Hydrogel membranes based on gum tragacanth with tunable structure and properties. I. Preparation method using Taguchi experimental design

Abstract

Gum tragacanth (GT) was exploited to create a series of novel hydrogel membranes with diverse swelling properties. The films of this biopolymer were crosslinked with applying heat only, as well as application of four types of chemical crosslinking reagents, including glycerin, ethylene glycol, triethylene glycol, and glutaraldehyde. The effects of the crosslinking agent concentration, crosslinking reaction temperature (57-97 C) and reaction time (2-24 h) on the equilibrium swelling of each series of the synthesized hydrogels were investigated by the aid of Taguchi method of experimental design. This approach facilitated the study of interaction of a large number of variables spanned by factors and their levels with a small number of experimental runs. In all cases, it was found that by increasing the concentration of each type of the crosslinking reagent and extension of the crosslinking reaction time, the swelling capacity of the prepared hydrogel films decreased. However, by increasing the crosslinking temperature, the equilibrium swelling capacity changed by passing through a minimum. As a whole, the equilibrium swelling values of the hydrogels proved that a broad range of hydrogel membranes having the crosslinking densities of 0.83-23.87 Â 10 À6 mol/cm 3 and swelling capacities of 120-1580 g/g was achieved successfully from GT. Thus, GT was assigned as a promising biopolymer for preparing membranes with diverse structural and swelling characteristics.

Tragacanth gum as a natural polymeric wall for producing antimicrobial nanocapsules loaded with plant extract

“…The physical, chemical and biological properties of TG including structure, thermal behavior, emulsifying, viscosity, acidity, stability, and also rheological, antibacterial, biocompatibility and biodegradability have been reported by various researchers [2,4,6,10,12,[18][19][20][21]. In recent years, several works are reported on the application of TG in the wound and burn dressing [22], synthesis of silver nanoparticles [2], hydrogel membranes [20], superabsorbent hydrogel [3,23] matrix of verapamil hydrochloride tablets [24], matrix for cell immobilization [10] and drug encapsulation [5,25,26].…”

“…It has not allergenic, mutagenic, teratogenic, carcinogenic and toxicological effects on the human body and makes a suitable medium for cell growth [1,3,10]. TG has been accepted since 1961 as generally recognized as safe (GRAS) at the level of 0.2-1.3 % and in Europe has E-number E413 on the list of additives approved by the Scientific Committee for Food of the European Community [5,11,12].…”

“…TG obtains in two different forms of ribbon and flake. The name tragacanth is originated from two Greek words of tragos (goat) and akantha (thorn) showing its curved shape [1][2][3][4].…”

“…This polysaccharide is composed of two fractions of water-soluble and highly branched fraction and bassorin have the spheroidal and rod-like molecular shape, respectively [2,3,[5][6][7][8][9].…”

Synthesis of nanohydrogels based on tragacanth gum biopolymer and investigation of swelling and drug delivery

“…Tragacanth gum (TG)is a highly branched heterogeneous polysaccharide and consists of two fractions named as tragacanthic acid and arabinogalactan [11]. TG is the most viscous of natural plant gum, is extracting as a dried exudation from the stems and branches of Astragalusgummifer, is highly hydrophilic, nontoxic, biocompatible, has outstanding structural stability to heat, acidity, and aging, and safe for oral intake and medicinally imported polysaccharide [12,13]. The hydroxyl units of TG provide the reactive sites for modification and cross-linking reactions.…”