Three-dimensional bio-printing and bone tissue engineering: technical innovations and potential applications in maxillofacial reconstructive surgery

Background Bone grafting has been considered the gold standard for hard tissue reconstructive surgery and is widely used for large mandibular defect reconstruction. However, the midface encompasses delicate structures that are surrounded by a complex bone architecture, which makes bone grafting using traditional methods very challenging. Three-dimensional (3D) bioprinting is a developing technology that is derived from the evolution of additive manufacturing. It enables precise development of a scaffold from different available biomaterials that mimic the shape, size, and dimension of a defect without relying only on the surgeon’s skills and capabilities, and subsequently, may enhance surgical outcomes and, in turn, patient satisfaction and quality of life. Review This review summarizes different biomaterial classes that can be used in 3D bioprinters as bioinks to fabricate bone scaffolds, including polymers, bioceramics, and composites. It also describes the advantages and limitations of the three currently used 3D bioprinting technologies: inkjet bioprinting, micro-extrusion, and laser-assisted bioprinting. Conclusions Although 3D bioprinting technology is still in its infancy and requires further development and optimization both in biomaterials and techniques, it offers great promise and potential for facial reconstruction with improved outcome

Multicomponent polysaccharide alginate-based bioinks

3D-Bioprinting has seen a rapid expansion in the last few years, with an increasing number of reported bioinks. Alginate is a natural biopolymer that forms hydrogels by ionic cross-linking with calcium ions. Due to its biocompatibility and ease of gelation, it is an ideal ingredient for bioinks. This review focuses on recent advances on bioink formulations based on the combination of alginate with other polysaccharides. In particular, the molecular weight of the alginate and its loading level has an impact on materials performance, as well as the loading of the divalent metal salt and its solubility, which affects the cross-linking of the gel. Alginate is often combined with other polysaccharides that can sigificantly modify the properties of the gel, and can optimise alginate for use in different biological applications. It is also possible to combine alginate with sacrificial polymers, which can temporarily reinforce the 3D printed construct, but then be removed at a later stage. Other additives can be formulated into the gels to enhance performance, including nanomaterials that tune rheological properties, peptides to encourage cell adhesion, or growth factors to direct stem cell differentiation. The ease of formulating multiple components into alginate gels gives them considerable potential for further development. In summary, this review will facilitate the identification of different alginate-polysaccharide bioink formulations and their optimal applications, and help inform the design of second generation bioinks, allowing this relatively simple gel system to achieve more sophisticated control over biological processes

Leveraging Advancements in Tissue Engineering for Bioprinting Dental Tissues

3D bioprinting allows biocompatible materials and cells to be deposited in precise locations in three-dimensional space, enabling researchers to surpass the limitations of traditional 2D cell culture and to create innovative therapies. 3D bioprinting is one of the newest tools developed in the field of tissue engineering, which has traditionally utilized a paradigm revolving around scaffolds, cells, and signals. In this review, we discuss how new developments in each of these three research areas relates to bioprinting dental tissues – specifically teeth, periodontal ligament, and alveolar bone. Important considerations include how scaffold materials and geometry affect regeneration of dental tissues, the importance of using dental cells in these applications, and the role of signaling molecules for creating a clinically relevant bioengineered dental implant. We conclude with potential new directions for research that would allow the burgeoning field of regenerative dentistry to achieve its lofty goals