Effect of fatty acid ester structure on cytotoxicity of self-emulsified nanoemulsion and transport of nanoemulsion droplets

Evaluation of the Anti-Toxoplasma gondii Efficacy, Cytotoxicity, and GC/MS Profile of Pleopeltis crassinervata Active Subfractions

Pleopeltis crassinervata (Pc) is a fern that, according to ethnobotanical records, is used in Mexican traditional medicine to treat gastrointestinal ailments. Recent reports indicate that the hexane fraction (Hf) obtained from Pc methanolic frond extract affects Toxoplasma gondii tachyzoite viability in vitro; therefore, in the present study, the activity of different Pc hexane subfractions (Hsf) obtained by chromatographic methods was evaluated in the same biological model. Gas chromatography/mass spectrometry (GC/MS) analysis was carried out for hexane subfraction number one (Hsf1), as it showed the highest anti-Toxoplasma activity with a half-maximal inhibitory concentration (IC₅₀) of 23.6 µg/mL, a 50% cytotoxic concentration (CC₅₀) of 398.7 µg/mL in Vero cells, and a selective index (SI) of 16.89. Eighteen compounds were identified by Hsf1 GC/MS analysis, with the majority being fatty acids and terpenes. Hexadecanoic acid, methyl ester was the most commonly found compound (18.05%) followed by olean-13(18)-ene, 2,2,4a,8a,9,12b,14a-octamethyl-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,12,12a,12b,13,14,14a,14b-eicosahydropicene, and 8-octadecenoid acid, methyl ester, which were detected at 16.19%, 12.53%, and 12.99%, respectively. Based on the mechanisms of action reported for these molecules, Hsf1 could exert its anti-Toxoplasma activity mainly on T. gondii lipidomes and membranes.

Physicochemical studies of novel sugar fatty acid esters based on (R)-3-hydroxylated acids derived from bacterial polyhydroxyalkanoates and their potential environmental impact

Sugar fatty acids esters are popular compounds widely used in both the nutritional, cosmetic and pharmaceutical industries due to their amphiphilic structure and consequent ability to reduce the surface tension of solutions. Furthermore, an important aspect in the implementation of any additives and formulations is their environmental impact. The properties of the esters depend on the type of sugar used and the hydrophobic component. In this work, selected physicochemical properties of new sugar esters based on lactose, glucose and galactose and hydroxy acids derived from bacterial polyhydroxyalkanoates are shown for the first time. Values for critical aggregation concentration, surface activity and pH make it possible that these esters could compete with other commercially used esters of similar chemical structure. The investigated compounds showed moderate emulsion stabilization abilities presented on the example of water-oil systems containing squalene and body oil. Their potential environmental impact appears to be low, as the esters are not toxic to Caenorhabditis elegans even at concentrations much higher than the critical aggregation concentration.

Effects of topical docosahexaenoic acid on postoperative fibrosis in an animal model of glaucoma filtration surgery

PURPOSE

The aim of this study was to evaluate docosahexaenoic acid (DHA) as a potential antifibrotic agent after glaucoma filtration surgery (GFS) in rats.

METHODS

A total of 36 10-week-old Brown Norway rats underwent GFS. Animals were equally divided into three groups: a control group, a DHA group and a mitomycin C (MMC) group. Intraocular pressure (IOP) was measured using a dynamic rebound tonometer, and a photograph of the surgical site was taken on days 1, 3, 7, 10, 14 and 17. The incorporation of DHA into fibroblasts was evaluated by gas chromatography. The expression of alfa-smooth muscle actin (α-SMA) and Smad proteins was assessed by Western blotting.

RESULTS

IOP decreased after surgery in animals from the three groups on day 1 after surgery. Over time, IOP remained lower in the DHA and MMC groups than in the control group (median [interquartile range] 8.0 [7.0-8.0] and 8.0 [7.3-8.0] mmHg vs. 9.0 [8.0-9.0] mmHg, respectively; p < 0.001). Bleb area in the DHA and MMC groups remained larger than that of the control group from day 7 to day 14 (3.9 [2.9-5.2] and 3.5 [2.3-4.4] mm² vs. 2.3 [2.0-2.8] mm² , respectively; p = 0.0021). We did not observe any change in DHA concentrations in the fibroblasts of the DHA group compared with the other groups.

CONCLUSION

The impact of DHA on IOP and bleb area was similar to that of MMC. The mechanisms of action of DHA in rat eye fibroblasts deserve further investigation.

