Synthetic and Marine-Derived Porous Scaffolds for Bone Tissue Engineering

Abstract

Bone is a vascularized and connective tissue. The cortical bone is the main part responsible for the support and protection of the remaining systems and organs of the body. The trabecular spongy bone serves as the storage of ions and bone marrow. As a dynamic tissue, bone is in a constant remodelling process to adapt to the mechanical demands and to repair small lesions that may occur. Nevertheless, due to the increased incidence of bone disorders, the need for bone grafts has been growing over the past decades and the development of an ideal bone graft with optimal properties remains a clinical challenge. This review addresses the bone properties (morphology, composition, and their repair and regeneration capacity) and puts the focus on the potential strategies for developing bone repair and regeneration materials. It describes the requirements for designing a suitable scaffold material, types of materials (polymers, ceramics, and composites), and techniques to obtain the porous structures (additive manufacturing techniques like robocasting or derived from marine skeletons) for bone tissue engineering applications. Overall, the main objective of this review is to gather the knowledge on the materials and methods used for the production of scaffolds for bone tissue engineering and to highlight the potential of natural porous structures such as marine skeletons as promising alternative bone graft substitute materials without any further mineralogical changes, or after partial or total transformation into calcium phosphate.

Comparative Efficacy of Commonly Available Human Bone Graft Substitutes as Tested for Posterolateral Fusion in an Athymic Rat Model

“…Some materials were downsized to fit the animal; however, the ''ideal'' particle size for rats is unknown. Fusion rates show dependency on particle size (unpublished pilot studies 78 ). Histology showed residual acellular graft, likely oversized, in some nonfusing materials.…”

Regeneration of segmental defects in metatarsus of sheep with vascularized and customized 3D-printed calcium phosphate scaffolds

“…They are made at high sintering temperatures and are generally used as granules or porous blocks. Although these bioceramics share some compositional similarities with bone minerals, the conventional processes employed to manufacture them limit the possibilities to tune their pore architecture, often lacking interconnections and hindering their osteogenic potential to support healing of large bone defects [11][12][13][14] . Recently, biomimetic calcium phosphates consisting of calcium-deficient hydroxyapatite (CDHA) that can be manufactured at ambient temperature have been developed and have shown to have enhanced surface area and promote osteogenic differentiation and bone healing compared to their sintered counterparts 15,16 .…”

Review on calcium‐ and magnesium‐based silicates for bone tissue engineering applications

“…About 80% of bone in the human body is comprised of strong, dense, and robust cortical bone while 20% of it is made with spongy and mechanically weak trabecular bone. An osteonal architectural pattern of cortical bone made it stronger than cancellous bone under compression (Baron, ; Cowin, ; Gong et al, ; Neto & Ferreira, ; Osterhoff et al, ). Since the musculoskeletal locomotion, support, and protection to the internal organs depend on the mechanical strength and elasticity of the bone, the biomaterial for tissue engineering applications should meet the need of mechanical parameters associated with both types of bone through resorption and regeneration (Liao et al, ).…”