Enhancing the Antitumor Efficacy of Oncolytic Adenovirus Through Sonodynamic Therapy-Augmented Virus Replication.

The therapeutic efficacy of oncolytic adenoviruses (OAs) relies on efficient viral transduction and replication. However, the limited expression of coxsackie-adenovirus receptors in many tumors, along with the intracellular antiviral signaling, poses significant obstacles to OA infection and oncolysis. Here, we present sonosensitizer-armed OAs (saOAs) that potentiate the antitumor efficacy of oncolytic virotherapy through sonodynamic therapy-augmented virus replication. The saOAs could not only efficiently infect tumor cells via transferrin receptor-mediated endocytosis but also exhibit enhanced viral replication and tumor oncolysis under ultrasound irradiation. We revealed that the sonosensitizer loaded on the viruses induced the generation of ROS within tumor cells, which triggered JNK-mediated autophagy, ultimately leading to the enhanced viral replication. In mouse models of malignant melanoma, the combination of saOAs and sonodynamic therapy elicited a robust antitumor immune response, resulting in significant inhibition of melanoma growth and improved host survival. This work highlights the potential of sonodynamic therapy in enhancing the effectiveness of OAs and provides a promising platform for fully exploiting the antitumor efficacy of oncolytic virotherapy.

Peptide-TLR7/8a-Coordinated DNA Vaccines Elicit Enhanced Immune Responses against Infectious Diseases.

DNA vaccines represent an innovative approach for the immunization of diverse diseases. However, their clinical trial outcomes are constrained by suboptimal transfection efficiency and immunogenicity. In this work, we present a universal methodology involving the codelivery of Toll-like receptor 7/8 agonists (TLR7/8a) and antigen gene using TLR7/8a-conjugated peptide-coated poly(ß-amino ester) (PBAE) nanoparticles (NPs) to augment delivery efficiency and immune response. Peptide-TLR7/8a-coated PBAE NPs exhibit advantageous biophysical attributes, encompassing diminutive particle dimensions, nearly neutral ζ potential, and stability in the physiological environment. This synergistic approach not only ameliorates the stability of plasmid DNA (pDNA) and gene delivery efficacy but also facilitates subsequent antigen production. Furthermore, under optimal formulation conditions, the TLR7/8a-conjugated peptide coated PBAE NPs exhibit a potent capacity to induce robust immune responses. Collectively, this nanoparticulate gene delivery system demonstrates heightened transfection efficacy, stability, biodegradability, immunostimulatory effect, and low toxicity, making it a promising platform for the clinical advancement of DNA vaccines.

Effects of Surface IR783 Density on the In Vivo Behavior and Imaging Performance of Liposomes.

Background: Nanoparticles conjugated with fluorescent probes have versatile applications, serving not only for targeted fluorescent imaging but also for evaluating the in vivo profiles of designed nanoparticles. However, the relationship between fluorophore density and nanoparticle behavior remains unexplored. Methods: The IR783-modified liposomes (IR783-sLip) were prepared through a modified ethanol injection and extrusion method. The cellular uptake efficiency of IR783-sLip was characterized by flow cytometry and fluorescence microscope imaging. The effects of IR783 density on liposomal in vivo behavior were investigated by pharmacokinetic studies, biodistribution studies, and in vivo imaging. The constitution of protein corona was analyzed by the Western blot assay. Results: Dense IR783 modification improved cellular uptake of liposomes in vitro but hindered their blood retention and tumor imaging performance in vivo. We found a correlation between IR783 density and protein corona absorption, particularly IgM, which significantly impacted the liposome performance. Meanwhile, we observed that increasing IR783 density did not consistently improve the effectiveness of tumor imaging. Conclusions: Increasing the density of modified IR783 on liposomes is not always beneficial for tumor near-infrared (NIR) imaging yield. It is not advisable to prematurely evaluate novel nanomaterials through fluorescence dye conjugation without carefully optimizing the density of the modifications.

Supramolecular Cyclic Dinucleotide Nanoparticles for STING-Mediated Cancer Immunotherapy.

