title: 3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration.
abstract: Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1-2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing.
authors: Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States; Department of Biomedical Engineering, University of Rochester, 207 Robert B. Goergen Hall, Rochester, NY 14642, United States. Electronic address: jason_inzana@urmc.rochester.edu.
authors: Jason A
authors: JA
authors: Inzana
authors: Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States; Department of Biomedical Engineering, University of Rochester, 207 Robert B. Goergen Hall, Rochester, NY 14642, United States. Electronic address: diana_olvera@urmc.rochester.edu.
authors: Diana
authors: D
authors: Olvera
authors: Kazuo Inamori School of Engineering, Alfred University, 1 Saxon Drive, Alfred, NY 14802, United States. Electronic address: smf13@alfred.edu.
authors: Seth M
authors: SM
authors: Fuller
authors: Kazuo Inamori School of Engineering, Alfred University, 1 Saxon Drive, Alfred, NY 14802, United States; Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Drive - MC 0411, La Jolla, CA 92093-0411, United States. Electronic address: jkelly@eng.ucsd.edu.
authors: James P
authors: JP
authors: Kelly
authors: Kazuo Inamori School of Engineering, Alfred University, 1 Saxon Drive, Alfred, NY 14802, United States; Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Drive - MC 0411, La Jolla, CA 92093-0411, United States. Electronic address: ograeve@ucsd.edu.
authors: Olivia A
authors: OA
authors: Graeve
authors: Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States; Department of Biomedical Engineering, University of Rochester, 207 Robert B. Goergen Hall, Rochester, NY 14642, United States; Department of Orthopaedics, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, United States. Electronic address: edward_schwarz@urmc.rochester.edu.
authors: Edward M
authors: EM
authors: Schwarz
authors: Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States; Department of Biomedical Engineering, University of Rochester, 207 Robert B. Goergen Hall, Rochester, NY 14642, United States; Department of Orthopaedics, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, United States. Electronic address: stephen_kates@urmc.rochester.edu.
authors: Stephen L
authors: SL
authors: Kates
authors: Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, United States; Department of Biomedical Engineering, University of Rochester, 207 Robert B. Goergen Hall, Rochester, NY 14642, United States; Department of Orthopaedics, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, United States. Electronic address: hani_awad@urmc.rochester.edu.
authors: Hani A
authors: HA
authors: Awad
mesh_terms: D000818:Animals; D001861:Bone Regeneration; D002130:Calcium Phosphates / Q000737:chemistry*; D002470:Cell Survival / Q000187:drug effects; D003094:Collagen / Q000737:chemistry*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D066330:Printing, Three-Dimensional; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000009:adverse effects / Q000737:chemistry*; D014783:Viscosity
chemical_list: D002130:Calcium Phosphates; D003094:Collagen; C020243:calcium phosphate
keywords: Bone regeneration; Calcium phosphate scaffold; Collagen; Three dimensional printing; Tissue engineering