Antibacterial and Healing Potential of Zn-Al LDHs/Cellulose Acetate Nanocomposite in Burns and Wounds: A Study on Earthworms as a Human Skin Model

Abstract

Protection against microbial invasion has gained much attention to accelerate wound healing. Layered double hydroxides (LDHs) have antimicrobial properties due to their partial release of metallic ions. In this study, Zn-Al LDHs was chemically prepared and then supported on cellulose acetate (CA) in the form of nanocomposite. This novel Zn-Al LDHs/CA nanocomposite was in vitro characterized, and its antibacterial efficacy was determined using the agar well diffusion method. Moreover, healing capabilities of the nanocomposite were evaluated via topical application on wounds and burns induced in earthworms as a model of human skin like. The average crystallite sizes of Zn-Al LDHs and 50% Zn-Al/CA nanocomposite were 18.4 nm and 14.8 nm, respectively. TEM micrographs revealed that pure CA, pure Zn-Al LDHs, and 50% Zn-Al LDHs/CA nanocomposites had an average particle size of 27.7 ± 13.5, 296.2 ± 123, and 223.2 ± 83.4 nm, respectively. Pure Zn-Al LDHs showed antibacterial activity against different bacterial strains (Inhibition zone: 15 ± 2 to 20 ± 4 mm). However, when 50% Zn-Al LDHs was supported on CA, the inhibition zone was significantly higher (20 ± 3 to 26 ± 2 mm). Visual inspection, scanning electron microscopy and histological studies of earthworm skin revealed better morphology and shorter healing duration with Zn-Al LDHs/CA nanosystem (66 h for wounds and 144 h for burns) when compared with untreated control (> 400 h). In conclusion, these findings reveal that Zn-Al LDHs/CA nanocomposite is a promising promoter for wound and burn healing due to its biocompatibility and antibacterial activity.