Design variables for mechanical properties of bone tissue scaffolds

Daniel Howk, T.M. Gabriel Chu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The reconstruction of segmental defect in long bone is a clinical challenge. Multiple surgeries are typically required to restore the structure and function of the affected defect site. In order to overcome this defect a biodegradable bone tissue engineering scaffold is used. This scaffold acts as a carrier of proteins and growth factors, while also supporting the load that the bone would normally sustain, until the natural bone can regenerate in its place. Work was done to optimize an existing solid free-form scaffold design. The goal of the optimization was to increase the porosity of the scaffold while maintaining the strength of a previously-tested prototype design. With this in mind, eight new designs were created. These designs were drawn using CAD software and then through the use of finite element analysis the theoretical ultimate compressive strength of each design was obtained. Each scaffold design was constructed by casting a thermal-curable poly(propylene fumarate)/tricalcium phosphate (PPF/TCP) suspension into wax molds fabricated on inkjet printing rapid prototyping machine. The constructs were then experimentally tested by applying a uniaxial compressive load. The theoretical and experimental values of ultimate compressive strength and specific strength of each design were compared. Theoretically, the best scaffold design produced from this work improved upon the current design by increasing the porosity by 46% and also increasing the ultimate compressive strength by 27%. The experimental data was found to match the theoretical strength in four designs, but deviate from the theoretical strength in five designs. The reasons for the deviations and their relation to the rapid prototyping manufacturing technique were discussed. The results of this work show that it is possible to increase the porosity and strength of a bone tissue engineering scaffold through simple iterations in architectural design.

Original languageEnglish
Title of host publicationTechnical Papers of ISA
Pages278-283
Number of pages6
Volume464
StatePublished - 2006
Event43rd Annual Rocky Mountain Bioengineering Symposium and 43rd International ISA Biomedical Sciences Instrumentation Symposium - Terre Haute, IN, United States
Duration: Apr 7 2006Apr 9 2006

Other

Other43rd Annual Rocky Mountain Bioengineering Symposium and 43rd International ISA Biomedical Sciences Instrumentation Symposium
CountryUnited States
CityTerre Haute, IN
Period4/7/064/9/06

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Keywords

  • Biodegradable scaffold
  • Finite element analysis
  • Rapid prototyping
  • Segmental defect
  • Specific strength
  • Uniaxial compression

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering
  • Computer Science Applications

Cite this

Howk, D., & Chu, T. M. G. (2006). Design variables for mechanical properties of bone tissue scaffolds. In Technical Papers of ISA (Vol. 464, pp. 278-283)