A Self-Emulsified Adjuvant System Containing the Immune Potentiator Alpha Tocopherol Induces Higher Neutralizing Antibody Responses than a Squalene-Only Emulsion When Evaluated with a Recombinant Cytomegalovirus (CMV) Pentamer Antigen in Mice.

The development of new vaccine adjuvants represents a key approach to improvingi the immune responses to recombinant vaccine antigens. Emulsion adjuvants, such as AS03 and MF59, in combination with influenza vaccines, have allowed antigen dose sparing, greater breadth of responses and fewer immunizations. It has been demonstrated previously that emulsion adjuvants can be prepared using a simple, low-shear process of self-emulsification (SE). The role of alpha tocopherol as an immune potentiator in emulsion adjuvants is clear from the success of AS03 in pandemic responses, both to influenza and COVID-19. Although it was a significant formulation challenge to include alpha tocopherol in an emulsion prepared by a low-shear process, the resultant self-emulsifying adjuvant system (SE-AS) showed a comparable effect to the established AS03 when used with a quadrivalent influenza vaccine (QIV). In this paper, we first optimized the SE-AS with alpha tocopherol to create SE-AS44, which allowed the emulsion to be sterile-filtered. Then, we compared the in vitro cell activation cytokine profile of SE-AS44 with the self-emulsifying adjuvant 160 (SEA160), a squalene-only adjuvant. In addition, we evaluated SE-AS44 and SEA160 competitively, in combination with a recombinant cytomegalovirus (CMV) pentamer antigen mouse.

Formulation Design, Optimization and In Vivo Evaluations of an α-Tocopherol-Containing Self-Emulsified Adjuvant System using Inactivated Influenza Vaccine.

α-Tocopherol has been used as an immune supplement in humans, as an emulsion adjuvant component in several veterinary vaccines as well as an immunomodulatory component of AS03, an emulsion adjuvant that was used in an H1N1 pandemic vaccine (Pandemrix). AS03 is manufactured using microfluidization and high-pressure homogenization. Such high energy and complex manufacturing processes make it difficult and expensive to produce emulsion adjuvants on a large scale, especially in developing countries. In this study we have explored simpler, comparatively inexpensive methods, to formulate emulsion adjuvants containing α-tocopherol, that have the potential to be made in any well-established scale-up facility. This might facilitate producing and stock-piling adjuvant doses and therefore aide in pandemic preparedness. We used design of experiment as a tool to explore incorporating α-tocopherol into self-emulsified systems containing squalene oil and polysorbate 80. We created novel self-emulsified adjuvant systems (SE-AS) and evaluated their potency in vivo in BALB/c mice with inactivated quadrivalent influenza vaccine (QIV) and tested the cellular and humoral immune responses against the four vaccine strains.

CNS Delivery and Anti-Inflammatory Effects of Intranasally Administered Cyclosporine-A in Cationic Nanoformulations.

The main objective of this study was to develop and evaluate the CNS delivery efficiency, distribution, therapeutic efficacy, and safety of cyclosporine A (CSA) using a cationic oil-in-water nanoemulsion system upon intranasal administration. An omega-3 fatty acid-rich, flaxseed oil-based nanoemulsion was used for intranasal delivery to the brain, and further magnetic resonance imaging (MRI) was used to evaluate and confirm the transport of the positively charged CSA nanoemulsion (CSA-NE) in CNS. Furthermore, the anti-inflammatory potential of CSA peptide was evaluated using the lipopolysaccharide (LPS) model of neuroinflammation in rats. CSA-NE showed a good safety profile when tested in vitro in RPMI 2650 cells. Upon intranasal administration in rats, the nanoemulsion delivery system showed higher uptake in major regions of the brain based on changes in MRI T1 (longitudinal relaxation time) values. Additionally, CSA nanoemulsion showed improved therapeutic efficacy by inhibiting proinflammatory cytokines in the LPS-stimulated rat model of neuroinflammation compared with solution formulation. Preliminary safety evaluations show that the nanoemulsion system was well tolerated and did not cause any acute negative effects in rats. Based on these results, intranasal delivery of CSA and other "neuroprotective peptides" may provide a clinically translatable strategy for treating neurologic diseases.

MicroRNA-34a Encapsulated in Hyaluronic Acid Nanoparticles Induces Epigenetic Changes with Altered Mitochondrial Bioenergetics and Apoptosis in Non-Small-Cell Lung Cancer Cells.

