Platelet-Mimicking Nanosponges for Functional Reversal of Antiplatelet Agents.

BACKGROUND: During long-term antiplatelet agents (APAs) administration, patients with thrombotic diseases take a fairly high risk of life-threatening bleeding, especially when in need of urgent surgery. Rapid functional reversal of APAs remains an issue yet to be efficiently resolved by far due to the lack of any specific reversal agent in the clinic, which greatly restricts the use of APAs. METHODS: Flow cytometry analysis was first applied to assess the dose-dependent reversal activity of platelet-mimicking perfluorocarbon-based nanosponges (PLT-PFCs) toward ticagrelor. The tail bleeding time of mice treated with APAs followed by PLT-PFCs was recorded at different time points, along with corresponding pharmacokinetic analysis of ticagrelor and tirofiban. A hemorrhagic transformation model was established in experimental stroke mice with thrombolytic/antiplatelet therapy. Magnetic resonance imaging was subsequently applied to observe hemorrhage and thrombosis in vivo. Further evaluation of the spontaneous clot formation activity of PLT-PFCs was achieved by clot retraction assay in vitro. RESULTS: PLT-PFCs potently reversed the antiplatelet effect of APAs by competitively binding with APAs. PLT-PFCs showed high binding affinity comparable to fresh platelets in vitro with first-line APAs, ticagrelor and tirofiban, and efficiently reversed their function in both tail bleeding and postischemic-reperfusion models. Moreover, the deficiency of platelet intrinsic thrombotic activity diminished the risk of thrombogenesis. CONCLUSIONS: This study demonstrated the safety and effectiveness of platelet-mimicking nanosponges in ameliorating the bleeding risk of different APAs, which offers a promising strategy for the management of bleeding complications induced by antiplatelet therapy.

A Poly Aptamer Encoded DNA Nanocatcher Informs Efficient Virus Trapping.

Broad-spectrum antiviral platforms are always desired but still lack the ability to cope with the threats to global public health. Herein, we develop a poly aptamer encoded DNA nanocatcher platform that can trap entire virus particles to inhibit infection with a broad antiviral spectrum. Ultralong single-stranded DNA (ssDNA) containing repeated aptamers was synthesized as the scaffold of a nanocatcher via a biocatalytic process, wherein mineralization of magnesium pyrophosphate on the ssDNA could occur and consequently lead to the formation of nanocatcher with interfacial nanocaves decorated with virus-binding aptamers. Once the viruses were recognized by the apatmers, they would be captured and trapped in the nanocaves via multisite synergistic interactions. Meanwhile, the size of nanocatchers was optimized to prevent their cellular uptake, which further guaranteed inhibition of virus infection. By taking SARS-CoV-2 variants as a model target, we demonstrated the broad virus-trapping capability of a DNA nanocatcher in engulfing the variants and blocking the infection to host cells.

The Combination of Sinusoidal Perfusion Enhancement and Apoptosis Inhibition by Riociguat Plus a Galactose-PEGylated Bilirubin Multiplexing Nanomedicine Ameliorates Liver Fibrosis Progression.

Chronic liver injury and continuous wound healing lead to extracellular matrix (ECM) deposition and liver fibrosis. The elevated production of reactive oxygen species (ROS) in the liver leads to the apoptosis of hepatocytes and the activation of hepatic stellate cells (HSCs). In the current study, we describe a combination strategy of sinusoidal perfusion enhancement and apoptosis inhibition enabled by riociguat together with a tailor-designed galactose-PEGylated bilirubin nanomedicine (Sel@GBRNPs). Riociguat enhanced sinusoidal perfusion and decreased the associated ROS accumulation and inflammatory state of the fibrotic liver. Concurrently, hepatocyte-targeting galactose-PEGylated bilirubin scavenged excessive ROS and released encapsulated selonsertib. The released selonsertib inhibited apoptosis signal-regulating kinase 1 (ASK1) phosphorylation to alleviate apoptosis in hepatocytes. The combined effects on ROS and hepatocyte apoptosis attenuated the stimulation of HSC activation and ECM deposition in a mouse model of liver fibrosis. This work provides a novel strategy for liver fibrosis treatment based on sinusoidal perfusion enhancement and apoptosis inhibition.

