO as a novel, positive regulator in microbial engineering. Moreover, our work highlights the critical role of surface chemistry in modulating the interactions between nanomaterials and microorganisms.

Surface-engineered gold nanorods: promising DNA vaccine adjuvant for HIV-1 treatment.

With the intense international response to the AIDS pandemic, HIV vaccines have been extensively investigated but have failed due to issues of safety or efficacy in humans. Adjuvants for HIV/AIDS vaccines are under intense research but a rational design approach is still lacking. Nanomaterials represent an obvious opportunity in this field due to their unique physicochemical properties. Gold nanostructures are being actively studied as a promising and versatile platform for biomedical application. Herein, we report novel surface-engineered gold nanorods (NRs) used as promising DNA vaccine adjuvant for HIV treatment. We have exploited the effects of surface chemistry on the adjuvant activity of the gold nanorod by placing three kinds of molecules, that is, cetyltrimethylammonium bromide (CTAB), poly(diallydimethylammonium chloride) (PDDAC), and polyethyleneimine (PEI) on the surface of the nanorod. These PDDAC- or PEI-modified Au NRs can significantly promote cellular and humoral immunity as well as T cell proliferation through activating antigen-presenting cells if compared to naked HIV-1 Env plasmid DNA treatment in vivo. These findings have shed light on the rational design of low-toxic nanomaterials as a versatile platform for vaccine nanoadjuvants/delivery systems.

Precise Engineering of a Se/Te Nanochaperone for Reinvigorating Cancer Radio-Immunotherapy.

Facilely synthesized nanoradiosensitizers with well-controlled structure and multifunctionality are greatly desired to address the challenges of cancer radiotherapy. In this work, a universal method is developed for synthesizing chalcogen-based TeSe nano-heterojunctions (NHJs) with rod-, spindle-, or dumbbell-like morphologies by engineering the surfactant and added selenite. Interestingly, dumbbell-shaped TeSe NHJs (TeSe NDs) as chaperone exhibit better radio-sensitizing activities than the other two nanostructural shapes. Meanwhile, TeSe NDs can serve as cytotoxic chemodrugs that degrade to highly toxic metabolites in acidic environment and deplete GSH within tumor to facilitate radiotherapy. More importantly, the combination of TeSe NDs with radiotherapy significantly decreases regulatory T cells and M2-phenotype tumor-associated macrophage infiltrations within tumors to reshape the immunosuppressive microenvironment and induce robust T lymphocytes-mediated antitumor immunity, resulting in great abscopal effects on combating distant tumor progression. This study provides a universal method for preparing NHJ with well-controlled structure and developing nanoradiosensitizers to overcome the clinical challenges of cancer radiotherapy.

Universal Fe/Mn Nanoadjuvant with T1/T2 MRI Self-Navigation and Gas Generation for Ideal Vaccines with Precise Tracking.

Because of the distinguished properties between nanovaccine and traditional vaccine, the precise guidelines for nanovaccines with an optimal vaccination strategy to induce ideal immunities are greatly desired for combating major diseases, including cancer and infections. Herein, we designed and synthesized a self-navigating nanoadjuvant composed of Fe-doped manganese carbonate and its nanovaccine via a facile method. First, the degradation of the nanoadjuvant under acidic milieu of immune cells in lymph nodes would generate T1 and T2 MR imaging (MRI) signals to reflect the transformation dynamics of the nanovaccine and inform us when the next vaccination needed. Under this guideline, nanovaccines with a precise vaccination strategy triggered robust antigen-specific immune responses and immunological memory to effectively prevent ovalbumin (OVA)-expressing melanoma relapse by activating dendritic cells via a stimulator of interferon genes (STING) signaling pathway and inducing antigen cross-presentation by shaping lysosome integrity with CO2 generation and upregulating transporter associated antigen processing 1 (TAP-1) transporter. This study provides a universal nanoadjuvant with imaging self-guidance, immunopotentiating, and cross-priming activities for developing precise vaccines with an optimal immunization strategy to combat major diseases.

Designing Selenium Nanoadjuvant as Universal Agent for Live-Killed Virus-Based Vaccine.

