Hairy bacterial nanocellulose: preparation and bioconjugation with an antibacterial agent

It is hypothesized that during the periodate oxidation of bacterial cellulose (BC), the chains will be cleaved in the amorphous regions. Subsequent chlorite oxidation will cause highly charged cellulose chains on the outer surface of BC to go into solution and break up BC into smaller and thinner nanocellulose particles, to which the cleaved amorphous chains are attached resulting in electrosterically stabilized bacterial nanocellulose (EBNC). Since EBNC is expected to have carboxylated cellulose chains, it should be possible to chemically anchor antibacterial agents to them. EBNC was prepared by a two-step periodate and chlorite oxidation. Extensive structural characterization of EBNC has been performed. EBNC is a nanoparticle with a high charge density with most carboxyl groups located in the amorphous chains (hairs). DLS proved that the hairs contracted upon salt addition and morphological investigation showed that EBNC particles are rod-like with a length of ~ 200 nm and width of ~ 10 nm. Using a bioconjugation reaction, the antibacterial agent ɛ-poly-L-lysine (PLL) was grafted to EBNC. EBNC–PLL was fully characterized and its antibacterial effectiveness and non-cytotoxicity were evaluated. The successful bioconjugation reaction between EBNC and PLL resulted in a non-cytotoxic material which has antibacterial effectiveness against both Gram-negative and Gram-positive bacteria.