Antibacterial Multi-Layered Nanocellulose-Based Patches Loaded with Dexpanthenol for Wound Healing Applications

Abstract

Antibacterial multi-layered patches composed of an oxidized bacterial cellulose (OBC) membrane loaded with dexpanthenol (DEX) and coated with several chitosan (CH) and alginate (ALG) layers were fabricated by spin-assisted layer-by-layer (LbL) assembly. Four patches with a distinct number of layers (5, 11, 17, and 21) were prepared. These nanostructured multi-layered patches reveal a thermal stability up to 200 °C, high mechanical performance (Young's modulus ≥ 4 GPa), and good moisture-uptake capacity (240-250%). Moreover, they inhibited the growth of the skin pathogen Staphylococcus aureus (3.2-log CFU mL^-1 reduction) and were non-cytotoxic to human keratinocytes (HaCaT cells). The in vitro release profile of DEX was prolonged with the increasing number of layers, and the time-dependent data imply a diffusion/swelling-controlled drug release mechanism. In addition, the in vitro wound healing assay demonstrated a good cell migration capacity, headed to a complete gap closure after 24 h. These results certify the potential of these multi-layered polysaccharides-based patches toward their application in wound healing.

Keywords: alginate; chitosan; dexpanthenol; layer-by-layer assembly; multi-layered patches; oxidized bacterial cellulose; wound healing.

Figure 1

Schematic representation of (a) TEMPO-mediated oxidation of BC yielding OBC, (b) loading of OBC with DEX, (c) spin coating LbL assembly of the polysaccharides multi-layered patch with 5 layers, and (d) digital photographs of the OBC/DEX/CH/ALG patches with 5, 11, 17, and 21 layers.

Figure 2

(a,b) ATR-FTIR spectra (vibrational modes: ν = stretching, δ = bending) of BC, OBC, CH, ALG, DEX (a), OBC/DEX, and OBC/DEX/CH/ALG-based multi-layered patches with 5, 11, 17, and 21 layers (b), and (c) SEM surface micrographs (×30.0 k magnification) of OBC, OBC/DEX, and OBC/DEX/CH/ALG-based multi-layered patches with 5, 11, 17, and 21 layers.

Figure 3

(a) Thermograms and (b) derivative curves of the multi-layered patches: OBC/DEX/CH/ALG_5, OBC/DEX/CH/ALG_11, OBC/DEX/CH/ALG_17, and OBC/DEX/CH/ALG_21.

Figure 4

(a) Moisture-uptake capacity and (b) DEX cumulative release profile of OBC, OBC-loaded with DEX, and multi-layered polysaccharides-based patches.

Figure 5

(a) Antibacterial activity (24 h of exposure) of OBC, OBC-loaded with DEX, and multi-layered patches (the symbol * represents the means with a significant difference (p < 0.05) from the control and OBC); (b) cell viability of HaCaT cells after 24 h and 48 h of exposure to negative control, OBC, OBC/DEX, and OBC/DEX/CH/ALG_21, and (c) the corresponding optical micrographs of HaCaT cells after 24 h of exposure.

Figure 6

Optical micrographs of the scratch assay of the HaCaT cells after 9 and 24 h of exposure to control, OBC/DEX, OBC/DEX/CH/ALG_11, and OBC/DEX/CH/ALG_21 patches.