Methods of producing three dimensional electrospun scaffolds for bone tissue engineering: A review

Manufacturing 3D Biomimetic Tissue: A Strategy Involving the Integration of Electrospun Nanofibers with a 3D-Printed Framework for Enhanced Tissue Regeneration

3D printing and electrospinning are versatile techniques employed to produce 3D structures, such as scaffolds and ultrathin fibers, facilitating the creation of a cellular microenvironment in vitro. These two approaches operate on distinct working principles and utilize different polymeric materials to generate the desired structure. This review provides an extensive overview of these techniques and their potential roles in biomedical applications. Despite their potential role in fabricating complex structures, each technique has its own limitations. Electrospun fibers may have ambiguous geometry, while 3D-printed constructs may exhibit poor resolution with limited mechanical complexity. Consequently, the integration of electrospinning and 3D-printing methods may be explored to maximize the benefits and overcome the individual limitations of these techniques. This review highlights recent advancements in combined techniques for generating structures with controlled porosities on the micro-nano scale, leading to improved mechanical structural integrity. Collectively, these techniques also allow the fabrication of nature-inspired structures, contributing to a paradigm shift in research and technology. Finally, the review concludes by examining the advantages, disadvantages, and future outlooks of existing technologies in addressing challenges and exploring potential opportunities.

Recent Advancements in Bone Tissue Engineering: Integrating Smart Scaffold Technologies and Bio-Responsive Systems for Enhanced Regeneration

In exploring the challenges of bone repair and regeneration, this review evaluates the potential of bone tissue engineering (BTE) as a viable alternative to traditional methods, such as autografts and allografts. Key developments in biomaterials and scaffold fabrication techniques, such as additive manufacturing and cell and bioactive molecule-laden scaffolds, are discussed, along with the integration of bio-responsive scaffolds, which can respond to physical and chemical stimuli. These advancements collectively aim to mimic the natural microenvironment of bone, thereby enhancing osteogenesis and facilitating the formation of new tissue. Through a comprehensive combination of in vitro and in vivo studies, we scrutinize the biocompatibility, osteoinductivity, and osteoconductivity of these engineered scaffolds, as well as their interactions with critical cellular players in bone healing processes. Findings from scaffold fabrication techniques and bio-responsive scaffolds indicate that incorporating nanostructured materials and bioactive compounds is particularly effective in promoting the recruitment and differentiation of osteoprogenitor cells. The therapeutic potential of these advanced biomaterials in clinical settings is widely recognized and the paper advocates continued research into multi-responsive scaffold systems.

Electroceuticals for Regeneration of Long Nerve Gap Using Biodegradable Conductive Conduits and Implantable Wireless Stimulator

Regeneration of over 10 mm long peripheral nerve defects remains a challenge due to the failure of regeneration by prolonged axotomy and denervation occurring in long-term recovery. Recent studies reveal that conductive conduits and electrical stimulation accelerate the regeneration of long nerve defects. In this study, an electroceutical platform combining a fully biodegradable conductive nerve conduit and a wireless electrical stimulator is proposed to maximize the therapeutic effect on nerve regeneration. Fully biodegradable nerve conduit fabricated using molybdenum (Mo) microparticles and polycaprolactone (PCL) can eliminate the unwanted effects of non-degradable implants, which occupy nerve paths and need to be removed through surgery increasing the risk of complications. The electrical and mechanical properties of Mo/PCL conduits are optimized by controlling the amounts of Mo and tetraglycol lubricant. The dissolution behavior and electrical conductivity of biodegradable nerve conduits in the biomimetic solutions are also evaluated. In in vivo experiments, the integrated strategy of a conductive Mo/PCL conduit with controlled therapeutic electrical stimulation shows accelerated axon regeneration for long sciatic nerve defects in rats compared to the use of the Mo/PCL conduit without stimulation and has a significant therapeutic effect based on the results obtained from the functional recovery test.