Antioxidant Network Based on Sulfonated Polyhydroxyalkanoate and Tannic Acid Derivative

Abstract

A novel generation of gels based on medium chain length poly(3-hydroxyalkanoate)s, mcl-PHAs, were developed by using ionic interactions. First, water soluble mcl-PHAs containing sulfonate groups were obtained by thiol-ene reaction in the presence of sodium-3-mercapto-1-ethanesulfonate. Anionic PHAs were physically crosslinked by divalent inorganic cations Ca2+, Ba2+, Mg2+ or by ammonium derivatives of gallic acid GA-N(CH3)3+ or tannic acid TA-N(CH3)3+. The ammonium derivatives were designed through the chemical modification of gallic acid GA or tannic acid TA with glycidyl trimethyl ammonium chloride (GTMA). The results clearly demonstrated that the formation of the networks depends on the nature of the cations. A low viscoelastic network having an elastic around 40 Pa is formed in the presence of Ca2+. Although the gel formation is not possible in the presence of GA-N(CH3)3+, the mechanical properties increased in the presence of TA-N(CH3)3+ with an elastic modulus G’ around 4200 Pa. The PHOSO3−/TA-N(CH3)3+ gels having antioxidant activity, due to the presence of tannic acid, remained stable for at least 5 months. Thus, the stability of these novel networks based on PHA encourage their use in the development of active biomaterials.

Straightforward Way to Provide Antibacterial Properties to Healthcare Textiles through N-2-Hydroxypropyltrimethylammonium Chloride Chitosan Crosslinking

“…An attempt to graft quaternary ammonium, after chitosan crosslinking with glutaraldehyde, was achieved by immersing chitosan-crosslinked samples in 100 mL of a mixture of anhydrous ethanol and butyl acetate at 1:2 (v/v) in a 250 mL tree-neck round-bottom flask, with 4 mg of triphenylphosphine and 3 mL of GTMAC. The reaction medium was stirred at 80 °C for 48 h under an inert atmosphere . Then, they were washed by vortexing for 1 min in 5 mL of distilled water.…”

“…The reaction medium was stirred at 80 °C for 48 h under an inert atmosphere. 34 Then, they were washed by vortexing for 1 min in 5 mL of distilled water. 2.3.5.…”

Advances in Polyhydroxyalkanoate (PHA) Production, Volume 3

“…Due to the presence of tannic acid, gels prepared this way displayed high antioxidant activity and remained stable for several months. The authors suggest these novel mcl -PHA-based networks for future use as active soft biomaterials in biomedical applications [ 34 ].…”