Developing Antibacterial Nanocrystalline Cellulose Using Natural Antibacterial Agents

Abstract

We used hairy nanocrystalline cellulose functionalized with aldehyde groups, otherwise known as sterically stabilized nanocrystalline cellulose (SNCC), to facilitate the attachment of the antibacterial agents lysozyme and nisin. Immobilization was achieved using a simple, green process that does not require any linker or activator. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analyses showed successful attachment of both nisin and lysozyme onto the SNCC. The efficacy of the conjugated nanocellulose against the model bacteria Bacillus subtilis and Staphylococcus aureus was tested in terms of bacterial growth, cell viability, and biofilm formation/removal. The results show that the minimum inhibitory concentration of the conjugated nanocellulose is higher than that of lysozyme and nisin in free form, which was expected given that immobilization reduces the possible spatial orientations of these proteins. We observed that free nisin is not active against S. aureus after 24 h of exposure due to either deactivation of free nisin or development of resistance in S. aureus against free nisin. Interestingly, we did not observe this phenomenon when the bacteria were exposed to antibacterials immobilized on nanocellulose, suggesting that immobilization of antibacterial agents onto SNCC effectively retains their activity over long time periods. We suggest that antibacterial SNCC is a promising candidate for the development of antibacterial wound dressings.

A Review on Surface-Functionalized Cellulosic Nanostructures as Biocompatible Antibacterial Materials

“…SNCC is a copolymer of DAC and cellulose which is 4-8 nm wide and 100-200 nm long [53]. The aldehyde groups in aldehyde-modified cellulosic compounds (DAC or SNCC) can be readily further converted to carboxylic groups [59,66], primary alcohols [67], and imines (by a Schiff base reaction) [20] under certain conditions. Thus, DAC is an intermediate to make cellulosic materials for different applications such as dye and heavy metal removal adsorbents [68][69][70], drug carriers [20,71], stabilizers for proteins [72,73], carriers for antibodies [74], and tissue engineering scaffolds [75].…”

Versatile Application of Nanocellulose: From Industry to Skin Tissue Engineering and Wound Healing

“…The activity against Bacilus subtilis and Staphylococcus aureus was higher in nisin-TONFC composites than in free nisin [135]. In another nanocellulose-based material, i.e., nanocrystalline cellulose functionalized with aldehyde groups, also known as sterically stabilized nanocrystalline cellulose, nisin was combined with lysozyme, another antibacterial agent [102]. Other interesting molecules are alkannin, shikonin, and their derivatives, which are naturally occurring hydroxynaphthoquinones with wound healing potential and antimicrobial, anti-inflammatory, antioxidant, and antitumor activities.…”

Coaxial Spinning of All-Cellulose Systems for Enhanced Toughness: Filaments of Oxidized Nanofibrils Sheathed in Cellulose II Regenerated from a Protic Ionic Liquid

“…Compared to the washed sample, CSFw, more limited biofilm formation occurred on CF and CSFuw, which can be explained by the presence of sodium carboxylate groups and residual PIL, respectively. Growth inhibition and antibiofilm properties of CNMs have been described against S.aureus upon chemical modification by the addition of bactericidal agents such as lysozyme and nisin 104 and titanium-aluminium-niobium-gentamicin 105 . Moreover, cellulose/nanocellulose filters grafted with a zwitterionic poly(cysteine methacrylate) 106 have shown inhibition of biofilm formation and potential for water treatment applications.…”