Trends in Biotechnology
Rapid prototyping in tissue engineering: challenges and potential
Section snippets
Conventional scaffold fabrication methods
Conventional methods for manufacturing scaffolds include solvent casting and particulate leaching [6], gas foaming [7], fiber meshes and fiber bonding [8], phase separation [9], melt molding [10], emulsion freeze drying [11], solution casting and freeze drying [12]. However, there are inherent limitations in these processing methods, which offer little capability precisely to control pore size, pore geometry, pore interconnectivity, spatial distribution of pores and construction of internal
Advanced scaffold-fabrication methods
RP is a common name for a group of techniques that can generate a physical model directly from computer-aided design data. It is an additive process in which each part is constructed in a layer-by-layer manner. Table 1 presents and compares the RP techniques that can be used to fabricate scaffolds directly or indirectly.
Challenges of RP in tissue engineering
In spite of the increasing interest of tissue engineers in the use of RP, there are several challenges that need to be addressed, namely the limited range of materials, the optimal scaffold design, the bioactivity of the scaffold, as well as the issues of cell seeding and vascularization. Each of the issues will be discussed in detail.
Bioactivity of RP-fabricated scaffolds
The interaction of cells with the scaffold is governed by both structural and chemical signaling molecules that have a decisive role for cell adhesion and the further behavior of cells after initial contact [62].
The extent of initial cell adhesion decides the number, size, shape and distribution of focal adhesion plaques formed on the cell membrane, which subsequently describes the size and shape of the cell-spreading area. The extent of spreading is crucial for further migratory, proliferation
New development: automation and direct organ fabrication
Automated design, development and characterization: RP has the potential of automating the design and fabrication of patient-specific scaffolds. In the work of Cheah et al. [72], computer-aided design (CAD) data manipulation techniques were utilized to develop a program algorithm that can be used to design scaffold internal architectures from a selection of open-celled polyhedral shapes. The automated scaffold assembly algorithm can be interfaced with various RP technologies, to achieve
Conclusion
The emergence of various different approaches in tissue engineering, ranging from a scaffold-based approach to scaffold-free layer-by-layer manufacturing technique, has highlighted the fact that the field of tissue engineering is still growing. Looking towards the future, RP technologies hold great potential in the context of scaffold fabrication. This technology enables the tissue engineer to have full control over the design, fabrication and modeling of the scaffold being constructed,
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