Irradiated microparticles suppress prostate cancer by tumor microenvironment reprogramming and ferroptosis.

Immunogenic cell death (ICD) plays a crucial role in triggering the antitumor immune response in the tumor microenvironment (TME). Recently, considerable attention has been dedicated to ferroptosis, a type of ICD that is induced by intracellular iron and has been demonstrated to change the immune desert status of the TME. However, among cancers that are characterized by an immune desert, such as prostate cancer, strategies for inducing high levels of ferroptosis remain limited. Radiated tumor cell-derived microparticles (RMPs) are radiotherapy mimetics that have been shown to activate the cGAS-STING pathway, induce tumor cell ferroptosis, and inhibit M2 macrophage polarization. RMPs can also act as carriers of agents with biocompatibility. In the present study, we designed a therapeutic system wherein the ferroptosis inducer RSL-3 was loaded into RMPs, which were tested in in vitro and in vivo prostate carcinoma models established using RM-1 cells. The apoptosis inducer CT20 peptide (CT20p) was also added to the RMPs to aggravate ferroptosis. Our results showed that RSL-3- and CT20p-loaded RMPs (RC@RMPs) led to ferroptosis and apoptosis of RM-1 cells. Moreover, CT20p had a synergistic effect on ferroptosis by promoting reactive oxygen species (ROS) production, lipid hydroperoxide production, and mitochondrial instability. RC@RMPs elevated dendritic cell (DC) expression of MHCII, CD80, and CD86 and facilitated M1 macrophage polarization. In a subcutaneously transplanted RM-1 tumor model in mice, RC@RMPs inhibited tumor growth and prolonged survival time via DC activation, macrophage reprogramming, enhancement of CD8+ T cell infiltration, and proinflammatory cytokine production in the tumor. Moreover, combination treatment with anti-PD-1 improved RM-1 tumor inhibition. This study provides a strategy for the synergistic enhancement of ferroptosis for prostate cancer immunotherapies.

A broadly applicable protein-polymer adjuvant system for antiviral vaccines.

Although protein subunit vaccines generally have acceptable safety profiles with precise antigenic content, limited immunogenicity can lead to unsatisfactory humoral and cellular immunity and the need for vaccine adjuvants and delivery system. Herein, we assess a vaccine adjuvant system comprising Quillaja Saponaria-21(QS-21) and cobalt porphyrin polymeric micelles that enabling the display of His-tagged antigen on its surface. The nanoscale micelles promote antigen uptake and dendritic cell activation to induce robust cytotoxic T lymphocyte response and germinal center formation. Using the recombinant protein antigens from influenza A and rabies virus, the micelle adjuvant system elicited robust antiviral responses and protected mice from lethal challenge. In addition, this system could be combined with other antigens to induce high titers of neutralizing antibodies in models of three highly pathogenic viral pathogens: Ebola virus, Marburg virus, and Nipah virus. Collectively, our results demonstrate this polymeric micelle adjuvant system can be used as a potent nanoplatform for developing antiviral vaccine countermeasures that promote humoral and cellular immunity.

Photosensitizer-thioglycosides enhance photodynamic therapy by augmenting cellular uptake.

Photodynamic therapy (PDT) uses photosensitizing agents along with light to ablate tissue, including cancers. Such light-driven localized delivery of free-radical oxygen to kill target tissue depends on photosensitizer cell penetration efficacy. While the attachment of monosaccharides and disaccharides to photosensitizers has been shown to potentially provide improved photosensitizer delivery, the range of glycan entities tested thus far is limited. We sought to expand such knowledge by coupling N-acetylglucosamine (GlcNAc) to pyropheophorbides as thioglycosides, and then testing photosensitizer efficacy. To this end, GlcNAc was conjugated to both pyropheophorbide-a and methyl pyropheophorbide-a. Among the entities tested, the conjugation of N-acetylglucosamine to methyl pyropheophorbide-a ('PSe') as thioglycoside enhanced cell uptake both in the presence and absence of human serum proteins, relative to other compounds tested. The enhanced PSe penetrance into cells resulted in higher cell death upon illumination with 665 nm light. While acting as a potent photosensitizer, PSe did not affect cellular carbohydrate profiles. Overall, the study presents a new pyropheophorbide glycoconjugate with strong in vitro PDT efficacy.

