Influence of poly(L-lactic acid) nanofibers and BMP-2-containing poly(L-lactic acid) nanofibers on growth and osteogenic differentiation of human mesenchymal stem cells.
The aim of this study was to characterize synthetic poly-(L-lactic acid) (PLLA) nanofibers concerning their ability to promote growth and osteogenic differentiation of stem cells in vitro, as well as to test their suitability as a carrier system for growth factors. Fiber matrices composed of PLLA or BMP-2-incorporated PLLA were seeded with human mesenchymal stem cells and cultivated over a period of 22 days under growth and osteoinductive conditions, and analyzed during the course of culture, with respect to gene expression of alkaline phosphatase (ALP), osteocalcin (OC), and collagen I (COL-I). Furthermore, COL-I and OC deposition, as well as cell densities and proliferation, were analyzed using fluorescence microscopy. Although the presence of nanofibers diminished the dexamethasone-induced proliferation, there were no differences in cell densities or deposition of either COL-I or OC after 22 days of culture. The gene expression of ALP, OC, and COL-I decreased in the initial phase of cell cultivation on PLLA nanofibers as compared to cover slip control, but normalized during the course of cultivation. The initial down-regulation was not observed when BMP-2 was directly incorporated into PLLA nanofibers by electrospinning, indicating that growth factors like BMP-2 might survive the spinning process in a bioactive form.
Schofer
Markus D
MD
Department of Orthopedics, University Hospital of Marburg, Marburg, Baldingerstrasse, Germany. schofer@med.uni-marburg.de
Fuchs-Winkelmann
Susanne
S
Gräbedünkel
Christian
C
Wack
Christina
C
Dersch
Roland
R
Rudisile
Markus
M
Wendorff
Joachim H
JH
Greiner
Andreas
A
Paletta
Jürgen Rj
JR
Boudriot
Ulrich
U
D000469:Alkaline Phosphatase / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D002454:Cell Differentiation; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000737:chemistry*; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D013234:Stem Cells / Q000166:cytology; D023822:Tissue Engineering / Q000379:methods
D055396:Bone Morphogenetic Protein 2; D024042:Collagen Type I; D011091:Polyesters; D011108:Polymers; D015675:Osteocalcin; D019344:Lactic Acid; C033616:poly(lactide); D000469:Alkaline Phosphatase