Fisetin: hormesis accounts for many of its chemoprotective effects

The present paper provides the first integrated assessment of the capacity of the flavonol, fisetin, to induce hormetic dose responses. Fisetin was shown to induce hormetic dose responses in cellular and in vivo animal model systems affecting a broad range of endpoints of potential therapeutic and public health significance across the entire lifespan. Fisetin was effective in slowing aging processes, acting as a senolytic agent in multiple organ systems, in an hormetic fashion. In addition, fisetin was broadly neuroprotective, including during fetal development, and preventing the toxicity of methylmercury. Since these findings indicate that fisetin may have the potential to induce multi-system chemoprotective effects, it indicates the need to better clarify the absorption and bioavailability of fisetin and ways to enhance its efficiency.

Lipid nanoparticles-based RNA therapies for breast cancer treatment

Breast cancer (BC) prevails as a major burden on global healthcare, being the most prevalent form of cancer among women. BC is a complex and heterogeneous disease, and current therapies, such as chemotherapy and radiotherapy, frequently fall short in providing effective solutions. These treatments fail to mitigate the risk of cancer recurrence and cause severe side effects that, in turn, compromise therapeutic responses in patients. Over the last decade, several strategies have been proposed to overcome these limitations. Among them, RNA-based technologies have demonstrated their potential across various clinical applications, notably in cancer therapy. However, RNA therapies are still limited by a series of critical issues like off-target effect and poor stability in circulation. Thus, novel approaches have been investigated to improve the targeting and bioavailability of RNA-based formulations to achieve an appropriate therapeutic outcome. Lipid nanoparticles (LNPs) have been largely proven to be an advantageous carrier for nucleic acids and RNA. This perspective explores the most recent advances on RNA-based technology with an emphasis on LNPs' utilization as effective nanocarriers in BC therapy and most recent progresses in their clinical applications.

Advances in lipid-based carriers for cancer therapeutics: Liposomes, exosomes and hybrid exosomes

Cancer has recently surpassed heart disease as the leading cause of deaths worldwide for the age group 45-65 and has been the primary focus for biomedical researchers. Presently, the drugs involved in the first-line cancer therapy are raising concerns due to high toxicity and lack of selectivity to cancer cells. There has been a significant increase in research with innovative nano formulations to entrap the therapeutic payload to enhance efficacy and eliminate or minimize toxic effects. Lipid-based carriers stand out due to their unique structural properties and biocompatible nature. The two main leaders of lipid-based drug carriers: long known liposomes and comparatively new exosomes have been well-researched. The similarity between the two lipid-based carriers is the vesicular structure with the core's capability to carry the payload. While liposomes utilize chemically derived and altered phospholipid components, the exosomes are naturally occurring vesicles with inherent lipids, proteins, and nucleic acids. More recently, researchers have focused on developing hybrid exosomes by fusing liposomes and exosomes. Combining these two types of vesicles may offer some advantages such as high drug loading, targeted cellular uptake, biocompatibility, controlled release, stability in harsh conditions and low immunogenicity.

The impact of nucleoside base modification in mRNA vaccine is influenced by the chemistry of its lipid nanoparticle delivery system

The use of modified nucleosides is an important approach to mitigate the intrinsic immunostimulatory activity of exogenous mRNA and to increase its translation for mRNA therapeutic applications. However, for vaccine applications, the intrinsic immunostimulatory nature of unmodified mRNA could help induce productive immunity. Additionally, the ionizable lipid nanoparticles (LNPs) used to deliver mRNA vaccines can possess immunostimulatory properties that may influence the impact of nucleoside modification. Here we show that uridine replacement with N1-methylpseudouridine in an mRNA vaccine encoding influenza hemagglutinin had a significant impact on the induction of innate chemokines/cytokines and a positive impact on the induction of functional antibody titers in mice and macaques when MC3 or KC2 LNPs were used as delivery systems, while it impacted only minimally the titers obtained with L319 LNPs, indicating that the impact of nucleoside modification on mRNA vaccine efficacy varies with LNP composition. In line with previous observations, we noticed an inverse correlation between the induction of high innate IFN-α titers in the macaques and antigen-specific immune responses. Furthermore, and consistent with the species specificity of pathogen recognition receptors, we found that the effect of uridine replacement did not strictly translate from mice to non-human primates.