CoPoP liposomes displaying stabilized clade C HIV-1 Env elicit tier 2 multiclade neutralization in rabbits.

One of the strategies towards an effective HIV-1 vaccine is to elicit broadly neutralizing antibody responses that target the high HIV-1 Env diversity. Here, we present an HIV-1 vaccine candidate that consists of cobalt porphyrin-phospholipid (CoPoP) liposomes decorated with repaired and stabilized clade C HIV-1 Env trimers in a prefusion conformation. These particles exhibit high HIV-1 Env trimer decoration, serum stability and bind broadly neutralizing antibodies. Three sequential immunizations of female rabbits with CoPoP liposomes displaying a different clade C HIV-1 gp140 trimer at each dosing generate high HIV-1 Env-specific antibody responses. Additionally, serum neutralization is detectable against 18 of 20 multiclade tier 2 HIV-1 strains. Furthermore, the peak antibody titers induced by CoPoP liposomes can be recalled by subsequent heterologous immunization with Ad26-encoded membrane-bound stabilized Env antigens. Hence, a CoPoP liposome-based HIV-1 vaccine that can generate cross-clade neutralizing antibody immunity could potentially be a component of an efficacious HIV-1 vaccine.

The predominant Quillaja Saponaria fraction, QS-18, is safe and effective when formulated in a liposomal murine cancer peptide vaccine.

Extracts of the Chilean soapbark tree, Quillaja Saponaria (QS) are the source of potent immune-stimulatory saponin compounds. This study compared the adjuvanticity and toxicity of QS-18 and QS-21, assessing the potential to substitute QS-18 in place of QS-21 for vaccine development. QS-18, the most abundant QS saponin fraction, has been largely overlooked due to safety concerns. We found that QS-18 spontaneously inserted into liposomes, thereby neutralizing hemolytic activity, and following administration did not induce local reactogenicity in a footpad swelling test in mice. With high-dose intramuscular administration, transient weight loss was minor, and QS-18 did not induce significantly more weight loss compared to a liposome vaccine adjuvant system lacking it. Two days after administration, no elevation of inflammatory cytokines was detected in murine serum. In a formulation including cobalt-porphyrin-phospholipid (CoPoP) for short peptide sequestration, QS-18 did not impact the formation of peptide nanoparticles. With immunization, QS-18 peptide particles induced higher levels of cancer neoepitope-specific and tumor-associated antigen-specific CD8+ T cells compared to QS-21 particles, without indication of greater toxicity based on mouse body weight. T cell receptor sequencing of antigen-specific CD8+ T cells showed that QS-18 induced significantly more T cell transcripts. In two murine cancer models, vaccination with QS-18 peptide particles induced a similar therapeutic effect as QS-21 particles, without indication of increased toxicity. Antigen-specific CD8+ T cells in the tumor microenvironment were found to express the exhaustion marker PD-1, pointing to the rationale for exploring combination therapy. Taken together, these data demonstrate that QS-18, when formulated in liposomes, can be a safe and effective adjuvant to induce tumor-inhibiting cellular responses in murine models with potential to facilitate or diminish costs of production for vaccine adjuvant systems. Further studies are warranted to assess liposomal QS-18 immunogic, reactogenic and toxicological profiles in mice and other animal species.

Identification of Enhanced Vaccine Mimotopes for the p15E Murine Cancer Antigen.

