Chitosan film of thiolated TPGS-modified Au-Ag nanoparticles for combating multidrug-resistant bacteria
The widely used vitamin-E based amphiphilic material, tocopheryl polyethylene glycol succinate (TPGS) is further improvised as redox-sensitive thiolated TPGS (TPGS-SH), which has been developed by attaching 4-aminothiophenol. Further, TPGS and TPGS-SH-coated bimetallic gold-silver nanoparticles (TPGS-Au-Ag-NP and TPGS-SH-Au-Ag-NP) were formulated to explore their antibacterial and wound healing abilities. The prepared NP were monodispersed with a mean hydrodynamic diameter of 69.5±3.23 nm, 59.65±3.23 nm, PDI of 0.3±0.05, 0.2±0.03 and a zeta potential of +29.2±2.71 mV and +35.28±1.53 mV, respectively.
The TPGS and TPGS-SH modified Au-Ag-NP were tested for their antibacterial efficacy against methicillin-resistant Staphylococcus aureus (MRSA) and E. coli, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) results showed that TPGS Au-Ag-NP, TPGS-SH-Au-Ag-NP displayed significantly stronger antibacterial than their coating material alone. The anti-efflux pump activity of the most potent antibacterial agent TPGS-SH-Au-Ag-NP was found against MRSA. Toxicity assessment of TPGS-SH-Au-Ag-NP in human dermal fibroblasts showed 88% viability up to 125 µg/mL.
The TPGS-SH-Au-Ag-NP after incorporation in chitosan film (TPGS-SH-Au-Ag-NP-CS) exhibited sustained release and prolonged in-vivo residence characteristics of TPGS-SH-Au-Ag-NP, evaluated by IVIS. Results also revealed the treatment with TPGS-SH-Au-Ag-NP showed a significant 87% wound healing rate after 12 days of application in the rat model. Hence, we concluded that TPGS-SH-Au-Ag-NP was safe and effective against test bacteria MRSA and capable of efficient wound healing when incorporated in chitosan film.
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Materials
Gold (III) chloride trihydrate (HAuCl4.3H2O, 99.9%), silver nitrate (AgNO3, 99.9%). 3-(4,5-dimethylthiazole-2-yl)-2,5- diphenyltetrazolium bromide (MTT) were procured from Thermo Fisher Scientific. Chitosan (deacetylation degree ≤ 90% and MW ~ 1500 Da) and succinic anhydride were obtained from Sisco Research Laboratory Pvt. Ltd (SRL) India. Antares Health Products gifted TPGS (D-alpha-tocopheryl-polyethyleneglycol-1000-succinate).
Chandrashekhar Singh, Abhishesh Kumar Mehata, Matte Kasi Viswanadh, Punit Tiwari, Rajesh Saini, Sanjeev Kumar Singh, Ragini Tilak, Kavindra Nath Tiwari, Madaswamy S. Muthu, Chitosan film of thiolated TPGS-modified Au-Ag nanoparticles for combating multidrug-resistant bacteria, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2024, 133287, ISSN 0927-7757, https://doi.org/10.1016/j.colsurfa.2024.133287.