Dipalmitoylphosphatidylcholine (DPPC) is one of the most abundant lipids in the human body and carries out important physiological functions such as liver protection and fighting infections. This study was conducted to investigate the effect of ionising radiation on the chemical structure and surface characteristic of DPPC. Synthetic DPPC was dissolved in chloroform (1mg/ml) and irradiated with Cobalt-60 (dose range of 50 - 200 Gy). The change in surface characteristics due to gamma irradiation was determined by means of monolayer compression isotherms using a Langmuir trough. From the change in the isotherm features, the threshold dose that affected the surface characteristics of the DPPC monolayer was determined to be 60 Gy. With increasing dose value, the plateau feature in the DPPC isotherm became shorter and was shifted to higher surface pressures. Analysis using High Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS) suggested that gamma irradiation of DPPC destroyed the chemical structure of DPPC and produced two main radiolytic products, namely lisophosphatidylcholine, LPC (~495.3142 g/mol) and phosphatidic acid, PA (~718.916 g/mol) with an average percentage of LPC and PA of 23% and 74%, respectively.

Microencapsulation is a promising approach in drug delivery to protect the drug from degradation and allow controlled release of the drug in the body. Fucoxanthin-loaded microsphere (F-LM) was fabricated by two step w/o/w double emulsion solvent evaporation method with poly (L-lactic-coglycolic acid) (PLGA) as carrier. The effect of four types of surfactants (PVA, Tween-20, Span-20 and SDS), homogenization speed, and concentration of PLGA polymer and surfactant (PVA), respectively, on particle size and morphology of F-LM were investigated. Among the surfactants tested, PVA showed the best results with smallest particle size (9.18 ?m) and a smooth spherical surface. Increasing the homogenization speed resulted in a smaller mean F-LM particle size [d (0.50)] from 17.12 to 9.18 ?m. Best particle size results and good morphology were attained at homogenization speed of 20 500 rpm. Meanwhile, increased PLGA concentration from 1.5 to 11.0 (% w/v) resulted in increased F-LM particle size. The mean particle size [d (0.5)] of F-LM increased from 3.93 to 11.88 ?m. At 6.0 (% w/v) PLGA, F-LM showed the best structure and external morphology. Finally, increasing PVA concentration from 0.5 to 3.5 (% w/v) resulted in decreased particle size from 9.18 to 4.86 ?m. Fucoxanthin characterization before and after microencapsulation was carried out to assess the success of the microencapsulation procedure. Thermo gravimetry analysis (TGA), glass transition (Tg) temperature of F-LM and fucoxanthin measured using DSC, ATR-FTIR and XRD indicated that fucoxanthin was successfully encapsulated into the PLGA matrix, while maintaining the structural and chemical integrity of fucoxanthin. � 2016 by Japan Oil Chemists� Society.

Fucoxanthin has interesting anticancer activity, but is insoluble in water, hindering its use as a drug. Microencapsulation is used as a technique for improving drug delivery. This study aimed to formulate fucoxanthin-loaded microspheres (F-LM) for anticancer treatment of H1299 cancer cell lines and optimize particle size (PS) and encapsulation efficiency (EE). Using response surface methodology (RSM), a face centered central composite design (FCCCD) was designed with three factors: Polyvinylalcohol (PVA), poly(D,L-lactic-co-glycolic acid) (PLGA), and fucoxanthin concentration. F-LM was produced using a modified double-emulsion solvent evaporation method. The F-LM were characterized for release profile, release kinetics, and degradation pattern. Optimal F-LM PS and EE of 9.18 um and 33.09%, respectively, with good surface morphology, were achieved from a 0.5% (w/v) PVA, 6.0% (w/v) PLGA, 200 ug/mL fucoxanthin formulation at a homogenization speed of 20,500 rpm. PVA concentration was the most significant factor (p < 0.05) affecting PS. Meanwhile, EE was significantly affected by interaction between the three factors: PVA, PLGA, and fucoxanthin. In vitro release curve showed fucoxanthin had a high burst release (38.3%) at the first hour, followed by a sustained release stage reaching (79.1%) within 2 months. Release kinetics followed a diffusion pattern predominantly controlled by the Higuchi model. Biodegradability studies based on surface morphology changes on the surface of the F-LM, show that morphology changed within the first hour, and F-LM completely degraded within 2 months. RSM under FCCCD design improved the difference between the lowest and highest responses, with good correlation between observed and predicted values for PS and EE of F-LM.

Supercritical carbon dioxide (SC-CO2) extraction of fucoxanthin is more advantageous over conventional solvent extraction as it is less toxic, less hazardous to the environment and preserves the bioactivity of fucoxanthin. A face-centered central composite design (FCCCD) based on response surface methodology (RSM) was employed for SC-CO2 extraction of oils and fucoxanthin from the brown seaweed Sargassum binderi, with ethanol as a co-solvent. Three independent parameters namely, extraction temperature (A: 40, 50, 60�C), pressure (B: 2900, 3625, 4350 psig and particle size (C: 90, 500 and 1000 ?m) were investigated to optimize extraction oil yields (EOY) and fucoxanthin yields (FY). A regression model was developed, tested for quality of fit (R2) and expressed in the form of 3D response surface curve and 2D contour. The optimum extraction conditions were obtained at extraction temperature (A) 50�C, pressure (B) 3625 psig and particle size (C) 500 ?m. Under these conditions, optimal EOY and FY were 10.04 mg/g and 3188.99 ?g/g, respectively. The difference between the lowest and the highest response in EOY and FY were 5.44 - 10.04 mg/g and 2109.10 - 3188.90 ?g/g, respectively. The lowest yields were identified at 60�C, 2900 psig and 1000 ?m. The regression models generated showing interactions between the variables and EOY and FY response were significant as tested by ANOVA (p < 0.0005 and p < 0.0007, respectively) with high R2 values (0.9848 and 0.9829, respectively). Interactions between the parameters had a strong synergistic effect on EOY and FY values, as indicated by the 3D response surface curve and 2D contour. The experimental results matched the predicted results closely. This indicated the suitability of the models developed and the success of FCCCD under RSM in optimizing the S. binderi extraction conditions. � All Rights Reserved.