Coordination-Driven Self-Assembly Strategy-Activated Cu Single-Atom Nanozymes for Catalytic Tumor-Specific Therapy.

How to optimize the enzyme-like catalytic activity of nanozymes to improve their applicability has become a great challenge. Herein, we present an l-cysteine (l-Cys) coordination-driven self-assembly strategy to activate polyvinylpyrrolidone (PVP)-modified Cu single-atom nanozymes MoOx-Cu-Cys (denoted as MCCP SAzymes) aiming at catalytic tumor-specific therapy. The Cu single atom content of MCCP can be rationally modulated to 10.10 wt %, which activates the catalase (CAT)-like activity of MoOx nanoparticles to catalyze the decomposition of H2O2 in acidic microenvironments to increase O2 production. Excitingly, the maximized CAT-like catalytic efficiency of MCCP is 138-fold higher than that of typical MnO2 nanozymes and exhibits 14.3-fold higher affinity than natural catalase, as demonstrated by steady-state kinetics. We verify that the well-defined l-Cys-Cu···O active sites optimize CAT-like activity to match the active sites of natural catalase through an l-Cys bridge-accelerated electron transfer from Cys-Cu to MoOx disclosed by density functional theory calculations. Simultaneously, the high loading Cu single atoms in MCCP also enable generation of •OH via a Fenton-like reaction. Moreover, under X-ray irradiation, MCCP converts O2 to 1O2 for cascading radiodynamic therapy, thereby facilitating the multiple reactive oxygen species (ROS) for radiosensitization to achieve substantial antitumor.

Biogenetic Vesicle-Based Cancer Vaccines with Tunable Surface Potential and Immune Potency.

Cancer vaccines are designed to motivate antigen-specific immune responses and facilitate tumor regression with minimal side effects. To fully exert the potential of vaccines, rationally designed formulations that effectively deliver antigens and trigger potent immune reactions are urgently needed. This study demonstrates a simple and controllable vaccine-developing strategy that assembles tumor antigens into bacterial outer membrane vesicles (OMVs), natural delivery vehicles with intrinsic immune adjuvant properties, via electrostatic interaction. This OMV-delivered vaccine (OMVax) stimulated both innate and adaptive immune responses, leading to enhanced metastasis inhibition and prolonged survival of tumor-bearing mice. Moreover, the influence of different surface charged OMVax on antitumor immunity activation is investigated and declined immune response activation occurred with increased positive surface charge. Together, these findings suggest a simple vaccine formulation that can be enhanced by optimizing the surface charges of vaccine formulations.

Site-Specific Modification of Virus-Like Particles for Exogenous Tumor Antigen Display and Minimizing Preexisting Immunity.

The widespread preexisting immunity against virus-like particles (VLPs) seriously limits the applications of VLPs as vaccine vectors. Enabling technology for exogenous antigen display should not only ensure the assembly ability of VLPs and site-specific modification, but also consider the effect of preexisting immunity on the behavior of VLPs in vivo. Here, combining genetic code expansion technique and synthetic biology strategy, a site-specific modification method for hepatitis B core (HBc) VLPs via incorporating azido-phenylalanine into the desired positions is described. Through modification position screening, it is found that HBc VLPs incorporated with azido-phenylalanine at the main immune region can effectively assemble and rapidly conjugate with the dibenzocycolctyne-modified tumor-associated antigens, mucin-1 (MUC1). The site-specific modification of HBc VLPs not only improves the immunogenicity of MUC1 antigens but also shields the immunogenicity of HBc VLPs themselves, thereby activating a strong and persistent anti-MUC1 immune response even in the presence of preexisting anti-HBc immunity, which results in the efficient tumor elimination in a lung metastatic mouse model. Together, these results demonstrate the site-specific modification strategy enabled HBc VLPs behave as a potent antitumor vaccine and this strategy to manipulate immunogenicity of VLPs may be suitable for other VLP-based vaccine vectors.

Nanoscale Organization of TRAIL Trimers using DNA Origami to Promote Clustering of Death Receptor and Cancer Cell Apoptosis.

