Ompartments of the particles but remain separated from each and every other; the semi-permeable nature of the hydrogel allows the transport in the nutrients and cell aspects throughout the particles. This make the particles a promising three-dimensional platform for studying interactions in between unique cell forms.II. EXPERIMENTAL Particulars A. Material preparation2 w/w sodium alginate (Aladdin Chemistry Co., Ltd, China) dissolved in PBS Glucosylceramide Synthase (GCS) site buffer is utilised because the precursor answer. Immediately after sterilization by autoclaving at 121 C for 20 min, the precursor answer is then mixed with unique ingredients, for example dye molecules, cells or cell factors, to prepare the dispersed phases, which ultimately fill the various compartments on the final044117-Z. Liu and H. C. ShumBiomicrofluidics 7, 044117 (2013)particles. Dye molecules are introduced to facilitate visualization from the compartments. For the cell encapsulation experiments, 3T3 fibroblast cells are mixed with all the precursor answer to type a cell suspension with cell density of 1106 cells/ml. three w/w calcium chloride (Wing Hing PAI-1 Purity & Documentation Chemical Co., Ltd., Hong Kong) remedy is added to a collection bath for collecting the microdroplets. Immediately after the micro-droplets with multiple compartments are dropped into the bath containing calcium chloride remedy, the calcium ions (Ca2? cross-link the alginate chains and alginate hydrogel particles with multi-compartment morphology are formed, as shown in Fig. 1(c).B. Electrospray setupThe dispersed phases are driven by syringe pumps (Model Lsp01-2A, Baoding Longer Precision Pump Co., Ltd.). The diverse dispersed phases are 1st pumped through different metal needles after which merge into a single single stream inside a larger metal needle. High-strength electric field is formed involving the metal nozzle and a ground circular electrode connected to a higher voltage power supply, as shown in Fig. 1(a). With growing strength from the electric field, the dispersed liquid is steadily ionized and forms a tapered tip driven by the electrostatic force. Afterwards, the jet with the tapered tip shape breaks up into micro-droplets within the high-strength electric field, as shown in Fig. 1(b). The approach of droplets formation is captured utilizing a high speed camera (Phantom v9.1) equipped having a zoom lens (Nikon AFS DX 18-55 MM); an extra light source is added to provide the illumination necessary, as demonstrated in Figure 1(a).C. Cell culture and cells viability3T3 fibroblast cells were cultured at a temperature of 37 C in culture plates containing a culture medium which can be created up of High Glucose Dulbecco’s Modified Eagle Medium (DMEM-HG), 10 Fetal Bovine Serum (FBS) and 1 of Penicillin/Streptomycin (ten 000 units/ml penicillin and 10 000 lg/ml Streptomycin). Cells inside the multi-compartment particles are stained with calcein-AM/ethidium homodimer-1 Live/Dead assay (Life technologies, Hong Kong) for 1 h prior to the viability on the cells is tested beneath a fluorescence microscope (Model Eclipse TE2000-U, Nikon).FIG. 1. (a) Sketch in the experimental setup; (b) pictures of the droplet formation captured by a high speed camera; (c) optical microscope image of three-compartment particles.044117-Z. Liu and H. C. ShumBiomicrofluidics 7, 044117 (2013)III. Final results AND DISCUSSIONS A. Droplet formation and size distributionThe size with the droplets formed by electrospray depends critically on the strength on the applied electric field,20 as shown by Figures two(a)?(f). Normally, with an increase in.