This study was conducted to assess the repellent activity of Pogostemon cablin (Blanco) Benth. Lamiaceae essential oil (EO) and its nanoemulsion (NE) against Haemaphysalis longicornis nymphs. ...Pogostemon cablin EO nanoemulsion (PCNE) was prepared by ultrasonic emulsification using P. cablin EO and a surfactant, Tween 80. The results of gas chromatography-mass spectrometry analysis showed that the major component of P. cablin EO was patchouli alcohol (32.04%), followed by δ-guaiene (18.13%), α-guaiene (16.76%), seychellene (7.49%), and β-patchoulene (5.09%). The droplet sizes of PCNEs formulated using P. cablin EO and Tween 80 in ratios of 1:1, 1:2, and 1:3 were 23.8, 20.1 and 17.7 nm, respectively, indicating that the increase in the ratio of Tween 80 led to a decrease in droplet size. All essential oil preparations had an acceptable polydispersity index of 0.5 or less. The P. cablin EO and Tween 80 ratio of 1:3 was selected as the optimal formulation with the smallest droplet size; transmission electron microscopy indicated the formation of uniform spherical droplets. PCNE (84.0%) showed a higher repellent activity against H. longicornis nymphs than P. cablin EO (72.0%). The nanoemulsion is suitable for improving the repellent activity of P. cablin EO and is a potential repellent for H. longicornis.
Despite long-term immunosuppression, organ transplant recipients face the risk of immune rejection and graft loss. Tacrolimus (TAC, FK506, Prograf®) is an FDA-approved keystone immunosuppressant for ...preventing transplant rejection. However, it undergoes extensive first-pass metabolism and has a narrow therapeutic window, which leads to erratic bioavailability and toxicity. Local delivery of TAC directly into the graft, instead of systemic delivery, can improve safety, efficacy, and tolerability. Macrophages have emerged as promising therapeutic targets as their increased levels correlate with an increased risk of organ rejection and a poor prognosis post-transplantation. Here, we present a locally injectable drug delivery platform for macrophages, where TAC is incorporated into a colloidally stable nanoemulsion and then formulated as a reversibly thermoresponsive, pluronic-based nanoemulgel (NEG). This novel formulation is designed to undergo a sol-to-gel transition at physiological temperature to sustain TAC release in situ at the site of local application. We also show that TAC-NEG mitigates the release of proinflammatory cytokines and nitric oxide from lipopolysaccharide (LPS)-activated macrophages. To the best of our knowledge, this is the first TAC-loaded nanoemulgel with demonstrated anti-inflammatory effects on macrophages in vitro.
Carboxymethyl chitosan (CMCh)-peptide conjugates were produced by grafting CMCh with peptides from hemp seed, maize and casein. The nanoemulsions stabilized by these conjugates had smaller droplet ...size and better emulsifying properties. Nanoemulsions stabilized by conjugates were used to develop active films containing Camellia essential oil and the effect of conjugation on physicochemical properties of resulting films was evaluated. Water vapor and oxygen barrier properties, tensile strength, flexibility, and temperature of endothermic peak increased 6.6–19.8% and 6.9–27.2%, 40.1–96.6%, 61.4–83.3% and 7.8–18.5%, respectively when the CMCh-peptide conjugates were used to emulsify the essential oil. The conjugation helped to form compact structure. All of the films containing essential oil emulsions stabilized by conjugates showed the ability to extend the shelf-life of blueberry by maintaining the firmness, reducing the weight loss and slowing down the formation of soluble solids.
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The effect of formulation parameters namely oil type, emulsifier type and concentration was assessed on various properties of the nanoemulsions. All nanoemulsions yielded droplets with a desirable ...size ranged from 38.5 to 127.9 nm. The findings showed that emulsifier type had significant effects on the physicochemical properties of emulsions. Emulsifier concentration had a negative correlation with droplet diameter, turbidity and positive correlation with polydispersity index, viscosity and creaming stability. Nanoemulsions prepared from pomegranate seed oil were different from that of two other oils in droplet size, viscosity, creaming and turbidity because of its higher intrinsic viscosity and degree of unsaturation.