Mimotopes of short CD8+ T-cell epitopes generally comprise one or more mutated residues, and can increase the immunogenicity and function of peptide cancer vaccines. We recently developed a two-step approach to generate enhanced mimotopes using positional peptide microlibraries and herein applied this strategy to the broadly used H-2Kb-restricted murine leukemia p15E tumor rejection epitope. The wild-type p15E epitope (sequence: KSPWFTTL) was poorly immunogenic in mice, even when combined with a potent peptide nanoparticle vaccine system and did not delay p15E-expressing MC38 tumor growth. Following positional microlibrary functional screening of over 150 mimotope candidates, two were identified, both with mutations at residue 3 (p15E-P3C; "3C," and p15E-P3M; "3M") that better induced p15E-specific CD8+ T cells and led to tumor rejection. Although 3M was more immunogenic, 3C effectively delayed tumor growth in a therapeutic setting relative to the wild-type p15E. As 3C had less H-2Kb affinity relative to both p15E and 3M, 15 additional mimotope candidates (all that incorporated the 3C mutation) were assessed that maintained or improved predicted MHC-I affinity. Valine substitution at position 2 (3C2V, sequence: KVCWFTTL) led to improved p15E-specific immunogenicity, tumor rejection, and subsequent long-term antitumor immunity. 3C, 3M, and 3C2V mimotopes were more effective than p15E in controlling MC38 and B16-F10 tumors. T-cell receptor (TCR) sequencing revealed unique TCR transcripts for mimotopes, but there were no major differences in clonality. These results provide new p15E mimotopes for further vaccine use and illustrate considerations for MHC-I affinity, immunogenicity, and functional efficacy in mimotope design. SIGNIFICANCE: The MHC-I-restricted p15E tumor rejection epitope is expressed in multiple murine cancer lines and is used as a marker of antitumor cellular immunity, but has seen limited success as a vaccine immunogen. An in vivo screening approach based on a positional peptide microlibraries is used to identify enhanced p15E mimotopes bearing amino acid mutations that induce significantly improved functional immunogenicity relative to vaccination with the wild-type epitope.

Applications of Intravital Imaging in Cancer Immunotherapy.

Currently, immunotherapy is one of the most effective treatment strategies for cancer. However, the efficacy of any specific anti-tumor immunotherapy can vary based on the dynamic characteristics of immune cells, such as their rate of migration and cell-to-cell interactions. Therefore, understanding the dynamics among cells involved in the immune response can inform the optimization and improvement of existing immunotherapy strategies. In vivo imaging technologies use optical microscopy techniques to visualize the movement and behavior of cells in vivo, including cells involved in the immune response, thereby showing great potential for application in the field of cancer immunotherapy. In this review, we briefly introduce the technical aspects required for in vivo imaging, such as fluorescent protein labeling, the construction of transgenic mice, and various window chamber models. Then, we discuss the elucidation of new phenomena and mechanisms relating to tumor immunotherapy that has been made possible by the application of in vivo imaging technology. Specifically, in vivo imaging has supported the characterization of the movement of T cells during immune checkpoint inhibitor therapy and the kinetic analysis of dendritic cell migration in tumor vaccine therapy. Finally, we provide a perspective on the challenges and future research directions for the use of in vivo imaging technology in cancer immunotherapy.

Adjuvanted nanoliposomes displaying six hemagglutinins and neuraminidases as an influenza virus vaccine.

Inclusion of defined quantities of the two major surface proteins of influenza virus, hemagglutinin (HA) and neuraminidase (NA), could benefit seasonal influenza vaccines. Recombinant HA and NA multimeric proteins derived from three influenza serotypes, H1N1, H3N2, and type B, are surface displayed on nanoliposomes co-loaded with immunostimulatory adjuvants, generating "hexaplex" particles that are used to immunize mice. Protective immune responses to hexaplex liposomes involve functional antibody elicitation against each included antigen, comparable to vaccination with monovalent antigen particles. When compared to contemporary recombinant or adjuvanted influenza virus vaccines, hexaplex liposomes perform favorably in many areas, including antibody production, T cell activation, protection from lethal virus challenge, and protection following passive sera transfer. Based on these results, hexaplex liposomes warrant further investigation as an adjuvanted recombinant influenza vaccine formulation.

Biomimetic bright optotheranostics for metastasis monitoring and multimodal image-guided breast cancer therapeutics.

Nanoparticle formulations blending optical imaging contrast agents and therapeutics have been a cornerstone of preclinical theranostic applications. However, nanoparticle-based theranostics clinical translation faces challenges on reproducibility, brightness, photostability, biocompatibility, and selective tumor targeting and penetration. In this study, we integrate multimodal imaging and therapeutics within cancer cell-derived nanovesicles, leading to biomimetic bright optotheranostics for monitoring cancer metastasis. Upon NIR light irradiation, the engineered optotheranostics enables deep visualization and precise localization of metastatic lung, liver, and solid breast tumors along with solid tumor ablation. Metastatic cell-derived nanovesicles (∼80 ± 5 nm) are engineered to encapsulate imaging (emissive organic dye and gold nanoparticles) and therapeutic agents (anticancer drug doxorubicin and photothermally active organic indocyanine green dye). Systemic administration of biomimetic bright optotheranostic nanoparticles shows escape from mononuclear phagocytic clearance with (i) rapid tumor accumulation (3 h) and retention (up to 168 h), (ii) real-time monitoring of metastatic lung, liver, and solid breast tumors and (iii) 3-fold image-guided solid tumor reduction. These findings are supported by an improvement of X-ray, fluorescence, and photoacoustic signals while demonstrating a tumor reduction (201 mm3) in comparison with single therapies that includes chemotherapy (134 mm3), photodynamic therapy (72 mm3), and photothermal therapy (88mm3). The proposed innovative platform opens new avenues to improve cancer diagnosis and treatment outcomes by allowing the monitorization of cancer metastasis, allowing the precise cancer imaging, and delivering synergistic therapeutic agents at the solid tumor site.

