Experimental and numerical study on a novel microfluidic method to fabricate curcumin loaded calcium alginate microfibres

In this research, we first performed a computational fluid dynamics (CFD) study of the effects of the inlet solution's concentration and channel height to produce microfibres in a microfluidic system by COMSOL 5.3 to find the optimum ratio of sheath to core flow rate. It proved that the ratio of sheath to core flow rate should considered more than 1 to have jet regime in the microchannel. The results show that the level of Ca2+ diffusion in an alginate inlet solution has a direct and reverse correlation with the initial sheath solution's concentration and initial core solution's concentration, respectively. Secondly, the response surface methodology (RSM) in Design Expert 7.0.0, was used to investigate the effects of alginate and calcium chloride flow rates on the average microfibres' diameter. We found that the best value of Ca2+ concentration in the core flow to produce fine appropriate microfibres is 150mol/m(3). Then, we developed a microchip using lithography, in which a silicon wafer was etched vertically instead of using a SU-8 photo resist on glass, causing a significant improvement in the quality of channels and mould. The SEM images revealed low roughness of fabricated micro-channels, which was eye-catching. Eventually, the possibility of using the microfibres as polymeric carriers for hydrophobic drugs was investigated, and then fluorescent microscopic images of the loaded fibres indicated that the drug is well-loaded onto the fibres: the results are promising.