A Versatile Nanovaccine Enhancement Strategy Based on Suction-Inspired Physical Therapy.

Vaccine technology is effective in preventing and treating diseases, including cancers and viruses. The efficiency of vaccines can be improved by increasing the dosage and frequency of injections, but it would bring an extra burden to people. Therefore, it is necessary to develop vaccine-boosting techniques with negligible side effects. Herein, we reported a cupping-inspired noninvasive suction therapy that could enhance the efficacy of cancer/SARS-CoV-2 nanovaccines. Negative pressure caused mechanical immunogenic cell death and released endogenous adjuvants. This created a subcutaneous niche that would recruit and activate antigen-presenting cells. Based on this universal central mechanism, suction therapy was successfully applied in a variety of nanovaccine models, which include prophylactic/therapeutic tumor nanovaccine, photothermal therapy induced in situ tumor nanovaccine, and SARS-CoV-2 nanovaccine. As a well-established physical therapy method, suction therapy may usher in an era of noninvasive and high-safety auxiliary strategies when combined with vaccines.

Engineered Macrophage Membrane-Coated Nanoparticles with Enhanced CCR2 Expression Promote Spinal Cord Injury Repair by Suppressing Neuroinflammation and Neuronal death.

Spinal cord injury (SCI) is a severe neurological disorder characterized by significant disability and limited treatment options. Mitigating the secondary inflammatory response following the initial injury is the primary focus of current research in the treatment of SCI. CCL2 (C─C motif chemokine ligand 2) serves as the primary regulator responsible for inflammatory chemotaxis of the majority of peripheral immune cells, blocking the CCL2-CCR2 (C─C chemokine receptor type 2) axis has shown considerable therapeutic potential for inflammatory diseases, including SCI. In this study, it presents a multifunctional biomimetic nanoplatform (CCR2-MM@PLGA/Cur) specifically designed to target the CCL2-CCR2 axis, which consisted of an engineered macrophage membrane (MM) coating with enhanced CCR2 expression and a PLGA (poly (lactic-co-glycolic acid)) nanoparticle that encapsulated therapeutic drugs. CCR2 overexpression on MM not only enhanced drug-targeted delivery to the injury site, but also attenuated macrophage infiltration, microglia pro-inflammatory polarization, and neuronal apoptosis by trapping CCL2. Consequently, it facilitated neural regeneration and motor function recovery in SCI mice, enabling a comprehensive treatment approach for SCI. The feasibility and efficacy of this platform are confirmed through a series of in vitro and in vivo assays, offering new insights and potential avenues for further exploration in the treatment of SCI.

Antibacterial Fusobacterium nucleatum-Mimicking Nanomedicine to Selectively Eliminate Tumor-Colonized Bacteria and Enhance Immunotherapy Against Colorectal Cancer.

Clinical evidence indicates that tumor-colonizing bacteria can be closely related to the tumor development and therapeutic responses. Selectively eliminating bacteria within tumors may be an attractive approach to enhance cancer treatment without additional side effects. Herein, it is found that, owing to the high affinity between the membrane protein Fap-2 on Fusobacterium nucleatum and d-galactose-ß (1-3)-N-acetyl-d-galactosamine (Gal-GalNAc) overexpressed on colorectal tumor cells, F. nucleatum can colonize in colorectal tumors, as evidenced by both clinical samples and animal tumor models. Notably, F. nucleatum colonized in colorectal tumors can lead to an immunosuppressive tumor microenvironment, greatly reducing their responses to immune checkpoint blockade (ICB) therapy. Inspired by this finding, an F. nucleatum-mimetic nanomedicine is designed by fusing F. nucleatum cytoplasmic membrane (FM) with Colistin-loaded liposomes to achieve selective killing of tumor-colonizing F. nucleatum without affecting gut microbes. As a result, the therapeutic responses of F. nucleatum-colonized tumors to ICB therapies can be successfully restored, as demonstrated in an F. nucleatum-infected subcutaneous CT-26 tumor model, chemically induced spontaneous colorectal cancer models, and MC-38 tumor model. In summary, this work presents an F. nucleatum-mimicking nanomedicine that can selectively eliminate tumor-colonized bacteria, which is promising for enhancing the responses of cancer immunotherapy against F. nucleatum-colonized colorectal cancer.