One-year antibody durability induced by EuCorVac-19, a liposome-displayed COVID-19 receptor binding domain subunit vaccine, in healthy Korean subjects.

OBJECTIVE: EuCorVac-19 (ECV-19), an adjuvanted liposome-displayed receptor binding domain (RBD) COVID-19 vaccine, previously reported interim Phase 2 trial results showing induction of neutralizing antibodies 3 weeks after prime-boost immunization. The objective of this study was to determine the longer-term antibody response of the vaccine. METHODS: To assess immunogenicity 6 and 12 months after vaccination, participants in the Phase 2 trial (NCT04783311) were excluded if they: 1) withdrew, 2) reported COVID-19 infection or additional vaccination, or 3) exhibited increasing Spike (S) antibodies (representing possible non-reported infection). Following exclusions, of the 197 initial subjects, anti-S IgG antibodies and neutralizing antibodies were further assessed in 124 subjects at the 6-month timepoint, and 36 subjects at the 12-month timepoint. RESULTS: Median anti-S antibody half-life was 52 days (interquartile range [IQR]:42-70), in the "early" period from 3 weeks to 6 months, and 130 days (IQR:97-169) in the "late" period from 6 to 12 months. There was a negative correlation between initial antibody titer and half-life. Anti-S and neutralizing antibody responses were correlated. Neutralizing antibody responses showed longer half-lives; the early period had a median half-life of 120 days (IQR:81-207), and the late period had a median half-life of 214 days (IQR:140-550). CONCLUSION: These data establish antibody durability of ECV-19, using a framework to analyze COVID-19 vaccine-induced antibodies during periods of high infection.

SARS-CoV-2 Protein Nanoparticle Vaccines Formed In Situ From Lyophilized Lipids.

The receptor binding domain (RBD) of the SARS-CoV-2 Spike (S) glycoprotein is an appealing immunogen, but associated vaccine approaches must overcome the hapten-like nature of the compact protein and adapt to emerging variants with evolving RBD sequences. Here, a vaccine manufacturing methodology is proposed comprising a sterile-filtered freeze-dried lipid cake formulation that can be reconstituted with liquid proteins to instantaneously form liposome-displayed protein nanoparticles. Mannitol is used as a bulking agent and a small amount of Tween-80 surfactant is required to achieve reconstituted submicron particles that do not precipitate prior to usage. The lipid particles include an E. coli-derived monophosphoryl lipid A (EcML) for immunogenicity, and cobalt porphyrin-phospholipid (CoPoP) for antigen display. Reconstitution of the lipid cake with aqueous protein results in rapid conversion of the RBD into intact liposome-bound format prior to injection. Protein particles can readily be formed with sequent-divergent RBD proteins derived from the ancestral or Omicron strains. Immunization of mice elicits antibodies that neutralize respective viral strains. When K18-hACE2 transgenic mice are immunized and challenged with ancestral SARS-CoV-2 or the Omicron BA.5 variant, both liquid liposomes displaying the RBD and rapid reconstituted particles protect mice from infection, as measured by the viral load in the lungs and nasal turbinates.

Irradiated engineered tumor cell-derived microparticles remodel the tumor immune microenvironment and enhance antitumor immunity.

