title: UV-killed Staphylococcus aureus enhances adhesion and differentiation of osteoblasts on bone-associated biomaterials.
abstract: Titanium alloys (Ti) are the preferred material for orthopedic applications. However, very often, these metallic implants loosen over a long period and mandate revision surgery. For implant success, osteoblasts must adhere to the implant surface and deposit a mineralized extracellular matrix (ECM). Here, we utilized UV-killed Staphylococcus aureus as a novel osteoconductive coating for Ti surfaces. S. aureus expresses surface adhesins capable of binding to bone and biomaterials directly. Furthermore, interaction of S. aureus with osteoblasts activates growth factor-related pathways that potentiate osteogenesis. Although UV-killed S. aureus cells retain their bone-adhesive ability, they do not stimulate significant immune modulator expression. All of the abovementioned properties were utilized for a novel implant coating so as to promote osteoblast recruitment and subsequent cell functions on the bone-implant interface. In this study, osteoblast adhesion, proliferation, and mineralized ECM synthesis were measured on Ti surfaces coated with fibronectin with and without UV-killed bacteria. Osteoblast adhesion was enhanced on Ti alloy surfaces coated with bacteria compared to uncoated surfaces, while cell proliferation was sustained comparably on both surfaces. Osteoblast markers such as collagen, osteocalcin, alkaline phosphatase activity, and mineralized nodule formation were increased on Ti alloy coated with bacteria compared to uncoated surfaces.
authors: Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223-0001, USA. shankari.somayaji@carolinashealthcare.org
authors: Shankari N
authors: SN
authors: Somayaji
authors: Yvette M
authors: YM
authors: Huet
authors: Helen E
authors: HE
authors: Gruber
authors: Michael C
authors: MC
authors: Hudson
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D001861:Bone Regeneration; D001842:Bone and Bones / Q000737:chemistry / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D020007:Implants, Experimental; D008422:Materials Testing; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology*; D013211:Staphylococcus aureus / Q000166:cytology / Q000528:radiation effects*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D014025:Titanium