Activation of stimulator of interferon genes (STING) can reprogram the immunosuppressive tumor microenvironment (TME) by initiating innate and adaptive immunity. As natural STING agonists, clinical translation of cyclic dinucleotides (CDNs) has been challenged by their short half-life in circulation, poor stability, and low membrane permeability. Herein, we use the natural endogenous small molecules oleic acid and deoxycytidine to construct a ligand for the STING agonist c-di-GMP (CDG), a hydrophobic nucleotide lipid (3',5'-diOA-dC), which can assemble with CDG into stable cyclic dinucleotide nanoparticles (CDG-NPs) through various supramolecular forces driven by molecular recognition. CDG-NPs are homogeneous and stable spherical nanoparticles with an average diameter of 59.0 ± 13.0 nm. Compared with free CDG, CDG-NPs promote the retention and intracellular delivery of CDG in the tumor site, boost STING activation and TME immunogenicity, and potentiate STING-mediated anti-tumor immunity when administered by either intratumoral or systemic routes in melanoma-bearing mice. We propose a flexible supramolecular nanodelivery system for CDG by using endogenous small molecules, which provides a CDN delivery platform for STING-mediated cancer immunotherapy.

Cryo-Shocked Cancer Cells as an Oncolytic Adenovirus Reservoir for Glioblastoma Immunotherapy.

Glioblastoma is the most common type of primary brain tumor, which has a high recurrence rate and a high mortality rate. Immunotherapy shows promise in cancer therapy due to its capacity to manipulate the immune system to attack tumor cells with less toxic and durable immune responses. However, the low immunogenicity and limited immune cell infiltration in a glioblastoma lead to a weakened antitumor immune response, resulting in suboptimal therapeutic efficacy. A compelling solution is provided by oncolytic adenovirus (OAs), which can selectively replicate within tumor cells while simultaneously promoting antitumor immunity. Herein, we constructed an oncolytic adenovirus reservoir (OAR) by shocking OA-loaded tumor cells in liquid nitrogen to eliminate proliferation and pathogenicity. OARs showed sustained OAs release and effectively lysed tumor cells in vitro and in vivo. In a mouse intracranial glioblastoma model, OARs could efficiently induce dendritic cells' maturation, facilitate the tumor recruitment, and promote the infiltration of cytotoxic effector T lymphocytes via a single treatment, resulting in specific antitumor immune responses and long-term animal survival. Taken together, these results demonstrated that OAR is a promising synergistic therapeutic strategy for treating glioblastoma.

An Activity-Based Photosensitizer to Reverse Hypoxia and Oxidative Resistance for Tumor Photodynamic Eradication.

Photodynamic therapy (PDT) has been a well-accepted clinical treatment for malignant tumors owing to its noninvasiveness and high spatiotemporal selectivity. However, the treatment outcome of current PDT applications is hindered by hypoxia and intracellular oxidative resistance of solid tumors. Recent studies have shown that inhibiting histone deacetylases (HDACs) can induce cell ferroptosis, reverse hypoxia, and elevate oxidative status. Theoretically, the design and synthesis of activity-based photosensitizers that target HDACs can address the bottlenecks of PDT. Herein, the concept of an activity-based photosensitizer is presented for targeting HDACs, which is designed based on a quinoxalinone scaffold through a pharmacophore migration strategy. The developed activity-based photosensitizer can inhibit HDACs, and overcome hypoxia and intracellular oxidative resistance, realizing the full potential of photosensitizers for malignant tumor treatment. The molecular design strategy proposed in this project should provide theoretical guidance for the development of ideal photosensitizers for practical applications.

Peptide-decorated nanocarriers penetrating the blood-brain barrier for imaging and therapy of brain diseases.

Blood-Brain Barrier (BBB) is one of the most important physiological barriers strictly restricting the substance exchange between blood and brain tissues. While the BBB protects the brain from infections and toxins and maintains brain homeostasis, it is also recognized as the main obstacle to the penetration of therapeutics and imaging agents into the brain. Due to high specificity and affinity, peptides are frequently exploited to decorate nanocarriers across the BBB for diagnosis and/or therapy purposes. However, there are still some challenges that restrict their clinical application, such as stability, safety and immunocompatibility. In this review, we summarize the biological and pathophysiological characteristics of the BBB, strategies across the BBB, and recent progress on peptide decorated nanocarriers for brain diseases diagnosis and therapy. The challenges and opportunities for their translation are also discussed.

