Fabrication and Characterization of Thymol-Loaded Chitosan Nanogels: Improved Antibacterial and Anti-Biofilm Activities with Negligible Cytotoxicity.
Chem Biodivers
; 19(3): e202100426, 2022 Mar.
Article
en En
| MEDLINE
| ID: mdl-34989129
ABSTRACT
Thymol is a monoterpene phenolic derivative extracted from the Thymus vulgaris which has antimicrobial effects. In the present study, thymol-loaded chitosan nanogels were prepared and their physicochemical properties were characterized. The encapsulation efficiency of thymol into chitosan and its stability were determined. The inâ
vitro antimicrobial and anti-biofilm activities of thymol-loaded chitosan nanogel (Ty-CsNG), free thymol (Ty), and free chitosan nanogel (CsNG) were evaluated against both Gram-negative and Gram-positive multidrug-resistant (MDR) bacteria including Staphylococcus aureus, Acinetobacter baumanii, and Pseudomonas aeruginosa strains using the broth microdilution and crystal violet assay, respectively. After treatment of MDR strains with sub-minimum inhibitory concentration (Sub-MIC) of Ty-CsNG, free Ty and CsNG, biofilm gene expression analysis was studied. Moreover, cytotoxicity of Ty-CsNG, free Ty, and CsNG against HEK-293 normal cell line was determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. The average size of Ty-CsNG was 82.71±9.6â
nm, encapsulation efficiency was 76.54±0.62 % with stability up to 60â
days at 4 °C. Antibacterial activity test revealed that Ty-CsNG reduced the MIC by 4-6â
times in comparison to free thymol. In addition, the expression of biofilm-related genes including ompA, and pgaB were significantly down-regulated after treatment of strains with Ty-CsNG (P<0.05). In addition, free CsNG displayed negligible cytotoxicity against HEK-293 normal cell lines and presented a biocompatible nanoscale delivery system. Based on the results, it can be concluded that Ty-CsNG can be considered a promising candidate for enhancing antimicrobial and anti-biofilm activities.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Timol
/
Quitosano
Límite:
Humans
Idioma:
En
Revista:
Chem Biodivers
Asunto de la revista:
BIOQUIMICA
/
QUIMICA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Irán
Pais de publicación:
CH
/
SUIZA
/
SUÍÇA
/
SWITZERLAND