Inactivated virus vaccines with whole antigen spectra and good safety are the commonly used modality for preventing infections. However, the poor immunogenicity greatly limits its clinical applications. Herein, by taking advantages of the crucial roles of Se in the functions of immune cells and its biomineralization property, it successfully in-situ synthesized Se nanoadjuvant on inactivated viruses such as porcine epidemic diarrhea virus (PEDV), pseudorabies virus (PRV), and porcine reproductive and respiratory syndrome virus (PRRSV) in a facile method, which is universal to construct other inactivated virus vaccines. The nanovaccine can highly effectively enhance the uptake of PEDV/PRV/PRRSV into dendritic cells (DCs) and activate DCs via triggering TLR4 signaling pathways and regulating selenoproteins expressions. Furthermore, it exhibited better activities in triggering macrophages and natural killer cells-mediated innate immunity and T cells-mediated cellular immunity compared to PEDV and the commercial inactivated PEDV vaccine on both mice and swine models. This study provides a universal Se nanoadjuvant for developing inactivated viruses-based nanovaccines for preventing virus infections.

Selenadiazole derivative-loaded metal azolate frameworks facilitate NK cell immunotherapy by sensitizing tumor cells and shaping immuno-suppressive microenvironments.

The low sensitivity of tumor cells and immunosuppressive microenvironments lead to unsatisfactory efficacy of natural killer (NK) cell immunotherapy. In this work, we developed a safe and effective combination treatment strategy by integrating a selenadiazole derivative (PSeD)-loaded metal azolate framework (PSeD@MAF-4(R)) with NK cells derived from cancer patients against a xenograft human breast tumor model. Intriguingly, it was found that only PSeD@MAF-4(R) pretreatment on tumor cells exhibited synergistic effects with NK cells in inhibiting tumor cell growth by up-regulating NKG2D and its ligands to maximize the interactions between NK and MCF-7 cells. Moreover, PSeD@MAF-4(R) pretreatment could significantly enhance the degranulation of NK cells and regulate their secretions of pro- or anti-inflammatory cytokines (e.g. IL-6, IL-10, and TGF-ß). Furthermore, PSeD@MAF-4(R) could significantly enhance the penetration capability of NK cells into tumor spheroids. The combination treatment mainly induced G1 phase arrest and activated multiple caspase-mediated apoptosis of tumor cells. In vivo evidence showed that PSeD@MAF-4(R) combined with NK cells could highly efficiently combat breast tumor progression via inducing and activating innate immune cell (DC and NK cell) infiltrations within tumor tissues while shaping the suppressive tumor microenvironment by down-regulating the expression of TGF-ß. This developed strategy may provide important information for developing NK cell-based combination cancer immunotherapy with high efficacy and good safety profiles.

Metabolic Reprogramming of NK Cells by Black Phosphorus Quantum Dots Potentiates Cancer Immunotherapy.

Low persistence, metabolic dysfunction in microenvironment, and tumor-derived immunosuppression of Natural killer (NK) cells in patients are greatly limited the successful clinical application of NK cell-based cancer immunotherapy. Interestingly, herein that human serum albumin-encapsulated black phosphorus quantum dots (BPQDs@HSA) can effectively augment antitumor efficacy of clinical patients-derived NK cell immunotherapy is found. As the donor of phosphate group, BPQDs@HSA binds with the protein of phosphatidylinositol 4-phosphate 5-kinase type-1 gamma (PIP5K1A) and activates the downstream PI3K-Akt and mTOR signaling pathways to reprogram cell metabolism of glycolysis and further promote the oxidative phosphorylation, sequentially maintains the cell viability and immunity of NK cells. And multiomics analysis is therefore conducted to reveal the underlying immunoregulation mechanisms, and that BPQDs@HSA can interact with the Toll-like receptor (TLR) on the NK cell surface and increase the expression level of mTOR, and thus activate downstream NF-κB signalling pathways to regulate cytokine secretion and enhance immune tumoricidal is found. BPQDs@HSA can also enhance immune surveillance, relieve immune suppression, and inhibit tumor immune escape. Collectively, this study not only demonstrates a successful strategy for nanomedicine-potentiated immune-cancer therapy, but also sheds light on the understanding of interface between nanomedicine and immune cells activation.

Selective targeting of gold nanorods at the mitochondria of cancer cells: implications for cancer therapy.

