The objective of the study was to evaluate the properties of curcumin formulated in Virgin Coconut Oil (VCO) microemulsion system developed using food-acceptable grade surfactants of Tween 80, Span 80 and Span 40. Cytotoxicity analysis was carried out toward VCO microemulsion using normal L6 cells in vitro. The microemulsion was formulated using VCO as the oil phase with non-ionic surfactants mixture consist of Tween 80, Span 80 and Span 40. Curcumin was incorporated into VCO microemulsion as a cold mixture under mild agitation to form curcumin microemulsion. The physical stability of curcumin microemulsion was investigated and its characterisations were further studied according to its appearance (visual), morphology, turbidity, pH, droplet size, viscosity, conductivity, and polydispersity index. Based on the results of optimisation studies, the final 0.1 % (w/w) of curcumin concentration was successfully loaded into VCO microemulsion system. This formulation had clear transparent yellow curcumin colour without phase separation. The results indicated that the curcumin microemulsion had an average particle size about 43.15 nm and good stability with zeta potential -0.24 mV. The curcumin micoemulsion morphology had spherical in shape when observed under transmission electron microscopy (TEM), the curcumin microemulsion was slightly acidic with pH value 5.28, the conductivity was 241.2 ?S/cm and the viscosity was 8.5 cP.

Hydrogels have been demonstrated to exhibit distinct efficacy as matrices for 3D cell culture. As this research field advances, the needs for matrices combining both the benefits of natural and synthetic polymer hydrogels are becoming more apparent. In this study, kappa-carrageenan-PVP-PEG (κCA-PVP-PEG) hydrogels have been micropatterned with microwells to enhance human squamous carcinoma (HTB43™) spheroid growth. It was found that the hydrogels’ swelling ratios (SR) were 11.91, 11.67, and 11.67 for day 2, day 4, and day 8, respectively. A stable SR indicated no further swelling of hydrogels in the cell culture media, hence allowing spheroid growth in an intact mold without the rupture or dissolution of microwell templet. The comparison between unirradiated and irradiated hydrogel Fourier transform infrared (FTIR) spectra showed a slight shift of O-H (stretch) from 3,327 to 3,382 cm−1 and CH and CH2 (stretch) from 2,919 to 2,921 cm−1, respectively, whereas other functional peaks remained unchanged, suggesting the formation of interpenetrating network as the primary mechanism for hydrogels formation. The morphological study revealed the spherical shape of spheroids with measurements between 130 and 220 µm. Spheroids emit a signal in 4′,6-diamidino-2-phenylindole (DAPI) and fluorescein isothiocyanate (FIT-C) channels indicating spheroid viability. In conclusion, micropattern κCA-PVP-PEG hydrogels deemed suitable as a templet for generation and HTB43™ spheroid growth for 3D cell culture application.