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Abstract: Enhanced in vivo gene expression using non-viral vectors is a critical issue in gene therapy in general. Among the many potential utilities of non-viral vector-mediated gene delivery, its application in DNA-based vaccination is an attractive approach with several practical advantages over conventional vaccination. We have previously shown that the endosomolytic bacterial protein listeriolysin O (LLO) is capable of facilitating transfection in vitro using the LPDII (anionic liposome–polycation–DNA complexes) delivery system. In the present study we have extended and investigated the DNA delivery of LLO-containing LPDII to in vivo and evaluated its utility in DNA vaccination in mice. We further investigated the ability of this non-viral gene delivery system to elicit an immune response to a model antigen ovalbumin (OVA), particularly focusing on the OVA-specific CD8+ cytotoxic T lymphocyte (CTL) response, after delivery of a plasmid containing the OVA cDNA. A DNA prime and protein boost protocol was employed to generate cytotoxic T cell responses. Our results show that increased in vitro and in vivo transfection efficiencies were observed when LLO was incorporated into LPDII. This LLO-LPDII formulation produced an enhanced functional antigen-specific CD8+ T cell response in vivo compared to the heat-inactivated LLO-containing LPDII (HI-LLO-LPDII) formulation. Furthermore, a significantly higher CTL frequency was observed in the splenocytes isolated from the mice primed with LLO-LPDII by an enzyme-linked immunosorbent spot assay. Interferon-γ production upon specific stimulation by OVA-specific CD8+ peptide was also significantly stronger with the inclusion of LLO into LPDII. These findings suggest that the LLO-containing LPDII system possesses noteworthy potential as a candidate carrier for DNA vaccine delivery. [ABSTRACT FROM AUTHOR]

The success of lipid nanoparticles (LNPs) in treating COVID-19 promotes further research of mRNA vaccines for cancer vaccination. Aiming at overcoming the constraints of currently available mRNA carriers, various alternative nano-vectors have been developed for delivering tumor antigen encoding mRNA and showed versatility to induce potent anti-tumor immunity. The rationally designed nano-vaccines increase the immune activation capacity of the mRNA vaccines by promoting crucial aspects including mRNA stability, cellular uptake, endosomal escape and targeting of immune cells or organs. Herein, we summarized the research progress of various mRNA based nano-vaccines that have been reported for cancer vaccination, including LNPs, lipid enveloped hybrid nanoparticles, polymeric nanoparticles etc. Several strategies that have been reported for further enhancing the immune stimulation efficacy of mRNA nano-vaccines, including developing nano-vaccines for co-delivering adjuvants, combination of immune checkpoint inhibitors, and optimizing the injection routes for boosting immune responses, have been reviewed. The progress of mRNA nano-vaccines in clinical trials and the prospect of the mRNA vaccines for cancer vaccination are also discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

Vaccines represent one of the most powerful and cost-effective innovations for controlling a wide range of infectious diseases caused by various viruses and bacteria. Unlike mRNA and DNA-based vaccines, subunit vaccines carry no risk of insertional mutagenesis and can be lyophilized for convenient transportation and long-term storage. However, existing adjuvants are often associated with toxic effect and reactogenicity, necessitating expanding the repertoire of adjuvants with better biocompatibility, for instance, designing self-adjuvating polymeric carriers. We herein report a novel subunit vaccine delivery platform constructed via in situ free radical polymerization of C7A (2-(Hexamethyleneimino) ethyl methacrylate) and acrylamide around the surface of individual protein antigens. Using ovalbumin (OVA) as a model antigen, we observed substantial increases in both diameter (∼70 nm) and surface potential (−1.18 mV) following encapsulation, referred to as n(OVA)C7A. C7A's ultra pH sensitivity with a transition pH around 6.9 allows for rapid protonation in acidic environments. This property facilitates crucial processes such as endosomal escape and major histocompatibility complex (MHC)-I-mediated antigen presentation, culminating in the substantial CD8+ T cell activation. Additionally, compared to OVA nanocapsules without the C7A components and native OVA without modifications, we observed heightened B cell activation within the germinal center, along with remarkable increases in serum antibody and cytokine production. It's important to note that mounting evidence suggests that adjuvant effects, particularly its targeted stimulation of type I interferons (IFNs), can contribute to advantageous adaptive immune responses. Beyond its exceptional potency, the nanovaccine also demonstrated robust formation of immune memory and exhibited a favorable biosafety profile. These findings collectively underscore the promising potential of our nanovaccine in the realm of immunotherapy and vaccine development. Schematic illustration of the preparation process of bioresponsive nanovaccine (n(OVA)C7A) and the induction of adaptive immune responses. Firstly, pH-responsive 2-(hexamethyleneimino) ethyl methacrylate (C7A-MA) and acrylamide (AAm), along with the biodegradable crosslinker N,N′ -Bis(acryloyl) cystamine, were initially enriched on the surface of OVA through non-covalent bonding. Secondly, after subcutaneous injection of mice at the hind footpad, the developed nanovaccine n(OVA)C7A rapidly were accumulated in lymph nodes and promoted the uptake and maturation of lymph node-resident DCs, triggering a series of adaptive humoral and cellular immune responses. [Display omitted] • Vaccine carriers with dispersed C7A groups form polymer networks encompassing the antigen. • C7A's ultra pH sensitivity facilitates endosomal escape and MHC-I-mediated antigen presentation. • Self-adjuvanting polymeric nanovaccines (n(OVA)C7A) foster substantial cytotoxic T cell activation and IFNs production. • This nanoplatform has the potential to deliver a variety of protein antigens against viral infections and cancer. [ABSTRACT FROM AUTHOR]