Cancer Cell Membrane-Enveloped Dexamethasone Normalizes the Tumor Microenvironment and Enhances Gynecologic Cancer Chemotherapy.

The aberrant tumor microenvironment (TME), especially immature and leaky vessels, prevents the penetration and accumulation of chemotherapeutics and results in the failure of chemotherapy to treat gynecologic cancer. Herein, dexamethasone (Dex), a glucocorticoid steroid used to moderate tumor extracellular matrix and normalize vessels, was enclosed within a biocompatible material known as poly(lactic-co-glycolic acid) (PLGA), and the obtained Dex@PLGA was further coated with a mouse cervical cancer cell membrane (CM). The formulated Dex@PLGA-CM nanoparticles showed efficient extravascular diffusion within the tumor owing to the homologous targeting abilities inherited from the source cancer cells. The Dex@PLGA-CM nanoparticles greatly reshaped the TME, enhancing the penetration of Doxil and thus markedly improving the therapeutic effect of this drug against cervical cancers. Excitingly, the Dex@PLGA-CM nanoparticles coated with mouse ovarian cancer cell membranes also promoted Doxil-mediated chemotherapy effects in metastatic ovarian cancer when administered intraperitoneally. This work presents an effective nanomedicine for the efficient modification of the TME to enhance the effects of gynecologic cancer chemotherapy.

Bioinspired Tumor-Targeting and Biomarker-Activatable Cell-Material Interfacing System Enhances Osteosarcoma Treatment via Biomineralization.

Osteosarcoma is an aggressive malignant tumor that primarily develops in children and adolescents. The conventional treatments for osteosarcoma often exert negative effects on normal cells, and chemotherapeutic drugs, such as platinum, can lead to multidrug resistance in tumor cells. Herein, this work reports a new bioinspired tumor-targeting and enzyme-activatable cell-material interface system based on DDDEEK-pY-phenylboronic acid (SAP-pY-PBA) conjugates. Using this tandem-activation system, this work selectively regulates the alkaline phosphatase (ALP) triggered anchoring and aggregation of SAP-pY-PBA conjugates on the cancer cell surface and the subsequent formation of the supramolecular hydrogel. This hydrogel layer can efficiently kill osteosarcoma cells by enriching calcium ions from tumor cells and forming a dense hydroxyapatite layer. Owing to the novel antitumor mechanism, this strategy neither hurts normal cells nor causes multidrug resistance in tumor cells, thereby showing an enhanced tumor treatment effect than the classical antitumor drug, doxorubicin (DOX). The outcome of this research demonstrates a new antitumor strategy based on a bioinspired enzyme-responsive biointerface combining supramolecular hydrogels with biomineralization.

Biomineralized MnO2 Nanoplatforms Mediated Delivery of Immune Checkpoint Inhibitors with STING Pathway Activation to Potentiate Cancer Radio-Immunotherapy.

Radiotherapy (RT), as one of the main methods in the clinical treatment of various malignant tumors, would induce systemic immunotherapeutic effects by triggering immunogenic cell death (ICD) of cancer cells. However, the antitumor immune responses produced by RT-induced ICD alone usually are not robust enough to eliminate distant tumors and thus ineffective against cancer metastases. Herein, a biomimetic mineralization method for facile synthesis of MnO2 nanoparticles with high anti-programmed death ligand 1 (αPDL1) encapsulation efficiency (αPDL1@MnO2) is proposed to reinforce RT-induced systemic antitumor immune responses. This therapeutic nanoplatforms-mediated RT can significantly improve the killing of tumor cells and effectively evoke ICD by overcoming hypoxia-induced radio-resistance and reprogramming the immunosuppressive tumor microenvironment (TME). Furthermore, the released Mn2+ ions from αPDL1@MnO2 under acidic tumor pH can activate the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway and facilitate the dendritic cells (DCs) maturation. Meanwhile, αPDL1 released from αPDL1@MnO2 nanoparticles would further promote the intratumoral infiltration of cytotoxic T lymphocytes (CTLs) and trigger systemic antitumor responses, resulting in a strong abscopal effect to effectively inhibit tumor metastases. Overall, the biomineralized MnO2-based nanoplatforms offer a simple strategy for TME modulation and immune activation, which are promising for enhanced RT immunotherapy.

