title: Titanium implants coated with UV-irradiated vitamin D precursor and vitamin E: in vivo performance and coating stability.
abstract: OBJECTIVE
  This study aimed at evaluating the biological response of titanium implants coated with UV-irradiated 7-dehydrocholesterol (7-DHC) and vitamin E (VitE) in vivo and analyzing the effects of aging on their stability and bioactivity in vitro.
  
  
  METHODS
  Titanium surfaces were coated with 7-DHC and VitE, UV-irradiated and incubated for 48 h at 23°C to allow cholecalciferol synthesis. The in vivo biological response was tested using a rabbit tibia model after 8 weeks of healing by analyzing the wound fluid and the mRNA levels of several markers at the bone-implant interface (N = 8). The stability of the coating after storage up to 12 weeks was determined using HPLC analysis, and the bioactivity of the stored modified implants was studied by an in vitro study with MC3T3-E1 cells (N = 6).
  
  
  RESULTS
  A significant increase in gene expression levels of osteocalcin was found in the bone tissue attached to implants coated with the low dose of 7-DHC and VitE, together with a higher ALP activity in the wound fluid. Implants treated with the high dose of 7-DHC and VitE showed increased tissue necrosis and inflammation. Regarding the aging effects, coated implants were stable and bioactive up to 12 weeks when stored at 4°C and avoiding oxygen, light and moisture.
  
  
  CONCLUSIONS
  This study demonstrates that Ti implants coated with UV-irradiated 7-DHC and VitE promote in vivo gene expression of bone formation markers and ALP activity, while they keep their osteopromotive potential in vitro and composition when stored up to 12 weeks at 4°C.
authors.affiliation: Department of Fundamental Biology and Health Sciences, Research Institute on Health Sciences (IUNICS), University of Balearic Islands, Palma de Mallorca, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Satué
authors.affiliation: Department of Fundamental Biology and Health Sciences, Research Institute on Health Sciences (IUNICS), University of Balearic Islands, Palma de Mallorca, Spain.|Instituto de Investigación Sanitaria de Palma, Palma de Mallorca, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Monjo
authors.affiliation: Department of Prosthetics and Oral Function, Institute for Clinical Dentistry, University of Oslo, Oslo, Norway.
authors.forename: Hans Jacob
authors.initials: HJ
authors.lastname: Ronold
authors.affiliation: Department of Biomaterials, Institute for Clinical Dentistry, University of Oslo, Oslo, Norway.
authors.forename: Staale Petter
authors.initials: SP
authors.lastname: Lyngstadaas
authors.affiliation: Department of Fundamental Biology and Health Sciences, Research Institute on Health Sciences (IUNICS), University of Balearic Islands, Palma de Mallorca, Spain.|Instituto de Investigación Sanitaria de Palma, Palma de Mallorca, Spain.
authors.forename: Joana M
authors.initials: JM
authors.lastname: Ramis
mesh_terms: D000818:Animals; D002762:Cholecalciferol / Q000378:metabolism*; D020099:Coated Materials, Biocompatible; D003684:Dehydrocholesterols / Q000494:pharmacology*; D015921:Dental Implants; D004305:Dose-Response Relationship, Drug; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D015675:Osteocalcin / Q000235:genetics; D011817:Rabbits; D014466:Ultraviolet Rays; D014810:Vitamin E / Q000494:pharmacology*
chemical_list: D020099:Coated Materials, Biocompatible; D003684:Dehydrocholesterols; D015921:Dental Implants; D015675:Osteocalcin; D014810:Vitamin E; D002762:Cholecalciferol; C016705:7-dehydrocholesterol
keywords: 7-Dehydrocholesterol; bone formation; coating stability; dental implant; in vivo; titanium; vitamin D; vitamin E