Immobilization and Release Studies of Triazole Derivatives from Grafted Copolymer Based on Gellan-Carrying Betaine Units

Abstract

New polymer-bioactive compound systems were obtained by immobilization of triazole derivatives onto grafted copolymers and grafted copolymers carrying betaine units based on gellan and N-vinylimidazole. For preparation of bioactive compound, two new types of heterocyclic thio-derivatives with different substituents were combined in a single molecule to increase the selectivity of the biological action. The 5-aryl-amino-1,3,4 thiadiazole and 5-mercapto-1,2,4-triazole derivatives, each containing 2-mercapto-benzoxazole nucleus, were prepared by an intramolecular cyclization of thiosemicarbazides-1,4 disubstituted in acidic and basic medium. The structures of the new bioactive compounds were confirmed by elemental and spectral analysis (FT-IR and 1H-NMR). The antimicrobial activity of 1,3,4 thiadiazoles and 1,2,4 triazoles was tested on gram-positive and gram-negative bacteria. The triazole compound was chosen to be immobilized onto polymeric particles by adsorption. The Langmuir, Freundlich, and Dubinin–Radushkevich adsorption isotherm were used to describe the adsorption equilibrium. Also, the pseudo-first and pseudo-second models were used to elucidate the adsorption mechanism of triazole onto grafted copolymer based on N-vinylimidazole and gellan (PG copolymer) and grafted copolymers carrying betaine units (PGB1 copolymer). In vitro release studies have shown that the release mechanism of triazole from PG and PGB1 copolymers is characteristic of an anomalous transport mechanism.

Polybetaines in Biomedical Applications

“…In addition, the mechanism of triazole release from PG and PGB1 copolymers is more complex, being controlled by both swelling and diffusion processes. These results demonstrated that the graft copolymer with a betaine structure may be a potential candidate for the development of oral drug delivery systems as tablets or capsules [122].…”

“…These results demonstrated that the graft copolymer with a betaine structure may be a potential candidate for the development of oral drug delivery systems as tablets or capsules. [122].…”

“…The same group of researchers also performed immobilization studies of a 3-(benzoxazole-2 -yl-mercapto-methyl)-4-(p-methoxyphenyl)-5-mercapto-1,2,4-triazole on the same grafted copolymers [122]. The immobilization studies showed that triazole sorption was spontaneous and favored by the increase in temperature.…”

Insight into the interaction between tannin acid and bovine serum albumin from a spectroscopic and molecular docking perspective

“…The enthalpy changes of the reaction Δ H , the Gibbs free energy change Δ G and the entropy change Δ S can be calculated from Van't Hoff equation. 21 ln K 2 / K 1 = Δ H (1/ T 1 − 1/ T 2 )/ R Δ G = Δ H − T Δ S = − RT ln K T is the thermodynamic temperature, R is the gas constant (8.314 J (mol −1 K −1 )); K is the binding constant of TA and BSA at the corresponding temperature.…”

“…The enthalpy changes of the reaction DH, the Gibbs free energy change DG and the entropy change DS can be calculated from Van't Hoff equation. 21 ln…”