title: Coating cortical bone allografts with periosteum-mimetic scaffolds made of chitosan, trimethyl chitosan, and heparin.
abstract: Bone allografts have very limited healing leading to high rates of failure from non-union, fracture, and infection. The limited healing of bone allografts is due in large part to devitalization and removal of the periosteum, which removes osteogenic cells and osteoinductive signals. Here we report techniques for directly coating cortical bone with tissue scaffolds, and evaluate the scaffolds' capacity to support osteoprogenitor cells. Three types of coatings are investigated: N,N,N-trimethyl chitosan-heparin polyelectrolyte multilayers, freeze-dried porous chitosan foam coatings, and electrospun chitosan nanofibers. The freeze-dried and electrospun scaffolds are also further modified with polyelectrolyte multilayers. All of the scaffolds are durable to subsequent aqueous processing, and are cytocompatible with adipose-derived stem cells. Alkaline phosphatase and receptor activator of nuclear factor kappa-B ligand expression at days 7 and 21 suggest that these scaffolds support an osteoprogenitor phenotype. These scaffolds could serve as periosteum mimics, deliver osteoprogenitor cells, and improve bone allograft healing.
authors.affiliation: School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Raimundo
authors.initials: R
authors.lastname: Romero
authors.affiliation: Department of Clinical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Chubb
authors.affiliation: Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: John K
authors.initials: JK
authors.lastname: Travers
authors.affiliation: Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Gonzales
authors.affiliation: School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA; Department of Clinical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Nicole P
authors.initials: NP
authors.lastname: Ehrhart
authors.affiliation: School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA; Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO 80523, USA. Electronic address: Matthew.kipper@colostate.edu.
authors.forename: Matt J
authors.initials: MJ
authors.lastname: Kipper
mesh_terms: D064591:Allografts / Q000737:chemistry*; D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry / Q000494:pharmacology; D048271:Chitosan / Q000737:chemistry*; D005269:Femur / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006493:Heparin / Q000737:chemistry*; D006811:Humerus / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D010521:Periosteum; D013499:Surface Properties; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: C118071:N-trimethyl chitosan chloride; D006493:Heparin; D048271:Chitosan
keywords: Adipose-derived stem cell; Bone allograft; Bone tissue engineering; Chitosan; Heparin; Periosteum