Living Bacteria-Based Immuno-Photodynamic Therapy: Metabolic Labeling of Clostridium butyricum for Eradicating Malignant Melanoma.

Due to the complexity, aggressiveness, and heterogeneity of malignant melanoma, it is difficult to eradicate the whole tumor through conventional treatment. Herein, a strategy of metabolic engineering labeled anaerobic oncolytic bacteria (Clostridium butyricum) is demonstrated to achieve the ablation of melanoma. In this system, the metabolic substrate of C. butyricum d-alanine (d-Ala) is first conjugated with a photosensitizer (TPApy) showing aggregation-induced emission (AIE). The yielded metabolic substrate of d-Ala-TPAPy can be metabolically incorporated into bacterial peptidoglycan to form engineered C. Butyricum. Once the engineered C. butyricum is injected into melanoma, the bacteria can only proliferate in an anaerobic zone, stimulate the tumor immune microenvironment, and ablate the tumor hypoxia region. Following that, the relatively rich oxygen content in the peripheral area can induce the death of C. butyricum. The photosensitizer (PS) on the bacteria can subsequently exert a photodynamic effect in the oxygen-rich region and further remove the melanoma residue under light irradiation. Prominent in vivo melanoma ablation results revealed that the engineering oncolytic bacteria can provide a promising regime for solid tumor eradication.

A Virus-Mimicking Nucleic Acid Nanogel Reprograms Microglia and Macrophages for Glioblastoma Therapy.

Immunotherapy is recognized as one of the most promising approaches to treat cancers. However, its effect in glioblastoma (GBM) treatment is insufficient, which can in part be attributed to the immunosuppressive tumor microenvironment (TME). Microglia and macrophages are the main immune infiltrating cells in the TME of GBM. Unfortunately, instead of initiating the anti-tumor response, GBM-infiltrating microglia and macrophages switch to a tumor-promoting phenotype (M2), and support tumor growth, angiogenesis, and immunosuppression by the release of cytokines. In this work, a virus-mimicking membrane-coated nucleic acid nanogel Vir-Gel embedded with therapeutic miRNA is developed, which can reprogram microglia and macrophages from a pro-invasive M2 phenotype to an anti-tumor M1 phenotype. By mimicking the virus infection process, Vir-Gel significantly enhances the targetability and cell uptake efficiency of the miR155-bearing nucleic acid nanogel. In vivo evaluations demonstrate that Vir-Gel apparently prolongs the circulation lifetime of miR155 and endows it with an active tumor-targeting capability and excellent tumor inhibition efficacy. Owing to its noninvasive feature and effective delivery capability, the virus-mimicking nucleic acid nanogel provides a general and convenient platform that can successfully treat a wide range of diseases.

Carrier-Free Hybrid DNA Nanoparticles for Light-Induced Self-Delivery of Functional Nucleic Acid Enzymes.

Herein, we developed hybrid DNAzyme nanoparticles (NPs) to achieve light-induced carrier-free self-delivery of DNAzymes with sufficient cofactor supply and lysosome escape capacity. In this system, aggregation-induced emission (AIE) photosensitizer (PS) (TBD-Br) was grafted onto a phosphorothiolated DNAzyme backbone, which automatically self-assembled to form NPs and the surface phosphorothioate group could easily coordinate with the cofactor Zn2+ in the buffer. When the yielded hybrid DNAzyme NPs were located inside tumor cell lysosomes, the 1O2 from TBD-Br under light illumination could destroy lysosome structure and promote the Zn2+ coordinated DNAzyme NPs escape. Both in vitro and in vivo results demonstrated that the hybrid DNAzyme NPs could downregulate the early growth response factor-1 protein (EGR-1) to inhibit tumor cell growth in addition to induce tumor cell apoptosis by AIE PS (TBD-Br) under light irradiation.

A Novel Small Peptide H-KI20 Inhibits Retinal Neovascularization Through the JNK/ATF2 Signaling Pathway.