Through inducing death receptor (DR) clustering to activate downstream signaling, tumor necrosis factor related apoptosis inducing ligand (TRAIL) trimers trigger apoptosis of tumor cells. However, the poor agonistic activity of current TRAIL-based therapeutics limits their antitumor efficiency. The nanoscale spatial organization of TRAIL trimers at different interligand distances is still challenging, which is essential for the understanding of interaction pattern between TRAIL and DR. In this study, a flat rectangular DNA origami is employed as display scaffold, and an "engraving-printing" strategy is developed to rapidly decorate three TRAIL monomers onto its surface to form DNA-TRAIL3 trimer (DNA origami with surface decoration of three TRAIL monomers). With the spatial addressability of DNA origami, the interligand distances are precisely controlled from 15 to 60 nm. Through comparing the receptor affinity, agonistic activity and cytotoxicity of these DNA-TRAIL3 trimers, it is found that ≈40 nm is the critical interligand distance of DNA-TRAIL3 trimers to induce death receptor clustering and the resulting apoptosis.Finally, a hypothetical "active unit" model is proposed for the DR5 clustering induced by DNA-TRAIL3 trimers.

Tumor-Targeted Delivery of IL-2 by Fusing with a pH Low Insertion Peptide for Antitumor Immunotherapy.

As a pleiotropic cytokine, interleukin-2 (IL-2) can effectively regulate lymphocyte proliferation, survival, and active antitumor immune responses in tumor microenvironments. Although the ability of IL-2 to boost immune responses was reported in cancer patients, its short circulating half-life and high toxicity hinder its broad and continual clinical application. Herein, we developed a novel tumor target agent by fusing pH low insertion peptides (pHLIP) with IL-2, forming the fusion protein pHLIP-IL2. Based on the low pH insertion property of pHLIP, the pHLIP-IL2 fusion protein could be selectively delivered to the acidic tumor microenvironments and then promote the proliferation of killer immune cells to elicit tumor regression. We found that pHLIP-IL2 fusion proteins can be significantly enriched in tumor tissues and can effectively reduce tumor size in diverse tumor models, including breast cancer and melanoma, without apparent adverse effects. These data suggest that the pHLIP-IL2 fusion protein may be a promising solution for the continual and extensive application of IL-2, and pHLIP-IL2 is a potential and valuable therapeutic drug for cancer patients with antitumor immunotherapy.

Injectable Immunotherapeutic Hydrogel Containing RNA-Loaded Lipid Nanoparticles Reshapes Tumor Microenvironment for Pancreatic Cancer Therapy.

Pancreatic cancer immunotherapy is becoming a promising strategy for improving the survival rate of postsurgical patients. However, the low response rate to immunotherapy suggests a low number of antigen-specific T cells and a high number of immunosuppressive tumor-associated macrophages in the pancreatic tumor microenvironment. Herein, we developed an in situ injectable thermosensitive chitosan hydrogel loaded with lipid-immune regulatory factor 5 (IRF5) mRNA/C-C chemokine ligand 5 (CCL5) siRNA (LPR) nanoparticle complexes (LPR@CHG) that reprogram the antitumoral immune niche. The LPR@CHG hydrogel upregulates IRF5 and downregulates CCL5 secretion, which contribute to a significant increase in M1 phenotype macrophages. Tumor growth is controlled by effective M1 phenotype macrophage that initiate T cell-mediated immune responses. Overall, the LPR@CHG hydrogel is expected to be a meaningful immunotherapy platform that can reshape the immunosuppressive tumor microenvironment and improve the efficacy of current pancreatic immunotherapies while minimizing systemic toxicity.

Targeted Degradation of PD-L1 and Activation of the STING Pathway by Carbon-Dot-Based PROTACs for Cancer Immunotherapy.

Proteolysis targeting chimeras (PROTACs) technology is an emerging approach to degrade disease-associated proteins. Here, we report carbon-dot (CD)-based PROTACs (CDTACs) that degrade membrane proteins via the ubiquitin-proteasome system. CDTACs can bind to programmed cell death ligand 1 (PD-L1), recruit cereblon (CRBN) to induce PD-L1 ubiquitination, and degrade them with proteasomes. Fasting-mimicking diet (FMD) is also used to enhance the cellular uptake and proteasome activity. More than 99 % or 90 % of PD-L1 in CT26 or B16-F10 tumor cells can be degraded by CDTACs, respectively. Furthermore, CDTACs can activate the stimulator of interferon genes (STING) pathway to trigger immune responses. Thus, CDTACs with FMD treatment effectively inhibit the growth of CT26 and B16-F10 tumors. Compared with small-molecule-based PROTACs, CDTACs offer several advantages, such as efficient membrane protein degradation, targeted tumor accumulation, immune system activation, and in vivo detection.

