Bone Tissue Engineering: State of the Art and Future Trends

Abstract

Although several major progresses have been introduced in the field of bone regenerative medicine during the years, current therapies, such as bone grafts, still have many limitations. Moreover, and in spite of the fact that material science technology has resulted in clear improvements in the field of bone substitution medicine, no adequate bone substitute has been developed and hence large bone defects/injuries still represent a major challenge for orthopaedic and reconstructive surgeons. It is in this context that TE has been emerging as a valid approach to the current therapies for bone regeneration/substitution. In contrast to classic biomaterial approach, TE is based on the understanding of tissue formation and regeneration, and aims to induce new functional tissues, rather than just to implant new spare parts. The present review pretends to give an exhaustive overview on all components needed for making bone tissue engineering a successful therapy. It begins by giving the reader a brief background on bone biology, followed by an exhaustive description of all the relevant components on bone TE, going from materials to scaffolds and from cells to tissue engineering strategies, that will lead to "engineered" bone. Scaffolds processed by using a methodology based on extrusion with blowing agents.

Microporous bacterial cellulose as a potential scaffold for bone regeneration

“…Another graft option is synthetics, like metals and ceramics, which have been used primarily in hip implants [3]. Their limitations are that they do not provide optimal mechanical properties, they exhibit poor overall osseointegration [3], and they eventually fail due to infection or fatigue loading [4,5]. Together these findings underscore the major clinical need for new bone grafting materials.…”

“…Together these findings underscore the major clinical need for new bone grafting materials. Indeed, one million cases per year require bone-graft procedures [5] which makes bone the second most transplanted tissue after blood. Due to a lack of available tissue, efforts have been underway for the past decade to construct alternative materials that can be readily processed into larger, complex structures and can guide the body's own repair mechanism.…”

“…These materials -derived from synthetic or natural starting materials -have different properties and exhibit different degradation rates. Ceramics such as coralline hydroxyapatite have been used as bone substitutes in the regenerative field as they are osteoconductive and osteoinductive [5]. However, their drawbacks are that they are brittle and have low mechanical stability.…”

“…Synthetic polymers are commonly used in the biomedical engineering field and some of their properties such as degradation time can be tailored during the polymer processing. The most widely used are poly(a-hydroxy acids) (such as poly(ecaprolactone), poly(lactic acid), poly(glycolic acid), and their copolymers), poly(carbonates), and poly(anhydrides) [5]. Natural polymers, obtained from animal or vegetal sources, include proteins such as collagen and fibrinogen, and polysaccharides such as chitosan, starch and hyaluronic acid [5].…”

Biomimicry, Biofabrication, and Biohybrid Systems: The Emergence and Evolution of Biological Design

“…[82][83][84][85] Approaches for engineering other types of vascularized tissue, such as bone, kidney, and pancreas, have also met with significant success. [86][87][88] Many others have cataloged the progress of tissue engineering and the advances in manufacturing technologies and novel materials that have rendered possible medical applications of biofabrication. [88][89][90][91] Rather than replicating these reviews, we will devote the next section to a discussion on how the reverse engineering of microscale and macroscale biological structures has contributed to a greater understanding of adaptive response in natural systems.…”