1.1.4 Carrageenan
Carrageenan is a negatively charged linear sulfur sugar acquired from
algae such as Chondrus cripus , Gigartina stellate ,Hypnea , Halurus and Solieria (Prajapati et al.,
2014). Carrageenan is made up of 3,6 anhydro galactopyranose and
galactose linked by galactose α-1,3 and β -1, 4 glycosidic bonds. The
residue 3, 6-anhyro-D-galactose is essential for forming gel by
carrageenan (Venkatesan et al., 2015). Carrageenans are easily soluble
in water, biocompatible, nontoxic, highly viscous, high gelling capacity
and stable in a wide pH range. It exists in the form of nanoparticles,
hydrogels, microspheres, nanofibers, wafers, films, pellets and
microspheres and it has an application in tissue designing, drug
transport, wound healing, pharmaceutical formulations, and biosensing
(Pacheco-Quito et al., 2020).