Induction of antigen-specific immune tolerance for the treatment of allergic or autoimmune diseases is an attractive strategy. Herein, we investigated the protective effect of a transdermal microneedle patch against allergic asthma by stimulating allergen-specific immune tolerance. We fabricated biodegradable tolerogenic nanoparticles (tNPs) that are loaded with a model allergen ovalbumin (OVA) and an immunomodulator rapamycin, and filled the tNPs into microneedle tips by centrifugation to form sustained-release microneedles. After intradermal immunization, the microneedles successfully delivered the cargos into the skin and sustainedly released them for over 96 h. Importantly, the microneedles induced allergen-specific regulatory T cells (Treg), decreased the levels of pro-inflammatory cytokines and antibodies while increased anti-inflammation cytokines, finally leading to restored immune homeostasis. The lung tissue analysis illustrated that the sustained-release microneedles significantly reduced the infiltration of eosinophils, decreased the accumulation of mucus and collagen, and significantly relived asthma symptoms. Our results suggested that the sustained-release microneedle-based transdermal delivery system can induce antigen-specific immune tolerance with improved compliance and efficacy, providing a new therapeutic strategy for the treatment of allergic and autoimmune diseases. Sustained-release microneedles induced allergen-specific immune tolerance to protect against allergic asthma. The sustained-release microneedles successfully co-delivered allergens and immunomodulators into the skin, down-regulated co-stimulatory molecules of DCs and induced allergen-specific Tregs, restored the immune response, and finally reduced inflammatory cell infiltration in the lung, inhibited airway mucus accumulation and prevented allergic asthma progression. [Display omitted] • Tolerogenic nanoparticle-loaded microneedles induce effective immune tolerance against asthma. • The incorporation of tolerogenic nanoparticles can improve the immune-tolerance induction efficiency of microneedles. • Microneedle-mediated intradermal vaccination of auto-antigen increases the recruitment of antigen-presenting cells. • Co-administration of auto-antigen and immune-modulator is crucial for immune tolerance induction. [ABSTRACT FROM AUTHOR]

Cholesterol is an indispensable component of most liposomes, heavily influencing their physical and surface properties. In this study, cholesterol in non-PEGylated liposomes was replaced by its analog, asiatic acid (AA), to generate liposomes with an alternative composition. These AA liposomes are generally smaller and more rigid than conventional liposomes, circulate longer in the body, and accumulate more in primary tumors and lung metastases in vivo. On the other hand, as an active ingredient, AA can decrease TGF-β secretion to inhibit the epithelial-mesenchymal transition (EMT) process, increase the sensitivity of tumor cells to doxorubicin (DOX), and synergize with DOX to enhance the immune response, thus improving their antitumor and anti-metastasis efficiency. Based on this rationale, DOX-loaded AA liposomes were fabricated and tested against triple-negative breast cancer (TNBC). Results showed that compared with conventional liposomes, the DOX-AALip provided approximately 28.4% higher tumor volume reduction with almost no metastatic nodules in the mouse model. Our data demonstrate that AA liposomes are safe, simple, and efficient, and thus in many situations may be used instead of conventional liposomes, having good potential for further clinical translational development. (A) Structure of AA and cholesterol. (B) Schematic diagram of the preparation process of DOX-Lip and DOX-AALip. (C) Schematic illustration of the suppression of tumor development and metastasis by DOX-AALip in a TNBC mouse model [Display omitted] • Asiatic acid (AA) may both work as a cholesterol replacement and as an anti-tumor agent. • These AA liposomescould achieve simultaneous targeting of primary tumors and metastatic lesions. • DOX-AALip is prepared in the same way as conventional liposomes. [ABSTRACT FROM AUTHOR]

To reduce recurrence rate after transurethral resection of bladder tumor, long-term intravesical instillations of Bacillus Calmette-Guérin (BCG) and/or chemotherapeutic drugs is the standard treatment for non-muscle invasive bladder carcinoma. However, the main challenges of intravesical therapy, such as short retention time and poor permeability of drugs in the bladder, often require frequent and high-dose administrations, leading to significant adverse effects and financial burden for patients. Aiming at addressing these challenges, we developed a novel approach, in which the cell-penetrating peptide modified oxaliplatin prodrug liposomes and a low-dose BCG were co-delivered via a viscous chitosan solution (LRO-BCG/CS). LRO-BCG/CS addressed these challenges by significantly improving the retention capability and permeability of chemotherapy agents across the bladder wall. Then, oxaliplatin triggered the immunogenic cell death, and the combination of BCG simultaneously further activated the systemic anti-tumor immune response in the MB49 orthotopic bladder tumor model. As a result, LRO-BCG/CS demonstrated superior anti-tumor efficacy and prolonged the survival time of tumor-bearing mice significantly, even at relatively low doses of oxaliplatin and BCG. Importantly, this combinational chemo-immunotherapy showed negligible side effects, offering a promising and well-tolerated therapeutic strategy for bladder cancer patients. [Display omitted] • Positive charged liposomes can penetrate the bladder tumor tissue deeper. • Chitosan solution promotes the retention capability of drugs in bladder. • Oxaliplatin and Bacillus Calmette-Guérin synergistically activate immune responses. [ABSTRACT FROM AUTHOR]

At present, the most widely used aluminum adjuvants have poor ability to induce effective Th1 type immune responses. Existing evidence suggests that manganese is a potential metal adjuvant by activating cyclic guanosine phospho-adenosine synthase (cGAS)-interferon gene stimulator protein (STING) signaling pathway to enhance humoral and cellular immune response. Hence, the effective modulation of metal components is expected to be a new strategy to improve the efficiency of vaccine immunization. Here, we constructed a manganese and aluminum dual-adjuvant antigen co-delivery system (MnO 2 -Al-OVA) to enhance the immune responses of subunit vaccines. Namely, the aluminum hydroxide was first fused on the surface of the pre-prepared MnO 2 nanoparticles, which were synthesized by a simple redox reaction with potassium permanganate (KMnO 4) and oleic acid (OA). The engineered MnO 2 -Al-OVA could remarkably promote cellular internalization and maturation of dendritic cells. After subcutaneous vaccination, MnO 2 -Al-OVA rapidly migrated into the lymph nodes (LNs) and efficiently activate the cGAS-STING pathway, greatly induced humoral and cellular immune responses. Of note, our findings underscore the importance of coordination manganese adjuvants in vaccine design by promoting the activation of the cGAS-STING-IFN-I pathway. With a good safety profile and facile preparation process, this dual-adjuvant antigen co-delivery nanovaccine has great potential for clinical translation prospects. A sketch of the preparation of a manganese and aluminum dual adjuvant antigen delivery system (MnO 2 -Al-OVA) and its use for targeting lymph nodes (LN) and effective induction of antitumor immune response. [Display omitted] [ABSTRACT FROM AUTHOR]