Flavonoids Enhance Lipofection Efficiency and Ameliorate Cytotoxicity in Colon26 and HepG2 Cells via Oxidative Stress Regulation

The generation of reactive oxygen species (ROS) can affect cationic liposome-mediated transfection. In this study, we focused on a specific class of antioxidants, flavonoids, to investigate the transfection efficiency using cationic liposome/plasmid DNA complexes (lipoplexes) in 2D and 3D cultures of Colon26 and HepG2 cells, respectively. All tested flavonoids enhanced the transfection efficiency in 2D Colon26 and HepG2 cells. Among the tested flavonoids, 25 µM quercetin showed the highest promotion effect of 8.4- and 7.6-folds in 2D Colon26 and HepG2 cells, respectively. Transfection was also performed in 3D cultures of Colon26 and HepG2 cells using lipoplexes with quercetin. Quercetin (12.5 µM) showed the highest transfection efficiency at all transfection timings in 3D Colon26 and HepG2 cells with increased cell viability. Flow cytometry revealed that quercetin treatment reduced the population of gene expression-negative cells with high ROS levels and increased the number of gene expression-positive cells with low ROS levels in HepG2 cells. Information from this study can be valuable to develop strategies to promote transfection efficiency and attenuate cytotoxicity using lipoplexes.

The Current Landscape of mRNA Vaccines Against Viruses and Cancer-A Mini Review

Both infectious viral diseases and cancer have historically been some of the most common causes of death worldwide. The COVID-19 pandemic is a decidedly relevant example of the former. Despite progress having been made over past decades, new and improved techniques are still needed to address the limitations faced by current treatment standards, with mRNA-based therapy emerging as a promising solution. Highly flexible, scalable and cost-effective, mRNA therapy is proving to be a compelling vaccine platform against viruses. Likewise, mRNA vaccines show similar promise against cancer as a platform capable of encoding multiple antigens for a diverse array of cancers, including those that are patient specific as a novel form of personalized medicine. In this review, the molecular mechanisms, biotechnological aspects, and clinical developments of mRNA vaccines against viral infections and cancer are discussed to provide an informative update on the current state of mRNA therapy research.

Conjugation-Free Multilamellar Protein-Lipid Hybrid Vesicles for Multifaceted Immune Responses

Various lipid-based nanocarriers have been developed for the co-delivery of protein antigens with immunological adjuvants. However, their in vivo potency in vaccine delivery is limited by structural instability, which causes off-target delivery and low cross-presentation efficacies. Recent works employ covalent cross-linking to stabilize the lipid nanostructures, though the immunogenicity and side effects of chemically modified protein antigens and lipids can cause a long-lasting safety issue. Here robust "conjugation-free" multilamellar protein antigen-lipid hybrid nanovesicles (MPLVs) are introduced through the antigen-mediated self-assembly of unilamellar lipid vesicles for the co-delivery of protein antigens and immunologic adjuvants. The nanocarriers coated with monophosphoryl lipid A and hyaluronic acids elicit highly increase antigen-specific immune responses in vitro and in vivo. The MPLVs increase the generation of immunological surface markers and cytokines in mouse-derived bone-marrow dendritic cells compared to soluble antigens with adjuvants. Besides, the vaccination of mice with the MPLVs significantly increase the production of anti-antigen antibody and interferon-gamma via the activation of CD4⁺ and CD8⁺ T cells, respectively. These findings suggest that MPLVs can serve as a promising nanovaccine delivery platform for efficient antigen cross-presentation through the efficient co-delivery of protein antigens with adjuvants.

Protective Effect of Edaravone against Cationic Lipid-Mediated Oxidative Stress and Apoptosis

Liposomes containing ionizable cationic lipids have been widely used for the delivery of nucleic acids such as small-interfering RNA and mRNA. The utility of cationic lipids with a permanent positive charge, however, is limited to in vitro transfection of cultured cells due to its dose-limiting toxic side effects observed in animals. Several reports have suggested that the permanently charged cationic lipids induce reactive oxygen species (ROS) and ROS-mediated toxicity in cells. We therefore hypothesized that the concomitant use of ROS inhibitor could reduce toxicity and improve drug efficacy. In this study, suppression of the cationic toxicity was evaluated using an ROS scavenger, edaravone, which is a low-molecular-weight antioxidant drug clinically approved for acute-phase cerebral infarction and amyotrophic lateral sclerosis. Cell viability assay in the mouse macrophage-like cell line RAW264 indicated that the concomitant use of edaravone were not able to suppress the cytotoxicity induced by cationic liposomes comprised of monovalent cationic lipid N-(1-[2,3-dioleyloxy]propyl)-N,N,N-trimethylammonium chloride (DOTMA) over a short period of time. Cationic lipids-induced necrosis was assumed to be involved in the cytotoxicity upon short-term exposure to cationic liposomes. On the other hand, the significant improvement of cell viability was observed when the short treatment with cationic liposomes was followed by exposure to edaravone for 24 h. It was also confirmed that apoptosis inhibition by ROS elimination might have contributed to this effect. These results suggest the utility of continuous administration with edaravone as concomitant drug for suppression of adverse reactions in therapeutic treatment using cationic liposomes.

