Insights into the release mechanisms of antioxidants from nanoemulsion droplets

Autoxidation interference assay to evaluate the protection against lipid oxidation of antioxidant administration: Comparison of the efficiency of progressive release or total administration

Lipid oxidation is a cause of food spoilage, and antioxidants are used to retard it, but the timing of administration is important for this effect. The research aims to evaluate the protective efficiency against oxidative deterioration through the prolonged or complete addition of antioxidants without retention in the matrix. For this purpose, three modes of administration of the synthetic antioxidant BHT and oregano essential oil were evaluated: 100, 50, and 25 in which 100 % was incorporated at the beginning, 50 % in two aliquots, and 25 % in 4 aliquots. After adding the aliquots, all treatments reached 0.02 w/w of antioxidant in oil. An accelerated oxidation study was performed at 60 °C for 12 days, and chemical indicators (Peroxide and Conjugated Dienes value) along with volatiles (2-Heptenal and 2,4-Decadienal EE) were assessed. The order of protection shows that the initial addition of antioxidants yielded the highest efficiency.

Formulation of a Novel Hesperetin-Loaded Nanoemulsion and Its Promising Effect on Osteogenesis

Alternative therapies associating natural products and nanobiotechnology show new perspectives on controlled drug release. In this context, nanoemulsions (NEs) present promising results for their structural design and properties. Hesperetin (HT), a flavonoid mainly found in citrus fruits, presents highlighted bone benefits. In this context, we developed a hesperetin-loaded nanoemulsion (HT-NE) by sonication method and characterized it by dynamic light scattering, analyzing its encapsulation efficiency, and cumulative release. The biocompatibility in human osteoblasts Saos-2-like was evaluated by the cytotoxicity assay and IC50. Then, the effects of the HT-NE on osteogenesis were evaluated by the cellular proliferation, calcium nodule formation, bone regulators gene expression, collagen quantification, and alkaline phosphatase activity. The results showed that the formulation presented ideal values of droplet size, polydispersity index, and zeta potential, and the encapsulation efficiency was 74.07 ± 5.33%, showing a gradual and controlled release. Finally, HT-NE was shown to be biocompatible and increased cellular proliferation, and calcium nodule formation, regulated the expression of Runx2, ALPL, and TGF-β genes, and increased the collagen formation and alkaline phosphatase activity. Therefore, the formulation of this NE encapsulated the HT appropriately, allowing the increasing of its effects on mechanisms to improve or accelerate the osteogenesis process.

Encapsulation of Black Rice Bran Extract in a Stable Nanoemulsion: Effects of Thermal Treatment, Storage Conditions, and In Vitro Digestion

This study aimed to improve the dispersibility of phenolic compounds from black rice bran through the encapsulation process within nanoemulsion. The study focused on assessing the stability of the nanoemulsions, which were prepared using a combination of surfactants with distinct hydrophilic-lipophilic balance (HLB) values and sunflower oil under different thermal treatments and storage conditions. The study revealed a significant correlation between the mixed surfactant HLB value and the nanoemulsions properties, including average particle size, polydispersity index (PDI), and ζ-potential. Specifically, an increase in the HLB value was associated with a decrease in the initial average particle size. The encapsulated polyphenols exhibited remarkable stability over a storage period of up to 30 days at different temperatures with no significant changes observed in particle size or PDI. The study also investigated the impact of different ionic strengths (0.2, 0.5, and 1.00 mol L-1 NaCl) on the physical stability and antioxidant black rice bran extract nanoemulsion, and the results revealed that adding NaCl influenced the particle size and surface charge of the nanoemulsions. Total phenolic content and DPPH results demonstrated a significant impact of salt concentration on antioxidant properties, with varying trends observed among the HLB formulations. Furthermore, the behavior of the encapsulated extracts during digestion was examined, and their antioxidant activity was evaluated.

