# Structural and biological characterization of carbon–graphene biomaterials derived from black liquor with functional properties for bone tissue engineering

## TL;DR

This study explores carbon-based biomaterials for bone tissue engineering, showing that a carbon-graphene scaffold promotes significant bone repair in rats.

## Contribution

A novel carbon-graphene biomaterial derived from black liquor is shown to enhance bone regeneration in vivo.

## Key findings

- The carbon-graphene scaffold (CAG) achieved 89% bone repair in 30 days in rat tibias.
- All tested scaffolds were biocompatible and promoted bone neoformation and vascular channel formation.
- CAG outperformed other carbon-based scaffolds in bone regeneration effectiveness.

## Abstract

Carbon-based biomaterials are promising for the field of tissue bioengineering due to their biocompatibility, high porosity, and physicochemical properties that allow functionalization and combination with other materials. In this study, carbon derived from black liquor was used to develop bone grafts. This carbon matrix (CA) was associated with nanomaterials—graphene, graphene oxide, and nano-graphite (CAG, CAGO, and CANG, respectively)—for potential applications in the repair of orofacial malformations. The scaffolds were evaluated for biocompatibility and their effect on cell viability using mesenchymal stem cells, followed by implantation in 16 male Wistar rats with non-critical bone defects in both tibias. Histological analysis demonstrated that all scaffolds were biocompatible, with defects showing repair, osteoprogenitor cell presence, and vascular channel formation. Histomorphometric assessment of bone neoformation revealed the highest repair potential in the CAG group (89% at 30 days), while the other groups showed similar bone formation: CA = 72%, CAGO = 69%, and CANG = 80%. All scaffolds promoted bone tissue formation, with the carbon-graphene scaffold yielding the greatest percentage of new bone.