Insulin-like growth factor I-releasing alginate-tricalciumphosphate composites for bone regeneration

Vera Luginbuehl, Esther Wenk, Annette Koch, Bruno A. Gander, H.P. Merkle, Lorenz Meinel
Purpose. Development and characterization of an in situYforming, osteoconductive, and growth factorYreleasing bone implant. Methods. Injectable in situYforming scaffolds were prepared from a 2% (m/v) alginate solution, tricalciumphosphate (TCP) granules, and poly(lactide-co-glycolide) microspheres (MS), loaded with the osteoinductive growth factor insulin-like growth factor I (IGF-I). Scaffolds were prepared by mixing the components followed by hydrogel formation through calcium
more » ... d physical cross-linking of the alginate at slightly acidic pH. Physical-chemical properties and cell biocompatibility using osteoblast-like cells (MG-63 and Saos-2) of these scaffolds were investigated. Results. The addition of TCP to the alginate resulted in reduced swelling and gelation time and an increase in stiffness. Osteoblast-like cells (MG-63 and Saos-2) did not show toxic reactions and adhered circumferentially to the TCP granules surface. The addition of the IGF-I MS resulted in an up to sevenfold increased proliferation rate of MG-63 cells as compared to scaffold preparations without IGF-I MS. The alkaline phosphate (ALP) activityVa parameter for osteblastic activityVincreased with increasing amounts of TCP in Saos-2 loaded composite scaffolds. Conclusions. A prototype in situYhardening composite system for conformal filling of bone defects supporting osteoblastic activity for further clinical testing in relevant fracture models was developed and characterized.
doi:10.3929/ethz-b-000032618 fatcat:vyjrufydmfey7bowk6w3czayvy