Graphene oxide produced from spent coffee grounds in electrospun cellulose acetate scaffolds for tissue engineering applications

Abstract

Biomaterials are widely used in the field of tissue engineering as coatings, scaffolds, or injectables. Since these materials need to be compatible with the biological conditions of the human body, improving the sources and methods of production for biomaterials call for continuous innovation. In this study, fibers were electrospun from cellulose acetate (CA) polymer solution using graphene oxide (GO) as a filler, for bone tissue engineering applications. The GO was synthesized from spent coffee grounds, a carbonaceous source that is discarded abundantly. A non-energy-intensive methodology was used for the production. CA with 5 wt% of GO nanoparticles was dissolved in a dimethylacetamide and acetone solvent mixture to produce the polymer solution. The nanofibrous scaffolds were tested for their morphological and mechanical properties as well as their biocompatibility. Scanning electron microscopy (SEM) results showed that electrospinning produced smooth nanofibers with very few beads. Fiber diameters decreased with the addition of GO nanoparticles. Mechanical testing showed that modified CA scaffolds exhibited an improved tensile strength of 115.75 kPa on average compared to the pristine ones. In addition, a cell culture study revealed that using graphene oxide as a modifier of the matrix is non-toxic and promoted cell growth. The oxygen-rich and hydrophilic nature of GO played a role in the biocompatibility of the produced fibers. In general, this study showed that agro-residual biomass can be used to produce and modify biomaterials. This aspect contributes to research on sustainable bio-composites and the effort in environmental conservation.