Controlled dissolution of freeform 3D printed carbohydrate glass scaffolds in hydrogels using a hydrophobic spray coating

M. C. Gryka, T. J. Comi, R. A. Forsyth, P. M. Hadley, S. Deb, Rohit Bhargava

Research output: Contribution to journalArticle

Abstract

Freeform 3D printing combined with sacrificial molding promises to lead advances in production of highly complex tubular systems for biomedical applications. Here we leverage a purpose-built isomalt 3D printer to generate complex channel geometries in hydrogels which would be inaccessible with other techniques. To control the dissolution of the scaffold, we propose an enabling technology consisting of an automated nebulizer coating system which applies octadecane to isomalt scaffolds. Octadecane, a saturated hydrocarbon, protects the rigid mold from dissolution and provides ample time for gels to set around the sacrificial structure. With a simplified model of the nebulizer system, the robotic motion was optimized for uniform coating. Using a combination of stimulated Raman scattering (SRS) microscopy and X-ray computed tomography, the coating was characterized to assess surface roughness and consistency. Colorimetric measurements of dissolution rates allowed optimization of sprayer parameters, yielding a decrease in dissolution rates by at least 4 orders of magnitude. High fidelity channels are ensured by surfactant treatment of the coating, which prevents bubbles from clinging to the surface. Spontaneous Raman scattering microspectroscopy and white light microscopy indicate cleared channels are free of octadecane following gentle flushing. The capabilities of the workflow are highlighted with several complex channel architectures including helices, blind channels, and multiple independent channels within polyacrylamide hydrogels of varying stiffnesses.

Original languageEnglish (US)
Pages (from-to)193-201
Number of pages9
JournalAdditive Manufacturing
Volume26
DOIs
StatePublished - Mar 1 2019

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Hydrogels
Carbohydrates
Scaffolds
Dissolution
Glass
Coatings
3D printers
Stimulated Raman scattering
Hydrocarbons
Polyacrylates
Surface-Active Agents
Molding
Optical microscopy
Tomography
Raman scattering
Printing
Microscopic examination
Robotics
Surface active agents
Gels

Keywords

  • Carbohydrate glass
  • Direct-write printing
  • Isomalt
  • Monolithic hydrogel casting
  • Nebulized protective coatings
  • Octadecane

ASJC Scopus subject areas

  • Biomedical Engineering
  • Materials Science(all)
  • Engineering (miscellaneous)
  • Industrial and Manufacturing Engineering

Cite this

Controlled dissolution of freeform 3D printed carbohydrate glass scaffolds in hydrogels using a hydrophobic spray coating. / Gryka, M. C.; Comi, T. J.; Forsyth, R. A.; Hadley, P. M.; Deb, S.; Bhargava, Rohit.

In: Additive Manufacturing, Vol. 26, 01.03.2019, p. 193-201.

Research output: Contribution to journalArticle

Gryka, M. C. ; Comi, T. J. ; Forsyth, R. A. ; Hadley, P. M. ; Deb, S. ; Bhargava, Rohit. / Controlled dissolution of freeform 3D printed carbohydrate glass scaffolds in hydrogels using a hydrophobic spray coating. In: Additive Manufacturing. 2019 ; Vol. 26. pp. 193-201.
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