Therapies targeting epigenetic changes for cancer treatment are in Phase I/II trials; however, all of these target only nuclear DNA. Emerging evidence suggests presence of methylation marks on mitochondrial DNA (mtDNA); but their contribution in cancer is unidentified. Expression of genes encoded on mtDNA are altered in cancer cells, along with increased glycolytic flux. Such glycolytic flux and elevated reactive oxygen species is supported by increased antioxidant; glutathione. MicroRNA-34a can translocate to mitochondria, mediate downstream apoptotic effects of tumor suppressor P53, and inhibit the antioxidant response element Nrf-2, resulting in depleted glutathione levels. Based on such strong rationale, we encapsulated microRNA-34a in our well-established Hyaluronic-Acid nanoparticles and delivered to cisplatin-sensitive and cisplatin-resistant A549-lung adenocarcinoma cells. Successful delivery and uptake in cells resulted in altered ATP levels, decreased glycolytic flux, Nrf-2 and glutathione levels, ultimately resulting in caspase-3 activation and apoptosis. Most important were the concurrent underlying molecular changes in epigenetic status of D-loop on the mtDNA and transcription of mtDNA-encoded genes. Although preliminary, we provide a novel therapeutic approach in form of altered mitochondrial bioenergetics and redox status of cancer cells with underlying changes in epigenetic status of mtDNA that can subsequently results in induction of cancer cell apoptosis.

Therapeutic Efficacy of an ω-3-Fatty Acid-Containing 17-ß Estradiol Nano-Delivery System against Experimental Atherosclerosis.

Atherosclerosis and its consequences remain prevalent clinical challenges throughout the world. Initiation and progression of atherosclerosis involves a complex, dynamic interplay among inflammation, hyperlipidemia, and endothelial dysfunction. A multicomponent treatment approach targeted for delivery within diseased vessels could prove beneficial in treating atherosclerosis. This study was undertaken to evaluate the multimodal effects of a novel ω-3-fatty acid-rich, 17-ß-estradiol (17-ßE)-loaded, CREKA-peptide-modified nanoemulsion system on experimental atherosclerosis. In vitro treatment of cultured human aortic endothelial cells (ECs) with the 17-ßE-loaded, CREKA-peptide-modified nanoemulsion system increased cellular nitrate/nitrite, indicating improved nitric oxide formation. In vivo, systemic administration of this nanoemulsion system to apolipoprotein-E knock out (ApoE-/-) mice fed a high-fat diet significantly improved multiple parameters related to the etiology and development of occlusive atherosclerotic vasculopathy: lesion area, circulating plasma lipid levels, and expression of aortic-wall inflammatory markers. These salutary effects were attributed selectively to the 17-ßE and/or ω-3 polyunsaturated fatty acid components of the nano-delivery system. At therapeutic doses, the 17-ßE-loaded, CREKA-peptide modified nanoemulsion system appeared to be biocompatible in that it elicited no apparent adverse/toxic effects, as indexed by body weight, plasma alanine aminotransferase/aspartate aminotransferase levels, and liver and kidney histopathology. The study demonstrates the therapeutic potential of a novel, 17-ßE-loaded, CREKA-peptide-modified nanoemulsion system against atherosclerosis in a multimodal fashion by reducing lesion size, lowering the levels of circulating plasma lipids and decreasing the gene expression of inflammatory markers associated with the disease.

Targeted delivery systems for biological therapies of inflammatory diseases.

INTRODUCTION: Inflammatory diseases, including autoimmune diseases and autoinflammatory diseases, are characterized by the imbalance of pro-inflammatory cytokines and anti-inflammatory cytokines. Targeted systems allow for specific delivery and sustained release of biological agents to inflamed tissues and macrophages, hence reducing their side effects. AREAS COVERED: This review discusses various targeting strategies for biological therapies of inflammatory diseases, with a focus on modulating macrophage functional polarization from an M1 to M2 phenotype. Furthermore, recent advances in the development of targeted delivery systems for gene therapy against inflammatory diseases including liposomal therapeutics, polymeric nanoparticles and microspheres, and multi-compartmental delivery systems are summarized. EXPERT OPINION: Molecular advances have uncovered various targets for biological therapies against inflammatory diseases. Despite substantial promise, the potential translation from the bench to the clinic is limited due to poor systemic stability of the delivery systems, low tissue distribution, and safety concerns. In order to develop clinically translatable targeted delivery systems, thorough evaluation of the efficacy and toxicity in relevant animal models and in different inflammatory diseases is needed. In addition, issues related to long-term storage stability, scale-up and manufacturing of the systems need to be addressed.

Comparative pharmacokinetics and tissue distribution analysis of systemically administered 17-ß-estradiol and its metabolites in vivo delivered using a cationic nanoemulsion or a peptide-modified nanoemulsion system for targeting atherosclerosis.

