title: Effect of type I collagen on the adhesion, proliferation, and osteoblastic gene expression of bone marrow-derived mesenchymal stem cells.
abstract: OBJECTIVE
  To investigate the effects of porous poly lactide-co-glycolide (PLGA) modified by type I collagen on the adhesion, proliferation, and differentiation of rabbit marrow-derived mesenchymal stem cells (MSCs).
  
  
  METHODS
  The third generation MSCs isolated from mature rabbits by density gradient centrifugation were cultured at different initial concentrations on 0.3 cm x 1.2 cm x 2.0 cm 3-D porous PLGA coated by type I collagen in RPMI 1640 containing 10% fetal calf serum, while cultured on PLGA without type I collagen as control. The cells adhesive and proliferative behavior at 7, 14, and 21 days after inoculation was assessed by determining the incorporation rate of [(3)H]-TdR. In order to examine MSCs differentiation, the expression of osteoblasts marker genes, osteocalcin (OCN), alkaline phosphatase (ALP), osteopontin (OPN) mRNA, were evaluated by reverse transcription-polymerase chain reaction (RT-PCR), and further more, the cell morphology at 21 days was also observed by scanning electron microscope (SEM).
  
  
  RESULTS
  Type I collagen promoted cell adhesion on PLGA. The valve was significantly higher than controls (6 h, 2144 cpm+/-141 cpm vs. 1797 cpm+/-118 cpm, P=0.017; 8 h, 2311 cpm+/-113 cpm vs. 1891 cpm+/-103 cpm, P=0.01). The cells which cultured on PLGA coated with type I collagen showed significantly higher cell proliferation than controls on the 7 th day (1021 cpm+/-159 cpm vs. 451 cpm+/-67 cpm, P=0.002), the 14th day (1472 cpm+/-82 cpm vs. 583 cpm+/-67 cpm, P<0.001) and 21 th day (1728 cpm+/-78 cpm vs. 632 cpm+/-55 cpm, P<0.001). Osteoblasts markers, OCN, ALP, OPN mRNA, were all detected on PLGA coated by type I collagen on the 21 th day, but OCN, OPN mRNA could not be found in controls. Spindle and polygonal cells well distributed on the polymer coated by type I collagen while cylindric or round cells in controls.
  
  
  CONCLUSIONS
  Type I collagen is effective in promoting the adhesion, proliferation and differentiation of MSCs on PLGA.
authors.affiliation: Department of Orthopedics, Nanjing General Hospital, Nanjing Military District, Nanjing, Jiangsu 210001, China. liugangnj@yahoo.com.cn
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Yun-Yu
authors.initials: YY
authors.lastname: Hu
authors.forename: Jian-Ning
authors.initials: JN
authors.lastname: Zhao
authors.forename: Su-Jia
authors.initials: SJ
authors.lastname: Wu
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Xiong
authors.forename: Rong
authors.initials: R
authors.lastname: Lu
mesh_terms: D001672:Biocompatible Materials / Q000494:pharmacology*; D002448:Cell Adhesion; D049109:Cell Proliferation; D024042:Collagen Type I / Q000494:pharmacology*; D015870:Gene Expression; D006801:Humans; D019344:Lactic Acid / Q000494:pharmacology*; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D010006:Osteoblasts / Q000502:physiology*; D011100:Polyglycolic Acid / Q000494:pharmacology*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D024042:Collagen Type I; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid