A new hybrid scaffold using rapid prototyping and electrohydrodynamic direct writing for bone tissue regeneration

Fiber-based tissue engineering: Progress, challenges, and opportunities

“…This means that a continuous fiber is formed as it is written (printed) on a substrate creating a porous structure. Direct writing techniques are time consuming, but it is feasible to create complex 3D scaffolds by stacking multiple 2D layers for various tissue engineering applications such as bone (Kim et al, 2011, Landers, Pfister, 2002, Lee, Park, 2011b), cartilage (Neves, Moreira Teixeira, 2011), and heart tissue engineering (Berry et al, 2011, Gaetani et al, 2012). In addition, various materials including natural and synthetic polymers can be used for writing (Fedorovich, Moroni, 2010).…”

“…The L-PLA scaffold offered the lowest degradation rate among the studied materials. Kim et al used direct writing and a repetition of writing and electrospinning to form PCL scaffolds for bone tissue engineering (Kim, Ahn, 2011). The scaffolds fabricated by direct writing method showed a higher mechanical strength compared to those produced by repetition of writing and elecrospinning.…”

Combined additive manufacturing approaches in tissue engineering

“…Hierarchical 3D structures were obtained by alternating layers of PCL microsized melt plotted struts and highly roughened microsized treads (Table II.b). A significant increment of cell viability and bone mineralization compared to bare AM scaffolds (~2 and 2.5-fold increase, respectively) was registered after in vitro cell culture in combination with osteoblast-like cells [63]. As a further advancement, the authors further optimized the EHD process, using an ethanol bath as the target medium.…”

“…Osteochondral TE source: [50] *All example figures are reprinted with permission from the respective publishers (indicated in the source) Bone, cartilage, muscle, annulus fibrosus repair and vascular grafts source: [56] b AM (melt-plotter) and Electrohydrodynamic processes (e.g. electrohydrodynamic direct writing, EHD) [63,64]  The highly roughened microsized threads provide large cell-anchorage area  Applicable to a limited set of biomaterials AM compartment: PCL Microsized threads: PCL Type-I collagen biomimetic coating [64] Bone source: [63] c AM (screw extrusion system) and…”

Finite element modelling of bone tissue scaffolds

“…However, CAD-based scaffold fabrication with rapid prototyping shows low resolution of struts and very smooth struts, the latter being counter-benefi cial for initial cell adhesion. Nevertheless, despite possible solutions to such an issue having been proposed in the recent literature (Kim et al , 2011), the appearance of plenty of highly controllable novel techniques in the literature (see e.g., the review of Karageorgiou and Kaplan, 2005) has therefore defi nitely confi ned CAD usage strictly to the reconstruction of the acquired scaffold geometries .…”