Recent studies in several neuronal lineages suggest that extrinsic factors such as polypeptide growth factors regulate various stages of neuronal development, from initial commitment of multipotent progenitors to induction of specific gene expression that is characteristic of terminal neuronal diffe
Adsorption and release of insulin-like growth factor-I on porous tricalcium phosphate implant
β Scribed by Laffargue, Philippe ;Fialdes, Patrice ;Frayssinet, Patrick ;Rtaimate, Mohamed ;Hildebrand, Hartmut F. ;Marchandise, Xavier
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 177 KB
- Volume
- 49
- Category
- Article
- ISSN
- 0021-9304
No coin nor oath required. For personal study only.
β¦ Synopsis
In order to develop bone substitutes, the design of biomaterials like calcium phosphate ceramic loaded with bone growth factor are of great interest. However, it is necessary to control the amount of growth factor adsorbed onto ceramics and the kinetics of its release. Radiolabeling of insulin-like growth factor-I (IGF-I) with 125-iodine ([ 125 I]-IGF-I) and its adsorption onto porous tricalcium phosphate (TCP) cylinders enabled us to establish the time-adsorption and time-release curves using various concentrations of IGF-I. The adsorption curve increased rapidly and then flattened out at 72 h; 90% of the maximum was already reached at 24 h; and 20% of the adsorbed IGF-I was released in water within 4 days. In human serum the release was faster at 82% within 4 days. In vivo evaluation on an animal model was then performed. Rabbits' bilateral femoral cylindrical bone defects were filled with the TCP cylinders, which were either carrying IGF-I or implanted alone as a control in each rabbit. Bone turnover and ceramic resorption were stimulated by IGF-I loaded TCP according to standard radiography, dual-energy X-ray absorptiometry, histology, and histomorphometry.
π SIMILAR VOLUMES
Insulinlike growth factor s (IGFs) stimulate skeletal muscle cell differentiatio n in association with an increase in the mRNA of myogenin, a member of the MyoD family of skeletal muscle-specific transcriptio n factor s that plays an essential role in the differentiatio n process. However, this is a
Bone cells synthesize and respond to IGF-I and IGF-II which contribute to bone remodeling and linear growth. In osteoblasts, prostaglandin (PG)E 2 stimulates IGF-I but not IGF-II synthesis through a cAMP-dependent protein kinase A (PKA)-related event. However, protein kinase C (PKC) activation by PG
## Insulin -like growth factor-I (IGF-I) has trophic and plastic effects on neurons and glial cells and modulates neuroendocrine events by acting at the level of the hypothalamus. IGF-I and estrogen signaling interact to regulate in vitro hypothalamic neuronal survival and differentiation. In vivo
Effects of insulin-like growth factor-I (IGF-I), corticosterone, and triiodothyronine (T 3 ) on in vitro growth of vertebral cartilage of the clearnose skate, Raja eglanteria, were investigated. Uptake of [ 35 S]sulfate in cultured vertebrae was used to characterize glycosaminoglycan (GAG) synthesis
Insulin-like growth factor binding protein (IGFBP)-3 effects proliferation and differentiation of numerous cell types by binding to insulin-like growth factors (IGF) and attenuating their activity or by directly affecting cells in an IGFindependent manner. Consequently, IGFBPs produced by specific c