Arginine-Coated Nanoglobules for the Nasal Delivery of Insulin

Multiple daily injections via subcutaneous route are the primary modes of insulin delivery for patients with Diabetes Mellitus. While this process is invasive, painful and may cause patients to develop lipohypertrophy at injection site, the perception of fear surrounding this process causes patients to delay in initiation and remain persistent with insulin therapy over time. Moreover, poor glycemic control may often lead to acute complications, such as severe hypoglycemia and nocturnal hypoglycemia, especially in older patients with diabetes. To address the imperative need for a patient-convenient non-invasive insulin therapy, an insulin-loaded arginine-coated self-emulsifying nanoglobule system (INS-LANano) was developed for nasal delivery of insulin with a biodegradable cationic surfactant-Lauroyl Ethyl Arginate (LAE). Incorporation of LAE resulted in formation of positively charged nanoglobules with L-arginine oriented on the surface. LANano enabled binding of insulin molecules on the surface of nanoglobules via an electrostatic interaction between negatively charged α-helix and LAE molecules at physiological pH. INS-LANano showed a hydrodynamic diameter of 23.38 nm with a surface charge of +0.118 mV. The binding efficiency of insulin on LANano globules was confirmed by zeta potential, circular dichroism (CD) spectroscopy and centrifugal ultrafiltration studies. The attachment of insulin with permeation-enhancing nanoglobules demonstrated significantly higher in vitro permeability of insulin of 15.2% compared to insulin solution across human airway epithelial cell (Calu-3) monolayer. Upon intranasal administration of INS-LANano to diabetic rats at 2 IU/kg insulin dose, a rapid absorption of insulin with significantly higher Cmax of 14.3 mU/L and relative bioavailability (BA) of 23.3% was observed. Therefore, the INS-LANano formulation significant translational potential for intranasal delivery of insulin.

Fabrication and Characterization of Prochloraz Nanoemulsion against Penicillium citrinum for the Postharvest Storage of Navel Oranges

Nanoemulsions have become extremely popular water-insoluble pesticide delivery systems in recent years. In this study, prochloraz nanoemulsions were obtained by selecting the mixing ratio of surfactants (6:1, 3:1, 2:1, 1:1, 1:2, 1:3, and 1:6), surfactant concentration, and shearing time. The optimal formula was 10 wt % prochloraz, 6 wt % surfactant (2 wt % CO-100 + 4 wt % CO-360) dissolved in 6 wt % hydrocarbon solvent (S-100A), and deionized water replenished to 100 wt %. This formula meets the quality index standards of the Food and Agriculture Organization. Compared with oil-in-water emulsion (EW), the prochloraz nanoemulsion exhibited higher antifungal activity against Penicillium citrinum in vitro (lower LC₅₀ of 1.17 mg L^-1) and in vivo (fewer lesions). In addition, the L02 cells treated with the nanoemulsion had a higher survival rate and lower apoptosis rate at the same concentration. Results showed that the toxicity of the prochloraz nanoemulsion on L02 cells was lower than that of EW. The findings provide an important method for developing an efficient, safe, and environment-friendly nanoemulsion for postharvest fruit storage.

Preparation of thermosensitive buprofezin-loaded mesoporous silica nanoparticles by the sol-gel method and their application in pest control

BACKGROUND

Environmental stimuli-responsive release is one important way to reduce the dosage of pesticide, increase the usage efficiency and improve environmental compatibility.

RESULTS

On this basis, we synthesized mesoporous silica nanoparticles (MSNs) and modified them to develop a thermosensitive pesticide controlled release formulation (CRF). In this study, MSNs prepared by the sol-gel method were used as the core, poly (N-IsoPropylAcrylaMide) [P (NIPAM-MAA)] was used as the shell, and buprofezin (Bup) was loaded by adsorption. The prepared Bup@MSNs@P(NIPAM-MAA) could effectively prevent the degradation of buprofezin under UV light and exhibited excellent adhesion to rice leaves. The bioassay results showed that the mortality of Nilaparvata lugens (Stål) treated by Bup@MSNs@P(NIPAM-MAA) was positively correlated with temperature, resulting mainly from the change of release amount of buprofezin caused by temperature variation. Bup@MSNs@P(NIPAM-MAA) had long duration (20 days) for controlling N. lugens, and did not hinder the growth of rice. Meanwhile, Bup@MSNs@P(NIPAM-MAA) had low toxicity to zebrafish and human pneumonocyte BEAS-2B cells.

CONCLUSION

This novel thermosensitive pesticide CRF can be applied widely to other insecticides, thus greatly promoting the development of intelligent pesticide formulations. © 2021 Society of Chemical Industry.