Nanomedicine targets iron metabolism for cancer therapy.

Iron is an essential element for cell proliferation and homeostasis by engaging in cell metabolism including DNA synthesis, cell cycle, and redox cycling; however, iron overload could contribute to tumor initiation, proliferation, metastasis, and angiogenesis. Therefore, manipulating iron metabolisms, such as using iron chelators, transferrin receptor 1 (TFR1) Abs, and cytotoxic ligands conjugated to transferrin, has become a considerable strategy for cancer therapy. However, there remain major limitations for potential translation to the clinic based on the regulation of iron metabolism in cancer treatment. Nanotechnology has made great advances for cancer treatment by improving the therapeutic potential and lowering the side-effects of the proved drugs and those under various stages of development. Early studies that combined nanotechnology with therapeutic means for the regulation of iron metabolism have shown certain promise for developing specific treatment options based on the intervention of cancer iron acquisition, transportation, and utilization. In this review, we summarize the current understanding of iron metabolism involved in cancer and review the recent advances in iron-regulatory nanotherapeutics for improved cancer therapy. We also envision the future development of nanotherapeutics for improved treatment for certain types of cancers.

Antigen Capture and Immune Modulation by Bacterial Outer Membrane Vesicles as In Situ Vaccine for Cancer Immunotherapy Post-Photothermal Therapy.

Tumor antigens released from tumor cells after local photothermal therapy (PTT) can activate the tumor-specific immune responses, which are critical for eliminating the residual lesions and distant metastases. However, the limited recognition efficiency of released tumor antigens by the immune system and the immunosuppressive microenvironment lead to ineffective antitumor immunity. Here, an in situ multifunctional vaccine based on bacterial outer membrane vesicles (OMVs, 1-MT@OMV-Mal) is developed by surface conjunction of maleimide groups (Mal) and interior loading with inhibitor of indoleamine 2, 3-dioxygenase (IDO), 1-methyl-tryptophan (1-MT). 1-MT@OMV-Mal can bind to the released tumor antigens after PTT, and be efficiently recognized and taken up by dendritic cells. Furthermore, in situ injection of 1-MT@OMV-Mal simultaneously overcomes the immune inhibition of IDO on tumor-infiltrating effector T cells, leading to remarkable inhibition on both primary and distant tumors. Together, a promising in situ vaccine based on OMVs to facilitate immune-mediated tumor clearance after PTT through orchestrating antigen capture and immune modulation is presented.

A DNA nanodevice-based vaccine for cancer immunotherapy.

A major challenge in cancer vaccine therapy is the efficient delivery of antigens and adjuvants to stimulate a controlled yet robust tumour-specific T-cell response. Here, we describe a structurally well defined DNA nanodevice vaccine generated by precisely assembling two types of molecular adjuvants and an antigen peptide within the inner cavity of a tubular DNA nanostructure that can be activated in the subcellular environment to trigger T-cell activation and cancer cytotoxicity. The integration of low pH-responsive DNA 'locking strands' outside the nanostructures enables the opening of the vaccine in lysosomes in antigen-presenting cells, exposing adjuvants and antigens to activate a strong immune response. The DNA nanodevice vaccine elicited a potent antigen-specific T-cell response, with subsequent tumour regression in mouse cancer models. Nanodevice vaccination generated long-term T-cell responses that potently protected the mice against tumour rechallenge.

Self-assembled peptide hydrogel scaffolds with VEGF and BMP-2 enhanced in vitro angiogenesis and osteogenesis.