Regulating the Obesity-Related Tumor Microenvironment to Improve Cancer Immunotherapy.

Obesity usually induces systemic metabolic disturbances, including in the tumor microenvironment (TME). This is because adaptive metabolism related to obesity in the TME with a low level of prolyl hydroxylase-3 (PHD3) depletes the major fatty acid fuels of CD8+ T cells and leads to the poor infiltration and unsatisfactory function of CD8+ T cells. Herein, we discovered that obesity could aggravate the immunosuppressive TME and weaken CD8+ T cell-mediated tumor cell killing. We have thus developed gene therapy to relieve the obesity-related TME to promote cancer immunotherapy. An efficient gene carrier was prepared by modifying polyethylenimine with p-methylbenzenesulfonyl (abbreviated as PEI-Tos) together with hyaluronic acid (HA) shielding, achieving excellent gene transfection in tumors after intravenous administration. HA/PEI-Tos/pDNA (HPD) containing the plasmid encoding PHD3 (pPHD3) can effectively upregulate the expression of PHD3 in tumor tissues, revising the immunosuppressive TME and significantly increasing the infiltration of CD8+ T cells, thereby improving the responsiveness of immune checkpoint antibody-mediated immunotherapy. Efficient therapeutic efficacy was achieved using HPD together with αPD-1 in colorectal tumor and melanoma-bearing obese mice. This work provides an effective strategy to improve immunotherapy of tumors in obese mice, which may provide a useful reference for the immunotherapy of obesity-related cancer in the clinic.

In Situ Polymerization of Zwitterions on Therapeutic Proteins to Enable Their Effective Oral Delivery.

Oral administration of protein drugs has always been challenging owing to various intestinal barriers. Herein, we developed an efficient oral protein delivery strategy by using in situ polymerization of zwitterions to encapsulate proteins, which were then loaded into enteric coated capsules for oral feeding. After oral administration of such capsules, the enteric coating would be degraded once the capsule enters the intestine, releasing polyzwitterion/protein nanocomplexes. With the help of polyzwitterion modification, such nanocomplexes were able to pass through the mucus and cellular barriers, likely by the proton-assisted amino acid transporter 1 (PAT1) pathway. Such a polyzwitterion-based protein encapsulation strategy could allow for effective oral delivery of different proteins, including bovine serum albumin (BSA), insulin, and antibodies. Using this strategy, the oral bioavailabilities of insulin and immunoglobin G (IgG) were measured to be as high as 16.9% and 12.5%, respectively. Notably, oral feeding of polyzwitterion/insulin capsules could effectively lower the blood glucose level of diabetic animals (mice, rats, and pigs). Moreover, polyzwitterion/antiprogramed death-1 (αPD-1) capsules were able to induce efficient antitumor immune responses, showing significant tumor inhibition effects toward B16F10- and 4T1-tumor bearing mouse models after oral administration. No significant toxic effect was observed for such oral protein formulations in the treated animals. Our work presents a strategy for the efficient oral delivery of protein drugs, including those with large molecular weights (e.g., antibodies) that can hardly be orally delivered using existing technologies.

Applications and challenges of biomaterial mediated mRNA delivery.

With the rapid development of gene therapy technology and the outbreak of coronavirus disease 2019 (COVID-19), messenger RNA (mRNA) therapeutics have attracted more and more attention, and the COVID-19 mRNA vaccine has been approved by the Food and Drug Administration (FDA) for emergency authorization. To improve the delivery efficiency of mRNA in vitro and in vivo, researchers have developed a variety of mRNA carriers and explored different administration routes. This review will systematically introduce the types of mRNA vectors, routes of administration, storage methods, safety of mRNA therapeutics, and the type of diseases that mRNA drugs are applied for. Finally, some suggestions are supplied on the development direction of mRNA therapeutic agents in the future.

Analysis of combination therapy of immune checkpoint inhibitors in osteosarcoma.

