Chitosan–Iron Oxide Coated Graphene Oxide Nanocomposite Hydrogel: A Robust and Soft Antimicrobial Biofilm

Abstract

We report a robust biofilm with antimicrobial properties fabricated from chitosan-iron oxide coated graphene oxide nanocomposite hydrogel. For the first time, the coprecipitation method was used for the successful synthesis of iron oxide coated graphene oxide (GIO) nanomaterial. After this, films were fabricated by the gel-casting technique aided by the self-healing ability of the chitosan hydrogel network system. Both the nanomaterial and the nanocomposite films were characterized by techniques such as scanning electron microscopy, FT-IR spectroscopy, X-ray diffraction, and vibrating sample magnetometry. Measurements of the thermodynamic stability and mechanical properties of the films indictaed a significant improvement in their thermal and mechanical properties. Moreover, the stress-strain profile indicated the tough nature of the nanocomposite hydrogel films. These improvements, therefore, indicated an effective interaction and good compatibility of the GIO nanomaterial with the chitosan hydrogel matrix. In addition, it was also possible to fabricate films with tunable surface properties such as hydrophobicity simply by varying the loading percentage of GIO nanomaterial in the hydrogel matrix. Fascinatingly, the chitosan-iron oxide coated graphene oxide nanocomposite hydrogel films displayed significant antimicrobial activities against both Gram-positive and Gram-negative bacterial strains, such as methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, and Escherichia coli, and also against the opportunistic dermatophyte Candida albicans. The antimicrobial activities of the films were tested by agar diffusion assay and antimicrobial testing based on direct contact. A comparison of the antimicrobial activity of the chitosan-GIO nanocomposite hydrogel films with those of individual chitosan-graphene oxide and chitosan-iron oxide nanocomposite films demonstrated a higher antimicrobial activity for the former in both types of tests. In vitro hemolysis potentiality tests and MTT assays of the nanocomposite films indicated a noncytotoxic nature of the films, which conveyed the possibility of potential applications of these soft and tough films in biomedical as well as in the food industry.

Protective Effect of Bioactivity Guided Fractions of Ziziphus jujuba Mill. Root Bark against Hepatic Injury and Chronic Inflammation via Inhibiting Inflammatory Markers and Oxidative Stress

“…Tetrazolium salt assay (MTT) was used to determine the cytotoxic concentration of ZJME and ZJWF (Kalita S. et al, 2015, 2016; Kandimalla et al, 2016b; Konwar et al, 2016). Briefly, the cells from the culture flask were trypsinized and seeded in 96-well plate at 5 × 10 3 cells/well in a culture medium and incubated in the CO 2 incubator at 37°C for 24 h. Then the culture medium from the wells was replaced with new media and ZJME and ZJWF at different concentrations (5, 25, 50,125, 250, and 500 μg/mL).…”

Microneedles of chitosan‐porous carbon nanocomposites: Stimuli (pH and electric field)‐initiated drug delivery and toxicological studies

“…32 In our case, we are using 100 non-hallow MNs array with the area 0.25 cm 2 , which undergo the applied stress up to MNs breaking point by varying different concentration of GAPC into CS-CPL nanocomposite. 25,26,45 In the spectrum of GAPC (marked III), the peak value at 1732 cm −1 (C O) fits to the carboxylic groups tretching and peak value at 1630 cm −1 , was of characteristic O H bond of water molecule. Neat CS-CPL MNs film showed a tensile strength of $80 MPa.…”

“…CS MNs (marked as II) showed a strong peaks, at 3356 cm −1 (O H), 2950 cm −1 (N H), 1635-1631 cm −1 (C C), 1596 cm −1 (N H, amino group), 1405 cm −1 (C OH, carboxylic group), 1000 cm −1 -1100 cm −1 (C O), and at 1533 cm −1 (N H) present in the CS MNs as reported by many research groups. 25,26,45 In the spectrum of GAPC (marked III), the peak value at 1732 cm −1 (C O) fits to the carboxylic groups tretching and peak value at 1630 cm −1 , was of characteristic O H bond of water molecule.…”

Current Approaches for Exploration of Nanoparticles as Antibacterial Agents

“…Agar disk diffusion tests performed both according to the standardized protocols and with modifications are frequently used for susceptibility assessment and evaluation of antimicrobial activity of nanoparticles [109,[121][122][123][124]. Paper disc method has been employed as an alternative to standardized single disk method [112].…”