The Effect of Hot-Melt Extrusion of Mulberry Leaf on the Number of Active Compounds and Antioxidant Activity.

The aim of this study is to compare the functions of the physiologically active compounds of three types of mulberry leaf by cultivar, and to confirm the changes using hot-melt extrusion (HME-ML). The active components of mulberry leaf were analyzed using the HPLC system, and total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity were measured. Among the three varieties, the highest contents of rutin and isoquercetin were detected in Cheongil, of TPC in Cheongol, and of TFC in Cheongil. It was confirmed that this bio-accessibility was increased in HME-ML compared with the control. The DPPH radical scavenging activity of Cheongol showed greater antioxidant properties, and HME showed improvement in the antioxidant properties of all mulberry leaves. These results suggest that the application of HME technology can improve the biological activities of mulberry leaf.

Green Synthesis of Silver Nanoparticles (AgNPs) of Angelica Gigas Fabricated by Hot-Melt Extrusion Technology for Enhanced Antifungal Effects.

Green synthesis for synthesizing silver nanoparticles (AgNPs) has been suggested as an environmentally friendly alternative to conventional physical/chemical methods. In this study, we report the green synthesis of AgNPs using a hot-melt extrusion-processed Angelica gigas Nakai (AGN) (HME-AGN) extract as a reducing agent to increase the water solubility of the active ingredient compared to the existing AGN. The mixture of the AGN extract and AgNO3 at about 420 nm could not confirm the formation of AgNPs. The synthesis of AgNPs was found to be most advantageous at 60 °C when the mixing ratio of the HME-AGN extract was 9:1 (AgNO3-extract, v/v) using 3 mM AgNO3. The physicochemical properties of the optimized AgNPs were characterized by UV-Vis spectrophotometer, dynamic light scattering (DLS), zeta potential, transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffractometer (XRD). DLS showed the particle size average of 102.3 ± 1.35 nm and polydispersity index (PDI) value of 0.314 ± 0.01. The particle surface charge was -35 ± 0.79 mV, confirming the stability of the particles. The particle shape was spherical, as shown through TEM analysis, and the presence of silver ions was confirmed through the EDS results. FT-IR data showed functional groups of biomolecules of the extract involved in the synthesis of AgNPs. The face-centered cubic (FCC) lattice of AgNPs was confirmed in the XRD pattern. The AgNPs had an effective antifungal activity against Candida albicans (C. albicans) that was better than that of the HME-AGN extract. In conclusion, this study suggests that the synthesis of AgNPs was improved by using the HME-AGN extract with increased water solubility through HME. In addition, it was suggested that the synthesized AgNPs can be used as an improved antifungal agent compared with the HME-AGN extract with antifungal activity.

An Enhanced Water Solubility and Stability of Anthocyanins in Mulberry Processed with Hot Melt Extrusion.

Mulberry fruits are rich sources of anthocyanins that exhibit beneficial biological activity. These anthocyanins become instable in an aqueous media, leading to their low bioavailability. In this study, a colloidal dispersion was produced by processing mulberry samples with hot-melt extrusion. In this process, hydrophilic polymer matrices were used to disperse the compound in an aqueous media. Mulberry samples were processed with hot-melt extrusion and in the presence of an ionization agent and sodium alginate to form mulberry-extrudate solid formulations. The particle size of mulberry-extrudate solid formulations decreased, while the total phenol content, the total anthocyanin content, and solubility increased. Fourier transform infrared spectroscopy (FT-IR) revealed that mulberry-extrudate solid formulations now contained new functional groups, such as -COOH group. We investigated whether mulberry-extrudate solid formulations had a positive impact on the stability of anthocyanins. The non-extrudate mulberry sample and mulberry-extrudate solid formulations were incubated with a simulated gastric fluid system and an intestinal fluid system. The number of released anthocyanins was determined with HPLC. We found that anthocyanins were released rapidly from non-extrudate mulberry extract. Mulberry-extrudate solid formulations contained a large number of available anthocyanins even after being incubated for 180 min in the intestinal fluid system. Thus, hot-melt extrusion enhanced water solubility and stability of anthocyanins with the prolonged release.

Biodegradable Nanoparticles-Loaded PLGA Microcapsule for the Enhanced Encapsulation Efficiency and Controlled Release of Hydrophilic Drug.

Recently, nano- and micro-particulate systems have been widely utilized to deliver pharmaceutical compounds to achieve enhanced therapeutic effects and reduced side effects. Poly (DL-lactide-co-glycolide) (PLGA), as one of the biodegradable polyesters, has been widely used to fabricate particulate systems because of advantages including controlled and sustained release, biodegradability, and biocompatibility. However, PLGA is known for low encapsulation efficiency (%) and insufficient controlled release of water-soluble drugs. It would result in fluctuation in the plasma levels and unexpected side effects of drugs. Therefore, the purpose of this work was to develop microcapsules loaded with alginate-coated chitosan that can increase the encapsulation efficiency of the hydrophilic drug while exhibiting a controlled and sustained release profile with reduced initial burst release. The encapsulation of nanoparticles in PLGA microcapsules was done by the emulsion solvent evaporation method. The encapsulation of nanoparticles in PLGA microcapsules was confirmed by scanning electron microscopy and confocal microscopy. The release profile of hydrophilic drugs can further be altered by the chitosan coating. The chitosan coating onto alginate exhibited a less initial burst release and sustained release of the hydrophilic drug. In addition, the encapsulation of alginate nanoparticles and alginate nanoparticles coated with chitosan in PLGA microcapsules was shown to enhance the encapsulation efficiency of a hydrophilic drug. Based on the results, this delivery system could be a promising platform for the high encapsulation efficiency and sustained release with reduced initial burst release of the hydrophilic drug.