State of the Art Technology of Electroactive and Conductive Scaffolds for Bone Tissue Engineering

The promising outcome of Bone Tissue Engineering (BTE) via scaffolds for treating segmental bone defects (SBDs) has led the interdisciplinary field of Materials Science to take a new turn and explore innovative biomaterials that enhance tissue regeneration. The most recent advancement is the application of electrical stimulation with the use of conductive and piezoelectric biomaterials to develop conductive and electroactive (EA) scaffolds that activate osteoblast formation, leading to a significantly faster and more robust bone healing process. Researchers have explored plenty of biomaterials and scaffold fabrication techniques. This article presents a comprehensive review of the popular biomaterials that include Conductive Polymers (PANI, Poly-pyrrole, PEDOT), Piezoelectric Polymers (PVDF, TrFE, PLLA, PAs), Metallic Nanoparticles (NPs) (Ag, TiO₂), and Carbon-based NPs (CNTs, Graphene, Graphene Oxide) used for the development of conductive and EA biocompatible scaffolds. Various innovative conductive and electroactive scaffold fabricating methods, like 3D printing, bio-printing, electrospinning, etc., that precisely command over the conductive filler distribution, porosity, and pore size interconnectivity are highlighted. Tests explored by researchers for investigating the conductive and piezoelectric properties of the developed scaffolds and their osteogenic potential (in vitro and in vivo) are also presented. Apart from this, standard protocols for the conduction of these tests, regulatory pathways, scope for clinical translations, and their respective challenges have been reviewed. Most importantly, the review not only focuses on the material versatility and fabrication techniques but also critically analyzes the challenges involved in optimizing the biomaterials and fabrication parameters to develop bone scaffolds with the best-optimized physicochemical, mechanical, biological, and conductive properties.