We have observed that Au nanorods (NRs) have distinct effects on cell viability via killing cancer cells while posing negligible impact on normal cells and mesenchymal stem cells. Obvious differences in cellular uptake, intracellular trafficking, and susceptibility of lysosome to Au NRs by different types of cells resulted in selective accumulation of Au NRs in the mitochondria of cancer cells. Their long-term retention decreased mitochondrial membrane potential and increased reactive oxygen species level that enhances the likelihood of cell death. These findings thus provide guidance for the design of organelle-targeted nanomaterials in tumor therapy.

Ruthenium complexes boost NK cell immunotherapy via sensitizing triple-negative breast cancer and shaping immuno-microenvironment.

Discovery of effective chemical sensitizers to synergize with natural killer cells immunotherapy is urgently desired to overcome its unsatisfactory efficacy in clinic. Herein, we design a series of ruthenium (Ru) polypyridyl complex to systematically explore their potentials in facilitating NK cells treatment. Intriguingly, the chemical structure greatly determines the activity of Ru complexes, while only RuPOP effectively regulates the immuno-suppressors and target proteins within tumor cells. This unique property contributes to its good capability in enhancing the sensitivity of MDA-MB-231 cells to NK cells from cancer patients. Furthermore, besides directly damaging tumor cells, RuPOP pretreatment together with NK cells can also induce robust ROS generation, activate multiple apoptosis-related receptors like TNF-R1, DR5, Fas and maximize the interactions between NK and tumor cells via up-regulating NKG2D and its multiple ligands to trigger caspase 3-dependent apoptosis. Moreover, the combination treatment exhibits high in vivo therapeutic efficacy against breast tumor through boosting the infiltration of NK cells and reducing the protumoral capability of myeloid-derived suppressor cells (MDSC). This study sheds lights for designing metal complexes to potentiate NK cells immunotherapy with clear action mechanisms and provides important information for developing more effective adoptive cell transfer therapy in clinic.

Immunosuppressive Nanoparticles for Management of Immune-Related Adverse Events in Liver.

Immune checkpoint blockade (ICB) therapy has been considered as an effective way to boost immune cells to recognize and attack tumors. However, side effects known as immune-related adverse events (irAEs) should be carefully managed. Here, we engineer immunosuppressive nanoparticles by coating PD-L1 overexpressed mesenchymal stem cells (MSCs) plasma membrane on poly lactic-co-glycolic acid nanoparticles (MSC-PD-L1+ NPs) for managing and reducing irAEs induced by immune checkpoint inhibitors. The nanoparticles can enrich at liver site after intravenous administration. In the high dose of anti-PD-L1 mAb-induced irAEs clinically relevant mouse model, a low dose of MSC-PD-L1+ NPs (2 mg/kg) sufficiently rescues hepatitis by inactivating T cells and macrophages in the liver tissue. More intriguingly, due to the dose threshold for nanoparticles to the tumor site, we unexpectedly find that the injected NPs do not affect the efficiency of ICB therapy to inhibit solid tumor growth. Such a strategy shows potential for managing the various cancer immunotherapy associated irAEs in clinical applications.

Designing immunogenic nanotherapeutics for photothermal-triggered immunotherapy involving reprogramming immunosuppression and activating systemic antitumor responses.

Low tumor mutational burden and absence of T cells within the tumor sites are typical characteristics of "cold immune tumors" that paralyzes the immune system. The strategy of reversing "cold tumors" to "hot tumors" infiltrated high degree of T cells in order to activate anti-tumor immunity has attracted lots of attentions. Herein, immunogenic core-shell Au@Se NPs is fabricated by gold-selenium coordination bond to realize nanoparticles-mediated local photothermal-triggered immunotherapy. As expected, incorporation of gold nanostars (AuNSs) with improved photothermal stability and conversion efficiency promotes the disintegration and transformation of selenium nanoparticles (SeNPs), thus leading to enhanced cancer cells apoptosis by producing higher hyperthermia. Moreover, the results of in vivo experiments demonstrate that the synergy between SeNPs-mediated chemotherapy and AuNSs-induced photothermal therapy not only generated a localized antitumor-immune response with excellent cancer killing effect under the presence of tumor-associated antigens, but also effectively reprogrammed the tumor associated macrophages (TAMs) from M2 to M1 phenotype with tumoricidal activity to devour distant tumors. Without a doubt, this study not only provides a potent strategy to reverse the immunosuppressive tumor microenvironment, but also offers a new insight for potential clinical application in tumor immunotherapy.

