ABSTRACT
BACKGROUND:Results of recent studies demonstrated the modulation of thymosin β4 on hair cycle and regeneration, but the mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism by which thymosinβ4 increases hair regeneration through Wnt signal pathway. METHODS:After the mouse model of depilation was established using rosin/paraffin mixed agents, the experimental animals were randomly assorted to three different groups, including low-dose, high-dose and control groups, and a dose of 0.3μg/50μL, 3μg/50μL thymosinβ4 and PBS was administered on the depilated backs every 12 hours, respectively. Then photography, hematoxylin-eosin staining, immunohistochemistry and in situ hybridization were applied to observe the growth of hair, and the expressions ofβ-catenin and LEF-1 mRNA in different groups at different time were quantitatively evaluated. RESULTS AND CONCLUSION:The hair growth of the low-dose group was faster than that of the other groups. Hematoxylin-eosin staining demonstrated inflammatory cel s infiltration in the dermis after depilation, and the number of hair fol icles that were in the phase of anagen was much more than the other groups as time went by. Immunohistochemistry ofβ-catenin showed the accumulation of intra-cel ularβ-catenin in the low-dose group at the bulge of fol icles assessed by integrated absorbance analysis (P<0.05), so did the in situ hybridization of LEF-1 mRNA. Low-dose thymosinβ4 accelerates hair growth through Wnt signal pathway by elevating the level ofβ-catenin and LEF-1 mRNA.
ABSTRACT
Oligopeptide T2, a kind of PA (Peptide Amphiphile) molecule, which could build up nano-fiber by self-assembly was designed and synthesized in this study. And the double-diffusion gel system was applied on this molecule to investigate its biomineralization features in vitro. The results showed that T2 could obviously reduce the hydroxyapatite (HA) formation period. And HA was found to possess the characteristics of non-crystalline by analysis of X-ray diffraction (XRD) and scanning electronic microscopy (SEM). These findings point to the conclusion that the negatively charged zone in T2 might make this molecule have the function of promoting HA biomineralization in vitro. And the mechanism responsible for the procession of HA biomineralization needs further research.
Subject(s)
Biocompatible Materials , Chemistry , Bone Substitutes , Chemistry , Calcification, Physiologic , Durapatite , Chemistry , Oligopeptides , ChemistryABSTRACT
Objective: To evaluate the possibility of self-assembly oligopeptide(T2) for dental enamel biomimetics, especially for the prism’s crystal texture since it could prompt calcium phosphate precipitated in gel carrier. Methods:SEM (Scaning electron microscope) and TEM (Transmission electron microscope) were used to observe the morphologic presentation and ED(Electron diffraction) to crystal texture comparing with the human molar enamel powder. Results: (a) Flake-like and needle-like octacalcium phosphate precipitated in the gel carrier with self-assemble oligopeptide(T2). They transformed into rod-like hydroxyapatite crystals gradually in the following 2-4 weeks. (b) The rod-like hydroxyapatite may arrange or grow into bundles which are similar to the human enamel prisms in both appearance and size. (c) The rod-like hydroxyapatite showed polycrystal while the enamel prisms showed monocrystal under examination of ED. Conclusion:The self-assemble oligopeptide(T2) could regulate the speed of nucleation and crystallization of hydroxyapatite in morphology and crystalline size. Thus, the self-assembly oligopeptide and the gel carrier mineralization system could be primarily applied in biomimetic use for the crystallization of hydroxyaptite in dental prism in vitro.