Cleaner approach of preparing antibacterial bioaerogel scaffolds using oil palm waste nanocellulose

Abstract

In this study, cellulose nano fibers (CNF) were isolated from oil palm empty fruit bunch using modified method of supercritical carbon dioxide (ScCO 2 ) treatment of bleached fibers. Bioaerogel scaffolds were prepared from isolated CNF using high-pressure homogenization and freeze-drying techniques. Chitosan (CS) was used to enhance the mechanical properties of bioaerogels, while cinnamon essential oil (CEO) as a natural antibacterial agent and to enhance the biocompatibility of the scaffolds. The results confirm that using ScCO 2 enhanced the yield of CNF isolation and reduced the resulted ash. Scanning Electron Microscopes analysis revealed highly porosity of the bioaerogel architecture that resulted from the excellent homogeneity of the materials. The porosity, density and surface area of the bioaerogels ranged from 90.8% to 99.1%, 8.11–141.2 mg/cm 3 , and 18.7–145.3 m 2 /g respectively. FT-IR analysis confirm the hydrogen bonding between CNFs and CS that enhanced the mechanical properties and reduced the in vitro water up take of the bioaerogels. Although, CEO slightly reduced the hardness and surface area of bioaerogels, it makes the bioaerogels exhibit stronger antibacterial activity against S. aureus and E. coli . CEO also significantly enhanced the proliferation of L929 fibroblast cell compared with pure biopolymeric aerogels. Such novel bioaerogel scaffolds generated from wastes materials have promising potentials in several biomedical applications such as skin regeneration and wound healing. • Nanocellulose from oil palm empty fruit bunch was used to synthesize high porosity bioaerogels scaffolds. • Pure CNF aerogel had the highest porosity, water absorption and surface area. • Chitosan enhanced the mechanical properties of CNF aerogels in addition to reducing its water uptake. • Loading cinnamon essential oil into the aerogel makes it exhibit stronger antibacterial activity and enhanced biocompatibility