title: Improving PEEK bioactivity for craniofacial reconstruction using a 3D printed scaffold embedded with mesenchymal stem cells.
abstract: Polyetheretherketone (PEEK) is a bioinert thermoplastic that has been investigated for its potential use in craniofacial reconstruction; however, its use in clinical practice is limited by a poor integration with adjacent bone upon implantation. To improve the bone-implant interface, two strategies have been employed: to modify its surface or to impregnate PEEK with bioactive materials. This study attempts to combine and improve upon the two approaches by modifying the internal structure into a trabecular network and to impregnate PEEK with mesenchymal stem cells. Furthermore, we compare the newly designed PEEK scaffolds' interactions with both bone-derived (BMSC) and adipose (ADSC) stem cells.
  
  
  
  Customized PEEK scaffolds were designed to incorporate a trabecular microstructure using a computer-aided design program and then printed via selective laser sintering (SLS), a 3D-printing process with exceptional accuracy. The scaffold structure was evaluated using microCT. Scanning electron microscopy (SEM) was used to evaluate scaffold morphology with and without mesenchymal stem cells (MSCs). Adipose and bone marrow mesenchymal cells were isolated from rats and cultured on scaffolds. Cell proliferation and differentiation were assessed using alamarBlue and alkaline phosphatase assays, respectively. Cell morphology after one week of co-culturing cells with PEEK scaffolds was evaluated using SEM.
  
  
  
  SLS 3D printing fabricated scaffolds with a porosity of 36.38% ± 6.66 and density of 1.309 g/cm(2). Cell morphology resembled viable fibroblasts attaching to the surface and micropores of the scaffold. PEEK scaffolds maintained the viability of both ADSCs and BMSCs; however, ADSCs demonstrated higher osteodifferentiation than BMSCs (p < 0.05).
  
  
  
  This study demonstrates for the first time that SLS 3D printing can be used to fabricate customized porous PEEK scaffolds that maintain the viability of adipose and bone marrow-derived MSCs and induce the osteodifferentiation of the adipose-derived MSCs. The combination of 3D printed PEEK scaffolds with MSCs could overcome some of the limitations using PEEK biopolymers for load-bearing bone regeneration in craniofacial reconstruction.
authors.affiliation: Department of Otolaryngology - Head & Neck Surgery, McGill University, Montreal, QC, Canada Craniofacial Stem Cell and Tissue Engineering Laboratory, McGill University, Montreal, QC, CA.
authors.forename: Michael
authors.initials: M
authors.lastname: Roskies
authors.affiliation: Craniofacial Stem Cell and Tissue Engineering Laboratory, McGill University, Montreal, QC, CA.
authors.forename: Jack O
authors.initials: JO
authors.lastname: Jordan
authors.affiliation: Craniofacial Stem Cell and Tissue Engineering Laboratory, McGill University, Montreal, QC, CA.
authors.forename: Dongdong
authors.initials: D
authors.lastname: Fang
authors.affiliation: Faculty of Dentistry, McGill University, Montreal, QC, Canada.
authors.forename: Mohamed-Nur
authors.initials: MN
authors.lastname: Abdallah
authors.affiliation: Department of Otolaryngology - Head & Neck Surgery, McGill University, Montreal, QC, Canada.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Hier
authors.affiliation: Department of Otolaryngology - Head & Neck Surgery, McGill University, Montreal, QC, Canada.
authors.forename: Alex
authors.initials: A
authors.lastname: Mlynarek
authors.affiliation: Faculty of Dentistry, McGill University, Montreal, QC, Canada.
authors.forename: Faleh
authors.initials: F
authors.lastname: Tamimi
authors.affiliation: Craniofacial Stem Cell and Tissue Engineering Laboratory, McGill University, Montreal, QC, CA Faculty of Dentistry, McGill University, Montreal, QC, Canada simon.tran@mcgill.ca.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Tran
mesh_terms: D000818:Animals; D001577:Benzophenones; D001861:Bone Regeneration / Q000502:physiology; D018786:Bone Substitutes / Q000138:chemical synthesis; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D017076:Computer-Aided Design; D019465:Craniofacial Abnormalities / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007659:Ketones / Q000737:chemistry*; D045164:Mesenchymal Stem Cell Transplantation / Q000295:instrumentation*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers; D066330:Printing, Three-Dimensional; D017755:Prosthesis Fitting / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D023822:Tissue Engineering / Q000295:instrumentation*; D054457:Tissue Scaffolds
chemical_list: D001577:Benzophenones; D018786:Bone Substitutes; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols
keywords: PEEK; Tissue engineering; bone regeneration; craniofacial reconstruction; selective laser sintering; stem cells