Table 3.

Alginate composite fibre prepared via microfluidic technique.

Filler	Cell incorporation	Composite preparation	Composite characterisation	Ref.
ECM, Methacrylated gelatin (GelMA)	Liver HepG2, embryo fibroblast cells (NIH 3T3), Human umbilical vein endothelial cells (HUVECs)	Microfluidic system: multibarrel capillary inlet and several single-barrel capillaries inlet Sodium alginate/ECM/GelMA solution injected into tapered multibarrel capillary, while CaCl2 solution pumped along the same direction into collection capillary	Addition of ECM filler reconstruct a microenvironment for cell growth. Addition of GelMA promotes construction of vessels for human umbilical vein endothelial cells	[70]
GelMA	HUVECs, Human osteoblast-like cells (MG63)	Microfluidic system: double coaxial laminar flow microfluidic system with 3 capillary inlet. The system outlet is immersed in CaCl2 solution. 2% hyaluronic acid injected into 1st capillary while sodium alginate/GelMA was pumped into 2nd and 3rd capillary in order to prepare double-layer hollow composite Incorporation of human umbilical vascular endothelial cells (HUVACs) and human osteoblast-like cells (MG63) by mixing with sodium alginate/GelMA solution	Addition of filler aimed to offer additional assembly network, strengthen mechanical and biological activity Composite fibre exhibited higher mechanical modulus, better stretching, and lower swelling compared to pure alginate fibre.	[73]
Collagen	Pancreatic islets from sprague-dawley rat	Microfluidic system: polydimethylsiloxane (pdms) mould with integrated cylindrical and coaxial flow channels fabricated using soft lithography sodium alginate/filler with pancreatic islet injected at 1.2 ml/h into cylindrical channel, while cacl2 solution injected at 30 ml/h into coaxial channel	Collagen added to mimic the native islet microenvironment.	[71]
Gelatin or urinary bladder material (ubm)	Osteosarcoma cell (saos-2)	Microfluidic system: micromachined acetal resin serve as template during ‘hydrogel shrinking’ fabrication of microfluidic chip the chip comprises of two inlet channels integrated into one outlet output channel. the channel is either designed in straight fashion or designed with snake-like fashion to induce micromixing sodium alginate/gelatin or sodium alginate/ubm injected at 1.5 ml/min to one inlet channel, and sodium alginate/cells injected at 1.5 ml/min to another inlet channel, and the output fibre transferred into coagulation solution (either bacl2, cacl2, or srcl2)	Gelatin or ubm promote extracellular matrix environment and positively influencing the viability and osteogenic mineralization. Composite fibre produced from microfluidic system with snake-like channel pattern promote homogenous distribution of embedded cells	[69]
No filler	Mesenchymal stem cells (MSCs)	Microfluidic system: Main inlet channel comprised of 150 – 550 µm diameter glass channel inserted into 1.5 mm rectangular glass tube. Side channel of 1 mm diameter connected to the periphery of rectangular glass tube Sodium alginate/cells injected at varied flowrate (5 – 40 µl/min) to main inlet, while CaCl2 solution injected at 3.6 ml/min to side channel	Composite fibre shows retention strength value of 0.54 N, which is within the range of the strength needed for tissue engineered tubular graft (0.5 – 0.7 N) Composite fibre with diameter 500 µm is used to encapsulate cell	[74]
Methacrylated hyaluronic acid (MA-HA) or Methacrylated chondroitin sulfate (MA-CS) with chitosan as complexion agent	Human tendon derived cells (hTDCs)	Microfluidic system: Polydimethysiloxane chip designed with two inlet channel (1 mm diameter) joined to form one common outlet channel (1 mm diameter) Sodium alginate/MA-HA or sodium alginate/MA-CS injected at 0.2 ml/min to one inlet channel, while chitosan injected at 0.2 ml/min to another inlet channel. The fibre obtained at output channel crosslinked in 2% CaCl2 bath and methacrylate constituent within the fibre further cured with UV exposure (320 – 500 nm, 30 s) For cell-laden fibre, hTDC cells suspended at a density of 106/ml in either sodium alginate/MA-HA or sodium alginate/MA-CS solution	Composite fibre did not affect cell viability and cells were also able to maintain their function of producing extracellular matrix up to 21 d in culture	[72]
Chitosan	Liver HepG2	Microfluidic system: Polydimethysiloxane chip with a tubular core (connected to 1st inlet channel) surrounded with 3 layer of sheath (inner-sheath layer connected to 2nd inlet channel, mid-sheath layer connected to 3rd inlet channel, and outer-sheath layer connected to 4th inlet channel) Methyl cellulose/cells solution injected into 1st inlet channel at varied flowrate (0.5 – 2.5 µl/min), chitosan solution injected into 2nd inlet channel at varied flowrate (0.1 – 0.8 µl/min), sodium alginate solution injected into 3rd inlet channel at varied flowrate (2.5 – 40 µl/min), and CaCl2 solution injected into 4th inlet channel designed with two inlet channel (1 mm diameter) joined to form one common outlet channel (1 mm diameter)	The hollow region of fibre composite with chitosan inner coating is able to resist disintegration upon immersion in saline solution. Introduction of inner chitosan coating facilitated the cell adhesion and culture in the composite fibre	[75]