Behaviour of human osteoblastic cells cultured on plasma-sprayed titanium implants in the presence of nicotine.
OBJECTIVE
The aim of this work was to analyse the behaviour of human bone marrow osteoblastic cells cultured on the surface of routinely used plasma-sprayed titanium implants in the presence of plasmatic and salivary nicotine levels reported in smokers.


METHODS
Human bone marrow cells (first subculture) were seeded on titanium implants and cultured for 35 days in alpha-minimal essential medium supplemented with 10% foetal bovine serum, 50 microg/ml ascorbic acid, 10 mM beta-glycerophosphate and 10 nM dexamethasone. Seeded implants were exposed to nicotine, 10-1 mg/ml, from days 1 to 35, and characterized for cell morphology, viability/proliferation, alkaline phosphatase (ALP) activity and matrix mineralization.


RESULTS
Low levels of nicotine, 10 and 50 ng/ml, representative of the plasma concentrations reported in smokers, did not cause significant effects in the cell behaviour, although a small induction in cell growth and functional activity appeared to occur. Higher nicotine levels, 0.01-1 mg/ml, within those attained in saliva through tobacco use, caused evident dose-dependent effects in osteoblastic cell behaviour, i.e., a stimulatory effect in cell growth, ALP activity and matrix mineralization, at concentrations up to 0.2 mg/ml, and a deleterious effect at higher levels.


CONCLUSIONS
Considering the high tissue diffusion potential of nicotine, the results suggest the possibility of a direct modulation of the osteoblast activity as a contributing factor to the overall effect of nicotine in the bone microenvironment around dental implants.
Pereira
Maria Lurdes
ML
Laboratório de Farmacologia e Biocompatibilidade Celular, Faculdade de Medicina Dentária, Universidade do Porto, Porto, Portugal.
Carvalho
João Costa
JC
Peres
Fernando
F
Gutierres
Manuel
M
Fernandes
Maria Helena
MH
D000328:Adult; D000469:Alkaline Phosphatase / Q000187:drug effects / Q000378:metabolism; D000704:Analysis of Variance; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D003757:Dental Implantation / Q000295:instrumentation*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology; D010949:Plasma; D018709:Statistics, Nonparametric; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology
D020099:Coated Materials, Biocompatible; D018722:Nicotinic Agonists; D009538:Nicotine; D014025:Titanium; D000469:Alkaline Phosphatase