Table 1.

Alginate composite fibre prepared via wet spinning technique.

Additive material	Additive material content (%,wt)	Composite preparation	Composite characterisation	Ref.
Graphene oxide	2–8	Sodium alginate/graphene oxide solution extruded via syringe into CaCl2 bath followed by fibre stretching in CaCl2 bath at 50% and 100% draw ratio	Highest modulus of 9.39 GPa (▲118%) and highest strength of 0.86 GPa (▲169%) obtained at 4% graphene oxide content Water absorbency ranged between 0.93 – 1.06 g/g and independent of graphene oxide content	[47]
Carboxyl methyl chitosan	10–70	4% sodium alginate/5% carboxylmethyl chitosan blend at 9/1, 7/3, 5/5, 3/7 ratio blend solution extruded via spinneret (30 holes, 0.08 mm diameter) into 5% cacl2 bath followed by fibre stretching in water at 20% draw ratio	Highest tenacity of 13.8 cn/tex (▲35%) obtained at 30% filler content highest elongation of 23.1% (▲27%) obtained at 10% filler content water retention increased in range of 130% – 398% for filler loaded fibre compared to 91% for pure alginate fibre	[39]
Gelatin	9–33	4% sodium alginate/4% gelatin blend at 10/5, 10/4, 10/3, 10/2, 10/1 ratio 5% oxidized starch added to blend mixture sodium alginate/gelatin/starch solution extruded via spinneret (900 holes, 70 µm diameter) into 5% cacl2 bath followed by fibre stretching in ethanol at 150% draw ratio	Highest tenacity of 1.29 cn/dtex and highest elongation of 4.41% obtained at 16.7% gelatin content highest water absorption of 335% (▲19%) and highest water retention of 311% (▲19%) obtained at 16.7% gelatin content	[44]
Cellulose nanocrystal	0.5–16	Sodium alginate/cellulose nanocrystal solution extruded via spinneret into 5% CaCl2 bath followed by fibre stretching at 1.2 draw ratio	Highest tenacity of 2.05 cN/dtex (▲33%) and highest elongation of 15% (▲82%) obtained at 2% cellulose nanocrystal content	[42]
Chitosan	1–2 (w/v chitosan solution)	10% sodium alginate solution extruded via spinneret (1 hole, 0.6 mm diameter) into 8% CaCl2 bath Extruded fibre immersed in 1% or 2% chitosan bath	Highest modulus of 0.43 cN/dtex (▲13%), highest strength of 1.77 cN/dtex (▲13%) and highest elongation of 10% (▲4%) obtained when alginate fibre immersed in 1% chitosan bath	[40]
Methylene blue nanocapsule	3–15	Nanocapsule first created by blending methylene blue and NaHCO3 with alginate solution Nanocapsule then mixed to 3.5% alginate solution and extruded via spinneret (50 holes, 70 µm diameter) into 2.5% CaCl2 bath followed by fibre stretching at 1:5 draw ratio	Highest tenacity of 15 cN/dtex (▲16%) obtained at 6% nanocapsule content Absorption capacity enhanced from 1.1 – 1.2 g/g in water to 13 – 66 g/g in saline solution	[48]
Chitin	33–75	Alginic acid/chitin dissolved in 1-ethyl-3-methylimidazolium acetate ionic liquid and extruded via syringe into CaCO3 bath. 1.75 wt% chitin to 0.58 wt% alginic acid in ionic liquid yield the optimal fibre	Composite fibre exhibited 22% decrease in modulus (6.9 GPa), 16% decrease in strength (216 MPa), 9% decrease in elongation (4.1%), and 19% decrease in water uptake (2.06 g/g), but still strong enough to be used directly as structural material for wound care	[37]
Silver nanoparticle	0.05 or 0.005 mM silver nitrate solution	2% sodium alginate solution extruded via syringe into 1 M CaCl2 bath. Extruded fibre immersed in silver nitrate solution (1 h) followed by sodium borohydride (10 min) to obtain reduced metallic silver nanoparticle.	Composite fibre promote faster wound closure, increased epidermal thickness, and decreased neutrophil at local wound site	[31]
Starch, salicylic acid drug	10–70	Sodium alginate/starch solution extruded via spinneret (30 holes, 0.08 mm diameter) into 10% CaCl2 bath followed by fibre stretching in water at 20% draw ratio Drug-laden fibre was loaded with salicylic acid	Highest tenacity of 14.2 cN/tex (▲29%) obtained at 10% starch content. Highest elongation of 27% (▲69%) obtained at 30% starch content.	[45]
Carrageenanchondrocyte cells	20–50	Two type of alginate used in blend: k-carrageenan and l-carrageenan. Sodium alginate/carrageenan solution extruded via syringe into CaCl2/2% KCl bath. For cell-laden fibre, chondrocyte cells (ATDC5) encapsulated in fibre precursor at concentration of 1 × 106 cells/ml	Noncytotoxic. Higher viability of cells after 3 weeks in k- type compared to l- type alginate/carrageenan composite	[43]
Chitosan whisker	0.2–1.0	Sodium alginate/chitosan whisker solution extruded via spinneret (30 holes, 0.02 mm diameter) into 1st coagulation bath (5% CaCl2 in 50% MeOH) and 2nd coagulation bath (MeOH) followed by fibre stretching at 1.2 draw ratio	Highest tenacity of 10 cN/tex (▲67%) obtained at 1% whisker content. Highest elongation of 28% (▼42%) obtained at 0.6% whisker content.	[41]
Chitin whisker	0.05–2	Sodium alginate/chitin whisker solution extruded via spinneret (30 holes, 0.02 mm diameter) into 1st coagulation bath (5% CaCl2 in 50% MeOH) and 2nd coagulation bath (MeOH) followed by fibre stretching at 1.2 draw ratio	Highest tenacity of 10.4 cN/tex (▲16%) obtained at 0.15% whisker content. Highest elongation of 26% (▲44%) obtained at 0.10% whisker content	[38]
Single walled carbon nanotube (SWCNT)	0.6–23	Sodium alginate/SWCNT solution extruded via syringe (0.85 mm diameter) into 1st coagulation (15% CaCl2, 15 min) and 2nd coagulation bath (3% CaCl2, overnight)	Highest modulus of 6.67 GPa (▲93%) and highest strength of 250 MPa (▲25%) obtained at 1.2% SWCNT content At 23 wt% filler loading, resistivity decreased one to two order of magnitude	[30]
Polypyrrole	72	SWCNT is added for the final ratio of pyrrole monomer/sodium alginate/SWCNT at 2.63/1/0.04 Sodium alginate/polypyrrole and sodium alginate/polypyrrole/SWCNT solution extruded via continuous wet-spinning into 5% CaCl2 bath and polymerization line	Addition of polypyrrole decrease composite strength by 61% (140 MPa) and elongation by 33% (8%), which may be attributed to the low compatibility of alginate and polypyrrole Addition of carbon nanotube increased composite fibre strength by 79% (250 MPa) and elongation by 25% (10%) Alginate/polypyrrole/SWCNT composite fibre gave significantly higher electrical conductivity compared to non-composite fibre, potential as support for biomedical sensor and actuators	[46]