One of the most common primary bone malignant tumors is osteosarcoma (OS), possessing a high tendency of local invasion and distant metastasis. Although surgery combined with chemotherapy can extend the patients' survival time, the prognosis for most patients with metastases or relapses is poor. Immunotherapy has been proved to be a promising treatment alternative for malignant tumors. Although there is a significant amount of animal- and cell-based evidence supporting the relationship between immune checkpoint inhibitors (anti-PD-1, anti-PD-L1, anti-CTLA-4) and cancers, no pan-cancer analysis is available. Simultaneously, immune checkpoint inhibitors have demonstrated satisfactory clinical results in some tumors; however, only a small fraction of patients with certain cancer types have been benefitted. Therefore, based on the TCGA dataset, we first explored the potential roles of immune checkpoints in 33 tumors. Programmed death receptor 1 (PD-1), programmed cell death ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) were not consistently expressed in the same direction in all tumors; however, the direction of expression change was the same in most immune cells. Although there is no well-established relationship between the expression of PD-1/PD-L1/CTLA-4 genes and the prognosis of patients with sarcomas, their interaction and extent of immune cell infiltration into sarcomas are probably the key determinants of therapeutic response. Our first pan-cancer study provides a relatively comprehensive understanding of immune checkpoint inhibitors in different sarcomas.

Combining mannose receptor mediated nanovaccines and gene regulated PD-L1 blockade for boosting cancer immunotherapy.

Tumor nanovaccines have potential applications in the prevention and treatment of malignant tumors. However, it remains a longstanding challenge in exploiting efficient nanocarriers for inducing potent specifically cellular immune responses. Toward this objective, we herein explore an intensive tumor immunotherapeutic strategy by combining mannosylated nanovaccines and gene regulated PD-L1 blockade for immune stimulation and killing activity. Here, we fabricate a mannose modified PLL-RT (Man-PLL-RT) mediated nanovaccines with dendritic cells (DCs) targeting capacity. Man-PLL-RT is capable of co-encapsulating with antigen (ovalbumin, OVA) and adjuvant (unmethylated cytosine-phosphate-guanine, CpG) by electrostatic interaction. This positively charged Man-PLL-RT/OVA/CpG nanovaccines can facilitate the endocytosis, maturation and cross presentation in DCs. However, the nanovaccines arouse limited inhibition of tumor growth, which is mainly due to the immunosuppressed microenvironment of tumors. Combining tumor nanovaccines with gene regulated PD-L1 blockade leads to an obvious tumor remission in B16F10 melanoma bearing mice. The collaborative strategy provides essential insights to boost the benefits of tumor vaccines by regulating the checkpoint blockade with gene therapy.

Combination of epigenetic regulation with gene therapy-mediated immune checkpoint blockade induces anti-tumour effects and immune response in vivo.

Immunotherapy has become a powerful cancer treatment, but only a small fraction of patients have achieved durable benefits due to the immune escape mechanism. In this study, epigenetic regulation is combined with gene therapy-mediated immune checkpoint blockade to relieve this immune escape mechanism. PPD (i.e., mPEG-b-PLG/PEI-RT3/DNA) is developed to mediate plasmid-encoding shPD-L1 delivery by introducing multiple interactions (i.e., electrostatic, hydrogen bonding, and hydrophobic interactions) and polyproline II (PPII)-helix conformation, which downregulates PD-L1 expression on tumour cells to relieve the immunosuppression of T cells. Zebularine (abbreviated as Zeb), a DNA methyltransferase inhibitor (DNMTi), is used for the epigenetic regulation of the tumour immune microenvironment, thus inducing DC maturation and MHC I molecule expression to enhance antigen presentation. PPD plus Zeb combination therapy initiates a systemic anti-tumour immune response and effectively prevents tumour relapse and metastasis by generating durable immune memory. This strategy provides a scheme for tumour treatment and the inhibition of relapse and metastasis.

Photothermal-Chemotherapy Enhancing Tumor Immunotherapy by Multifunctional Metal-Organic Framework Based Drug Delivery System.

Immunotherapy holds great promise for patients undergoing tumor treatment. However, the clinical effect of immunotherapy is limited because of tumor immunogenicity and its immunosuppressive microenvironment. Herein, the metal-organic framework (MIL-100) loaded with chemotherapeutic agent mitoxantrone (MTO) was combined with photothermal-chemotherapy for enhancing immunogenic cell death. MIL-100 loaded with MTO and hyaluronic acid as nanoparticles (MMH NPs) yielded an NP with two therapeutic properties (photothermal and chemotherapy) with dual imaging modes (photoacoustic and thermal). When MMH NPs were coinjected with an anti-OX40 antibody in colorectal cancer, the highest antitumor efficacy and a robust immune effect were achieved. This work provides a novel combined therapeutic strategy, which will hold great promise in future tumor therapy.

