title: [Preparation of enamel matrix proteins controlled release microspheres and their biological effects on the proliferation and differentiation of human periodontal ligament cells in vitro].
abstract: OBJECTIVE
  To prepare enamel matrix proteins (EMPs) loaded dextran-based hydrogel microspheres (EMPs-dex-MPs), and to evaluate their EMPs controlled release property and their biological effects on the proliferation and differentiation of human periodontal ligament cells (PDLCs) in vitro.
  
  
  METHODS
  Using dimethylbenzene as the oil phase, EMPs-dex-MPs were achieved by emulsion-chemical crosslinking technique. The process of the recombination preparation was optimized by orthogonal factorization method. The configuration and size of EMPs-dex-MPs were determined by scanning electron microscope. The EMPs loading content and encapsulation rate of EMPs-dex-MPs, and their biodegradation characteristic were studied by routine analysis methods. Dynamic dialysis method was used to determine the release characteristic of EMPs-dex-MPs in vitro and its influencing factors. The proliferation of cultured PDLCs was measured by MTF method and the differentiation of PDLCs was measured by their alkaline phosphatase (ALP) activities.
  
  
  RESULTS
  The results showed that EMPs-dex-MPs were homogenous and stable with the average diameter 25 microm, and the EMPs loading content was (32.8 +/- 1.2)%, the encapsulation rate was (78.9 +/- 1.0)%. Under 9% physiological saline solution contained a very thimbleful quantity of dextranase EMPs-dex-MPs could be biodegraded completely during about 40 days. The in vitro experiments showed that about 80% of EMPs could be released out in 20 days. Using EMPs-dex-MPs could enhance the proliferation responses and ALP activities of PDLCs more than 12 days.
  
  
  CONCLUSIONS
  As a new sustained release system of growth factors, the dex-MPs is stable, workable and biodegradable. EMPs-dex-MPs, whose drug release can be controlled by preparation technique, may be more effective in promoting periodontal tissue regeneration.
authors.affiliation: Dept of Periodontology and Oral Medicine, College of Stomatology, The Fourth Military Medical University, Xi'an, China.
authors.forename: Fa-ming
authors.initials: FM
authors.lastname: Chen
authors.forename: Zhi-fen
authors.initials: ZF
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
authors.forename: Hong
authors.initials: H
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Du
authors.forename: Guo-fang
authors.initials: GF
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Nie
mesh_terms: D002454:Cell Differentiation; D002478:Cells, Cultured; D003692:Delayed-Action Preparations; D003746:Dental Enamel Proteins; D003911:Dextrans; D006801:Humans; D066298:In Vitro Techniques; D008863:Microspheres; D010513:Periodontal Ligament; D012038:Regeneration
chemical_list: D003692:Delayed-Action Preparations; D003746:Dental Enamel Proteins; D003911:Dextrans; C109069:enamel matrix proteins