With the rapid development of nanotechnology as well as growing interest in immunotherapy, a great number of vaccine delivery vehicles have been explored in order to elicit potent adaptive immune responses against various infections or tumors. Recent studies have shown that targeting vaccine to antigen-presenting cells (APCs) within lymph nodes is an effective strategy for improving antigen-specific adaptive immune response. However, the characteristics of vaccine vehicles, such as size, surface charge and the degree of PEGylation, affect lymph node transfer and subsequent APC uptake, leading to different levels of immune responses. Thus, a comprehensive review of barriers, difficulties and corresponding strategies in lymph node targeting is important. In this review, we summarize the critical factors that affect lymph node delivery and survey recently reported successful vaccine carriers, which may be helpful for the rational design of vaccine vehicles. [ABSTRACT FROM AUTHOR]

The development of vaccines has always been an essential task worldwide since vaccines are regarded as powerful weapons in protecting the global population. Although the vast majority of currently authorized human vaccinations are administered intramuscularly or subcutaneously, exploring novel routes of immunization has been a prominent area of study in recent years. This is particularly relevant in the face of pandemic diseases, such as COVID-19, where respiratory immunization offers distinct advantages, such as inducing systemic and mucosal responses to prevent viral infections in both the upper and lower respiratory tracts and also leading to higher patient compliance. However, the development of respiratory vaccines confronts challenges due to the physiological barriers of the respiratory tract, with most of these vaccines still in the research and development stage. In this review, we detail the structure of the respiratory tract and the mechanisms of mucosal immunity, as well as the obstacles to respiratory vaccination. We also examine the considerations necessary in constructing a COVID-19 respiratory vaccine, including the dosage form of the vaccines, potential excipients and mucosal adjuvants, and delivery systems and devices for respiratory vaccines. Finally, we present a comprehensive overview of the COVID-19 respiratory vaccines currently under clinical investigation. We hope this review can provide valuable insights and inspiration for the future development of respiratory vaccinations. [Display omitted] [ABSTRACT FROM AUTHOR]

Traditional photothermal therapy ablates tumor cells by a high temperature (> 50 °C). Although it has shown good anti-tumor effect in animal models, the potential damages to healthy tissues and the unnecessary inflammatory reactions caused by the high temperature have hindered the clinical transitions of traditional photothermal therapy. In this study, we used polydopamine (PDA) as a mild photothermal material and control the maximum temperature below 45 °C, which not only avoided the side effects caused by a high temperature, but also ablated a fraction of tumor cells and produced tumor antigens. Meanwhile, the near-infrared (NIR) light also served as a "switch" to trigger the release of CRISPR/Cas9 RNP from Fe 3 O 4 nanoparticles (Fe 3 O 4 NPs) after their accumulation to tumor sites via magnetic targeting. The triple functional mild photothermal therapy achieved significant PD-L1 gene knockout efficiency in the tumor-bearing mice, reversed the condition of immunosuppression in the tumor microenvironment, led to a higher level of anti-tumor immune responses and effectively inhibited the growth of melanoma. We anticipate that this triple functional mild photothermal therapy would provide a potential new approach for the treatment of malignant tumors. [Display omitted] • Tumor targeted delivery of CRISPR/Cas9 RNP by mesoporous polydopamine coated Fe 3 O 4 NPs. • Laser-triggered the responsive release of CRISPR/Cas9 RNP. • Triple functional mild photothermal therapy combined with gene editing effectively inhibited the growth of malignant tumor. • ICD effect and the knockdown of PD-L1 gene significantly enhanced the anti-tumor immune responses. [ABSTRACT FROM AUTHOR]

Tumor peptide vaccines contain only key amino acid sequences of tumor neoantigens, and therefore can provide precise activation of immune responses. Recent research has found that short peptide vaccines restricted to MHC-I epitopes are insufficient to activate effective CD8+ T cell responses for tumor elimination, and assistance from CD4+ T cell immunity could significantly improve the therapeutic outcome. Herein, we proposed an innovative peptide vaccine strategy to simultaneously activate CD8+ and CD4+ T cell responses by combining MHC-I and MHC-II epitopes into one long peptide antigen. To further strengthen the anti-tumor immune response induced by this dual-epitope peptide, we engineered a PEG derivative (PpASE) stabilized aluminum nanoparticle for delivering the synthetic long peptides (ANLs). The synthesized nanovaccine with a diameter of ~100 nm showed good stability and enhanced antigen uptake by antigen-presenting cells (APCs). As a result, ANLs promoted the presentation of MHC-I epitope in APCs and induced stronger activation and proliferation of CD8+ T cells as compared to aluminum nanoparticle loaded with MHC-I epitope restricted peptides (ANSs). After subcutaneous vaccination, the developed nanovaccine significantly inhibited tumor growth and prolonged mouse survival in both B16-OVA and B16F10 tumor models. Finally, ANLs were also able to elevate the maturation level of human dendritic cells (DCs), showing a great possibility of clinical translation. [Display omitted] • Dual-epitope synthetic long peptides (SLPs) were innovatively engineered by linking the MHC-I and MHC-II epitopes together. • The SLPs can be encapsulated and delivered to antigen presenting cells by precisely designed aluminum nanoparticles (ANLs). • The ANLs can induce strong Th1 and CD8 T cell responses in mice. • The ANLs demonstrate potent immune activation capacity for tumor inhibition. • The ANLs can improve the cellular uptake and maturation of the human DCs. [ABSTRACT FROM AUTHOR]

