Water-in-Oil-in-Water Double Emulsions as Protective Carriers for Sambucus nigra L. Coloring Systems

The use of natural colorants is needed to overcome consumer concerns regarding synthetic food colorants′ safety. However, natural pigments have, in general, poor stability against environmental stresses such as temperature, ionic strength, moisture, light, and pH, among others. In this work, water-in-oil-in-water (W1/O/W2) emulsions were used as protective carriers to improve color stability of a hydrophilic Sambucus nigra L. extract against pH changes. The chemical system comprised water and corn oil as the aqueous and oil phases, respectively, and polyglycerol polyricinoleate (PGPR), Tween 80, and gum Arabic as stabilizers. The primary emulsion was prepared using a W1/O ratio of 40/60 (v/v). For the secondary emulsion, W1/O/W2, different (W1/O)/W2 ratios were tested with the 50/50 (v/v) formulation presenting the best stability, being selected as the coloring system to test in food matrices of different pH: natural yogurt (pH 4.65), rice drink (pH 6.01), cow milk (pH 6.47), and soy drink (pH 7.92). Compared to the direct use of the extract, the double emulsion solution gave rise to higher color stability with pH change and storage time, as corroborated by visual and statistical analysis.

Co-Entrapment of Sorafenib and Cisplatin Drugs and iRGD Tumour Homing Peptide by Poly[ε-caprolactone-co-(12-hydroxystearate)] Copolymer

The drug-loaded nanocarriers have overcome various challenges compared with the pure chemotherapeutic drug, such as limited bioavailability, multiple drug resistance, poor patient compliance, and adverse drug reactions, offering advantages such as protection from degradation in the blood stream, better drug solubility, and improved drug stability. One promising group of controlled and targeted drug delivery systems is polymer-based nanoparticles that can sustain the release of the active agent by diffusion and their degradation. Sorafenib is the only drug that can prolong the life of patients suffering from hepatocellular carcinoma. Cisplatin remains one of the most widely used broad-spectrum anticancer drugs for the treatment of a variety of solid tumours. Nanoformulations can exert a synergistic effect by entrapping two drugs with different modes of action, such as sorafenib and cisplatin. In our study, polymeric nanoparticles were prepared with a good production yield by an improved double emulsion solvent evaporation method using the copolymer of 12-hydroxystearic acid with ε-caprolactone (12CL), a biocatalytically synthesised biocompatible and biodegradable carrier, for the co-entrapment of sorafenib and cisplatin in nanotherapeutics. A bovine serum albumin (BSA) model compound was used to increase the cisplatin incorporation; then, it was successfully substituted by a iRGD tumour penetrating peptide that might provide a targeting function of the nanoparticles.

5-Fluorouracil-Impregnated PLGA Coated Gold Nanoparticles for Augmented Delivery to Lung Cancer: in vitro Investigations

Background and Objective: The study aimed to investigate the augmented cytotoxic effects of polymer-coated (poly-lactic-co-glycolic acid-PLGA) gold nanoparticles (GNPs) carrying 5-fluorouracil (5-FU) in the management of lung cancer. Materials and Methods: In this study, several formulations were prepared using a double emulsion (water-oil-water) method and evaluated for drug release behavior, compatibility, cell line toxicity (A549), and apoptosis assessment. Results: Characterization results showed spherical polydispersed particles with size 29.11-178.21 nm, polydispersity index (PDI) 0.191-292, and zeta potential (ZP) 11.19-29.21 (-mV), respectively. The optimized polymer-coated 5-FU loaded gold nanoparticles (PFGNPs) illustrated a maximum drug loading (93.09 ± 10.75%) compared to others. The percent cumulative drug release of polymer-coated 5-FU loaded nanoparticles (PFNPs), 5-FU loaded gold nanoparticles (FGNPs), (PFGNPs) and 5-FU solution were 47.87± 1.5, 41.09±1.8, 56.31±1.05, and 98.8±4.2%, respectively, over 10 h. following zero-order release kinetics (except 5-FU solution). From the MTT results, the cytotoxic effect of PFGNPs on the A549 cells was 82.89 % compared to the 5-FU solution (74.91 %). EGFR and KRAS gene expression analysis under the influence of PFNPs, FGNPs, PFGNPs, and 5-FU was studied and observed maximum potency for PFNPs. Conclusion: PLGA coated biogenic gold nanoparticles have a combined effect to achieve high drug loading, sustained delivery, improved efficacy, and enhanced permeation. Conclusively, the approach may be promising to control lung cancer with reduced toxicity and improved efficacy.

Influence of Aqueous Phase Composition on Double Emulsion Stability and Colour Retention of Encapsulated Anthocyanins

Water-in-oil-in-water (W1/O/W2) emulsions (double emulsions) have often been used for the encapsulation of bioactive compounds such as anthocyanins. Instability of both anthocyanins and double emulsions creates a need for a tailored composition of the aqueous phase. In this work, double emulsions with a gelled internal water phase were produced and monitored over a 20-day storage period. The effect of the electrolyte phase composition (varying electrolyte components, including adipic acid, citric acid, and varying concentration of potassium chloride (KCl)) on anthocyanin and double emulsion stability was analysed using colour analysis, droplet sizing, and emulsion rheology. The effect of electrolytes on colour retention was shown to differ between the primary W1/O emulsion and the secondary W1/O/W2 emulsion. Furthermore, droplet size analysis and emulsion rheology highlighted significant differences in the stability and structural behaviour of the emulsions as a function of electrolyte composition. In terms of colour retention and emulsion stability, a citrate-buffered system performed best. The results of this study highlight the importance of strict control of aqueous phase constituents to prevent anthocyanin degradation and maximise double emulsion stability. Additional experiments analysed the effect of pectin chemistry on the anthocyanin colour retention and leakage, finding no conclusive difference between the unmodified and amidated pectin.

Addition of Trans-Resveratrol-Loaded Highly Concentrated Double Emulsion to Yoghurts: Effect on Physicochemical Properties

Trans-resveratrol (RSV) needs to be encapsulated to maintain its beneficial properties on the human body. This is due to its extreme photosensitivity, short biological half-life, and easy oxidation. In this study, the use of double emulsions for RSV encapsulation and their further application on functional yoghurts was studied. Different types of yoghurts were prepared: with and without RSV and with two types of volumetric emulsion formulations (20/80 and 30/70). In order to study the influence of the addition of double emulsions to the physical properties of the prepared yoghurts, they were characterised fresh and after a month under storage at 4 °C, in terms of droplet size, morphology, stability, rheology, texturometry, colorimetry, and antioxidant capacity. Results obtained showed that the presence of emulsion in the yoghurts produced a generalised decrease in the predominant droplet size (from 48 µm to 15–25 µm) and an increase in the stability. Additionally, a predominantly elastic character was observed. The firmness values obtained were very similar for all the yoghurts analysed and did not suffer important modifications with time. A slight colour variation was observed with storage time in the control sample, whereas a more notable variation in the case of emulsion yoghurts was observed. An appreciable increase of the antioxidant capacity of the final functional yoghurt (100 g) was observed when it contained 5–8 mg of RSV. Encapsulated RSV added to yoghurts presented a larger protection against RSV oxidation compared with free RSV, presenting a larger antioxidant inhibition after one month of storage. Moreover, the antioxidant capacity of yoghurts with encapsulated RSV was not affected under storage, since slight reductions (3%) were registered after one month of storage at 4 °C.