Curcumin has various bio-functional properties; however, curcumin poor bioavailability reduces its efficacy. Nanoemulsion delivery system is an alternative method improving curcumin bioavailability in which surfactant and oil used, play an important role in determining nanoemulsion properties. Several studies on curcumin nanoemulsions apply synthetic surfactants which can be harmful if they are added excessively. This study aims to use a natural emulsifying agent, namely okra mucilage extract (OME), and determine its effectiveness as co surfactant. OME is safe to use as an emulsifying agent because it is natural, harmless, safe, biodegradable and eco-friendly. Liquid-liquid and microwave extraction methods were used to obtain OME which was further identified using Fourier Transfer Infrared Spectroscopy (FTIR). Meanwhile, sonication method was used to produce curcumin nano-emulsion (CurN). The particle size and polydispersity index of curcumin nano-emulsion were measured using Particle Size Analyzer (PSA) with Dynamic Light Scattering (DLS) technique, while the morphology of the nanoemulsion was observed using a Digital Imaging Microscope and Confocal Laser Scanning Microscope (CLSM). The results showed that the addition of 0.0160 g OME at a ratio of 1:5 (OME: Tween 80) in the preparation of 5 mL of CurN was able to reduce the particle size and polydispersity index from 740.80 ± 9.70 nm to 289.20 ± 2.23 and 0.340 ± 0.005 to 0.165 ± 0.008 respectively. OME increased the encapsulation efficiency from 77.93 ± 6.59% to 87.17 ± 1.12% which was confirmed by the augmentation of the fluorescence intensity of curcumin from 192.82 to 388.55. The addition of OME also maintained the stability of the CurN up to 14 days of storage at 4°C.

Curcumin is a natural product with potential pharmaceutical applications that can be augmented by drug delivery technology such as nano emulsion. Our study focuses on microscopic structural and dynamics response of curcumin encapsulation in micellar system with lecithin as a natural surfactant under variations of composition and temperature using molecular dynamics (MD) simulations. The results highlight the self-assembly of lecithin micelle, with curcumin encapsulated inside, from initial random configurations in the absence of external field. The variation of composition shows that lecithin can aggregate into spherical and rod-like micelle with the second critical micelle concentration lies between 0.17-0.22 mol dm−3. The radial local density centering at the micelle center of mass shows that the effective radius of micelle is indeed defined by the hydrophilic groups of lecithin molecule and theencapsulated curcumin molecules are positioned closer to these hydrophilic groups than the innermost part of the micelle. The spherical micelle is shown to be thermally stable within the temperature range of 277-310 K without a perceivable change in the spherical eccentricity. The dynamics of micelle are enhanced by the temperature, but it is shown to be insensitive to the variation of lecithin-curcumin composition within the studied range. Simulation results are in agreement with the pattern obtained from experimental results based on particle size, polydispersity index, and encapsulation efficiency.

Ischemic Stroke is a disease that inhibits blood supply to the brain. One method in handling ischemic stroke patient is Intra Arterial Heparin Flushing (IAHF) which has been claimed to be able to improve motoric function of a patient. However, in vitro clinical research to understand IAHF is scarce. One of in vitro methods can be applied is using microfluidic. This research aims to create a microfluidic system that can represents blood vessel system of a stroke patient and to quantify volumetric flow rate of 1,3-Propanediol (as a blood model) in microfluidic channels. Microfluidic which is made of acrylic with a square-wave design, is employed to represent a thrombotic ischemic stroke and embolic ischemic with the addition of wax to represent plaque in blood vessel. Various viscosity of 1,3-propanediol are applied (1.5 mPa. s; 4 mPa. s; 7.2 mPa. s) to represent the effects of heparin drug. The results indicate that fluid Reynold number in the microfluidic channel are 8.8023 x10⁻⁴ and 12.3230 x10⁻⁴ which is fall in the area of Reynold number laminar flow such as in blood vessels. Volumetric flow rate of 1,3-propanediol decreases when the viscosity increases and when wax is situated in the microfluidic channel. Diluted 1,3-propanediol (at a viscosity of 1.5 mpas) shows similar volumetric flow rate (when it passes through microfluidic channels with wax) with normal blood viscosity 4,0 mpas (when it passes microfluidic channels without wax). This similarity indicates an increase of blood flow when heparin is added in excess in IAHF method, which induces an improvement of organ motoric function.

Curcumin is one of the most popular medicines due to its various pharmacological properties. Nonetheless, curcumin has low bioavailability, insoluble in water, and aggregates easily. This can be overcome by formulating curcumin into nanoemulsion. One of the methods to produce nanoemulsion is wet-ball milling. The aims of this study are, firstly, to determine the optimum milling time to produce curcumin nanoemulsion in the Virgin Coconut Oil (VCO)-Tween 80 system, and secondly to determine the curcumin loading capacity and efficiency of encapsulation. The optimum milling time is evaluated based on the particle size, polydispersity index, and nanoemulsion stability. Curcumin loading capacity and efficiency of encapsulation is analyzed based on the maximum mass of curcumin added in the system which still can maintain particle size in the range of nanoemulsion (under 1000 nm) and the amount of curcumin entrapped in the droplets. Curcumin nanoemulsion was made by the combination of 1 mg curcumin powder, 200 µl VCO as oil phase, 60 µl Tween 80 as surfactant, and 5 ml distilled water as the dispersion medium. Meanwhile, the milling time is varied at 1, 4, 8 and 24 hours. Particle size and polydispersity index are measured using Particle Size Analyzer using Dynamic Light Scattering technique while encapsulation efficiency is calculated based on the curcumin absorption using UV-Vis spectrophotometer. The results show that curcumin nanoemulsion system milled for 24 hours produce smallest particle size (160 nm), lowest polydispersity index (0.176), and stable during 30 days in the storage at room temperature (25 °C) and refrigerator temperature (4 °C). The maximum of curcumin that can be added in the nanoemulsion and produce particle size below 500 nm is 300 mg. Encapsulation efficiency obtained is 78.13 % of the total curcumin in the nanoemulsion system. In summary, the current work has demonstrated the successful incorporation of curcumin into oil in water (O/W) nanoemulsion particles with small particle size, low index polydispersity, good physical stability, and high encapsulation efficiency.

Advances in microfluidics, optogenetics and electronics have enabled the study of dynamically controlled inputs on cellular fate. Here, we applied a microfluidic system to deliver periodic inputs of growth factors to pheochromocytoma cells and measured the extent of premature differentiation as a function of input frequency. Epidermal growth factor-triggered differentiation peaked at two cycles/hour, while nerve growth factor-triggered differentiation peaked at one cycle/hour. To interpret the results, we analyzed a published model that attributed pheochromocytoma cell differentiation to the linear combination of activated enzymes extracellular signal-regulated kinase (ERK), cAMP response element binding protein (CREB), protein kinase B (AKT) and c-Jun N-terminal kinase (JNK) at specific times after step input stimulation. Transfer functions for enzyme activation were derived from the published time-domain activation kinetics and these transfer functions were combined in a parallel architecture as a predictor of neurite outgrowth, as a function of input frequency. Qualitative agreement was observed between the model and the experiments.