Current clinical agents for autoimmunity disorders treatment often cause substantial adverse effects and safety concerns, owing to non-specific immune modulation. Due to the prominent contribution of effector T cells in pathogenesis of rheumatoid arthritis (RA) and inflammatory bowel disease (IBD), and preferential location of co-stimulatory receptor-ligand pair OX40-OX40L at the inflamed sites, selectively targeting autoaggressive T cells by blockade OX40-OX40L, might represent an alternative strategy. Herein, we developed a new strategy to antagonize OX40-OX40L interaction by engineering a cell membrane derived nanovesicles (NVs) expressing OX40 receptors (OX40 NVs), and explored their potential for autoimmune disorders therapy. OX40 NVs showed specific binding capability to inflamed HUVECs in vitro, it also possessed distinct arthritic-targeting capacity in RA inflamed joints, and preferential accumulation in IBD inflamed colon. OX40 NVs efficiently suppressed the progression of both RA and IBD diseases through reducing CD4+OX40+ T cells population, and proinflammatory cytokines (i.e. , TNF-α and IL-1β), while reinforcing Tregs immune-suppressive effect, with superior therapeutic efficacy than anti-OX40L. Additionally, dexamethasone (DEX) loading can further enhance the potential of OX40 NVs for RA treatment. Owing to their preferential localization to inflamed sites, and potent immune-suppression ability, targeting OX40-OX40L blockade by OX40 NVs for autoimmune therapy is highly promising. [Display omitted] • Selectively targeting autoaggressive T cells through blockade co-stimulatory OX40-OX40L pair was developed for autoimmune diseases therapy. • OX40 NVs showed distinct arthritic-targeting capacity in RA joints and preferential accumulation in IBD colon. • OX40 NVs treatment alleviated cytokines production, reduced CD4+OX40+ T cells population and reinforced Tregs immune-suppressive effect. • OX40 NVs could also service as vehicles to delivery therapeutics into RA sites. [ABSTRACT FROM AUTHOR]

Transdermal drug delivery systems for rheumatoid arthritis (RA) have been receiving increasing attention as they can potentially overcome drawbacks which exist in traditional oral or injection strategies, including low patient compliance and serious gastrointestinal side effects. However, transdermal delivery of RA drugs especially biological drugs suffers from low drug delivery efficiency due to the robust skin barrier. Herein, we fabricated melittin-loaded hyaluronic acid (HA) microneedles and investigated their capacity for inhibiting RA. We showed that melittin-loaded HA microneedles possessed high mechanical strength for successful delivery of melittin into the skin and effectively inhibited RA progression in adjuvant induced both rodent and murine models, as shown by results in histological, paw swelling and arthritis score. Furthermore, after modifying HA with cross-linkable groups, the fabricated microneedles with sustained release properties could further improve the therapeutic potency. Cytokine and T cell analysis in the paws and lymphatic organs indicated that the application of microneedles suppressed the levels of pro-inflammation cytokines including IL-17 and TNF-α, and increased the percentage of regulatory CD4 T cells. Our study revealed that polymeric microneedle-mediated transdermal delivery of melittin could serve as a new therapy with high compliance and good therapeutic efficacy for RA and other autoimmune diseases. [Display omitted] [ABSTRACT FROM AUTHOR]

Sustained release vaccine carriers can facilitate an increased interaction time between the antigen and immune system to strengthen immune responses, but their promotion on adaptive immune responses, especially cellular immunity, are still unfavorable. Herein, we report a sustained antigen delivery vector, which carries abundant antigens, a nucleic acid adjuvant and pathogen-associated molecular patterns to simulate a natural pathogen to reinforce immune responses. Specifically, murine colorectal cancer cells MC38 lysate and Toll-like receptor 9 agonist CpG are loaded into yeast derived β-glucan particles (GPs). After vaccination, these particles can form a vaccine depot that continuously release the antigen similar to the traditional aluminum hydroxide gel, but recruit more immune cells and induce more cytokine secretion at the injection site. Stronger antibody responses, Th1 and Th17 biased cellular immunity and immune memory are achieved compared with aluminum hydroxide gel. More importantly, treatment with these particles significantly suppress tumor growth in a therapeutic tumor model. This work shed light on the efficacy of combining sustained antigen release with pathogen-mimicking manner in vaccine design. [Display omitted] • Tumor cell lysate and CpG were loaded into yeast derived β-glucan particles to obtain a pathogen-mimicking vaccine (GTC). • GTC formed a vaccine depot and triggered cellular infiltration at the injection site. • GTC generated stronger immune responses and better therapeutic effect against tumor compared with aluminum hydroxide gel. [ABSTRACT FROM AUTHOR]

An ideal cancer vaccine should contain both strongly immunogenic cancer-specific antigen and potent adjuvant for stimulating robust cellular immunity which are pivotal for clearance of cancer cells. However, most of commercially available adjuvants such as aluminum phosphate gel cannot stimulate robust cellular immune response. In the current study, we reformed microscale aluminum phosphate gel adjuvant into nanoscale and fabricated CpG loaded and B16F10 tumor cell membrane coated aluminum phosphate nanoparticles (APMC). The resultant nano-vaccines showed a size of around 60 nm and a negative surface charge of −40 mV. Tumor cell membrane not only served as tumor antigens but also effectively improved the colloidal dispersion of aluminum phosphate nanoparticles. Subcutaneously injected APMC were efficiently drained to mouse lymph nodes, significantly increased co-uptake of tumor antigen and CpG by lymph node resident antigen presenting cells, promoted maturation of these cells and enhanced lysosomal antigen escape. After immunizing mice, they triggered robust cellular immunity, including potent IFN-γ+CD4+ T cells, IFN-γ+CD8+ T cells, cytotoxic T lymphocytes and cytokine excretion in spleen and lymph node cells. The elicited responses significantly suppressed tumor growth and prolonged survival of mice in both prophylactic and therapeutic melanoma models. This promising vaccine delivery system shows great potential to clinical transformation and can be further developed for personalized cancer vaccines. Unlabelled Image • Microscale aluminum phosphate adjuvant was reformed to nanoscale and loaded with B16F10 tumor cell membrane and CpG (APMC). • APMC carrying comprehensive tumor antigens showed enhanced immunogenicity, dispersion and mobility. • APMC targeted to lymph nodes and co-delivered tumor cell membrane and CpG to lymph node resident DCs and macrophages. • APMC compensated the shortcomings of aluminum phosphate gel and elicited potent cellular immunity against tumor. [ABSTRACT FROM AUTHOR]