Radiotherapy (RT), administered to roughly half of all cancer patients, occupies a crucial role in the landscape of cancer treatment. However, expanding the clinical indications of RT remains challenging. Inspired by the radiation-induced bystander effect (RIBE), we used the mediators of RIBE to mimic RT. Specifically, we discovered that irradiated tumor cell-released microparticles (RT-MPs) mediated the RIBE and had immune activation effects. To further boost the immune activation effect of RT-MPs to achieve cancer remission, even in advanced stages, we engineered RT-MPs with different cytokine and chemokine combinations by modifying their production method. After comparing the therapeutic effect of the engineered RT-MPs in vitro and in vivo, we demonstrated that tIL-15/tCCL19-RT-MPs effectively activated antitumor immune responses, significantly prolonged the survival of mice with malignant pleural effusion (MPE), and even achieved complete cancer remission. When tIL-15/tCCL19-RT-MPs were combined with PD-1 monoclonal antibody (mAb), a cure rate of up to 60% was achieved. This combination therapy relied on the activation of CD8+ T cells and macrophages, resulting in the inhibition of tumor growth and the establishment of immunological memory against tumor cells. Hence, our research may provide an alternative and promising strategy for cancers that are not amenable to conventional RT.

Nanomaterial-based contrast agents.

Medical imaging, which empowers the detection of physiological and pathological processes within living subjects, has a vital role in both preclinical and clinical diagnostics. Contrast agents are often needed to accompany anatomical data with functional information or to provide phenotyping of the disease in question. Many newly emerging contrast agents are based on nanomaterials as their high payloads, unique physicochemical properties, improved sensitivity and multimodality capacity are highly desired for many advanced forms of bioimaging techniques and applications. Here, we review the developments in the field of nanomaterial-based contrast agents. We outline important nanomaterial design considerations and discuss the effect on their physicochemical attributes, contrast properties and biological behaviour. We also describe commonly used approaches for formulating, functionalizing and characterizing these nanomaterials. Key applications are highlighted by categorizing nanomaterials on the basis of their X-ray, magnetic, nuclear, optical and/or photoacoustic contrast properties. Finally, we offer our perspectives on current challenges and emerging research topics as well as expectations for future advancements in the field.

Circularized Nanodiscs for Multivalent Mosaic Display of SARS-CoV-2 Spike Protein Antigens.

The emergence of vaccine-evading SARS-CoV-2 variants urges the need for vaccines that elicit broadly neutralizing antibodies (bnAbs). Here, we assess covalently circularized nanodiscs decorated with recombinant SARS-CoV-2 spike glycoproteins from several variants for eliciting bnAbs with vaccination. Cobalt porphyrin-phospholipid (CoPoP) was incorporated into the nanodisc to allow for anchoring and functional orientation of spike trimers on the nanodisc surface through their His-tag. Monophosphoryl-lipid (MPLA) and QS-21 were incorporated as immunostimulatory adjuvants to enhance vaccine responses. Following optimization of nanodisc assembly, spike proteins were effectively displayed on the surface of the nanodiscs and maintained their conformational capacity for binding with human angiotensin-converting enzyme 2 (hACE2) as verified using electron microscopy and slot blot assay, respectively. Six different formulations were prepared where they contained mono antigens; four from the year 2020 (WT, Beta, Lambda, and Delta) and two from the year 2021 (Omicron BA.1 and BA.2). Additionally, we prepared a mosaic nanodisc displaying the four spike proteins from year 2020. Intramuscular vaccination of CD-1 female mice with the mosaic nanodisc induced antibody responses that not only neutralized matched pseudo-typed viruses, but also neutralized mismatched pseudo-typed viruses corresponding to later variants from year 2021 (Omicron BA.1 and BA.2). Interestingly, sera from mosaic-immunized mice did not effectively inhibit Omicron spike binding to human ACE-2, suggesting that some of the elicited antibodies were directed towards conserved neutralizing epitopes outside the receptor binding domain. Our results show that mosaic nanodisc vaccine displaying spike proteins from 2020 can elicit broadly neutralizing antibodies that can neutralize mismatched viruses from a following year, thus decreasing immune evasion of new emerging variants and enhancing healthcare preparedness.

Vaccine approaches for antigen capture by liposomes.