Nanomaterials in tumor immunotherapy: new strategies and challenges

Tumor immunotherapy exerts its anti-tumor effects by stimulating and enhancing immune responses of the body. It has become another important modality of anti-tumor therapy with significant clinical efficacy and advantages compared to chemotherapy, radiotherapy and targeted therapy. Although various kinds of tumor immunotherapeutic drugs have emerged, the challenges faced in the delivery of these drugs, such as poor tumor permeability and low tumor cell uptake rate, had prevented their widespread application. Recently, nanomaterials had emerged as a means for treatment of different diseases due to their targeting properties, biocompatibility and functionalities. Moreover, nanomaterials possess various characteristics that overcome the defects of traditional tumor immunotherapy, such as large drug loading capacity, precise tumor targeting and easy modification, thus leading to their wide application in tumor immunotherapy. There are two main classes of novel nanoparticles mentioned in this review: organic (polymeric nanomaterials, liposomes and lipid nanoparticles) and inorganic (non-metallic nanomaterials and metallic nanomaterials). Besides, the fabrication method for nanoparticles, Nanoemulsions, was also introduced. In summary, this review article mainly discussed the research progress of tumor immunotherapy based on nanomaterials in the past few years and offers a theoretical basis for exploring novel tumor immunotherapy strategies in the future.

Nanomaterials: Breaking through the bottleneck of tumor immunotherapy

Immunotherapy exerts its excellent anti-tumor effects by stimulating and enhancing the immune response of the body, and has become another important class of anti-tumor therapy besides chemotherapy, targeted therapy and radiotherapy. Various types of immunotherapeutic drugs have gained their clinical values, but the in vivo delivery of drugs still faces many challenges, such as poor tumor permeability and low tumor cell uptake rate. In recent years, owing to highly targeting properties, better biocompatibility, and easy functionalization, nanomaterials have been widely applicated in tumor treatment, especially in tumor immunotherapy. Furthermore, nanomaterials have large drug loading capacity, strong tumor targeting and easy modification, which can effectively overcome the drawbacks of traditional immunotherapy. This paper reviews the progress of nanomaterial-based tumor immunotherapy in recent years and provides a theoretical basis for exploring new nanomaterial-based tumor immunotherapy strategies.

Effect of Nanoemulsion Containing Enterocin GR17 and Cinnamaldehyde on Microbiological, Physicochemical and Sensory Properties and Shelf Life of Liquid-Smoked Salmon Fillets

The spoilage of liquid-smoked salmon represented a serious restriction for shelf life, due to the loss of taste, smell, color and consistency in product quality. The objective of this study was to investigate the feasibility of applying a nanoemulsion delivery system co-encapsulated enterocin Gr17 and essential oils (EOs) to the refrigerated storage of liquid-smoked salmon. The synergistic inhibiting effects of enterocin Gr17 and EOs were evaluated, a nanoemulsion delivery system with the optimal combination was developed, and the evolution of the microbiological, physicochemical, and sensory properties of liquid-smoked salmon fillets were analyzed during a 49-day period of refrigerated storage. The results showed that the combination of enterocin Gr17 and cinnamaldehyde essential oil (CEO) displayed the strongest synergistic inhibiting effect on foodborne pathogens. A nanoemulsion system incorporating enterocin Gr17 and CEO was successfully developed and presented a broad spectrum of activity against most of the tested bacteria. A nanoemulsion system incorporating enterocin Gr17 and CEO (CO-NE) could significantly inhibit the growth of microflora, suppress the accumulation of total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substance (TBARS), and maintain better color, texture, and sensory profiles during smoked salmon storage at 4 °C. Overall, from a microbiological, physicochemical, and sensory point of view, the CO-NE treatment could extend the shelf life to 42 days and maintain the relatively low TVB-N value (≤15.38 mg/100 g), TBARS value (≤2.51 mg MDA/kg), as well as a relatively high sensory score (≥5.83) during the whole storage period. Hence, a nanoemulsion system incorporating enterocin Gr17 and CEO could be a promising bio-preservative technology and alternative to the conventional processes used for improving the safety and quality of chilled liquid-smoked salmon.