Emerging advances in cationic liposomal cancer nanovaccines: opportunities and challenges

Advancements in the field of cancer therapeutics have witnessed a recent surge in the use of liposomes. The physicochemical characteristics of the liposomes and their components, including the lipid phase transition temperature, vesicular size and size distribution, surface properties, and route of administration, play a significant role in the modulation of the immune response as an adjuvant and for loaded antigen (Ag). Cationic liposomes, concerning their potential ability to amplify the immunogenicity of the loaded Ag/adjuvant, have received enormous interest as a promising vaccine delivery platform for cancer immunotherapy. In the present review, the physicochemical considerations for the development of Ag/adjuvant-loaded liposomes and the cationic liposomes' effectiveness for promoting cancer immunotherapy have been summarized.

Stabilization of liposomes with silicone layer improves their elastomechanical properties while not compromising biological features

The liposomes are among the most promising types of drug delivery systems but low stability significantly limits their application. Some approaches proposed to overcome this drawback may affect the liposomes toxicity profile. It is assumed that developed by us and presented here stabilization method involving formation of silicone network within the liposomal bilayer will improve elastomechanical properties of vesicles while not deteriorating their biocompatibility. The silicone-stabilized liposomes were prepared by base-catalyzed polycondensation process of the 1,3,5,7-tetramethylcyclotetrasiloxane (D₄^H) within the liposomal bilayer. The systematic biological in vitro studies of vesicles obtained were carried out. Moreover, the elastomechanical features investigation employing atomic force microscopy (AFM) measurements was performed. These properties of the liposome membrane are of great importance since they define the nanocarriers' stability as well as play a significant role in their cellular uptake via endocytosis. Applying the Derjaguin-Muller-Toporov (DMT) model, the elastic modulus of the silicone-stabilized liposomes was determined and compared to that characteristic for the pristine liposomes. The in vitro biological evaluation of silicone-stabilized liposomes demonstrated that these vesicles are not toxic for blood cells isolated from healthy donors and they do not induce oxidative stress in HepG2 cells. AFM results confirmed the stabilizing effect of silicone and revealed that the silicone network improves the elastomechanical properties of the resulted liposomes. This is the first report demonstrating that the silicone-stabilized liposomes retain biocompatibility of pristine liposomes' while acquire significantly better elastomechanical features.

Immunogenicity and Protection Efficacy of a Naked Self-Replicating mRNA-Based Zika Virus Vaccine

To combat emerging infectious diseases like Zika virus (ZIKV), synthetic messenger RNAs (mRNAs) encoding viral antigens are very attractive as they allow a rapid, generic, and flexible production of vaccines. In this work, we engineered a self-replicating mRNA (sr-mRNA) vaccine encoding the pre-membrane and envelope (prM-E) glycoproteins of ZIKV. Intradermal electroporation of as few as 1 µg of this mRNA-based ZIKV vaccine induced potent humoral and cellular immune responses in BALB/c and especially IFNAR1^-/- C57BL/6 mice, resulting in a complete protection of the latter mice against ZIKV infection. In wild-type C57BL/6 mice, the vaccine resulted in very low seroconversion rates and antibody titers. The potency of the vaccine was inversely related to the dose of mRNA used in wild-type BALB/c or C57BL/6 mice, as robust type I interferon (IFN) response was determined in a reporter mice model (IFN-β^+/Δβ-luc). We further investigated the inability of the sr-prM-E-mRNA ZIKV vaccine to raise antibodies in wild-type C57BL/6 mice and found indications that type I IFNs elicited by this naked sr-mRNA vaccine might directly impede the induction of a robust humoral response. Therefore, we assume that the efficacy of sr-mRNA vaccines after intradermal electroporation might be increased by strategies that temper their inherent innate immunogenicity.