OBJECTIVES: The reconstruction of bone defects remains a major clinical issue. Our study aims to investigate the ability of RATEA16 (RA, [CH3CONH] RADARADARADARADA-[CONH2]) for the sustained delivering VEGF and BMP-2 to promote angiogenesis and osteogenesis in bone reconstruction. MATERIALS AND METHODS: We prepared and investigated the characterization of RATEA16. The survival of human umbilical vein endothelial cells (HUVECs) and human stem cells of the apical papilla (SCAPs) encapsulated in RATEA16 hydrogel was detected. Then, we established RA-VEGF/BMP-2 drug delivery systems and measured their drug release pattern. The effects of RA-VEGF scaffolds on HUVECs angiogenesis were investigated in vitro. Then, osteoblastic differentiation capacity of SCAPs with RA-BMP-2 scaffolds was analyzed by ALP activity and expression of osteoblast-related genes. RESULTS: A porous nanofiber microstructure endowed this scaffold with the ability to maintain the survival of HUVECs and SCAPs. The RA-VEGF/BMP-2 drug delivery systems exhibited several advantagesin vitro: injectability, biodegradability, good biocompatibility, and noncytotoxicity. Released rhVEGF165 /BMP-2 were proved to promote angiogenesis of HUVECs as well as osteogenesis of SCAPs abilities. CONCLUSION: RATEA16 loading with VEGF and BMP-2 might be a potential clinical strategy for tissue engineering, especially in bone reconstruction, due to its ability of delivering growth factors effectively and efficiently.

In Situ Transforming RNA Nanovaccines from Polyethylenimine Functionalized Graphene Oxide Hydrogel for Durable Cancer Immunotherapy.

Messenger RNA (mRNA) vaccine is a promising candidate in cancer immunotherapy as it can encode tumor-associated antigens with an excellent safety profile. Unfortunately, the inherent instability of RNA and translational efficiency are major limitations of RNA vaccine. Here, we report an injectable hydrogel formed with graphene oxide (GO) and polyethylenimine (PEI), which can generate mRNA (ovalbumin, a model antigen) and adjuvants (R848)-laden nanovaccines for at least 30 days after subcutaneous injection. The released nanovaccines can protect the mRNA from degradation and confer targeted delivering capacity to lymph nodes. The data show that this transformable hydrogel can significantly increase the number of antigen-specific CD8+ T cells and subsequently inhibit the tumor growth with only one treatment. Meanwhile, this hydrogel can generate an antigen specific antibody in the serum which in turn prevents the occurrence of metastasis. Collectively, these results demonstrate the potential of the PEI-functionalized GO transformable hydrogel for effective cancer immunotherapy.

Platelet-Membrane-Coated Nanoparticles Enable Vascular Disrupting Agent Combining Anti-Angiogenic Drug for Improved Tumor Vessel Impairment.

Compared with traditional chemotherapeutics, vascular disruption agents (VDAs) have the advantages of rapidly blocking the supply of nutrients and starving tumors to death. Although the VDAs are effective under certain scenarios, this treatment triggers angiogenesis in the later stage of therapy that frequently leads to tumor recurrence and treatment failure. Additionally, the nonspecific tumor targeting and considerable side effects also impede the clinical applications of VDAs. Here we develop a customized strategy that combines a VDA with an anti-angiogenic drug (AAD) using mesoporous silica nanoparticles (MSNs) coated with platelet membrane for the self-assembled tumor targeting accumulation. The tailor-made nanoparticles accumulate in tumor tissues through the targeted adhesion of platelet membrane surface to damaged vessel sites, resulting in significant vascular disruption and efficient anti-angiogenesis in animal models. This study demonstrates the promising potential of combining VDA and AAD in a single nanoplatform for tumor eradication.

Effect of Different Absorption Enhancers on the Nasal Absorption of Nalmefene Hydrochloride.

