Enhancement of bone-titanium integration profile with UV-photofunctionalized titanium in a gap healing model.
In this study, we tested the potential of UV-photofunctionalized titanium surfaces to overcome compromised bone-titanium integration in a gap healing model. Titanium in rod and disk forms was acid etched and then stored for 4 weeks under dark ambient conditions. Titanium rods with and without UV pretreatment were placed into a rat femur with (contact healing) or without (gap healing) contact with the innate cortical bone. The titanium implants were subjected to a biomechanical push-in test, micro-CT bone morphometry, and surface elemental analysis after 2 weeks of healing. The strength of bone-titanium integration in the gap healing model was one-third of that in the contact healing model. However, UV-treated implants in the gap healing condition produced a strength of bone-titanium integration equivalent to that of untreated implants in the contact healing condition. Bone volume around UV-treated implants was 2- to 3-fold greater than that around the untreated implants in the gap healing model. A bone generation profile drawn along the long axis of the implant exhibited greater contrast between the untreated and UV-treated surfaces in the cortical area than in the bone marrow area. The bone tissue formed on UV-treated implants showed a higher Ca/P ratio than that formed on untreated titanium. The rate of cell proliferation, alkaline phosphatase activity, and calcium deposition in femoral periosteal cells and in bone marrow-derived osteoblasts were greater in cultures on UV-treated titanium disks than in cultures on untreated disks. The UV-enhanced function in periosteal cells was more pronounced when they were co-cultured with bone marrow-derived osteoblasts, indicating a synergistic effect of UV-treated titanium with biological signals from bone marrow-derived osteoblasts. Within the limitation of the model used in this study, UV-photofunctionalized titanium surfaces may overcome the challenging condition of bone-titanium integration without cortical bone support. UV treatment of implants induced marked improvements in the behavior of bone formation and quantity and quality of bone tissue around the implants. These effects may be related to the promoted function of both periosteum- and bone marrow-derived osteogenic cells at the local level around UV-treated titanium surfaces.
Ueno
Takeshi
T
Laboratory for Bone and Implant Sciences (LBIS), The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, 10833 Le Conte Avenue, Los Angeles, CA 90095-1668, USA.
Yamada
Masahiro
M
Suzuki
Takeo
T
Minamikawa
Hajime
H
Sato
Naoko
N
Hori
Norio
N
Takeuchi
Kazuo
K
Hattori
Masami
M
Ogawa
Takahiro
T
D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D001854:Bone Marrow Cells / Q000166:cytology; D001842:Bone and Bones / Q000187:drug effects* / Q000473:pathology*; D049109:Cell Proliferation / Q000187:drug effects; D005269:Femur / Q000187:drug effects / Q000473:pathology; D023421:Models, Animal; D016348:Osseointegration / Q000187:drug effects*; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D010521:Periosteum / Q000166:cytology; D019736:Prostheses and Implants; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties / Q000187:drug effects; D014025:Titanium / Q000494:pharmacology* / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014945:Wound Healing / Q000187:drug effects*
D014025:Titanium