Purpose: Abundant evidence has shown benefits of antivascular endothelial growth factor (anti-VEGF) therapies in neovascular eye diseases. However, the high cost, side effects, and inconvenience of frequent injections demand alternative novel drug candidates. This study aimed to analyze antiangiogenic effects of peptide H-KI20 and illustrated signaling mechanisms. Methods: Live cell culture and tracing, wound healing assay, and tube formation were performed in human retinal microvascular endothelial cells (HRECs). The chick embryo chorioallantoic membrane and mouse oxygen-induced ischemic retinopathy model were applied to examine the effects of H-KI20 in vivo. The intracellular signaling pathways were examined. Molecular docking and surface plasmon resonance assay were used to validate the direct interaction of H-KI20 and c-Jun N-terminal kinase 2 (JNK2). Results: H-KI20 had high penetration ability in vitro and in vivo. It inhibited motility, migration, and tube formation of HRECs, without cytotoxicity, and inhibited angiogenesis in vivo. Furthermore, H-KI20 treatment reduced the phosphorylation level of activating transcription factor 2 (ATF2) stimulated by VEGF via downregulating p-JNK. H-KI20 bound to JNK2 directly with a dissociation constant value of 83.68 µM. The knockdown of ATF2 attenuated VEGF-induced tube formation and decreased the movement speed of HRECs. Conclusions: H-KI20 inhibited angiogenesis both in vitro and in vivo. The ratios of p-ATF2/ATF2 and p-JNK/JNK stimulated by VEGF were decreased by H-KI20, and H-KI20 targeted JNK2 directly. In addition, the pivotal role of ATF2 in VEGF-induced retinal neovascularization was elucidated for the first time. Taken together, H-KI20 displays potential for pathological retinal angiogenesis as a sustained and low-toxic peptide.

An electric-field-responsive paramagnetic contrast agent enhances the visualization of epileptic foci in mouse models of drug-resistant epilepsy.

For patients with drug-resistant focal epilepsy, excision of the epileptogenic zone is the most effective treatment approach. However, the surgery is less effective in the 15-30% of patients whose lesions are not distinct when visualized by magnetic resonance imaging (MRI). Here, we show that an intravenously administered MRI contrast agent consisting of a paramagnetic polymer coating encapsulating a superparamagnetic cluster of ultrasmall superparamagnetic iron oxide crosses the blood-brain barrier and improves lesion visualization with high sensitivity and target-to-background ratio. In kainic-acid-induced mouse models of drug-resistant focal epilepsy, electric-field changes in the brain associated with seizures trigger breakdown of the contrast agent, restoring the T1-weighted magnetic resonance signal, which otherwise remains quenched due to the distance-dependent magnetic resonance tuning effect between the cluster and the coating. The electric-field-responsive contrast agent may increase the probability of detecting seizure foci in patients and facilitate the study of brain diseases associated with epilepsy.

Virus-mimetic systems for cancer diagnosis and therapy.

Over past decades, various strategies have been developed to enhance the delivery efficiency of therapeutics and imaging agents to tumor tissues. However, the therapeutic outcome of tumors to date have not been significantly improved, which can be partly attributed to the weak targeting ability, fast elimination, and low stability of conventional delivery systems. Viruses are the most efficient agents for gene transfer, serving as a valuable source of inspiration for designing nanoparticle-based delivery systems. Based on the properties of viruses, including well-defined geometry, precise composition, easy modification, stable construction, and specific infection, researchers attempt to design biocompatible delivery vectors by mimicking virus assembly and using the vector system to selectively concentrate drugs or imaging probes in tumors with mitigated toxicity and improved efficacy. In this review, we introduce common viruses features and provide an overview of various virus-mimetic strategies for cancer therapy and diagnosis. The challenges faced by virus-mimetic systems are also discussed. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Imaging epileptic foci in mouse models via a low-density lipoprotein receptor-related protein-1 targeting strategy.