Adjuvants that contain pathogen-associated molecular patterns (PAMPs) can enhance vaccination efficacy by binding to pattern recognition receptors (PRRs), thereby stimulating immune responses. Particularly effective may be the combination of multiple PAMPs that activate different PRRs, which occurs with natural pathogens. Here we hypothesized the enhanced effects would occur in two adjuvants that stimulate different PRRs: CpG oligodeoxynucleotide (CpG-ODN), which is Toll-like receptor 9 agonist; and 5′-triphosphate, short, double-stranded RNA (3pRNA), which activates retinoic acid-inducible gene I (RIG-I). The model antigen ovalbumin (OVA) was loaded and adjuvants were surface-adsorbed to aluminum hydroxide nanoparticles (hereafter NP-3pRNA-CpG) by electrostatic interaction with an average size of 120 nm and a negative surface charge for targeting lymph nodes. These nanoparticles were efficiently internalized by antigen-presenting cells (APCs) in the lymph nodes, and the resulting APC activation and antigen cross-presentation generated strong humoral immunity and cytotoxic T lymphocyte responses and IFN-γ secretion. NP-3pRNA-CpG significantly suppressed B16-OVA tumor growth and prolonged survival of tumor-bearing mice in therapeutic and prophylactic models, illustrating the enhanced effects of CpG-ODN and 3pRNA. Our study highlights the potential of combining multiple adjuvants for effective vaccine design. Unlabelled Image • Nano sized aluminum hydroxide combined two adjuvants (NP-3pRNA-CpG) for activating different pattern recognition receptors. • NP-3pRNA-CpG accumulated in the lymph nodes and could be effectively ingested by DCs and macrophages. • NP-3pRNA-CpG generated enhanced humoral and cellular immune responses. [ABSTRACT FROM AUTHOR]

Malignant melanoma, a highly dangerous type of skin cancer, is usually resistant to pro-apoptosis agents such as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) due to low death receptor expression levels. After verifying combination of chemotherapy drug paclitaxel (PTX) and TRAIL could significantly enhance their anti-melanoma effects, we developed a liposomal melanoma target-delivery system with tumor microenvironment responsiveness (TRAIL-[Lip-PTX]C18-TR) to co-deliver TRAIL and PTX. TRAIL is attached to negatively-charged liposome surface while PTX is encapsulated inside, with final surface modification of a stearyl chain (C18) fused pH-sensitive cell-penetrating peptide (TR). Here, C18-TR could specifically binds to melanoma-rich integrin receptors α v β 3 for melanoma targeting, help release TRAIL in low pH microenvironment by reversing the liposomal charge, and facilitate consequent liposome internalization. TRAIL-[Lip-PTX]C18-TR displayed significantly better in vitro half-maximal inhibitory concentration (IC 50) than other formulations, and an in vivo tumor inhibition rate of 93.8%. Mechanistic study revealed that this synergistic effect is associated with the upregulation of death receptors DR4/5 by PTX. This co-delivery system significantly improved TRAIL-based therapy against melanoma, and provided a simple platform to co-deliver other drugs/agents for melanoma treatment. Unlabelled Image • The multifunctional system is tumor microenvironment responsive and active targeting. • Synergistic antitumor effect is associated with the upregulation of death receptors. • A platform that can improve the resistance of TRAIL-based therapies in melanoma. • Chemotherapy drugs and biomolecules could be site-specifically delivered to tumor sites. [ABSTRACT FROM AUTHOR]

To date, cancer phototherapy remains as an unsatisfactory method of cancer treatment due to the high probability of cancer recurrence - an effect that is partly driven by tumor-driven immunosuppression. Therefore, we propose inducing adequate immune responses after photo tumor ablation may be critical to achieve a long term therapeutic effect of phototherapy. Here, we engineered the photosensitizer chlorin e6 (Ce6) and the time-honored immunoadjuvant aluminum hydroxide into bovine serum albumin by albumin-based biomineralization as a novel nanosystem (Al-BSA-Ce6 NPs). After intravenous injection, the nanoparticles not only destroyed tumor cells effectively but also protected animals against tumor rechallenge and metastasis by strongly inducing a systemic anti-tumor immune response. Subsequent analysis demonstrated T cells accumulated in lymph nodes and infiltrated the tumor site, elevating levels of immune indicators including serum antibody, cytokine level and higher proportions of cytotoxic T cells and Th1 cells. These protective effects were not observed with commercially available alumina gels, or when the aluminum hydroxide in the nanoparticles was replaced with ferric hydroxide. Therefore, we present Al-BSA-Ce6 NPs as a novel and unique system for alumina adjuvants that serves as an effective approach for cancer therapy. Unlabelled Image • A nanoparticle system (Al-BSA-Ce6 NPs) synthesized by a biomineralization method for photo-immunotherapy against melanoma. • Unique immunological properties and therapeutic effect were confirmed by comparison with alumina gel and Fe-BSA-Ce6 NPs. • A simple synthesis method using only FDA approved excipients provides great potential for clinical translation. [ABSTRACT FROM AUTHOR]

Glomerulonephritis related renal failure is a frequent cause of end-stage renal disease, and immunoglobulin A nephropathy (IgAN) is the most frequent type of primary glomerulonephritis. As damage induced by IgAN mostly attributes to inflammation responses, inhibiting inflammation in glomerulus can protect normal renal function and delay the onset of renal failure. Hence, reducing levels of p38 MAPK and p65 which are essential regulators in p38 MAPK and NF-κB related inflammation responses could be effective against IgAN. Here, we rationally designed and constructed size- and surface charge- dependent glomerulus-targeting liposomal nanoparticles which are loaded with both p38α MAPK and p65 siRNA. Experiments show that our nanoparticles successfully crossed fenestrated endothelium, accumulated in mesangial cells and endothelial cells, efficiently silenced p38α MAPK and p65 genes, and eventually alleviated proteinuria, inflammation and excessive extracellular matrix deposition in mouse IgAN models. This siRNA co-delivery system thus represents a promising treatment option for IgAN and offers a versatile platform for other glomerular problems. Our work also highlights a novel strategy of glomerulus-targeting and an encouraging therapeutic route for other inflammatory diseases. Unlabelled Image • An effective system by precisely inhibiting inflammation inside of glomeruli based on RNAi technology. • Nano-liposomal carriers accumulating in glomerular, showing dual targeting capability. • The specific simultaneous inhibition of p38 MAPK and NF-κB pathways displayed excellent anti-inflammation efficacy. • A platform that can be used to deliver drugs to glomerulus for various glomerular problems. [ABSTRACT FROM AUTHOR]

