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.

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.

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.