BACKGROUND: In the setting of drug-resistant epilepsy (DRE), the success of surgery depends on the ability to accurately locate the epileptic foci to be resected or disconnected. However, the epileptic foci in a considerable percentage of the DRE patients cannot be adequately localised. This warrants the need for a reliable imaging strategy to identify the "concealed" epileptic regions. METHODS: Brain specimens from DRE patients and kainate-induced epileptic mouse models were immuno-stained to evaluate the integrity of the blood-brain barrier (BBB). The expression of low-density lipoprotein receptor-related protein-1 (LRP1) in the epileptic region of DRE patients and kainate models was studied by immunofluorescence. A micellar-based LRP1-targeted paramagnetic probe (Gd3+-LP) was developed and its ability to define the epileptic foci was investigated by magnetic resonance imaging (MRI). FINDINGS: The integrity of the BBB in the epileptic region of DRE patients and kainate mouse models were demonstrated. LRP1 expression levels in the epileptic foci of DRE patients and kainate models were 1.70-2.38 and 2.32-3.97 folds higher than in the control brain tissues, respectively. In vivo MRI demonstrated that Gd3+-LP offered 1.68 times higher (P < 0.05) T1-weighted intensity enhancement in the ipsilateral hippocampus of chronic kainite models than the control probe without LRP1 specificity. INTERPRETATION: The expression of LRP1 is up-regulated in vascular endothelium, activated glia in both DRE patients and kainate models. LRP1-targeted imaging strategy may provide an alternative strategy to define the "concealed" epileptic foci by overcoming the intact BBB. FUNDING: This work was supported by the National Natural Science Foundation, Shanghai Science and Technology Committee, Shanghai Municipal Science and Technology, Shanghai Municipal Health and Family Planning Commission and the National Postdoctoral Program for Innovative Talents.

Engineering extracellular vesicles for cancer therapy: recent advances and challenges in clinical translation.

Extracellular vesicles (EVs) are receiving increasing attention in recent years in the field of cancer treatment. EVs contain specific contents closely related to their donor cells, such as miRNAs, proteins and dsDNAs. As endogenous vesicles, EVs naturally have the characteristics of low toxicity and low immunogenicity and can stably pass through the circulatory system to reach the recipient cells, which make them good carriers to deliver therapeutic agents such as nucleic acid sequences and chemotherapeutics. In many preclinical studies and clinical trials, EVs have demonstrated their unlimited advantages in the field of cancer therapy. However, there are still some challenges that restrict their clinical application, such as yield, heterogeneity, safety, and specificity. In this review, we will focus on the latest breakthrough of EVs in the field of cancer treatment and discuss the challenges in the clinical translation of EVs.

Engineering macrophage-derived exosomes for targeted chemotherapy of triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most metastatic and recurrent subtype of all breast cancers. Owing to the lack of therapeutic targets, chemotherapy and surgical intervention are the only treatments for TNBC. However, the effectiveness of chemotherapeutics is limited by its shortcomings such as poor targeting, easy removal and high toxicity. Recently, exosomes have attracted more and more attention as a drug delivery system. As endogenous vesicles, exosomes ensure low immunogenicity, nontoxicity, and long blood circulation time. In addition, immune cell-derived exosomes can mimic the immune cell to target tumor cells. Herein, we developed a macrophage-derived exosome-coated poly(lactic-co-glycolic acid) nanoplatform for targeted chemotherapy of TNBC. To further improve the tumor targetability, the surface of the exosome was modified with a peptide to target the mesenchymal-epithelial transition factor (c-Met), which is overexpressed by TNBC cells. The results showed that the engineered exosome-coated nanoparticles significantly improved the cellular uptake efficiency and the antitumor efficacy of doxorubicin. In vivo study demonstrated that the nanocarriers exhibited remarkable tumor-targeting efficacy, led to increased inhibition of tumor growth and induced intense tumor apoptosis. These results indicated that the engineered macrophage exosome-coated nanoparticles were a promising drug delivery strategy for TNBC treatment.

Polydopamine-coated nucleic acid nanogel for siRNA-mediated low-temperature photothermal therapy.