Currently, most anti-cancer therapies are still haunted by serious and deleterious adverse effects. Here, we report a highly biocompatible tumor cell-targeting delivery systems utilizing exosome-like vesicles (ELVs) that delivers a low-toxicity anti-cancer agent imperialine against non-small cell lung cancer (NSCLC). First, we introduced a novel micelle-aided method to efficiently load imperialine into intact ELVs. Then, integrin α3β1-binding octapeptide cNGQGEQc was modified onto ELV platform for tumor targeting as integrin α3β1 is overexpressed on NSCLC cells. This system not only significantly improved imperialine tumor accumulation and retention, but also had extremely low systemic toxicity both in vitro and in vivo. Our discoveries offer new ways to utilize ELV more efficiently for both drug loading and targeting. The solid pharmacokinetics improvement and extraordinary safety of this system also highlight possibilities of alternative long course cancer therapies using similar strategies. Unlabelled Image [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) have high surface area, tunable pore size, and high loading capacity, making them promising for drug delivery. However, their synthesis requires organic solvents, high temperature and high pressure that are incompatible with biomacromolecules. Zeolitic imidazole frameworks (ZIF-8) which forms through coordination between zinc ions and 2-methylimidazole (MeIM) have emerged as an advanced functional material for drug delivery due to its unique features such as high loading and pH-sensitive degradation. In this study, we took advantage of a natural biomineralization process to create aluminum-containing nanoZIF-8 particles for antigen delivery. Without organic solvents or stabilizing agent, nanoparticles (ZANPs) were synthesized by a mild and facile method with aluminum, model antigen ovalbumin (OVA) and ZIF-8 integrated. A high antigen loading capacity (%) of 30.6% and a pH dependent antigen release were achieved. A Toll-like receptor 9 agonist cytosine-phosphate-guanine oligodeoxynucleotides (CpG) was adsorbed on the surface of ZANPs (hereafter CpG/ZANPs) to boost the immune response. After subcutaneous injection in vivo, CpG/ZANPs targeted lymph nodes (LNs), where their cargo was efficiently internalized by LN-resident antigen-presenting cells (APCs). ZANPs decomposition in lysosomes released antigen into the cytoplasm and enhanced cross-presentation. Moreover, CpG/ZANPs induced strong antigen-specific humoral and cytotoxic T lymphocyte responses that significantly inhibited the growth of EG7-OVA tumors while showing minimal cytotoxicity. We demonstrate that ZANPs may be a safe and effective vehicle for the development of cancer vaccines. We describe the synthesis of aluminum integrated MOFs (ZANPs) for efficiently vaccine delivery. ZANPs were accumulated in lymph node and taken up by DCs after subcutaneous injection after which potent antigen-specific humoral and cellular immune response were generated in immunized mice. Unlabelled Image • A facile and green synthesis method of aluminum adjuvant-integrated zeolitic imidazolate framework was developed by taking advantage of a natural biomineralization process. • This pH-responsive aluminum-integrated zeolitic imidazolate framework can serve as a potential vaccine delivery platform to induce strong humoral and cellular immune responses. [ABSTRACT FROM AUTHOR]

Abstract Parkinson's disease (PD), one of the most common movement and neurodegenerative disorders, is challenging to treat, largely because the blood-brain barrier blocks passage of most drugs. Here we find exosomes from blood showing natural brain targeting ability which involved the transferrin-transferrin receptor interaction. Thus, we develop a biocompatible platform based on blood exosomes for delivering drugs across the blood-brain barrier. Blood exosomes show sizes between 40 and 200 nm and spherical morphology, and dopamine can be efficiently loaded into blood exosomes by a saturated solution incubation method. Further in vitro and in vivo studies demonstrates these exosomes successfully delivered dopamine to brain, including the striatum and substantia nigra. Brain distribution of dopamine increased >15-fold by using the blood exosomes as delivery system. Dopamine-loaded exosomes show much better therapeutic efficacy in a PD mouse model and lower systemic toxicity than free dopamine after intravenous administration. These results suggest that blood exosomes can be used as a promising drug delivery platform for targeted therapy against PD and other diseases of the central nervous system. Graphical abstract Unlabelled Image Highlights • Blood exosomes released by reticulocytes have natural brain targeting ability. • The targeting mechanism involves the transferrin-transferrin receptor interaction. • Crude blood exosomes can serve as drug carriers for brain targeted drug delivery. • Dopamine-loaded blood exosomes improve the treatment of Parkinson's disease. [ABSTRACT FROM AUTHOR]

Salmonella VNP20009 inhibits tumor growth in preclinical models but its efficacy in humans is limited, potentially because cells mount an autophagy response that destroys the therapeutic bacteria. To neutralize this protective response, we combined VNP20009 with long-circulating liposomes containing the autophagy arrest agent hydroxychloroquine. This combination was associated with significantly larger numbers of intracellular Salmonella, accumulated autophagic vacuoles and much greater cell death in vitro . The combination was also associated with greater tumor-targeting ability, slower tumor growth and longer survival than free hydroxychloroquine in a murine model of melanoma. Our results suggest that combining tumor-targeting Salmonella with autophagy arrest may be effective for treating highly aggressive melanoma. [ABSTRACT FROM AUTHOR]

The chemotherapy of aggressive breast tumor is usually accompanied by a poor prognosis because of the metastasis of tumor cells. Thus, it is important to simultaneously enhance antitumor and anti-metastasis efficacy. Fibronectin and its complexes are expressed on the walls of tumor vessels and in tumor stroma. Moreover, the expression of fibronectin in metastatic sites is even higher than that in primary tumors. Herein, we designed a fibronectin-targeting CREKA-modified liposomal doxorubicin (CREKA-Lipo-Dox) for the therapy of metastatic breast tumor. CREKA-Lipo was uniformly formed with high entrapment efficiency. It exhibited longer blood circulation time compared with free Dox, and there was no significant change compared with PEG-Lipo-Dox. Immunofluorescence results revealed that the CREKA-Lipo-Dox could specifically bind to fibronectin in the tumor vessels and tumor stroma. The antitumor and anti-metastasis efficacy of CREKA-loaded liposome was more obvious than that of free Dox or unmodified Dox-Lipo. Taken together, binding fibronectin by CREKA could be an attractive therapeutic strategy for metastatic breast cancer in the future. [ABSTRACT FROM AUTHOR]

