Evaluation of the effects of nicotine on the friction of the articular cartilage and the reversion of the estrogen in vitro

Background Osteoarthritis is a severe disease for menopausal women, especially for those who exposed in the smoking and second hand-smoking. This study investigated the effect of the nicotine and estrogen on the articular cartilage. Methods The articular cartilages were treated by nicotine and estrogen in vitro. Then the frictional properties and morphology on the surface were investigated using atomic force microscope. Proteoglycan 4(PRG4), as the key boundary lubricant of articular cartilage was characterized. Results Nicotine down-regulates the friction coefficient and secretion of PRG4 significantly and then the estrogen increase them again. The adhesion forces also showed the same trend due to the content of anti-adhesive PRG4. Discussion This study demonstrated that the present concentration nicotine has a negative effect on the articular cartilage and the estrogen has a better protecting effect. This may provide a potential guide for OA prevention and treatment.