A functionally gradient variational porosity architecture for hollowed scaffolds fabrication

Biofabrication. 2011 Sep;3(3):034106. doi: 10.1088/1758-5082/3/3/034106. Epub 2011 Jul 1.

Abstract

This paper presents a novel continuous tool-path planning methodology for hollowed scaffold fabrication in tissue engineering. A new functionally gradient porous architecture is proposed with a continuous material deposition planning scheme. A controllable variational pore size and hence the porosity have been achieved with a combination of two geometrically oriented consecutive layers. The desired porosity has been achieved with consecutive layers by geometrically partitioning each layer into sub-regions based on the area and the tissue scaffold design constraints. A continuous, interconnected and optimized tool-path for layers has been generated for a three-dimensional biomaterial deposition/printing process. A zigzag pattern tool-path has been proposed for an accumulated sub-region layer, and a concentric spiral-like optimal tool-path pattern has been generated for the successive layer to ensure continuity along the structure. Three-dimensional layers, formed by the proposed tool-path plan, vary the pore size and the porosity based on the biological and mechanical requirements. Several examples demonstrate the proposed methodology along with illustrative results. Also a comparative study between the proposed design and conventional Cartesian coordinate scaffolds has been performed. The results demonstrate a significant reduction in design error with the proposed method. Moreover, sample examples have been fabricated using a micro-nozzle biomaterial deposition system, and characterized for validation.

MeSH terms

  • Alginates / chemistry
  • Biocompatible Materials / chemistry
  • Computer-Aided Design
  • Glucuronic Acid / chemistry
  • Hexuronic Acids / chemistry
  • Humans
  • Hydrogels / chemistry
  • Models, Anatomic
  • Porosity
  • Spine / anatomy & histology
  • Tissue Engineering*
  • Tissue Scaffolds*

Substances

  • Alginates
  • Biocompatible Materials
  • Hexuronic Acids
  • Hydrogels
  • Glucuronic Acid