Shrimp oil (SO) nanoemulsions stabilized by fish myofibrillar protein, considered as functional foods, were prepared
via
microfluidization and ultrasonication. The study explored varying ...microfluidization (pressure and cycles) and ultrasonication (amplitude and sonication time) conditions that influenced emulsion properties and stability. Ultrasonicated emulsions exhibited superior emulsifying properties, adsorbed protein content, thermal stability, and centrifugal stability than microfluidized emulsions (
p
< 0.05). Microfluidization at 6.89 and 13.79 MPa with 2 or 4 cycles yielded larger droplets (536 to 638 nm) (
p
< 0.05), while ultrasonication at 40% and 50% amplitude for 5, 10 and 15 min produced smaller droplets (426 to 494 nm) (
p
< 0.05). Optimal conditions were obtained for microfluidization (13.79 MPa, 2 cycles) and ultrasonication (50% amplitude, 10 min). Ultrasonicated emulsions had generally smaller
d
32
and
d
43
, lower polydispersity and higher
ζ
-potential than their microfluidized counterparts. Microstructural analysis and CLSM images confirmed their superior stability during storage. SO nanoemulsions could be applied as functional food.
Shrimp oil (SO) nanoemulsions stabilized by fish myofibrillar protein, considered as functional foods, were prepared
via
microfluidization and ultrasonication.
Essential oil from Melaleuca alternifolia (also known as Tea tree essential oil, TTO) is used as traditional medicine and used as therapeutic in medicine, food and cosmetic sectors. However, this oil ...is highly unstable, volatile and prone to oxidation which limits its practical use. The objective of this study was synthesis of tea tree oil based O/W (oil/water) nanoemulsions (tea tree essential oil nanoemulsions, TNE) and evaluation of its biological potential. Physiological characterization was carried out using UV, fluorescent, and FT-IR techniques. Various biological activities such as anticancerous, antidiabetic and anti-inflammatory were also estimated. Pharmacokinetics study on TNE was carried out. Encapsulation efficiency of nanoemulsions was found to be 83%. Nanoemulsions were spherical in shape with globule size 308 nm, zeta potential −9.42 and polydispersity index was 0.31. Nanoemulsions were stable even after 50 days of storage at different temperatures. Anti-oxidant potential of TNE was conducted by various assays and IC50 were: Nitric oxide radical scavenging activity:225.1, DPPH radical scavenging activity:30.66, Iron chelating assay:38.73, and Iron reducing assay:39.36. Notable anticancer activity was observed with the percent cell viability of HeLa cells after treatment with 1, 2 and 5 µl of TNE was 82%, 41% and 24%, respectively. Antidiabetic study revealed that TNE inhibited -amylase in a dose-dependent manner, with 88% inhibition at its higher volume of 250 µl. Drug kinetic study revealed that nanoemulsions exhibited first-order model. Based on this, the possible role of M. alternifolia oil-based nanoemulsions in cosmetic, food, and pharma sectors has been discussed.
Nosocomial infections caused by Acinetobacter baumannii (A. baumannii) are exceedingly difficult to treat, particularly in immune-compromised patients. Nanoemulsions (NEs) are a distinctive category ...of disinfectants that have wide range of bactericidal, fungicidal and antiviral properties by damaging their outer membranes. The inhibiting potential of iron chelators such as deferiprone (DF) used as remedial agent for different microbial groups. Combining new generation disinfectant NEs and the iron chelator DF is a logical approach to control of A. baumannii planktonic and biofilm infections. Present studies investigated the bactericidal efficacy of NE with DF by testing their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against four strains of A. baumannii. We analyzed adherence of the planktonic form both with and without deferiprone to determine possible enhancement effects. The mechanism of nanoemulsion with deferiprone (NE/DF) was quantified by LIVE/DEAD staining biofilm assay and scanning electron microscopy. DF does not affect the stability of the nanoemulsion and the combined forms show high stability. From MBC, NE/DF showed enhanced activity up to 2- to 3.3-fold compared to nanoemulsion and deferiprone alone. Combined nanoemulsion with deferiprone showed higher adherence inhibition compared to the individual forms. From confocal imaging, the level of dead cell intensity was 84.9% to 96.6% in NE/DF treated groups. Bacteria treated with NE, DF and NE/DF confirms morphological variations when compared to pili-bonded integrated control cells. We propose that biofilm destruction starts from pili removal followed by membrane destruction. These results leave a concrete evidence for the employment of nanoemulsion with deferiprone for the treatment of against drug resistant A. baumannii.