INTRODUCTION: Liposomes have been used as carriers for vaccine adjuvants and antigens due to their inherent biocompatibility and versatility as delivery vehicles. Two vial admixture of protein antigens with liposome-formulated immunostimulatory adjuvants has become a broadly used clinical vaccine preparation approach. Compared to freely soluble antigens, liposome-associated forms can enhance antigen delivery to antigen-presenting cells and co-deliver antigens with adjuvants, leading to improved vaccine efficacy. AREAS COVERED: Several antigen-capture strategies for liposomal vaccines have been developed for proteins, peptides, and nucleic acids. Specific antigen delivery methodologies are discussed, including electrostatic adsorption, encapsulation inside the liposome aqueous core, and covalent and non-covalent antigen capture. EXPERT OPINION: Several commercial vaccines include active lipid components, highlighting an increasingly prominent role of liposomes and lipid nanoparticles in vaccine development. Utilizing liposomes to associate antigens offers potential advantages, including antigen and adjuvant dose-sparing, co-delivery of antigen and adjuvant to immune cells, and enhanced immunogenicity. Antigen capture by liposomes has demonstrated feasibility in clinical testing. New antigen-capture techniques have been developed and appear to be of interest for vaccine development.

Folate-Targeted Nanoliposomal Chemophototherapy.

Light-responsive liposomes have been developed for the on-demand release of drugs. However, efficient delivery of chemotherapeutic drugs to tumor for cancer theranostics remains a challenge. Herein, folic acid (FA), an established ligand for targeted drug delivery, was used to decorate light-sensitive porphyrin-phospholipid (PoP) liposomes, which were assessed for FA-targeted chemophototherapy (CPT). PoP liposomes and FA-conjugated PoP liposomes were loaded with Doxorubicin (Dox), and physical properties were characterized. In vitro, FA-PoP liposomes that were incubated with FA receptor-overexpressing human KB cancer cells showed increased uptake compared to non-targeted PoP liposomes. Dox and PoP contributed towards chemophototherapy (CPT) in vitro, and PoP and FA-PoP liposomes induced cell killing. In vivo, mice bearing subcutaneous KB tumors treated with PoP or FA-PoP liposomes loaded with Dox, followed by 665 nm laser treatment, had delayed tumor growth and improved survival. Dox delivery to tumors increased following laser irradiation for both PoP and FA-PoP liposomes. Thus, while Dox-FA-PoP liposomes were effective following systemic administration and local light irradiation in this tumor model, the FA targeting moiety did not appear essential for anti-tumor responses.

Orally-Delivered, Cytokine-Engineered Extracellular Vesicles for Targeted Treatment of Inflammatory Bowel Disease.

The use of orally-administered therapeutic proteins for treatment of inflammatory bowel disease (IBD) has been limited due to the harsh gastrointestinal environment and low bioavailability that affects delivery to diseased sites. Here, a nested delivery system, termed Gal-IL10-EVs (C/A) that protects interleukin 10 (IL-10) from degradation in the stomach and enables targeted delivery of IL-10 to inflammatory macrophages infiltrating the colonic lamina propria, is reported. Extracellular vesicles (EVs) carrying IL-10 are designed to be secreted from genetically engineered mammalian cells by a plasmid system, and EVs are subsequently modified with galactose, endowing the targeted IL-10 delivery to inflammatory macrophages. Chitosan/alginate (C/A) hydrogel coating on Gal-IL10-EVs enables protection from harsh conditions in the gastrointestinal tract and favorable delivery to the colonic lumen, where the C/A hydrogel coating is removed at the diseased sites. Gal-IL10-EVs control the production of reactive oxygen species (ROS) and inhibit the expression of proinflammatory cytokines. In a murine model of colitis, Gal-IL10-EVs (C/A) alleviate IBD symptoms including inflammatory responses and disrupt colonic barriers. Taken together, Gal-IL10-EVs (C/A) features biocompatibility, pH-responsive drug release, and macrophage-targeting as a therapeutic platform for oral delivery of bioactive proteins for treating intestinal diseases.

Anti-Tumor Immunity Induced by a Ternary Membrane System Derived From Cancer Cells, Dendritic Cells, and Bacteria.

