## Abstract Pulsed electromagnetic field (PEMF) stimulation promotes the healing of fractures in humans, though its effect is little known. The processes of tissue repair include protein synthesis and cell differentiation. The polyamines (PA) are compounds playing a relevant role in both protein sy
Osteoblasts respond to hydroxyapatite surfaces with immediate changes in gene expression
✍ Scribed by Xie, Jianwei ;Baumann, Melissa J. ;McCabe, Laura R.
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 324 KB
- Volume
- 71A
- Category
- Article
- ISSN
- 0021-9304
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Bone mineral contains hydroxyapatite (HA). This is the surface that mature osteoblasts and osteocytes interact with. Synthetic HA is widely used in orthopedic surgeries as an implant or implant coating. The bone‐like HA surfaces increase implant union and bone formation; however, the mechanisms accounting for this effect on osteoblasts are not known. In this study, we compared gene expression profiles of osteoblasts responding to HA or plastic surfaces for 24 h. Expression profiles were also compared between HA discs processed with gravity‐sieved compared with combined gravity and air‐jet‐sieved HA powders. The latter, composed of smaller HA particles, exhibits an increase in grain boundary surface area. Discs made with either HA powder similarly up‐regulated osteoblast expression of 10 genes (including proliferin 3, Glvr‐1, DMP‐1, and tenascin C) and down‐regulated 15 genes (such as osteoglycin) by more than 2‐fold compared with plastic surfaces. The overall changes are indicative of an immediate (24‐h) response to the HA surface and a trend toward osteoblast differentiation. In addition, subsets of modulated genes exist that are unique to each HA subtype. Taken together, we identified HA responsive genes evident within 24 h of surface contact, indicating a critical role for extracellular mineral surfaces in the regulation of osteoblast gene expression and phenotype. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 108–117, 2004
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