Scaffold Library for Tissue Engineering: A Geometric Evaluation

Nattapon Chantarapanich,Sedthawatt Sucharitpwatskul,Kriskrai Sitthiseripratip,Pongnarin Jeamwatthanachai,Puttisak Puttawibul,Samroeng Inglam

doi:10.1155/2012/407805

Abstract

Tissue engineering scaffold is a biological substitute that aims to restore, to maintain, or to improve tissue functions. Currently available manufacturing technology, that is, additive manufacturing is essentially applied to fabricate the scaffold according to the predefined computer aided design (CAD) model. To develop scaffold CAD libraries, the polyhedrons could be used in the scaffold libraries development. In this present study, one hundred and nineteen polyhedron models were evaluated according to the established criteria. The proposed criteria included considerations on geometry, manufacturing feasibility, and mechanical strength of these polyhedrons. CAD and finite element (FE) method were employed as tools in evaluation. The result of evaluation revealed that the close-cellular scaffold included truncated octahedron, rhombicuboctahedron, and rhombitruncated cuboctahedron. In addition, the suitable polyhedrons for using as open-cellular scaffold libraries included hexahedron, truncated octahedron, truncated hexahedron, cuboctahedron, rhombicuboctahedron, and rhombitruncated cuboctahedron. However, not all pore size to beam thickness ratios (PO : BT) were good for making the open-cellular scaffold. The PO : BT ratio of each library, generating the enclosed pore inside the scaffold, was excluded to avoid the impossibility of material removal after the fabrication. The close-cellular libraries presented the constant porosity which is irrespective to the different pore sizes. The relationship between PO : BT ratio and porosity of open-cellular scaffold libraries was displayed in the form of Logistic Power function. The possibility of merging two different types of libraries to produce the composite structure was geometrically evaluated in terms of the intersection index and was mechanically evaluated by means of FE analysis to observe the stress level. The couples of polyhedrons presenting low intersection index and high stress level were excluded. Good couples for producing the reinforced scaffold were hexahedron-truncated hexahedron and cuboctahedron-rhombitruncated cuboctahedron.

Highlights

Transplantation is a use of biological materials to replace the end state degenerative tissue [1, 2]
The principle of tissue engineering involves the extraction of cells from biopsy and proliferates them in the scaffold which serve as a guide for neotissue formation [14, 15]
The last group contained the polyhedrons having relatively low stress compared to the others, which were hexahedron (P-3), truncated octahedron

Summary

Introduction

Transplantation is a use of biological materials to replace the end state degenerative tissue [1, 2]. An alternative potential way to address these issues is to develop the synthetic biological substitute using concept of tissue engineering which can effectively mimic functions of tissue characteristics. Tissue engineering is a multidiscipline which applies the principles of engineering and sciences to develop the biological substitutes, known as “scaffold”, which restore, maintain, or improve tissue functions [9,10,11,12,13]. The principle of tissue engineering involves the extraction of cells from biopsy and proliferates them in the scaffold which serve as a guide for neotissue formation [14, 15]. Successful scaffold should meet the biological and mechanical requirements to encourage

Results

Discussion

Conclusion