title: Adsorption and release of insulin-like growth factor-I on porous tricalcium phosphate implant.
abstract: 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.
authors.affiliation: Clinique d'Orthopédie et de Traumatologie, Hôpital Roger Salengro, CHRU de Lille, 59037 Lille Cedex, France.
authors.forename: P
authors.initials: P
authors.lastname: Laffargue
authors.forename: P
authors.initials: P
authors.lastname: Fialdes
authors.forename: P
authors.initials: P
authors.lastname: Frayssinet
authors.forename: M
authors.initials: M
authors.lastname: Rtaimate
authors.forename: H F
authors.initials: HF
authors.lastname: Hildebrand
authors.forename: X
authors.initials: X
authors.lastname: Marchandise
mesh_terms: D000327:Adsorption; D000818:Animals; D018786:Bone Substitutes; D002130:Calcium Phosphates; D002516:Ceramics; D005269:Femur / Q000601:surgery; D006801:Humans; D066298:In Vitro Techniques; D007334:Insulin-Like Growth Factor I / Q000493:pharmacokinetics*; D007457:Iodine Radioisotopes; D008297:Male; D008422:Materials Testing; D019736:Prostheses and Implants; D011817:Rabbits
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D007457:Iodine Radioisotopes; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D007334:Insulin-Like Growth Factor I; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous