An innovative cell-laden α-TCP/collagen scaffold fabricated using a two-step printing process for potential application in regenerating hard tissues

Abstract

Cell-laden scaffolds are widely investigated in tissue engineering because they can provide homogenous cell distribution after long culture periods, and deposit multiple types of cells into a designed region. However, producing a bioceramic 3D cell-laden scaffold is difficult because of the low processability of cell-loaded bioceramics. Therefore, designing a 3D bioceramic cell-laden scaffold is important for ceramic-based tissue regeneration. Here, we propose a new strategy to fabricate an alpha-tricalcium-phosphate (α-TCP)/collagen cell-laden scaffold, using preosteoblasts (MC3T3-E1), in which the volume fraction of the ceramic exceeded 70% and was fabricated using a two-step printing process. To fabricate a multi-layered cell-laden scaffold, we manipulated processing parameters, such as the diameter of the printing nozzle, pneumatic pressure, and volume fraction of α-TCP, to attain a stable processing region. A cell-laden pure collagen scaffold and an α-TCP/collagen scaffold loaded with cells via a simple dipping method were used as controls. Their pore geometry was similar to that of the experimental scaffold. Physical properties and bioactivities showed that the designed scaffold demonstrated significantly higher cellular activities, including metabolic activity and mineralization, compared with those of the controls. Our results indicate that the proposed cell-laden ceramic scaffold can potentially be used for bone regeneration.

Accelerated hardening of nanotextured 3D-plotted self-setting calcium phosphate inks

“…[11,16,25,26] Recently, the possibility to fabricate low-temperature self-setting inks that do not require the sintering step has been proposed, using formulations based on beta-calcium silicate (-CaSiO 3 ), [20,27] magnesium phosphates [28] or calcium phosphates. [29,30] Most calcium phosphate self-setting inks are based on alpha-tricalcium phosphate (-TCP), which can be combined with different binders, like gelatine, [29] type I collagen [31] hydroxypropyl methylcellulose (HPMC), [32] Polysorbate 80 (Tween 80) and short-chain triglycerides (Miglyol 812), [30,33,34] polyvinyl alcohol [33] and alginic acid. [33] The hardening process of these inks is due to the hydrolysis of -TCP to a calcium deficient hydroxyapatite (CDHA), resulting in nano/micro structured crystals that are much closer to the mineral phase of bone than sintered CaPs.…”

Collagen as Bioink for Bioprinting: A Comprehensive Review

“…Kim et al . [ 29 ] have introduced bioceramic-based cell-printing technique and a cell-laden ceramic structure. Using 3D bioprinting technology, they created a cell-laden scaffold using α-tricalcium phosphate (α-TCP) type I collagen and MC3T3-E1 cells.…”

Advances in three‐dimensional bioprinting of bone: Progress and challenges

“…(Jariwala, Lewis, Bushman, Adair, & Donahue, ; Müller, Becher, Schnabelrauch, & Zenobi‐Wong, ; Yang et al, ) Inclusion of bioactive composites/ceramic particles in bioinks as osteopromotive elements (silica, borate, calcium, and phosphate) is another way to promote osteogenesis. These particles (from nanosized to microsized range) act either as nucleation centres for facilitating HA deposition on constructs or by releasing ions that induced stem cell differentiation, a process commonly termed as osteoinduction (Deng et al, ; Gao et al, ; Kim, Yun, & Kim, ; Sithole et al, ; Wenz, Borchers, Tovar, & Kluger, ; Zhai et al, ). Graphene is another material gaining momentum in bone regenerative studies (Hermenean et al, ; Lee et al, ; Lu et al, ; Shadjou & Hasanzadeh, ; Shin et al, ); however, its applicability to 3D bioprinted constructs is not fully explored yet (Wang et al, ; Sayyar, Officer, & Wallace, ; Zhou et al, ).…”