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The rate of infections caused by resistant bacteria to the antimicrobials available for human use grows exponentially every year, which generates major impacts on human health and the ...world economy. In the last two decades, human beings can witness the expressive increase in the Science and Technology worldwide, and areas such as Health Sciences have benefited from these advances in favor of human health, such as the advent of Pharmaceutical Nanotechnology as an important approach applied for bacterial infections treatment with resistance profile to available antibiotics. This review of the scientific literature brings the applicability of nanotechnology-based lipid systems as an innovative tool in the improvement of bacterial infections treatment. Important studies involving the use of liposomes, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, microemulsions and lipid nanocapsules were verified in the period from 2000 to 2020, where important scientific results were found and will serve as a basis for the use of these systems to remain in constant updating. This manuscript shows the use of these drug delivery systems as potential vehicles for antibacterial compounds, which opens a new hope in the complement of the antibacterial therapeutic arsenal. Important studies developed in the last 20 years are present in this review, and thus guarantees an update on the use of these drug delivery systems for researchers from different areas of Health Sciences.
Abstract Adjuvants are an essential component of modern vaccine development. Despite many decades of development, only a few types of adjuvants are currently included in vaccines approved for human ...use. In order to better understand the reasons that development of some adjuvants succeeded while many others failed, we discuss some of the common attributes of successful first generation adjuvants. Next, we evaluate current trends in the development of second generation adjuvants, including the potential advantages of rationally designed synthetic immune potentiators appropriately formulated. Finally, we discuss desirable attributes of next generation adjuvants. Throughout, we emphasize that the importance of formulation and analytical characterization in all aspects of vaccine adjuvant development is often underappreciated. We highlight the formulation factors that must be evaluated in order to optimize interactions between vaccine antigens, immune potentiators, and particulate formulations, and the resulting effects on safety, biological activity, manufacturability, and stability.
This study evaluates the effect of modified lecithin (ML) and sodium caseinate (SC) on the formulation, stability and bioaccessibility of astaxanthin (AXT) loaded oil-in-water (O/W) nanoemulsions. ...These nanoemulsions were formulated using high-pressure homogenization in four passes at 100MPa. The volume mean diameter (d4,3) of nanoemulsions produced by ML and SC were 163±5 and 144±12 nm, respectively. The physiochemical stability of nanoemulsions was recorded at 25°C. The nanoemulsions prepared by ML were stable for 30 minutes against a wide range of pH and heating temperatures (60–120 °C). However, ML-stabilized nanoemulsions showed droplet growth when treated at high NaCl concentrations. In comparison, droplet growth was observed in SC-stabilized nanoemulsions at pH4 and at high temperature treatment. However, SC-stabilized nanoemulsions were stable at high NaCl concentration (500 mM). The SC-stabilized nanoemulsions showed good physical and chemical stability (>70%) after 30 days of storage. The bioaccessibility of AXT in nanoemulsions was significantly higher in ML (33%) than in SC-stabilized nanoemulsions (6%), indicating a strong influence of emulsifier on bioaccessibility. These findings provide valuable information in designing nutritional products such as aqueous based AXT fortified beverages.
•Successful formulation of O/W nanoemulsions encapsulating AXT•Environmental factors influenced the AXT stability of O/W nanoemulsions.•Nanoemulsions exhibited good stability with ML and SC emulsifiers at 25°C.•Higher retention of AXT in SC stabilized nanoemulsions in comparison to ML.•ML-stabilized nanoemulsions have higher AXT bioaccessibility.
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