Biomimetic 3D Printing of Hierarchical and Interconnected Porous Hydroxyapatite Structures with High Mechanical Strength for Bone Cell Culture

Abstract

Human bone demonstrates superior mechanical properties due to its sophisticated hierarchical architecture spanning from the nano/microscopic level to the macroscopic. Bone grafts are in high demand due to the rising number of surgeries because of increasing incidence of orthopedic disorders, non‐union fractures, and injuries in the geriatric population. The bone scaffolds need to provide porous matrix with interconnected porosity for tissue growth as well as sufficient strength to withstand physiological loads, and be compatible with physiological remodeling by osteoclasts/osteoblasts. The‐state‐of‐art additive manufacturing (AM) technologies for bone tissue engineering enable the manipulation of gross geometries, for example, they rely on the gaps between printed materials to create interconnected pores in 3D scaffolds. Herein, the authors firstly print hierarchical and porous hydroxyapatite (HAP) structures with interconnected pores to mimic human bones from microscopic (below 10 µm) to macroscopic (submillimeter to millimeter level) by combining freeze casting and extrusion‐based 3D printing. The compression test of 3D printed scaffold demonstrates superior compressive stress (22 MPa) and strain (4.4%). The human mesenchymal stromal cells (MSCs) tests demonstrate the biocompatibility of printed scaffold.

3D-Printed Poly(ε-Caprolactone)/Hydroxyapatite Scaffolds Modified with Alkaline Hydrolysis Enhance Osteogenesis In Vitro

“…Additionally, 3D printing technology based on an additive manufacturing process can design and fabricate the internal structure of the scaffolds. This can greatly contribute to the production of highly interconnected porous scaffolds [ 8 ]. In particular, fused deposition modeling (FDM) 3D printers that utilize thermoplastic polymers present advantages, such as low price, fast production speed, and versatility of printing materials, and they are frequently used for tissue engineering research [ 9 ].…”

Direct Cryo Writing of Aerogels via 3D Printing of Aligned Cellulose Nanocrystals Inspired by the Plant Cell Wall

“…In this study, inspired by the plant cell wall structure, aerogels were prepared from aqueous mixtures of relatively low concentrations of CNCs (4 wt%) and XG using 3D printing via DCW to align the CNCs at cryogenic temperatures. Song et al recently published the DCW of hydroxyapatite aqueous mixtures (above 60 wt%) for a bone cell culture by printing on a cold stage whose temperature was continually lowered throughout the process [53]. Here, we explore the combination of freeze casting and 3D printing for systems containing a relatively low concentration of cellulose nanocrystals while the freezing process is conducted with a feedback-based temperature control.…”

Emerging trend in manufacturing of 3D biomedical components using selective laser sintering: A review

“…The compressive strength that the material has is anisotropic, a property that bears similarity to human bones. 3D printed hydroxyapatite has structural properties that allow it to bear load and have a high strain [36,37]. II) Hyperelastic bone -Hyperelastic bone is a 3D printing material, that is primarily composed of bone mineral or hydroxyapatite, along with a biocompatible material like polyglycolic acid [39,39].…”

“…---------- [24] 109±1 MPa -------------- [25] PA 2200 64.13 MPa -------------- [27] 48.1 MPa 0.93 g/cm 3 ---------- [29] Polyamide/ Hydroxyapatite Compressive Strength : 22 MPa --------------- [36]…”