The purpose of this work is to explore the effects of novel absorption enhancers on the nasal absorption of nalmefene hydrochloride (NMF). First, the influence of absorption enhancers with different concentrations and types and drug concentrations on the nasal absorption of NMF was investigated in vivo in rats. The absorption enhancers studied include n-dodecyl-ß-D-maltoside (DDM), hydroxypropyl-ß-cyclodextrin (HP-ß-CD), and polyethylene glycol (15)-hydroxy Stearate (Solutol®HS15). At the same time, the in situ toad palate model and rat nasal mucosa model were used to assess the cilia toxicity. The results showed that all the absorption enhancers investigated significantly promote the nasal absorption of NMF, but with different degrees and trends. Among them, the 0.5% (w/v) DDM had the strongest enhancement effect, followed by 0.5% (w/v) Solutol®HS15, 0.25% (w/v) DDM, 0.25% (w/v) Solutol®HS15, 0.1% (w/v) Solutol®HS15, 0.1% (w/v) DDM, and 0.25% (w/v) HP-ß-CD, with absolute bioavailability of 76.49%, 72.14%, 71.00%, 69.46%, 60.41%, 59.42%, and 55.18%, respectively. All absorption enhancers exhibited good safety profiles in nasal ciliary toxicity tests. From the perspective of enhancing effect and safety, we considered DDM to be a promising nasal absorption enhancer. And in addition to DDM, Solutol®HS15 can also promote intranasal absorption of NMF, which will provide another option for the development of nalmefene hydrochloride nasal spray.

Remodeling of Tumor Microenvironment by Tumor-Targeting Nanozymes Enhances Immune Activation of CAR T Cells for Combination Therapy.

Targeting B7-H3 chimeric antigen receptor (CAR) T cells has antitumor potential for therapy of non-small cell lung cancer (NSCLC) in preclinical studies. However, CAR T cell therapy remains a formidable challenge for the treatment of solid tumors due to the heterogeneous and immunosuppressive tumor microenvironment (TME). Nanozymes exhibit merits modulating the immunosuppression of the tumor milieu. Here, a synergetic strategy by combination of nanozymes and CAR T cells in solid tumors is described. This nanozyme with dual photothermal-nanocatalytic properties is endowed to remodel TME by destroying its compact structure. It is found that the B7-H3 CAR T cells infused in mice engrafted with the NSCLC cells have superior antitumor activity after nanozyme ablation of the tumor. Importantly, it is found that the changes altered immune-hostile cancer environment, resulting in enhanced activation and infiltration of B7-H3 CAR T cells. The first evidence that the process of combination nanozyme therapy effectively improves the therapeutic index of CAR T cells is presented. Thus, this study clearly supports that the TME-immunomodulated nanozyme is a promising tool to improve the therapeutic obstacles of CAR T cells against solid tumors.

Modulating the tumor microenvironment with new therapeutic nanoparticles: A promising paradigm for tumor treatment.

To better make nanomedicine entering the clinic, developing new rationally designed nanotherapeutics with a deeper understanding of tumor biology is required. The tumor microenvironment is similar to the inflammatory response in a healing wound, the milieu of which promotes tumor cell invasion and metastasis. Successful targeting of the microenvironmental components with effective nanotherapeutics to modulate the tumor microvessels or restore the homeostatic mechanisms in the tumor stroma will offer new hope for cancer treatment. We here highlight the progress in constructing nanotherapeutics to target or modulate the tumor microenvironment. We discuss the factors necessary for nanomedicines to become a new paradigm in cancer therapy, including the selection of drugs and therapeutic targets, controllable synthesis, and tempo-spatial drug release.

Metabonomic Investigation of Biological Effects of a New Vessel Target Protein tTF-pHLIP in a Mouse Model.

In recent years, tumor microenvironment (TME) has been recognized as potential targets for tumor treatment and the tumor vascular system is one of such targets. Fusing truncated tissue factor (tTF) with pH low insertion peptides (pHLIP), tTF-pHLIP, can target tumor vessels owing to its acidic TME and cause tumor vessel occlusion by blood clotting and subsequently effectively inhibit tumor growth. To evaluate its bioeffects, we exposed the tTF-pHLIP to normal mice and mice xenograft with B16F10 tumor and analyzed the metabolic profiling of various tissues and biofluids including plasma and urine from mice treated with and without tTF-pHLIP. A combination of nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry and ultra-high-performance liquid chromatography-mass spectrometry was employed in the study. We found that tTF-pHLIP treatment can effectively reduce tumor size and concurrently ameliorate tumor-induced alterations in the TCA cycle metabolism and lipid metabolism. In addition, we found that toxicity of tTF-pHLIP to normal mice is minor and exposure of the tTF-pHLIP induced oxidative stress to the system. Hence, we concluded that tTF-pHLIP is of low toxicity and effective in reducing tumor size as well as rebalancing tumor-induced metabolic derailment.