title: Simple coating with fibronectin fragment enhances stainless steel screw osseointegration in healthy and osteoporotic rats.
abstract: Metal implants are widely used to provide structural support and stability in current surgical treatments for bone fractures, spinal fusions, and joint arthroplasties as well as craniofacial and dental applications. Early implant-bone mechanical fixation is an important requirement for the successful performance of such implants. However, adequate osseointegration has been difficult to achieve especially in challenging disease states like osteoporosis due to reduced bone mass and strength. Here, we present a simple coating strategy based on passive adsorption of FN7-10, a recombinant fragment of human fibronectin encompassing the major cell adhesive, integrin-binding site, onto 316-grade stainless steel (SS). FN7-10 coating on SS surfaces promoted α5β1 integrin-dependent adhesion and osteogenic differentiation of human mesenchymal stem cells. FN7-10-coated SS screws increased bone-implant mechanical fixation compared to uncoated screws by 30% and 45% at 1 and 3 months, respectively, in healthy rats. Importantly, FN7-10 coating significantly enhanced bone-screw fixation by 57% and 32% at 1 and 3 months, respectively, and bone-implant ingrowth by 30% at 3 months compared to uncoated screws in osteoporotic rats. These coatings are easy to apply intra-operatively, even to implants with complex geometries and structures, facilitating the potential for rapid translation to clinical settings.
authors.affiliation: Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Rachit
authors.initials: R
authors.lastname: Agarwal
authors.affiliation: Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA; Biomedical Engineering Research Division, University of Glasgow, Glasgow, UK.
authors.forename: Cristina
authors.initials: C
authors.lastname: González-García
authors.affiliation: Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Brennan
authors.initials: B
authors.lastname: Torstrick
authors.affiliation: Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Guldberg
authors.affiliation: Biomedical Engineering Research Division, University of Glasgow, Glasgow, UK.
authors.forename: Manuel
authors.initials: M
authors.lastname: Salmerón-Sánchez
authors.affiliation: Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA. Electronic address: andres.garcia@me.gatech.edu.
authors.forename: Andrés J
authors.initials: AJ
authors.lastname: García
mesh_terms: D000818:Animals; D001863:Bone Screws; D002448:Cell Adhesion; D002454:Cell Differentiation; D002460:Cell Line; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D005353:Fibronectins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D039081:Integrin alpha5beta1 / Q000378:metabolism; D016348:Osseointegration; D010006:Osteoblasts / Q000166:cytology; D010012:Osteogenesis; D010024:Osteoporosis / Q000473:pathology / Q000628:therapy; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013193:Stainless Steel / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D005353:Fibronectins; D039081:Integrin alpha5beta1; D011994:Recombinant Proteins; D013193:Stainless Steel
keywords: Bone; Cell adhesion; Implant; Integrin