The primary objective of this study was to compare the biodistribution and pharmacokinetic profile of 17-ß-estradiol (17-ßE) on systemic delivery using either the cationic or the CREKA-peptide-modified (Cysteine-Arginine-Glutamic-acid-Lysine-Alanine) omega-3-fatty acid oil containing nanoemulsion system in vivo in the wild type C57BL/6 mice. Higher blood concentrations of 17-ßE, higher accumulation in the tissues of interest - heart and aorta, and higher accumulation within the other tissues - liver and kidney was observed on delivering 17-ßE using the CREKA-peptide-modified nanoemulsion system (AUClast in plasma - 263.89±21.81min*%/injected dose/ml) as compared to the cationic nanoemulsion (AUClast in plasma - 20.2±1.86min*%/injected dose/ml) and solution form (AUClast in plasma - 44.9±1.24min*%/injected dose/ml) respectively. Both, the cationic nanoemulsion and the CREKA-peptide-modified nanoemulsion showed a higher relative targeting efficiency of 4.57 and 4.86 respectively for 17-ßE than the relative targeting efficiency of 1.78 observed with the solution form. In conclusion, since the maximum exposure (highest AUClast for plasma and tissues) for 17-ßE was observed with the CREKA-peptide-modified nanoemulsion system, the study shows that CREKA-peptide-modified nanoemulsion system was the most suitable vehicle for systemic delivery of 17-ßE in the wild type C57BL/6 mice.

Multi-compartmental nanoparticles-in-emulsion formulation for macrophage-specific anti-inflammatory gene delivery.

PURPOSE: To develop a safe and effective non-viral vector for gene delivery and transfection in macrophages for potential anti-inflammatory therapy. METHODS: Solid nanoparticles-in-emulsion (NiE) multi-compartmental delivery system was designed using plasmid DNA-encapsulated type B gelatin nanoparticles suspended in the inner aqueous phase of safflower oil-containing water-in-oil-in-water (W/O/W) multiple emulsion. Control and NiE formulations were evaluated for DNA delivery and transfection efficiency in J774A.1 adherent murine macrophages. RESULTS: Using green fluorescent protein (GFP) and murine interleukin-10 (mIL-10) expressing plasmid DNA constructs, the NiE formulation was found superior in enhancing intracellular delivery and gene transfection efficiency in cells. Anti-inflammatory effects of transfected mIL-10 were examined by suppression of tumor necrosis factor-alpha (TNFα) and interleukin 1-beta (IL-1ß) production in lipopolysaccharide (LPS)-stimulated cells. CONCLUSIONS: Overall, the results were very encouraging towards development of a macrophage-specific NiE-based multi-compartmental gene delivery strategy that can potentially affect a number of acute and chronic inflammatory diseases.

Curcumin enhances oral bioavailability and anti-tumor therapeutic efficacy of paclitaxel upon administration in nanoemulsion formulation.

The aim of this study was to evaluate the effect of curcumin (CUR) in oral bioavailability and therapeutic efficacy of paclitaxel (PTX) administered in nanoemulsion to SKOV3 tumor-bearing nu/nu mice. Oral administration of the mice with CUR at 50 mg/kg for 3 consecutive days resulted in a down regulation of intestinal P-glycoprotein (Pgp) and cytochrome P450 3A2 (CYP3A2) protein levels. PTX, a Pgp and CYP3A2 substrate, was administered orally at 20 mg/kg in solution or nanoemulsion either as single agent or upon pretreatment with CUR at 50 mg/kg in tumor-bearing mice. Plasma AUC(0-∞) of PTX administered in nanoemulsion to CUR pretreated mice showed 4.1-fold increase relative to controls. Similarly, relative PTX bioavailability was increased by 5.2-fold, resulting in a 3.2-fold higher PTX accumulation in the tumor tissue. PTX administered in nanoemulsion to CUR pretreated mice also showed significantly enhanced anti-tumor activity. Preliminary safety evaluation showed that CUR + PTX combination did not induce any acute toxicity as measured by body weight changes, blood cell counts, liver enzyme levels, and liver histopathology. The results of this study suggest that combination of PTX and CUR, administered in nanoemulsions, could improve oral bioavailability and therapeutic efficacy in ovarian adenocarcinoma.

Development of novel biodegradable polymeric nanoparticles-in-microsphere formulation for local plasmid DNA delivery in the gastrointestinal tract.