Increasing attention has been paid to nasal delivery. Subunit vaccines based on antigenic proteins or polypeptides offer good safety. However, lack of delivery efficiency, particularly for nasal immunization, is a big issue. Here we designed a highly tunable polymeric hybrid micelle (PHM) system offering good vaccine efficacy after nasal administration. PHMs are formulated from two amphiphilic diblock copolymers, polycaprolactone-polyethylenimine (PCL-PEI) and polycaprolactone-polyethyleneglycol (PCL-PEG), the ratio of which determines PHM physicochemical properties. Citraconic anhydride-modified ovalbumin (Cit-OVA), as model antigen, was incorporated into PHMs via electrostatic interaction, giving antigen-loaded micelles of around 150 nm in size. Their surface characteristics which are found closely related to their in vivo kinetics can be modulated by adjusting the mass ratio of PCL-PEG and PCL-PEI. PHM/Cit-OVA complexes containing PCL-PEI and PCL-PEG in a 1:1 mass ratio induced strong immune responses in nasal mucosa and serum in vivo without causing obvious toxicity, and Cit-OVA was efficiently internalized by dendritic cells. These results demonstrate the promise of this multifunctional polymeric delivery system for nasal vaccination. [ABSTRACT FROM AUTHOR]

Blood-brain barrier (BBB) represents the greatest challenge that hampers therapeutic molecules entering the brain. Here, we described a novel brain-specific delivery strategy targeting to pyrilamine-sensitive H + /OC antiporter to facilitate therapeutic molecules cross the BBB and penetrate into the brain. In this study, four cyclic tertiary amines were selected as the brain-targeting moieties to modify naproxen (NP), a non-steroidal anti-inflammatory drug. The obtained NP conjugates displayed cell uptake efficiencies over 144-fold higher than that of unmodified NP in endothelial cells. The cell uptake process of the conjugates was primarily driven by pyrilamine-sensitive H + /OC antiporter in a pH-dependent, Na + -independent, and membrane potential-independent pathway, which could be further inhibited by pyrilamine, propranolol, and imipramine. Moreover, the NP conjugates showed significantly higher AUC 0 − t and C max in the brain compared with unmodified NP, and significantly higher accumulation than NP in the in situ brain perfusion study. Also, the conjugates showed superior neuroprotective effect in vitro and in vivo . Thus, the chemical modification of therapeutics with a cyclic tertiary amine moiety represents a promising and efficient strategy for brain-specific drug delivery via pyrilamine-sensitive H + /OC antiporter. [ABSTRACT FROM AUTHOR]

Effective treatment for rheumatoid arthritis is hindered by the lack of drugs that selectively target inflamed joints. Liposomes, nanoparticles and conventional micelles loaded with limited amounts of drugs may be unstable in the circulation and result in uncontrolled drug release kinetics. Here we developed a new drug delivery system of pH-sensitive polymeric micelles based on an acid-labile hydrazone bond. Amphiphilic conjugates of a PEG-based derivative and the hydrophobic drug prednisolone (PD) self-assembled into PD micelles with a drug loading of 19.29%. When the micelles reached the acidic environment of synovial fluid, the hydrazone bonds hydrolyzed, releasing free PD. Intravenous injection of PD micelles into mice with collagen-induced arthritis led to PD accumulation in affected joint tissues. PD concentrations in plasma and joints of arthritic mice were significantly higher after injection with PD micelles than after injection with free PD. The enhancement effect in joints was 4.63-fold based on the area under the concentration-time curve and 2.50-fold based on the maximum concentration (C max ). In vivo pharmacodynamics experiments showed PD micelles to have better anti-inflammatory and disease-modifying effects than free PD. Our results indicate the promise of PD micelles for targeted drug delivery in inflammatory disease. [ABSTRACT FROM AUTHOR]

Glucocorticoid (GC) is the cornerstone therapy of rheumatoid arthritis, but high doses are associated with serious adverse effects. In an effort to improve the efficacy of low-dose GC therapy, we developed a micelle system for targeted delivery to inflamed joints and validated the approach in a rat model of arthritis. Micelles loaded with dexamethasone (Dex) self-assembled from the amphipathic poly (ethylene glycol)-block–poly (ε­caprolactone) (PCL–PEG) polymer via film dispersion, and they were injected intravenously at a dose of only 0.8 mg/kg into rats with adjuvant-induced arthritis. The micelles persisted for a relatively long time in the circulation, and they accumulated preferentially in inflamed joints. Micelle-delivered Dex potently reduced joint swelling, bone erosion, and inflammatory cytokine expression in both joint tissue and serum. PCL–PEG micelles caused only moderate adverse effects on body weight, lymphocyte count and blood glucose concentration, and they weakly activated the host complement system. These results suggest that encapsulating Dex in PCL–PEG micelles may allow for safe and effective low-dose GC therapy targeting inflammatory disorders. [ABSTRACT FROM AUTHOR]

As a natural somatostatin analog, octreotide acetate (OCT) has been extensively used in cancer treatment and growth hormone related diseases. The clinical application of OCT, however, is greatly limited by its short half-life, rapid elimination and clearance in vivo . In the current study, a high content phospholipid-based phase separation gel platform (PPSG) was presented, which could be injected in the soluble state and underwent rapid phase-separation into a gel-like implant after a single subcutaneous injection. OCT was dispersed homogeneously in the PPSG pre-gel solution to afford OCT-loaded PPSG (OCT-PPSG) after a single subcutaneous injection, which displayed controlled and sustained release profiles for up to 30 days in rats, rabbits and Beagle dogs. OCT-PPSG showed a less significant burst phase followed by a steady plasma concentration of OCT compared with Sandostatin ® (LAR) in Beagle dogs. Moreover, OCT-PPSG was demonstrated to show remarkable antitumor efficacy in both a primary rat model and a xenograft mouse model of hepatocellular carcinoma (HCC). PPSG thus represented a promising and viable in situ forming gel platform material for the long-term sustained release of peptides and protein drugs. [ABSTRACT FROM AUTHOR]