A general strategy towards personalized nanovaccines based on fluoropolymers for post-surgical cancer immunotherapy.

Cancer metastases and recurrence after surgical resection remain an important cause of treatment failure. Here we demonstrate a general strategy to fabricate personalized nanovaccines based on a cationic fluoropolymer for post-surgical cancer immunotherapy. Nanoparticles formed by mixing the fluoropolymer with a model antigen ovalbumin, induce dendritic cell maturation via the Toll-like receptor 4 (TLR4)-mediated signalling pathway, and promote antigen transportation into the cytosol of dendritic cells, which leads to an effective antigen cross-presentation. Such a nanovaccine inhibits established ovalbumin-expressing B16-OVA melanoma. More importantly, a mix of the fluoropolymer with cell membranes from resected autologous primary tumours synergizes with checkpoint blockade therapy to inhibit post-surgical tumour recurrence and metastases in two subcutaneous tumour models and an orthotopic breast cancer tumour. Furthermore, in the orthotopic tumour model, we observed a strong immune memory against tumour rechallenge. Our work offers a simple and general strategy for the preparation of personalized cancer vaccines to prevent post-operative cancer recurrence and metastasis.

Nanoparticle-Enhanced Radiotherapy to Trigger Robust Cancer Immunotherapy.

External radiotherapy is extensively used in clinic to destruct tumors by locally applied ionizing-radiation beams. However, the efficacy of radiotherapy is usually limited by tumor hypoxia-associated radiation resistance. Moreover, as a local treatment technique, radiotherapy can hardly control tumor metastases, the major cause of cancer death. Herein, core-shell nanoparticles based poly(lactic-co-glycolic) acid (PLGA) are fabricate, by encapsulating water-soluble catalase (Cat), an enzyme that can decompose H2 O2 to generate O2 , inside the inner core, and loading hydrophobic imiquimod (R837), a Toll-like-receptor-7 agonist, within the PLGA shell. The formed PLGA-R837@Cat nanoparticles can greatly enhance radiotherapy efficacy by relieving the tumor hypoxia and modulating the immune-suppressive tumor microenvironment. The tumor-associated antigens generated postradiotherapy-induced immunogenic cell death in the presence of such R837-loaded adjuvant nanoparticles will induce strong antitumor immune responses, which together with cytotoxic T-lymphocyte associated protein 4 (CTLA-4) checkpoint blockade will be able to effectively inhibit tumor metastases by a strong abscopal effect. Moreover, a long term immunological memory effect to protect mice from tumor rechallenging is observed post such treatment. This work thus presents a unique nanomedicine approach as a next-generation radiotherapy strategy to enable synergistic whole-body therapeutic responses after local treatment, greatly promising for clinical translation.

Relaxin gene delivery mitigates liver metastasis and synergizes with check point therapy.

Activated hepatic stellate cell (aHSC)-mediated liver fibrosis is essential to the development of liver metastasis. Here, we discover intra-hepatic scale-up of relaxin (RLN, an anti-fibrotic peptide) in response to fibrosis along with the upregulation of its primary receptor (RXFP1) on aHSCs. The elevated expression of RLN serves as a natural regulator to deactivate aHSCs and resolve liver fibrosis. Therefore, we hypothesize this endogenous liver fibrosis repair mechanism can be leveraged for liver metastasis treatment via enforced RLN expression. To validate the therapeutic potential, we utilize aminoethyl anisamide-conjugated lipid-calcium-phosphate nanoparticles to deliver plasmid DNA encoding RLN. The nanoparticles preferentially target metastatic tumor cells and aHSCs within the metastatic lesion and convert them as an in situ RLN depot. Expressed RLN reverses the stromal microenvironment, which makes it unfavorable for established liver metastasis to grow. In colorectal, pancreatic, and breast cancer liver metastasis models, we confirm the RLN gene therapy results in significant inhibition of metastatic progression and prolongs survival. In addition, enforced RLN expression reactivates intra-metastasis immune milieu. The combination of the RLN gene therapy with PD-L1 blockade immunotherapy further produces a synergistic anti-metastatic efficacy. Collectively, the targeted RLN gene therapy represents a highly efficient, safe, and versatile anti-metastatic modality, and is promising for clinical translation.