A detailed guide to melt electro-writing for tissue engineering applications

Melt electro-writing (MEW) is an advanced 3D printing technique with significant potential in tissue engineering due to its ability to create highly precise microscale structures using biocompatible materials. This review provides a comprehensive guide to the principles, process parameters, and recent advancements in MEW technology, with a specific focus on its applications in tissue engineering. We explore the core mechanisms behind MEW, including the influence of material selection, nozzle temperature, voltage, and feed rate on scaffold architecture. The review examines both computational and experimental modelling of process parameters and their impact on resolution capabilities, including pore size, thickness, and achievable diameters, alongside their effects on cellular behaviour such as adhesion, proliferation, and differentiation. We also discuss the fabrication of custom MEW devices, the integration of machine learning, and the use of automated design tools to enhance scaffold precision and customization. Furthermore, we address key challenges limiting the widespread adoption of MEW, such as the high cost of commercially available devices and the complexity of building custom machines, while offering strategies to overcome these barriers. Recent<i>in vitro</i>and<i>in vivo</i>studies are discussed, demonstrating the promising potential of MEW in tissue regeneration, particularly in bone, cartilage, and soft tissue engineering. This review aims to serve as a valuable resource for researchers and practitioners working in the field of tissue engineering, offering insights into the capabilities, challenges, and future directions of MEW in advancing regenerative medicine.