Cancer vaccines generally are limited by insufficient tumor-specific cellular immunogenicity. Herein, a potent "ABC" ternary membrane-derived vaccine system blended from antigen-presenting mature dendritic cell membranes ("A"), bacterial E. coli cytoplasmic membranes ("B"), and cancer cell membranes ("C") is developed using a block-copolymer micelle-enabled approach. The respective ABC membrane components provide for a source of cellular immune communication/activation and enhanced accumulation in lymph nodes (A), immunological adjuvant (B), and tumor antigens (C). The introduction of dendritic cell (DC) membranes enables multiple cell-to-cell communication and powerful immune activation. ABC activates dendritic cells and promotes T-cell activation and proliferation in vitro. In vivo, ABC is 14- and 304-fold more immunogenic than binary (BC) and single (C) membrane vaccines, and immunization with ABC enhances the frequency of tumor-specific cytotoxic T lymphocytes, leading to an 80% cure rate in tumor-bearing mice. In a surgical resection and recurrence model, ABC prevents recurrence with vaccination from autologous cancer membranes, and therapeutic effects are observed in a lung metastasis model even with heterologous cancer cell membranes. ABCs formed from human cancer patient-derived tumor cells activate human monocyte-derived dendritic cells (moDC). Taken together, the ternary ABC membrane system provides the needed functional components for personalized cancer immunotherapy.

Topical Drug Delivery of Concentrated Cabazitaxel in an α-Tocopherol and DMSO Solution.

Topical chemotherapy approaches are relevant for certain skin cancer treatments. This study observes that cabazitaxel (CTX), a broad-spectrum second-generation taxane cytotoxic agent, can be dissolved in α-tocopherol at high concentrations exceeding 100 mg mL-1 . 2D nuclear magnetic resonance (NMR) analysis and molecular dynamics (MD) are used to study this phenomenon. The addition of 30% dimethyl sulfoxide (DMSO) to the α-tocopherol/CTX solution improves its working viscosity and enhances CTX permeation through human skin in vitro (over 5 µg cm-2 within 24 h), while no detectable drug permeates when CTX is dissolved in α-tocopherol alone. In a transepidermal water loss assay, the barrier impairment induced by CTX in 30% DMSO in α-tocopherol, but not in pure DMSO, is reversible 8 h after the formulation removal from the skin surface. Antitumor efficacy of the topical CTX formulation is evaluated in nude mice bearing A431 human squamous carcinoma skin cancer xenografts. With topical application of concentrated CTX solutions (75 mg mL-1 ), tumor growth is significantly suppressed compared to lower concentration groups (0, 25, or 50 mg mL-1 CTX). Taken together, these findings show that topical delivery of CTX using a DMSO and α-tocopherol solvent warrants further study as a treatment for skin malignancies.

Phospholipid Encapsulation of an Anti-Fibrotic Endopeptide to Enhance Cellular Uptake and Myocardial Retention.

BACKGROUND: Cardioprotective effects of N-acetyl-ser-asp-lys-pro (Ac-SDKP) have been reported in preclinical models of myocardial remodeling. However, the rapid degradation of this endogenous peptide in vivo limits its clinical use. METHOD: To prolong its bioavailability, Ac-SDKP was encapsulated by phosphocholine lipid bilayers (liposomes) similar to mammalian cell membranes. The physical properties of the liposome structures were assessed by dynamic light scattering and scanning electron microscopy. The uptake of Ac-SDKP by RAW 264.7 macrophages and human and murine primary cardiac fibroblasts was confirmed by fluorescence microscopy and flow cytometry. Spectrum computerized tomography and competitive enzyme-linked immunoassays were performed to measure the ex vivo cardiac biodistribution of Ac-SDKP. The biological effects of this novel synthetic compound were examined in cultured macrophages and cardiac fibroblasts and in a murine model of acute myocardial infarction induced by permanent coronary artery ligation. RESULTS: A liposome formulation resulted in the greater uptake of Ac-SDKP than the naked peptide by cultured RAW 264.7 macrophages and cardiac fibroblasts. Liposome-delivered Ac-SDKP decreased fibroinflammatory genes in cultured cardiac fibroblasts co-treated with TGF-ß1 and macrophages stimulated with LPS. Serial tissue and serum immunoassays showed the high bioavailability of Ac-SDKP in mouse myocardium and in circulation. Liposome-delivered Ac-SDKP improved cardiac function and reduced myocardial fibroinflammatory responses in mice with acute myocardial infarction. CONCLUSION: Encapsulation of Ac-SDKP in a cell membrane-like phospholipid bilayer enhances its plasma and tissue bioavailability and offers cardioprotection against ischemic myocardial injury. Future clinical trials can use this novel approach to test small protective endogenous peptides in myocardial remodeling.