A Strategy of Killing Three Birds with One Stone for Cancer Therapy through Regulating the Tumor Microenvironment by H2O2-Responsive Gene Delivery System.

Constructing an efficient in vivo gene delivery system has always been extremely challenging. Herein, a highly efficient H2O2-responsive in vivo polycationic gene delivery system is developed for the first time. The efficient vector PLL-RT (i.e., polylysine grafted with p-tosyl-l-arginine) is used to mediate plasmid DNA (pDNA) delivery, and H2O2-responsive thioketal dipropanedioic acid-modified dextran (TDPAD) is used as a shielding system for effectively coating vector/pDNA polyplexes. The constructed gene delivery system exhibits a prolonged circulatory half-life in vivo and accelerates the accumulation of vector/DNA polyplexes in tumor tissue by the enhanced permeability and retention (EPR) effect. Moreover, this gene delivery system exhibits highly efficient and synergistic antitumor effects through a strategy of killing three birds with one stone. First, upon the arrival of TDPAD/PLL-RT/pDNA [abbreviated as T(PD)] at the tumor site by the EPR effect, TDPAD reacts with excess H2O2 in tumor tissue, contributing to the detachment of TDPAD, and PLL-RT then mediates the enhanced endocytosis of pDNA encoding shVEGF and significantly downregulates the expression of vascular endothelial growth factor (VEGF) in tumor tissue, exhibiting an outstanding antitumor effect. Second, the H2O2 consumption by TDPAD significantly decreases the H2O2 level in tumor tissue, which synergistically suppresses tumor growth. Third, small-molecule product mercaptopropionic acid, generated by the reaction of TDPAD with H2O2, can induce cancer cell apoptosis and exert pronounced antitumor efficacy. This polycationic gene delivery system shows negligible toxicity in vitro and in vivo. This strategy provides an ideal platform for constructing an efficient in vivo gene delivery system and has bright prospects for cancer therapy.

Zinc ion coordination significantly improved the transfection efficiency of low molecular weight polyethylenimine.

Polycationic gene carriers are attracting increasing attention for their use as gene delivery systems. Herein, a novel and high-performance polycationic gene carrier (i.e., Zn-DPPA2) was constructed by introducing a dipicolylamine compound along with zinc ion coordination onto polyethylenimine (PEI1.8k) via Schiff base bonds. Zn-DPPA2 exhibited efficient transfection and negligible cytotoxicity. Zn-DPPA2/DNA complexes possessed significant endocytosis efficiency and excellent endosomal escape ability. Additionally, this polycaitionic gene carrier showed an excellent ability as an antiserum. The nanoscale size and good size stability ensured that Zn-DPPA2/DNA could accumulate in tumor tissue through the enhanced permeability and retention (EPR) effect. Moreover, Zn-DPPA2/DNA complexes exhibited efficient transfection in tumor tissue after intravenous injection. This strategy provided a new idea for polycationic gene carrier construction, which has prospects for widespread application in the field of gene therapy.

Molecular Strings Significantly Improved the Gene Transfection Efficiency of Polycations.

High transfection efficiency and low cytotoxicity are the two key factors to be considered in the design of gene carriers. Herein, a novel and versatile gene carrier (PLL-RT) was prepared by introducing "molecular string" RT (i.e., p-toluylsulfonyl arginine) onto the polylysine backbone. The introduction of RT string contributed to the formation of multiple interactions between the polycationic gene carriers and cell membrane or DNA, as well as adopting α-helix conformation, all of which would be beneficial to enhance the gene transfection. In addition, RT string grafted onto other polycations such as hyperbranced PEI25k and dendrimer PAMAM could also acquire improved transfection efficiency and low cytotoxicity. Moreover, PLL-RT presented significant tumor inhibition effect in vivo. This work provided an effective strategy for constructing novel gene carriers with high transfection and low cytotoxicity.