Bone tissue engineering scaffolding: computer-aided scaffolding techniques

Abstract

Tissue engineering is essentially a technique for imitating nature. Natural tissues consist of three components: cells, signalling systems (e.g. growth factors) and extracellular matrix (ECM). The ECM forms a scaffold for its cells. Hence, the engineered tissue construct is an artificial scaffold populated with living cells and signalling molecules. A huge effort has been invested in bone tissue engineering, in which a highly porous scaffold plays a critical role in guiding bone and vascular tissue growth and regeneration in three dimensions. In the last two decades, numerous scaffolding techniques have been developed to fabricate highly interconnective, porous scaffolds for bone tissue engineering applications. This review provides an update on the progress of foaming technology of biomaterials, with a special attention being focused on computer-aided manufacturing (Andrade et al. 2002) techniques. This article starts with a brief introduction of tissue engineering (Bone tissue engineering and scaffolds) and scaffolding materials (Biomaterials used in bone tissue engineering). After a brief reviews on conventional scaffolding techniques (Conventional scaffolding techniques), a number of CAM techniques are reviewed in great detail. For each technique, the structure and mechanical integrity of fabricated scaffolds are discussed in detail. Finally, the advantaged and disadvantage of these techniques are compared (Comparison of scaffolding techniques) and summarised (Summary).

Withdrawal: Synthesis of a Novel bFGF/nHAP/COL Bone Tissue Engineering Scaffold for Mandibular Defect Regeneration in a Rabbit Model

“…Porosity, swelling capacity, water absorption, compressive strength and compressive modulus analysis indicated that the physical properties of the scaff old met the basic requirements for use in tissue engineering [30][31][32][33] (Tables 1 and 2). One hour after the start of the experiment, the pH was approximately 7.0.…”

“…In general, an engineered tissue consists of a scaffold, cells, and essential growth factors [6][7][8] . Scaffolds with high porosity promote bone regeneration and vascularization 9) . therefore, the selection of materials and construction of scaff olds are very important considerations.…”

Fabrication of a composite of nanocrystalline carbonated hydroxyapatite (cHAP) with polylactic acid (PLA) and its surface topographical structuring with direct laser writing (DLW)

“…Therefore, various bioceramic-polymer composites for bone-grafting material were prepared and relationship between material structure and properties has been studied. [18][19][20] Among synthetic polymers used in bone tissue engineering the polylactic acid (PLA) is probably the most widely investigated biodegradable and bioresorbable polyester. 21 The degradation of bioceramic-polymer composite in a biological environment is a complex process and often is surface determined.…”

“…Over the years different technologies have been used for topographical structuring to alter the roughness, surface energy/charge/area, and enhance the cells adhesion, morphology, differentiation, proliferation and osteoconductivity. 18,[22][23][24][25][26][27] Surface of biomaterials can be altered both chemically and physically. In recent decades among physical methods direct laser writing (DLW) gained a lot of attention due to its capability to be used as a versatile tool producing topographical micro-and nanostructures 25,31,32 .…”

3D bioprinting technology for regenerative medicine applications

“…However, tissue engineered scaffolds do not completely mimic the native architecture of the tissues, have difficulties to support the growth of cells in 3D and have problems to deposit different cell types in the scaffolds at specified locations [8,9,11,12] . Besides, many of these fabrication methods involve the use of organic solvents which impair the cellular growth [13] . Further, tissue engineered scaffolds do not completely fulfill all the ideal requirements needed for tissue regeneration as discussed above.…”