There is a critical need for development of novel delivery systems to facilitate the translation of nucleic acid-based macromolecules into clinically-viable therapies. The aim of this investigation was to develop and evaluate a novel nanoparticles-in-microsphere oral system (NiMOS) for gene delivery and transfection in specific regions of the gastrointestinal (GI) tract. Plasmid DNA, encoding for the enhanced green fluorescent protein (EGFP-N1), was encapsulated in type B gelatin nanoparticles. NiMOS were prepared by further protecting the DNA-loaded nanoparticles in a poly(epsilon-caprolactone) (PCL) matrix to form microspheres of less than 5.0 microm in diameter. In order to evaluate the biodistribution following oral administration, radiolabeled ((111)In-labeled) gelatin nanoparticles and NiMOS were administered orally to fasted Balb/C mice. The results of biodistribution studies showed that, while gelatin nanoparticles traversed through the GI tract fairly quickly with more than 54% of the administered dose per gram localizing in the large intestine at the end of 2 h, NiMOS resided in the stomach and small intestine for relatively longer duration. Following oral administration of EGFP-N1 plasmid DNA at 100 microg dose in the control and test formulations, the quantitative and qualitative results presented in this study provide the necessary evidence for transfection potential of NiMOS upon oral administration. After 5 days post-administration, transgene expression in the small and large intestine of mice was observed. Based on these results, NiMOS show significant potential as novel gene delivery vehicle for therapeutic and vaccination purposes.

Improved oral bioavailability and brain transport of Saquinavir upon administration in novel nanoemulsion formulations.

The aim of this investigation was to develop novel oil-in-water (o/w) nanoemulsions containing Saquinavir (SQV), an anti-HIV protease inhibitor, for enhanced oral bioavailability and brain disposition. SQV was dissolved in different types of edible oils rich in essential polyunsaturated fatty acids (PUFA) to constitute the internal oil phase of the nanoemulsions. The external phase consisted of surfactants Lipoid-80 and deoxycholic acid dissolved in water. The nanoemulsions with an average oil droplet size of 100-200 nm, containing tritiated [(3)H]-SQV, were administered orally and intravenously to male Balb/c mice. The SQV bioavailability as well as distribution in different organ systems was examined. SQV concentrations in the systemic circulation administered in flax-seed oil nanoemulsions were threefold higher as compared to the control aqueous suspension. The oral bioavailability and distribution to the brain, a potential sanctuary site for HIV, were significantly enhanced with SQV delivered in nanoemulsion formulations. In comparing SQV in flax-seed oil nanoemulsion with aqueous suspension, the maximum concentration (C(max)) and the area-under-the-curve (AUC) values were found to be five- and threefold higher in the brain, respectively, suggesting enhanced rate and extent of SQV absorption following oral administration of nanoemulsions. The results of this study show that oil-in-water nanoemulsions made with PUFA-rich oils may be very promising for HIV/AIDS therapy, in particular, for reducing the viral load in important anatomical reservoir sites.

Poly-N-acetyl glucosamine-mediated red blood cell interactions.

BACKGROUND: Investigations were performed to assess the effect of poly-N-acetyl glucosamine (p-GlcNAc) fiber slurry-mediated hemostasis by interactions with red blood cells. METHODS: Red blood cell aggregation studies were performed using test material-coated microscope slides and multiphoton microscopic measurements. Enzymatic removal of red blood cell surface proteins was achieved using trypsin and neuraminidase treatment. Zeta-potential measurements (surface charge) were performed. RESULTS: Red blood cells interact directly with poly-N-acetyl glucosamine polymers through ionic interactions and cell-surface proteins. The effective concentration of poly-N-acetyl glucosamine fiber material for 50% red blood cell aggregation was 0.28 mg/mL. The p-GlcNAc beta-configuration fibers and an alpha-configuration structural modification of the fibers both produced maximal responses because of their zeta-potentials, whereas other chemically modified p-GlcNAcs and chitosans were ineffective. CONCLUSION: Poly-N-acetyl glucosamine-induced red blood cell aggregation is mediated by interactions with red blood cell surface charges.

Stomach-specific anti-H. pylori therapy. I: Preparation and characterization of tetracyline-loaded chitosan microspheres.

The main objective of the study was to develop a stomach-specific drug delivery system to increase the efficacy of tetracycline against Helicobacter pylori. Chitosan microspheres were prepared by ionic cross-linking and precipitation with sodium sulfate. Two different methods were used for drug loading. In method I, tetracycline was mixed with chitosan solution before the simultaneous cross-linking and precipitation. In method II, the drug was incubated with pre-formed microspheres for 48 h. The cumulative amount of tetracycline that was released from chitosan microspheres and the stability of the drug was examined in different pH medium at 37 degrees C. Microspheres with a spherical shape and an average diameter of 2.0-3.0 microm were formed. When the drug was added to the polymer solution before cross-linking and precipitation only 8% (w/w) was optimally incorporated in the final microsphere formulation. When the drug was incubated with the pre-formed microspheres, on the other hand, a maximum of 69% (w/w) could be loaded. Thirty percent of tetracycline either in solution or when released from microspheres was found to degrade at pH 1.2 in 12 h. The preliminary results from this study suggest that chitosan microspheres can be used to incorporate antibiotic drugs and may be effective when administered locally in the stomach against H. pylori.