Improving the Repeatability and Efficacy of Intradermal Electroporated Self-Replicating mRNA

Local administration of naked self-replicating mRNA (sr-mRNA) in the skin or muscle using electroporation is effective but hampered by low repeatability. In this manuscript, we demonstrated that intradermal electroporation of sr-mRNA in combination with a protein-based RNase inhibitor increased the expression efficiency, success rate, and repeatability of the data. The RNase inhibitor should be added just before administration because storage of the inhibitor together with the sr-mRNA at −80°C resulted in a partial loss of the beneficial effect. Furthermore, the location of intradermal electroporation also had a major effect on the expression of the sr-mRNA, with the highest and longest expression observed at the tail base of the mice. In contrast with previous work, we did not observe a beneficial effect of calcium ions on the efficacy of naked sr-mRNA after intradermal injection. Finally, another important finding was that the traditional representation of in vivo bioluminescence data as means in logarithmic graphs can mask highly variable data. A more truthful representation can be obtained by showing the individual data points or by displaying median values in combination with interquartile ranges. In conclusion, intradermal sr-mRNA electroporation can be improved by adding an RNase inhibitor and injecting at the tail base.

Edaravone, a cytoprotective drug, enhances transgene expression mediated by lipoplexes in HepG2 cells and mice

A requirement of gene therapy is efficient nucleic acid delivery. However, the application of cationic liposomes to gene therapy is restricted by their inefficient transfection capacity, which may be caused by cytotoxicity. This cytotoxicity is highly dependent on cationic lipid-induced reactive oxygen species (ROS). Here, to provide cellular protection, we used edaravone, an efficacious anti-oxidative drug, to scavenge ROS during transfection using cationic liposome/plasmid DNA complexes (lipoplexes). Both free edaravone and edaravone-loaded liposomes (EDLPs) enhanced transgene expression in the human hepatoma cell line, HepG2, while EDLPs decreased the effective dose of edaravone. The cellular protective effect of edaravone was found to decrease the cytotoxicity of cationic liposomes. Edaravone was also effective in the commercial product, Lipofectamine® 3000, which may expand the application of edaravone to promote transfection efficiency. Compared with free edaravone, EDLPs also showed superior transgene expression in mice. Our findings will promote the development of efficient and safe gene therapy.

Current advances in nanocarriers for biomedical research and their applications

Nanodrug delivery systems sometimes referred to as nanocarriers (NCs) are nanoengineered biocompatible materials or devices, which in conjugation with desired bioactive compounds plays an indispensable functional role in the field of pharmaceutical and allied sciences. The diversified ability of this bioengineered colloidal or noncolloidal molecule to breach the biological barriers to reach the targeted location in the biological system uplifts its other versatile natures of mono- or polydispersity in biodistribution. Furthermore, its nontoxicity and biodegradability result in making it a unique candidate for its purpose as drug delivery system. A number of different conjugations of chemical and biological substances are currently implemented for the synthesis of this biofunctional hybrid nanomaterial by simple methods. The use of these bioconjugated as a nanoparticulated system is currently being used for the treatment of various deadly incurable infectious diseases such as tuberculosis and disorders such as diabetes and cancers of various forms. Henceforth, the objective of the present review article is to provide overviews of the diversified and types of nanoparticulated systems, their beneficial as well as deleterious impacts along with the future prospect of nanodrug delivery system based on present status.

In Vitro and In Vivo Tumor Growth Inhibition by Glutathione Disulfide Liposomes

Glutathione disulfide (GSSG) is an endogenous peptide and the oxidized form of glutathione. The impacts of GSSG on cell function/dysfunction remain largely unexplored due to a lack of method to specifically increase intracellular GSSG. We recently developed GSSG liposomes that can specifically increase intracellular GSSG. The increase affected 3 of the 4 essential steps (cell detachment, migration, invasion, and adhesion) of cancer metastasis in vitro and, accordingly, produced a significant inhibition of cancer metastasis in vivo. In this investigation, the effect of GSSG liposomes on cancer growth was investigated with B16-F10 and NCI-H226 cells in vitro and with B16-F10 cells in C57BL/6 mice in vivo. Experiments were conducted to elucidate the effect on cell death through promotion of apoptosis and the effect on the cell cycle. The in vivo results with C57BL/6 mice implanted subcutaneously with B16-F10 cells showed that GSSG liposomes retarded tumor proliferation more effectively than that of dacarbazine, a chemotherapeutic drug for the treatment of melanoma. The GSSG liposomes by intravenous injection (GLS IV) and GSSG liposomes by intratumoral injection (GLS IT) showed a tumor proliferation retardation of 85% ± 5.7% and 90% ± 3.9%, respectively, compared with the phosphate-buffered saline (PBS) control group. The median survival rates for mice treated with PBS, blank liposomes, aqueous GSSG, dacarbazine, GLS IV, and GLS IT were 7, 7, 7.5, 7.75, 11.5, and 16.5 days, respectively. The effective antimetastatic and antigrowth activities warrant further investigation of the GSSG liposomes as a potentially effective therapeutic treatment for cancer.