Isomere Fullerentrimere wurden mechanochemisch hergestellt und Langmuir‐Filme von ihnen auf Au(111)‐Oberflächen durch Rastertunnelmikroskopie (RTM) untersucht. Jedes der Isomere zeichnet sich durch eine andere Oberflächenmorphologie aus. Die beobachtete Verteilung der Isomere ist im Einklang mit MO‐Rechnungen zu ihrer Stabilität. Durch RTM können die einzelnen Isomere unterschieden werden (Beispiel siehe Bild), was mit spektroskopischen Methoden schwierig ist.

We have studied the expression of FGF1 and FGF2 during mouse odontogenesis by immunohistochemistry. FGF1 was detected in differentiated odontoblasts and at the secretory pole of ameloblasts. Localization of FGF2 was mainly observed within the basement membrane interposed between dental epithelium and dental mesenchyme. These findings indicate that FGF1 and FGF2 may participate in the control of odontoblast and ameloblast differentiation. Thereafter, we studied the ability of FGF1 and FGF2, alone or in combination with TGF beta 1, to induce polarization and/or functional differentiation of preodontoblasts. Dental papillae (DP) obtained from first lower molars of 17-day-old mouse embryo were cultured in the presence or the absence of growth factors. DP cultured with FGF1 + TGF beta 1 showed gradients of odontoblast-like cell differentiation, which displayed alkaline phosphatase reactivity. DP treated with FGF2 + TGF beta 1 exhibited pre-odontoblast cell polarization, and the cell bodies displayed long cytoplasm processes. However, following this treatment we did not observe extracellular matrix secretion, and alkaline phosphatase activity was completely inhibited. In summary, our results show that exogenous addition of FGF1 to pre-odontoblasts induces their terminal differentiation, by synergistically acting with TGF beta 1. In contrast, FGF2 may regulate the effect of TGF beta 1, permitting cell polarization but restraining pre-odontoblast functions.

In this work, we investigated the effects of aFGF and bFGF alone or combined with TGFβ1 or IGF‐I on odontoblast differentiation. Trypsin‐isolated dental papillae from day 17 mandibular first molar were cultured in semisolid‐agar medium for 6 d. Our results demonstrated that aFGF, bFGF or combinations of these promoted cell polarization at the periphery of the dental Papillae. Moreover, simultaneous addition of aFGF and TGFβ1 to dental Papillae cultures induced both polarization and functional differentiation of odontoblast‐like cells, as well as extracellular matrix deposition. Combination of aFGF or bFGF with IGF‐I caused cell polarization at the surface of dental papillae, but matrix secretion was restricted to a few explants. In the presence of bFGF and TGFβ1, the explants had pronounced cell elongations but no matrix deposition. These results indicate that aFGF or bFGF is not able to induce odontoblast differentiation alone. However, both aFGF and bFGF can act synergistically with TGFβ1 and IGF‐I to strengthen their inductive effects and promote gradients of cytological and functional changes in odontoblast‐like cells.