Facing the threat of highly variable virus infection, versatile vaccination systems are urgently needed. Intranasal mRNA vaccination provides a flexible and convenient approach. However, the nasal epithelium remains a major biological barrier to deliver antigens to nasal associated lymphoid tissue (NALT). To address this issue, a potent polymer-based intranasal mRNA vaccination system for HIV-1 treatment was synthesized using cationic cyclodextrin-polyethylenimine 2k conjugate (CP 2k) complexed with anionic mRNA encoding HIV gp120. The delivery vehicle containing CP 2k and mRNA overcame the epithelial barrier by reversibly opening the tight junctions, enhanced the paracellular delivery of mRNA and consequently minimized absorption of toxins in the nasal cavity. Together with the excellent intracellular delivery and prolonged nasal residence time, strong system and mucosal anti-HIV immune responses as well as cytokine productions were achieved with a balanced Th1/Th2/Th17 type. Our study provided the first proof of evidence that cationic polymers can be used as safe and potent intranasal mRNA vaccine carriers to overcome the nasal epithelial barrier. The safe and versatile polymeric delivery system represents a promising vaccination platform for infectious diseases. [ABSTRACT FROM AUTHOR]

To inhibit both the local and systemic complications with acute pancreatitis, an effective therapy requires a drug delivery system that can efficiently overcome the blood–pancreas barrier while achieving lung-specific accumulation. Here, we report the first dual pancreas- and lung-targeting therapeutic strategy mediated by a phenolic propanediamine moiety for the treatment of acute pancreatitis. Using the proposed dual-targeting ligand, an anti-inflammatory compound Rhein has been tailored to preferentially accumulate in the pancreas and lungs with rapid distribution kinetics, excellent tissue-penetrating properties and minimum toxicity. Accordingly, the drug–ligand conjugate remarkably downregulated the proinflammatory cytokines in the target organs thus effectively inhibiting local pancreatic and systemic inflammation in rats. The dual-specific targeting therapeutic strategy may help pave the way for targeted drug delivery to treat complicated inflammatory diseases. [ABSTRACT FROM AUTHOR]

Neutral particles 20–45 nm in diameter showed potential as tumor antigen vectors because they targeted the draining lymph nodes after subcutaneous injection. However, they were weakly immune-stimulatory and could also spread throughout the body, raising the risk of systemic toxicity. Here we explored whether incorporating positively charged amphiphilic polymers into micelles improves their site specificity and immunogenicity. Cationic polyethylenimine (2k)-stearic acid (PSA) micelles were loaded with the melanoma antigen peptide Trp2; they showed an average size of 28.7 ± 8.2 nm and an encapsulation efficiency of 99.21 ± 5.38%. Empty PSA micelles acted as a robust adjuvant in vitro, promoting maturation, proliferation and migration of bone marrow-derived dendritic cells in a dose-dependent manner. After subcutaneous injection into mice, Trp2-loaded PSA micelles accumulated preferentially in the medulla and paracortex of the draining lymph nodes and were present at negligible levels in the systemic circulation. Mice immunized with Trp2-loaded PSA micelles showed significantly higher Trp2-specific cytotoxic T lymphocyte activity than mice immunized with free Trp2 or a mixture of Trp2 and empty PSA micelles. In a B16-F10 murine melanoma model, Trp2-loaded PSA micelles inhibited tumor growth significantly more than did free Trp2 and PSA micelles caused less systemic toxicity. These findings suggest that cationic PSA micelles loaded with Trp2 may be a potential approach for melanoma immunotherapy. [ABSTRACT FROM AUTHOR]

A co-delivery system that can transport cancer related microRNAs and chemotherapeutics to their distinct targets in the tumors is an attractive strategy to eliminate tumor relapse in lung cancer therapy. In this study, we developed a dual-drug delivery system for an endogenous microRNA (miR-34a) and paclitaxel (PTX) for synergistic cancer therapy. PTX (a meiotic inhibitor) and miR-34a were loaded into cationic solid lipid nanoparticles (miSLNs-34a/PTX) which were used to treat murine B16F10-CD44 + melanoma metastasized to the lungs of mice. This nanoparticle system demonstrated good protection for miR-34a and PTX from degradation in the serum, and had an average size of approximately 220 nm by photon correlation spectroscopy (PCS). In vitro , the parallel activity of PTX and miR-34a show synergistic anticancer efficacy. In vivo , miSLNs-34a/PTX showed passive targetability to the tumor-bearing lung tissues, and was demonstrated to be much more potent in inhibition of B16F10-bearing tumor growth and elimination of cancer cell populations in the lung than single drug-loaded solid lipid nanoparticles. It has been shown that such co-delivery of miR-34a and PTX is promising for enhanced cancer therapy to reduce tumor relapse. [ABSTRACT FROM AUTHOR]

Abstract: In order to develop a novel kidney-targeted drug delivery system, we synthesized prednisolone carbamate–glucosamine conjugate (PCG) using 2-glucosamine as a ligand, and investigated its potential targeting efficacy. In vitro studies demonstrated that PCG could remarkably improve the uptake of drug by kidney cells. And the specific uptake of PCG could be largely reduced by the inhibitors of megalin receptor. More importantly, PCG showed an excellent kidney targeting property in vivo, and the concentration of the conjugate in the kidney was 8.1-fold higher than that of prednisolone group at 60min after intravenous injection. Besides, PCG could significantly reverse the disease progression in renal ischemia–reperfusion (I/R) injury animal models. Furthermore, PCG presented no adverse effect on bone density while prednisolone resulted in severe osteoporosis. Thus, it indicated that 2-glucosamine could be a potential ligand for kidney-targeted delivery of prednisolone. [Copyright &y& Elsevier]

Summary: Polymeric hollow nanospheres were prepared by self-assembly of rod-coil complexes, in which the rod-like segments were formed by inclusion complexes of β-cyclodextrins (β-CDs) and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) diamines. Nanospheres encapsulating DNA or polyethylenimine/DNA (PEI/DNA) were synthesized and characterized in terms of their supramolecular structures, DNA binding and condensation ability, cytotoxicity, and in vitro gene transfection efficiency in HepG2 cells. [ABSTRACT FROM AUTHOR]