title: Modulated regeneration of acid-etched human tooth enamel by a functionalized dendrimer that is an analog of amelogenin.
abstract: In the bioinspired repair process of tooth enamel, it is important to simultaneously mimic the organic-matrix-induced biomineralization and increase the binding strength at the remineralization interface. In this work, a fourth-generation polyamidoamine dendrimer (PAMAM) is modified by dimethyl phosphate to obtain phosphate-terminated dendrimer (PAMAM-PO3H2) since it has a similar dimensional scale and peripheral functionalities to that of amelogenin, which plays important role in the natural development process of enamel. Its phosphate group has stronger affinity for calcium ion than carboxyl group and can simultaneously provide strong hydroxyapatite (HA)-binding capability. The MTT assay demonstrates the low cytotoxicity of PAMAM-PO3H2. Adsorption tests indicate that PAMAM-PO3H2 can be tightly adsorbed on the human tooth enamel. Scanning electron microscopy and X-ray diffraction are used to analyze the remineralization process. After being incubated in artificial saliva for 3weeks, there is a newly generated HA layer of 11.23μm thickness on the acid-etched tooth enamel treated by PAMAM-PO3H2, while the thickness for the carboxyl-terminated one (PAMAM-COOH) is only 6.02μm. PAMAM-PO3H2 can regulate the remineralization process to form ordered new crystals oriented along the Z-axis and produce an enamel prism-like structure that is similar to that of natural tooth enamel. The animal experiment also demonstrates that PAMAM-PO3H2 can induce significant HA regeneration in the oral cavity of rats. Thus PAMAM-PO3H2 shows great potential as a biomimetic restorative material for human tooth enamel.
authors.affiliation: College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Chen
authors.affiliation: College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China.
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
authors.forename: Jiyao
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
authors.forename: Kunneng
authors.initials: K
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
authors.forename: Libang
authors.initials: L
authors.lastname: He
authors.affiliation: College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China.
authors.forename: Zaifu
authors.initials: Z
authors.lastname: Lin
authors.affiliation: College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China.
authors.forename: Xingyu
authors.initials: X
authors.lastname: Chen
authors.affiliation: College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China.
authors.forename: Xiaokang
authors.initials: X
authors.lastname: Ren
authors.affiliation: College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China. Electronic address: jianshu_li@scu.edu.cn.
authors.forename: Jianshu
authors.initials: J
authors.lastname: Li
mesh_terms: D053523:Amelogenin; D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry / Q000494:pharmacology; D050091:Dendrimers / Q000737:chemistry / Q000494:pharmacology; D003743:Dental Enamel; D003764:Dental Materials / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D008297:Male; D064347:Microscopy, Electrochemical, Scanning; D051381:Rats; D017207:Rats, Sprague-Dawley; D014070:Tooth / Q000473:pathology / Q000648:ultrastructure; D014961:X-Ray Diffraction
chemical_list: D053523:Amelogenin; D050091:Dendrimers; D003764:Dental Materials; C104700:PAMAM Starburst
keywords: Biomimetic restorative material; Human tooth enamel; Hydroxyapatite; Phosphate-terminated dendrimer; Regeneration