title: Digital micromirror device (DMD)-based 3D printing of poly(propylene fumarate) scaffolds.
abstract: Our recent investigations into the 3D printing of poly(propylene fumarate) (PPF), a linear polyester, using a DMD-based system brought us to a resin that used titanium dioxide (TiO2) as an ultraviolet (UV) filter for controlling cure depth. However, this material hindered the 3D printing process due to undesirable lateral or "dark" curing (i.e., in areas not exposed to light from the DMD chip). Well known from its use in sunscreen, another UV filter, oxybenzone, has previously been used in conjunction with TiO2. In this study we hypothesize that combining these two UV filters will result in a synergistic effect that controls cure depth and avoids dark cure. A resin mixture (i.e., polymer, initiator, UV filters) was identified that worked well. The resin was then further characterized through mechanical testing, cure testing, and cytotoxicity testing to investigate its use as a material for bone tissue engineering scaffolds. Results show that the final resin eliminated dark cure as shown through image analysis. Mechanically the new scaffolds proved to be far weaker than those printed from previous resins, with compressive strengths of 7.8 ± 0.5 MPa vs. 36.5 ± 1.6 MPa, respectively. The new scaffolds showed a 90% reduction in elastic modulus and a 74% increase in max strain. These properties may be useful in tissue engineering applications where resorption is required. Initial cytotoxicity evaluation was negative. As hypothesized, the use of TiO2 and oxybenzone showed synergistic effects in the 3D printing of PPF tissue engineering scaffolds.
authors.affiliation: Department of Plastic Surgery, The Ohio State University, Columbus, OH 43210, United States.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Mott
authors.affiliation: Department of Neurological Surgery, Case Western Reserve University, Cleveland, OH 44106, United States.
authors.forename: Mallory
authors.initials: M
authors.lastname: Busso
authors.affiliation: Department of Neurological Surgery, Case Western Reserve University, Cleveland, OH 44106, United States.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Luo
authors.affiliation: Department of Plastic Surgery, The Ohio State University, Columbus, OH 43210, United States.
authors.forename: Courtney
authors.initials: C
authors.lastname: Dolder
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States.
authors.forename: Martha O
authors.initials: MO
authors.lastname: Wang
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States.
authors.forename: John P
authors.initials: JP
authors.lastname: Fisher
authors.affiliation: Department of Plastic Surgery, The Ohio State University, Columbus, OH 43210, United States. Electronic address: david.dean@osumc.edu.
authors.forename: David
authors.initials: D
authors.lastname: Dean
mesh_terms: D000818:Animals; D002460:Cell Line; D005650:Fumarates / Q000737:chemistry*; D008422:Materials Testing; D051379:Mice; D011126:Polypropylenes / Q000737:chemistry*; D066330:Printing, Three-Dimensional; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D005650:Fumarates; D011126:Polypropylenes; C097850:poly(propylene fumarate)
keywords: 3D printing; Bone tissue engineering; Digital micromirror device; Poly(propylene fumarate); Resorbable; UV filter
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