Photothermal therapy (PTT) normally requires to maintain the temperature of tumor lesions above 50 °C, which potentially induces local inflammation and tumor metastasis. To avoid these side effects, it is vital to achieve effective antitumor efficacy at relatively low temperature (42-45 °C) during the PTT treatment. Herein, we design a polydopamine (PDA)-coated nucleic acid nanogel as a therapeutic complex for siRNA-mediated low-temperature PTT. First, siRNAs that target the heat-shock-protein 70 (Hsp70) serve as crosslinkers to guide the DNA-grafted polycaprolactone (DNA-g-PCL) assemble into nanosized hydrogel particles through nucleic acid hybridization. Thereafter, the obtained siRNA-embedded nanogels are further coated with a thin layer of polydopamine, which not only protects the nanogels against enzymatic degradation but also endows the nanogels with excellent photothermal conversion capacity under near infrared (NIR) light irradiation. After surface PEGylation, this triple shield siRNA delivery complex shows the capability of effective ablating the tumor under relatively mild condition.

A Paclitaxel-Based Mucoadhesive Nanogel with Multivalent Interactions for Cervical Cancer Therapy.

Cervical cancer treatment is subject to limited drug access to locally diseased targets and generally resistant to chemotherapy, thus it is essential to develop a local drug delivery system to overcome these problems, premised on guaranteeing drug efficacy. With this goal in mind, a multivalent interactions-based mucoadhesive nanogel for vaginal delivery is proposed. Briefly, the nanogel is constructed with mucoadhesive poly(acrylic acid) as the backbone and multiple inclusions between ß-cyclodextrin and paclitaxel as the crosslinking points. The in vitro experiments demonstrate that nanogel exerts high cytotoxicity to cancer cells, reverses multidrug resistance effectively, and successfully promotes the permeation of drugs. More to the point, as proved in the in vivo experiments, the retention time in the vagina is prolonged and the tumor growth is effectively suppressed by the nanogel without any side effects in the orthotopic cervical cancer model. As mentioned above, this novel mucoadhesive nanogel is believed to be a useful tool toward designing drug delivery systems for cervical cancer treatment.

Rapid Detection of Exosomal MicroRNAs Using Virus-Mimicking Fusogenic Vesicles.

Exosomal microRNAs (miRNAs) are important biomarkers for clinical diagnosis and disease treatment monitoring. However, most approaches for exosomal miRNA detection are time-consuming, laborious, and expensive. Herein, we report a virus-mimicking fusogenic vesicle (Vir-FV) that enables rapid, efficient, and high-throughput detection of exosomal miRNAs within 2 h. Fusogenic proteins on Vir-FVs can specifically target the sialic-acid-containing receptors on exosomes, inducing efficient fusion of Vir-FVs and exosomes. Upon vesicle content mixing, the molecular beacons encapsulated in Vir-FVs specifically hybridize with the target miRNAs in the exosomes, generating fluorescence. Combined with flow cytometry, the Vir-FVs can not only detect exosomal miRNAs but also distinguish tumor exosomes from normal exosomes by sensing the tumor-related miRNAs, paving the way towards the rapid and efficient detection of exosomal miRNAs for diagnosis and prognosis prediction of diseases.

Two-in-One Chemogene Assembled from Drug-Integrated Antisense Oligonucleotides To Reverse Chemoresistance.

Combinatorial chemo and gene therapy provides a promising way to cure drug-resistant cancer, since the codelivered functional nucleic acids can regulate drug resistance genes, thus restoring sensitivity of the cells to chemotherapeutics. However, the dramatic chemical and physical differences between chemotherapeutics and nucleic acids greatly hinder the design and construction of an ideal drug delivery system (DDS) to achieve synergistic antitumor effects. Herein, we report a novel approach to synthesize a nanosized DDS using drug-integrated DNA with antisense sequences (termed "chemogene") to treat drug-resistant cancer. As a proof of concept, floxuridine (F), a typical nucleoside analog antitumor drug, was incorporated in the antisense sequence in the place of thymine (T) based on their structural similarity. After conjugation with polycaprolactone, a spherical nucleic acid (SNA)-like two-in-one chemogene can be self-assembled, which possesses the capabilities of rapid cell entry without the need for a transfection agent, efficient downregulation of drug resistance genes, and chronic release of chemotherapeutics for treating the drug-resistant tumors in both subcutaneous and orthotopic liver transplantation mouse models.